Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

94 files changed, 6012 insertions, 0 deletions

diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
new file mode 100644
index 000000000..7945de067
--- /dev/null
+++ b/arch/h8300/Kconfig
@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: GPL-2.0
+config H8300
+        def_bool y
+	select ARCH_32BIT_OFF_T
+	select ARCH_HAS_BINFMT_FLAT
+	select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
+	select BINFMT_FLAT_OLD_ALWAYS_RAM
+	select GENERIC_ATOMIC64
+	select HAVE_UID16
+	select VIRT_TO_BUS
+	select GENERIC_IRQ_SHOW
+	select FRAME_POINTER
+	select GENERIC_CPU_DEVICES
+	select MODULES_USE_ELF_RELA
+	select GENERIC_CLOCKEVENTS
+	select COMMON_CLK
+	select ARCH_WANT_FRAME_POINTERS
+	select OF
+	select OF_IRQ
+	select OF_EARLY_FLATTREE
+	select TIMER_OF
+	select H8300_TMR8
+	select HAVE_KERNEL_GZIP
+	select HAVE_KERNEL_LZO
+	select HAVE_ARCH_KGDB
+	select HAVE_ARCH_HASH
+	select CPU_NO_EFFICIENT_FFS
+	select SET_FS
+	select UACCESS_MEMCPY
+
+config CPU_BIG_ENDIAN
+	def_bool y
+
+config GENERIC_HWEIGHT
+	def_bool y
+
+config NO_IOPORT_MAP
+	def_bool y
+
+config GENERIC_CSUM
+        def_bool y
+
+config HZ
+	int
+	default 100
+
+config NR_CPUS
+	int
+	default 1
+
+source "arch/h8300/Kconfig.cpu"
diff --git a/arch/h8300/Kconfig.cpu b/arch/h8300/Kconfig.cpu
new file mode 100644
index 000000000..b5e14d513
--- /dev/null
+++ b/arch/h8300/Kconfig.cpu
@@ -0,0 +1,100 @@
+# SPDX-License-Identifier: GPL-2.0
+config CPU_H8300H
+	bool
+
+config CPU_H8S
+	bool
+
+config H83069
+	bool
+	select CPU_H8300H
+	select H8300_TMR16
+	select RENESAS_H8300H_INTC
+
+config H8S2678
+	bool
+	select CPU_H8S
+	select H8300_TPU
+	select RENESAS_H8S_INTC
+
+config RAMKERNEL
+	bool
+
+config ROMKERNEL
+	bool
+
+menu "Processor type and features"
+
+choice
+prompt "H8/300 platform"
+
+config H8300_AE3068
+	bool "AE-3068/69"
+	select H83069
+	select RAMKERNEL
+	help
+	  AKI-H8/3068F / AKI-H8/3069F Flashmicom LAN Board Support
+	  More Information. (Japanese Only)
+	  <http://akizukidenshi.com/catalog/default.aspx>
+	  AE-3068/69 Evaluation Board Support
+	  More Information.
+	  <http://www.microtronique.com/ae3069lan.htm>
+
+config H8300_H8MAX
+	bool "H8MAX"
+	select H83069
+	select RAMKERNEL
+	select HAVE_IDE
+	help
+	  H8MAX Evaluation Board Support
+	  More Information. (Japanese Only)
+	  <http://strawberry-linux.com/h8/index.html>
+
+config H8300_KANEBEBE
+	bool "KaneBebe"
+	select H83069
+	select RAMKERNEL
+	help
+	  KaneBebe Evalition Board Support
+	  More Information. (Japanese Only)
+	  <http://www.nissin-tech.com/2009/10/uclinuxkane-bebe-h83069f.html>
+
+config H8300H_SIM
+	bool "H8/300H GDB Simulator"
+	select H83069
+	select ROMKERNEL
+	help
+	  GDB Simulator Support
+	  More Information.
+	  <http://sourceware.org/sid/>
+
+config H8S_EDOSK2674
+	bool "EDOSK-2674"
+	select H8S2678
+	select RAMKERNEL
+	help
+	  Renesas EDOSK-2674 Evaluation Board Support
+	  More Information.
+	  <http://www.azpower.com/H8-uClinux/index.html>
+	  <http://www.renesas.eu/products/tools/introductory_evaluation_tools/evaluation_development_os_kits/edosk2674r/edosk2674r_software_tools_root.jsp>
+
+config H8S_SIM
+	bool "H8S GDB Simulator"
+	select H8S2678
+	select ROMKERNEL
+	help
+	  GDB Simulator Support
+	  More Information.
+	  <http://sourceware.org/sid/>
+
+endchoice
+
+config H8300_BUILTIN_DTB
+        string "Builtin DTB"
+	default ""
+
+config OFFSET
+        hex "Load offset"
+	default 0
+
+endmenu
diff --git a/arch/h8300/Kconfig.debug b/arch/h8300/Kconfig.debug
new file mode 100644
index 000000000..295942fe3
--- /dev/null
+++ b/arch/h8300/Kconfig.debug
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# dummy file, do not delete
diff --git a/arch/h8300/Makefile b/arch/h8300/Makefile
new file mode 100644
index 000000000..ba0f26cfa
--- /dev/null
+++ b/arch/h8300/Makefile
@@ -0,0 +1,50 @@
+#
+# arch/h8300/Makefile
+#
+# This file is subject to the terms and conditions of the GNU General Public
+# License.  See the file "COPYING" in the main directory of this archive
+# for more details.
+#
+# (C) Copyright 2002-2015 Yoshinori Sato <ysato@users.sourceforge.jp>
+#
+
+KBUILD_DEFCONFIG := edosk2674_defconfig
+
+cflags-$(CONFIG_CPU_H8300H)	:= -mh
+aflags-$(CONFIG_CPU_H8300H)	:= -mh -Wa,--mach=h8300h
+ldflags-$(CONFIG_CPU_H8300H)	:= -mh8300helf_linux
+cflags-$(CONFIG_CPU_H8S)	:= -ms
+aflags-$(CONFIG_CPU_H8S)	:= -ms -Wa,--mach=h8300s
+ldflags-$(CONFIG_CPU_H8S)	:= -mh8300self_linux
+
+KBUILD_CFLAGS += $(cflags-y)
+KBUILD_CFLAGS += -mint32 -fno-builtin
+KBUILD_CFLAGS += -D__linux__
+KBUILD_CFLAGS += -DUTS_SYSNAME=\"uClinux\"
+KBUILD_AFLAGS += $(aflags-y)
+KBUILD_LDFLAGS += $(ldflags-y)
+
+CHECKFLAGS += -msize-long
+
+ifeq ($(CROSS_COMPILE),)
+CROSS_COMPILE := $(call cc-cross-prefix, h8300-unknown-linux- h8300-linux-)
+endif
+
+core-y	+= arch/$(ARCH)/kernel/ arch/$(ARCH)/mm/
+core-y	+= arch/$(ARCH)/boot/dts/
+
+libs-y	+= arch/$(ARCH)/lib/
+
+boot := arch/h8300/boot
+
+archclean:
+	$(Q)$(MAKE) $(clean)=$(boot)
+
+vmlinux.srec vmlinux.bin zImage uImage.bin: vmlinux
+	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
+
+define archhelp
+  @echo  'vmlinux.bin  - Create raw binary'
+  @echo  'vmlinux.srec - Create srec binary'
+  @echo  'zImage       - Compressed kernel image'
+endef
diff --git a/arch/h8300/boot/Makefile b/arch/h8300/boot/Makefile
new file mode 100644
index 000000000..8e62df20e
--- /dev/null
+++ b/arch/h8300/boot/Makefile
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0
+# arch/h8300/boot/Makefile
+
+targets := vmlinux.srec vmlinux.bin zImage
+subdir- := compressed
+
+OBJCOPYFLAGS_vmlinux.srec := -Osrec
+OBJCOPYFLAGS_vmlinux.bin  := -Obinary
+OBJCOPYFLAGS_zImage := -O binary -R .note -R .comment -R .stab -R .stabstr -S
+
+UIMAGE_LOADADDR = $(CONFIG_RAMBASE)
+UIMAGE_ENTRYADDR = $(shell /bin/bash -c 'printf "0x%08x" \
+	$$[$(CONFIG_RAMBASE) + $(CONFIG_OFFSET)]')
+
+$(obj)/vmlinux.srec $(obj)/vmlinux.bin:  vmlinux FORCE
+	$(call if_changed,objcopy)
+
+$(obj)/zImage: $(obj)/compressed/vmlinux FORCE
+	$(call if_changed,objcopy)
+
+$(obj)/compressed/vmlinux: FORCE
+	$(Q)$(MAKE) $(build)=$(obj)/compressed $@
+
+$(obj)/uImage.bin: $(obj)/vmlinux.bin
+	$(call if_changed,uimage,none)
+
+CLEAN_FILES += arch/$(ARCH)/vmlinux.bin arch/$(ARCH)/vmlinux.srec arch/$(ARCH)/uImage.bin
diff --git a/arch/h8300/boot/compressed/Makefile b/arch/h8300/boot/compressed/Makefile
new file mode 100644
index 000000000..5942793f7
--- /dev/null
+++ b/arch/h8300/boot/compressed/Makefile
@@ -0,0 +1,43 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# linux/arch/sh/boot/compressed/Makefile
+#
+# create a compressed vmlinux image from the original vmlinux
+#
+
+targets		:= vmlinux vmlinux.bin vmlinux.bin.gz head.o misc.o piggy.o
+
+OBJECTS = $(obj)/head.o $(obj)/misc.o
+
+#
+# IMAGE_OFFSET is the load offset of the compression loader
+# Assign dummy values if these 2 variables are not defined,
+# in order to suppress error message.
+#
+CONFIG_MEMORY_START     ?= 0x00400000
+CONFIG_BOOT_LINK_OFFSET ?= 0x00280000
+IMAGE_OFFSET := $(shell printf "0x%08x" $$(($(CONFIG_MEMORY_START)+$(CONFIG_BOOT_LINK_OFFSET))))
+
+LIBGCC := $(shell $(CROSS-COMPILE)$(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name 2>/dev/null)
+LDFLAGS_vmlinux := -Ttext $(IMAGE_OFFSET) -estartup -T $(obj)/vmlinux.lds \
+	--defsym output=$(CONFIG_MEMORY_START)
+
+$(obj)/vmlinux: $(OBJECTS) $(obj)/piggy.o $(LIBGCC) FORCE
+	$(call if_changed,ld)
+
+$(obj)/vmlinux.bin: vmlinux FORCE
+	$(call if_changed,objcopy)
+
+suffix-$(CONFIG_KERNEL_GZIP)    := gzip
+suffix-$(CONFIG_KERNEL_LZO)     := lzo
+
+$(obj)/vmlinux.bin.$(suffix-y): $(obj)/vmlinux.bin FORCE
+	$(call if_changed,$(suffix-y))
+
+LDFLAGS_piggy.o := -r --format binary --oformat elf32-h8300-linux -T
+OBJCOPYFLAGS := -O binary
+
+$(obj)/piggy.o: $(obj)/vmlinux.scr $(obj)/vmlinux.bin.$(suffix-y) FORCE
+	$(call if_changed,ld)
+
+CFLAGS_misc.o = -O0
diff --git a/arch/h8300/boot/compressed/head.S b/arch/h8300/boot/compressed/head.S
new file mode 100644
index 000000000..11ef50957
--- /dev/null
+++ b/arch/h8300/boot/compressed/head.S
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  linux/arch/h8300/boot/compressed/head.S
+ *
+ *  Copyright (C) 2006 Yoshinori Sato
+ */
+
+#include <linux/linkage.h>
+
+	.section	.text..startup,"ax"
+	.global	startup
+startup:
+	mov.l	#startup, sp
+	mov.l	er0, er4
+	mov.l	#__sbss, er0
+	mov.l	#__ebss, er1
+	sub.l	er0, er1
+	shlr	er1
+	shlr	er1
+	sub.l	er2, er2
+1:
+	mov.l	er2, @er0
+	adds	#4, er0
+	dec.l	#1, er1
+	bne	1b
+	jsr	@decompress_kernel
+	mov.l	er4, er0
+	jmp	@output
+
+	.align	9
+fake_headers_as_bzImage:
+	.word	0
+	.ascii	"HdrS"		; header signature
+	.word	0x0202		; header version number (>= 0x0105)
+				; or else old loadlin-1.5 will fail)
+	.word	0		; default_switch
+	.word	0		; SETUPSEG
+	.word	0x1000
+	.word	0		; pointing to kernel version string
+	.byte	0		; = 0, old one (LILO, Loadlin,
+				; 0xTV: T=0 for LILO
+				;       V = version
+	.byte	1		; Load flags bzImage=1
+	.word	0x8000		; size to move, when setup is not
+	.long	0x100000	; 0x100000 = default for big kernel
+	.long	0		; address of loaded ramdisk image
+	.long	0		; its size in bytes
+
+	.end
diff --git a/arch/h8300/boot/compressed/misc.c b/arch/h8300/boot/compressed/misc.c
new file mode 100644
index 000000000..8915d8fe2
--- /dev/null
+++ b/arch/h8300/boot/compressed/misc.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * arch/h8300/boot/compressed/misc.c
+ *
+ * This is a collection of several routines from gzip-1.0.3
+ * adapted for Linux.
+ *
+ * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
+ *
+ * Adapted for h8300 by Yoshinori Sato 2006
+ */
+
+#include <linux/uaccess.h>
+
+/*
+ * gzip declarations
+ */
+
+#define OF(args)  args
+#define STATIC static
+
+#undef memset
+#undef memcpy
+#define memzero(s, n)     memset((s), (0), (n))
+
+extern int _end;
+static unsigned long free_mem_ptr;
+static unsigned long free_mem_end_ptr;
+
+extern char input_data[];
+extern int input_len;
+extern char output[];
+
+#define HEAP_SIZE             0x10000
+
+#ifdef CONFIG_KERNEL_GZIP
+#include "../../../../lib/decompress_inflate.c"
+#endif
+
+#ifdef CONFIG_KERNEL_LZO
+#include "../../../../lib/decompress_unlzo.c"
+#endif
+
+void *memset(void *s, int c, size_t n)
+{
+	int i;
+	char *ss = (char *)s;
+
+	for (i = 0; i < n; i++)
+		ss[i] = c;
+	return s;
+}
+
+void *memcpy(void *dest, const void *src, size_t n)
+{
+	int i;
+	char *d = (char *)dest, *s = (char *)src;
+
+	for (i = 0; i < n; i++)
+		d[i] = s[i];
+	return dest;
+}
+
+static void error(char *x)
+{
+	while (1)
+		;	/* Halt */
+}
+
+void decompress_kernel(void)
+{
+	free_mem_ptr = (unsigned long)&_end;
+	free_mem_end_ptr = free_mem_ptr + HEAP_SIZE;
+
+	__decompress(input_data, input_len, NULL, NULL, output, 0, NULL, error);
+}
diff --git a/arch/h8300/boot/compressed/vmlinux.lds b/arch/h8300/boot/compressed/vmlinux.lds
new file mode 100644
index 000000000..7f7bb419c
--- /dev/null
+++ b/arch/h8300/boot/compressed/vmlinux.lds
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+SECTIONS
+{
+        .text :
+        {
+        __stext = . ;
+	__text = .;
+	       *(.text..startup)
+	       *(.text)
+        __etext = . ;
+        }
+
+	.rodata :
+	{
+		*(.rodata)
+	}
+        . = ALIGN(0x4) ;
+        .data :
+
+        {
+        . = ALIGN(0x4) ;
+        __sdata = . ;
+        ___data_start = . ;
+                *(.data.*)
+	}
+        . = ALIGN(0x4) ;
+        .bss :
+        {
+        __sbss = . ;
+                *(.bss*)
+        . = ALIGN(0x4) ;
+        __ebss = . ;
+        }
+        _end = . ;
+}
diff --git a/arch/h8300/boot/compressed/vmlinux.scr b/arch/h8300/boot/compressed/vmlinux.scr
new file mode 100644
index 000000000..a08490360
--- /dev/null
+++ b/arch/h8300/boot/compressed/vmlinux.scr
@@ -0,0 +1,9 @@
+SECTIONS
+{
+  .data : {
+	input_len = .;
+	LONG(input_data_end - input_data) input_data = .;
+	*(.data)
+	input_data_end = .;
+	}
+}
diff --git a/arch/h8300/boot/dts/Makefile b/arch/h8300/boot/dts/Makefile
new file mode 100644
index 000000000..69fcd8178
--- /dev/null
+++ b/arch/h8300/boot/dts/Makefile
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0
+ifneq '$(CONFIG_H8300_BUILTIN_DTB)' '""'
+BUILTIN_DTB := $(patsubst "%",%,$(CONFIG_H8300_BUILTIN_DTB)).dtb.o
+endif
+
+obj-y += $(BUILTIN_DTB)
+
+dtb-$(CONFIG_H8300H_SIM) := h8300h_sim.dtb
+dtb-$(CONFIG_H8S_SIM) := h8s_sim.dtb
+dtb-$(CONFIG_H8S_EDOSK2674) := edosk2674.dtb
diff --git a/arch/h8300/boot/dts/edosk2674.dts b/arch/h8300/boot/dts/edosk2674.dts
new file mode 100644
index 000000000..d1733805e
--- /dev/null
+++ b/arch/h8300/boot/dts/edosk2674.dts
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/ {
+	compatible = "renesas,edosk2674";
+	#address-cells = <1>;
+	#size-cells = <1>;
+	interrupt-parent = <&h8intc>;
+
+	chosen {
+		bootargs = "console=ttySC2,38400";
+		stdout-path = &sci2;
+	};
+	aliases {
+		serial0 = &sci0;
+		serial1 = &sci1;
+		serial2 = &sci2;
+	};
+
+	xclk: oscillator {
+		#clock-cells = <0>;
+		compatible = "fixed-clock";
+		clock-frequency = <33333333>;
+		clock-output-names = "xtal";
+	};
+	pllclk: pllclk {
+		compatible = "renesas,h8s2678-pll-clock";
+		clocks = <&xclk>;
+		#clock-cells = <0>;
+		reg = <0xffff3b 1>, <0xffff45 1>;
+	};
+	core_clk: core_clk {
+		compatible = "renesas,h8300-div-clock";
+		clocks = <&pllclk>;
+		#clock-cells = <0>;
+		reg = <0xffff3b 1>;
+		renesas,width = <3>;
+	};
+	fclk: fclk {
+		compatible = "fixed-factor-clock";
+		clocks = <&core_clk>;
+		#clock-cells = <0>;
+		clock-div = <1>;
+		clock-mult = <1>;
+	};
+
+	memory@400000 {
+		device_type = "memory";
+		reg = <0x400000 0x800000>;
+	};
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		cpu@0 {
+			compatible = "renesas,h8300";
+			clock-frequency = <33333333>;
+		};
+	};
+
+	h8intc: interrupt-controller@fffe00 {
+		compatible = "renesas,h8s-intc", "renesas,h8300-intc";
+		#interrupt-cells = <2>;
+		interrupt-controller;
+		reg = <0xfffe00 24>;
+	};
+
+	bsc: memory-controller@fffec0 {
+		compatible = "renesas,h8s-bsc", "renesas,h8300-bsc";
+		reg = <0xfffec0 24>;
+	};
+
+	tpu: timer@ffffe0 {
+		compatible = "renesas,tpu";
+		reg = <0xffffe0 16>, <0xfffff0 12>;
+		clocks = <&fclk>;
+		clock-names = "fck";
+	};
+
+	timer8: timer@ffffb0 {
+		compatible = "renesas,8bit-timer";
+		reg = <0xffffb0 10>;
+		interrupts = <72 0>;
+		clocks = <&fclk>;
+		clock-names = "fck";
+	};
+
+	sci0: serial@ffff78 {
+		compatible = "renesas,sci";
+		reg = <0xffff78 8>;
+		interrupts = <88 0>, <89 0>, <90 0>, <91 0>;
+		clocks = <&fclk>;
+		clock-names = "fck";
+	};
+	sci1: serial@ffff80 {
+		compatible = "renesas,sci";
+		reg = <0xffff80 8>;
+		interrupts = <92 0>, <93 0>, <94 0>, <95 0>;
+		clocks = <&fclk>;
+		clock-names = "fck";
+	};
+	sci2: serial@ffff88 {
+		compatible = "renesas,sci";
+		reg = <0xffff88 8>;
+		interrupts = <96 0>, <97 0>, <98 0>, <99 0>;
+		clocks = <&fclk>;
+		clock-names = "fck";
+	};
+};
diff --git a/arch/h8300/boot/dts/h8300h_sim.dts b/arch/h8300/boot/dts/h8300h_sim.dts
new file mode 100644
index 000000000..595398b9d
--- /dev/null
+++ b/arch/h8300/boot/dts/h8300h_sim.dts
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/ {
+	compatible = "gnu,gdbsim";
+	#address-cells = <1>;
+	#size-cells = <1>;
+	interrupt-parent = <&h8intc>;
+
+	chosen {
+		bootargs = "earlyprintk=h8300-sim";
+		stdout-path = <&sci0>;
+	};
+	aliases {
+		serial0 = &sci0;
+		serial1 = &sci1;
+	};
+
+	xclk: oscillator {
+		#clock-cells = <0>;
+		compatible = "fixed-clock";
+		clock-frequency = <20000000>;
+		clock-output-names = "xtal";
+	};
+	core_clk: core_clk {
+		compatible = "renesas,h8300-div-clock";
+		clocks = <&xclk>;
+		#clock-cells = <0>;
+		reg = <0xfee01b 2>;
+		renesas,width = <2>;
+	};
+	fclk: fclk {
+		compatible = "fixed-factor-clock";
+		clocks = <&core_clk>;
+		#clock-cells = <0>;
+		clock-div = <1>;
+		clock-mult = <1>;
+	};
+
+	memory@400000 {
+		device_type = "memory";
+		reg = <0x400000 0x400000>;
+	};
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		cpu@0 {
+			compatible = "renesas,h8300";
+			clock-frequency = <20000000>;
+		};
+	};
+
+	h8intc: interrupt-controller@fee012 {
+		compatible = "renesas,h8300h-intc", "renesas,h8300-intc";
+		#interrupt-cells = <2>;
+		interrupt-controller;
+		reg = <0xfee012 7>;
+	};
+
+	bsc: memory-controller@fee01e {
+		compatible = "renesas,h8300h-bsc", "renesas,h8300-bsc";
+		reg = <0xfee01e 8>;
+	};
+
+	timer8: timer@ffff80 {
+		compatible = "renesas,8bit-timer";
+		reg = <0xffff80 10>;
+		interrupts = <36 0>;
+		clocks = <&fclk>;
+		clock-names = "fck";
+	};
+
+	timer16: timer@ffff68 {
+		compatible = "renesas,16bit-timer";
+		reg = <0xffff68 8>, <0xffff60 8>;
+		interrupts = <26 0>;
+		renesas,channel = <0>;
+		clocks = <&fclk>;
+		clock-names = "fck";
+	};
+
+	sci0: serial@ffffb0 {
+		compatible = "renesas,sci";
+		reg = <0xffffb0 8>;
+		interrupts = <52 0>, <53 0>, <54 0>, <55 0>;
+		clocks = <&fclk>;
+		clock-names = "fck";
+	};
+
+	sci1: serial@ffffb8 {
+		compatible = "renesas,sci";
+		reg = <0xffffb8 8>;
+		interrupts = <56 0>, <57 0>, <58 0>, <59 0>;
+		clocks = <&fclk>;
+		clock-names = "fck";
+	};
+};
diff --git a/arch/h8300/boot/dts/h8s_sim.dts b/arch/h8300/boot/dts/h8s_sim.dts
new file mode 100644
index 000000000..932cc3c5a
--- /dev/null
+++ b/arch/h8300/boot/dts/h8s_sim.dts
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/ {
+	compatible = "gnu,gdbsim";
+	#address-cells = <1>;
+	#size-cells = <1>;
+	interrupt-parent = <&h8intc>;
+
+	chosen {
+		bootargs = "earlyprintk=h8300-sim";
+		stdout-path = <&sci0>;
+	};
+	aliases {
+		serial0 = &sci0;
+		serial1 = &sci1;
+	};
+
+	xclk: oscillator {
+		#clock-cells = <0>;
+		compatible = "fixed-clock";
+		clock-frequency = <33333333>;
+		clock-output-names = "xtal";
+	};
+	pllclk: pllclk {
+		compatible = "renesas,h8s2678-pll-clock";
+		clocks = <&xclk>;
+		#clock-cells = <0>;
+		reg = <0xfee03b 2>, <0xfee045 2>;
+	};
+	core_clk: core_clk {
+		compatible = "renesas,h8300-div-clock";
+		clocks = <&pllclk>;
+		#clock-cells = <0>;
+		reg = <0xfee03b 2>;
+		renesas,width = <3>;
+	};
+	fclk: fclk {
+		compatible = "fixed-factor-clock";
+		clocks = <&core_clk>;
+		#clock-cells = <0>;
+		clock-div = <1>;
+		clock-mult = <1>;
+	};
+
+	memory@400000 {
+		device_type = "memory";
+		reg = <0x400000 0x800000>;
+	};
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		cpu@0 {
+			compatible = "renesas,h8300";
+			clock-frequency = <33333333>;
+		};
+	};
+
+	h8intc: interrupt-controller@fffe00 {
+		compatible = "renesas,h8s-intc", "renesas,h8300-intc";
+		#interrupt-cells = <2>;
+		interrupt-controller;
+		reg = <0xfffe00 24>;
+	};
+
+	bsc: memory-controller@fffec0 {
+		compatible = "renesas,h8s-bsc", "renesas,h8300-bsc";
+		reg = <0xfffec0 24>;
+	};
+
+	tpu: timer@ffffe0 {
+		compatible = "renesas,tpu";
+		reg = <0xffffe0 16>, <0xfffff0 12>;
+		clocks = <&fclk>;
+		clock-names = "fck";
+	};
+
+	timer8: timer@ffffb0 {
+		compatible = "renesas,8bit-timer";
+		reg = <0xffffb0 10>;
+		interrupts = <72 0>;
+		clocks = <&fclk>;
+		clock-names = "fck";
+	};
+
+	sci0: serial@ffff78 {
+		compatible = "renesas,sci";
+		reg = <0xffff78 8>;
+		interrupts = <88 0>, <89 0>, <90 0>, <91 0>;
+		clocks = <&fclk>;
+		clock-names = "fck";
+	};
+	sci1: serial@ffff80 {
+		compatible = "renesas,sci";
+		reg = <0xffff80 8>;
+		interrupts = <92 0>, <93 0>, <94 0>, <95 0>;
+		clocks = <&fclk>;
+		clock-names = "fck";
+	};
+};
diff --git a/arch/h8300/configs/edosk2674_defconfig b/arch/h8300/configs/edosk2674_defconfig
new file mode 100644
index 000000000..23791dcf6
--- /dev/null
+++ b/arch/h8300/configs/edosk2674_defconfig
@@ -0,0 +1,48 @@
+# CONFIG_LOCALVERSION_AUTO is not set
+# CONFIG_USELIB is not set
+CONFIG_CC_OPTIMIZE_FOR_SIZE=y
+# CONFIG_UID16 is not set
+# CONFIG_SYSFS_SYSCALL is not set
+# CONFIG_KALLSYMS is not set
+# CONFIG_BASE_FULL is not set
+# CONFIG_FUTEX is not set
+# CONFIG_EPOLL is not set
+# CONFIG_SIGNALFD is not set
+# CONFIG_TIMERFD is not set
+# CONFIG_EVENTFD is not set
+# CONFIG_AIO is not set
+# CONFIG_ADVISE_SYSCALLS is not set
+CONFIG_EMBEDDED=y
+# CONFIG_VM_EVENT_COUNTERS is not set
+# CONFIG_COMPAT_BRK is not set
+CONFIG_SLOB=y
+# CONFIG_BLOCK is not set
+CONFIG_H8S_SIM=y
+CONFIG_H8300_BUILTIN_DTB="h8s_sim"
+# CONFIG_BINFMT_SCRIPT is not set
+CONFIG_BINFMT_FLAT=y
+# CONFIG_COREDUMP is not set
+# CONFIG_UEVENT_HELPER is not set
+# CONFIG_STANDALONE is not set
+# CONFIG_PREVENT_FIRMWARE_BUILD is not set
+# CONFIG_FW_LOADER is not set
+# CONFIG_ALLOW_DEV_COREDUMP is not set
+# CONFIG_INPUT is not set
+# CONFIG_SERIO is not set
+# CONFIG_VT is not set
+# CONFIG_UNIX98_PTYS is not set
+# CONFIG_LEGACY_PTYS is not set
+# CONFIG_DEVKMEM is not set
+CONFIG_SERIAL_SH_SCI=y
+CONFIG_SERIAL_SH_SCI_CONSOLE=y
+# CONFIG_HW_RANDOM is not set
+# CONFIG_HWMON is not set
+# CONFIG_USB_SUPPORT is not set
+# CONFIG_FILE_LOCKING is not set
+# CONFIG_DNOTIFY is not set
+# CONFIG_INOTIFY_USER is not set
+# CONFIG_PROC_FS is not set
+# CONFIG_SYSFS is not set
+# CONFIG_MISC_FILESYSTEMS is not set
+CONFIG_DEBUG_INFO=y
+# CONFIG_ENABLE_MUST_CHECK is not set
diff --git a/arch/h8300/configs/h8300h-sim_defconfig b/arch/h8300/configs/h8300h-sim_defconfig
new file mode 100644
index 000000000..7fc9c2f0a
--- /dev/null
+++ b/arch/h8300/configs/h8300h-sim_defconfig
@@ -0,0 +1,48 @@
+# CONFIG_LOCALVERSION_AUTO is not set
+# CONFIG_USELIB is not set
+CONFIG_CC_OPTIMIZE_FOR_SIZE=y
+# CONFIG_UID16 is not set
+# CONFIG_SYSFS_SYSCALL is not set
+# CONFIG_KALLSYMS is not set
+# CONFIG_BASE_FULL is not set
+# CONFIG_FUTEX is not set
+# CONFIG_EPOLL is not set
+# CONFIG_SIGNALFD is not set
+# CONFIG_TIMERFD is not set
+# CONFIG_EVENTFD is not set
+# CONFIG_AIO is not set
+# CONFIG_ADVISE_SYSCALLS is not set
+CONFIG_EMBEDDED=y
+# CONFIG_VM_EVENT_COUNTERS is not set
+# CONFIG_COMPAT_BRK is not set
+CONFIG_SLOB=y
+# CONFIG_BLOCK is not set
+CONFIG_H8300H_SIM=y
+CONFIG_H8300_BUILTIN_DTB="h8300h_sim"
+# CONFIG_BINFMT_SCRIPT is not set
+CONFIG_BINFMT_FLAT=y
+# CONFIG_COREDUMP is not set
+# CONFIG_UEVENT_HELPER is not set
+# CONFIG_STANDALONE is not set
+# CONFIG_PREVENT_FIRMWARE_BUILD is not set
+# CONFIG_FW_LOADER is not set
+# CONFIG_ALLOW_DEV_COREDUMP is not set
+# CONFIG_INPUT is not set
+# CONFIG_SERIO is not set
+# CONFIG_VT is not set
+# CONFIG_UNIX98_PTYS is not set
+# CONFIG_LEGACY_PTYS is not set
+# CONFIG_DEVKMEM is not set
+CONFIG_SERIAL_SH_SCI=y
+CONFIG_SERIAL_SH_SCI_EARLYCON=y
+# CONFIG_HW_RANDOM is not set
+# CONFIG_HWMON is not set
+# CONFIG_USB_SUPPORT is not set
+# CONFIG_FILE_LOCKING is not set
+# CONFIG_DNOTIFY is not set
+# CONFIG_INOTIFY_USER is not set
+# CONFIG_PROC_FS is not set
+# CONFIG_SYSFS is not set
+# CONFIG_MISC_FILESYSTEMS is not set
+CONFIG_DEBUG_INFO=y
+# CONFIG_ENABLE_MUST_CHECK is not set
diff --git a/arch/h8300/configs/h8s-sim_defconfig b/arch/h8300/configs/h8s-sim_defconfig
new file mode 100644
index 000000000..23791dcf6
--- /dev/null
+++ b/arch/h8300/configs/h8s-sim_defconfig
@@ -0,0 +1,48 @@
+# CONFIG_LOCALVERSION_AUTO is not set
+# CONFIG_USELIB is not set
+CONFIG_CC_OPTIMIZE_FOR_SIZE=y
+# CONFIG_UID16 is not set
+# CONFIG_SYSFS_SYSCALL is not set
+# CONFIG_KALLSYMS is not set
+# CONFIG_BASE_FULL is not set
+# CONFIG_FUTEX is not set
+# CONFIG_EPOLL is not set
+# CONFIG_SIGNALFD is not set
+# CONFIG_TIMERFD is not set
+# CONFIG_EVENTFD is not set
+# CONFIG_AIO is not set
+# CONFIG_ADVISE_SYSCALLS is not set
+CONFIG_EMBEDDED=y
+# CONFIG_VM_EVENT_COUNTERS is not set
+# CONFIG_COMPAT_BRK is not set
+CONFIG_SLOB=y
+# CONFIG_BLOCK is not set
+CONFIG_H8S_SIM=y
+CONFIG_H8300_BUILTIN_DTB="h8s_sim"
+# CONFIG_BINFMT_SCRIPT is not set
+CONFIG_BINFMT_FLAT=y
+# CONFIG_COREDUMP is not set
+# CONFIG_UEVENT_HELPER is not set
+# CONFIG_STANDALONE is not set
+# CONFIG_PREVENT_FIRMWARE_BUILD is not set
+# CONFIG_FW_LOADER is not set
+# CONFIG_ALLOW_DEV_COREDUMP is not set
+# CONFIG_INPUT is not set
+# CONFIG_SERIO is not set
+# CONFIG_VT is not set
+# CONFIG_UNIX98_PTYS is not set
+# CONFIG_LEGACY_PTYS is not set
+# CONFIG_DEVKMEM is not set
+CONFIG_SERIAL_SH_SCI=y
+CONFIG_SERIAL_SH_SCI_CONSOLE=y
+# CONFIG_HW_RANDOM is not set
+# CONFIG_HWMON is not set
+# CONFIG_USB_SUPPORT is not set
+# CONFIG_FILE_LOCKING is not set
+# CONFIG_DNOTIFY is not set
+# CONFIG_INOTIFY_USER is not set
+# CONFIG_PROC_FS is not set
+# CONFIG_SYSFS is not set
+# CONFIG_MISC_FILESYSTEMS is not set
+CONFIG_DEBUG_INFO=y
+# CONFIG_ENABLE_MUST_CHECK is not set
diff --git a/arch/h8300/include/asm/Kbuild b/arch/h8300/include/asm/Kbuild
new file mode 100644
index 000000000..60ee7f0d6
--- /dev/null
+++ b/arch/h8300/include/asm/Kbuild
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+generic-y += asm-offsets.h
+generic-y += extable.h
+generic-y += kvm_para.h
+generic-y += mcs_spinlock.h
+generic-y += parport.h
+generic-y += spinlock.h
diff --git a/arch/h8300/include/asm/atomic.h b/arch/h8300/include/asm/atomic.h
new file mode 100644
index 000000000..a990d151f
--- /dev/null
+++ b/arch/h8300/include/asm/atomic.h
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ARCH_H8300_ATOMIC__
+#define __ARCH_H8300_ATOMIC__
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+#include <asm/cmpxchg.h>
+#include <asm/irqflags.h>
+
+/*
+ * Atomic operations that C can't guarantee us.  Useful for
+ * resource counting etc..
+ */
+
+#define atomic_read(v)		READ_ONCE((v)->counter)
+#define atomic_set(v, i)	WRITE_ONCE(((v)->counter), (i))
+
+#define ATOMIC_OP_RETURN(op, c_op)				\
+static inline int atomic_##op##_return(int i, atomic_t *v)	\
+{								\
+	h8300flags flags;					\
+	int ret;						\
+								\
+	flags = arch_local_irq_save();				\
+	ret = v->counter c_op i;				\
+	arch_local_irq_restore(flags);				\
+	return ret;						\
+}
+
+#define ATOMIC_FETCH_OP(op, c_op)				\
+static inline int atomic_fetch_##op(int i, atomic_t *v)		\
+{								\
+	h8300flags flags;					\
+	int ret;						\
+								\
+	flags = arch_local_irq_save();				\
+	ret = v->counter;					\
+	v->counter c_op i;					\
+	arch_local_irq_restore(flags);				\
+	return ret;						\
+}
+
+#define ATOMIC_OP(op, c_op)					\
+static inline void atomic_##op(int i, atomic_t *v)		\
+{								\
+	h8300flags flags;					\
+								\
+	flags = arch_local_irq_save();				\
+	v->counter c_op i;					\
+	arch_local_irq_restore(flags);				\
+}
+
+ATOMIC_OP_RETURN(add, +=)
+ATOMIC_OP_RETURN(sub, -=)
+
+#define ATOMIC_OPS(op, c_op)					\
+	ATOMIC_OP(op, c_op)					\
+	ATOMIC_FETCH_OP(op, c_op)
+
+ATOMIC_OPS(and, &=)
+ATOMIC_OPS(or,  |=)
+ATOMIC_OPS(xor, ^=)
+ATOMIC_OPS(add, +=)
+ATOMIC_OPS(sub, -=)
+
+#undef ATOMIC_OPS
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
+{
+	int ret;
+	h8300flags flags;
+
+	flags = arch_local_irq_save();
+	ret = v->counter;
+	if (likely(ret == old))
+		v->counter = new;
+	arch_local_irq_restore(flags);
+	return ret;
+}
+
+static inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
+{
+	int ret;
+	h8300flags flags;
+
+	flags = arch_local_irq_save();
+	ret = v->counter;
+	if (ret != u)
+		v->counter += a;
+	arch_local_irq_restore(flags);
+	return ret;
+}
+#define atomic_fetch_add_unless		atomic_fetch_add_unless
+
+#endif /* __ARCH_H8300_ATOMIC __ */
diff --git a/arch/h8300/include/asm/bitops.h b/arch/h8300/include/asm/bitops.h
new file mode 100644
index 000000000..7aa16c732
--- /dev/null
+++ b/arch/h8300/include/asm/bitops.h
@@ -0,0 +1,180 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _H8300_BITOPS_H
+#define _H8300_BITOPS_H
+
+/*
+ * Copyright 1992, Linus Torvalds.
+ * Copyright 2002, Yoshinori Sato
+ */
+
+#include <linux/compiler.h>
+
+#ifdef __KERNEL__
+
+#ifndef _LINUX_BITOPS_H
+#error only <linux/bitops.h> can be included directly
+#endif
+
+/*
+ * Function prototypes to keep gcc -Wall happy
+ */
+
+/*
+ * ffz = Find First Zero in word. Undefined if no zero exists,
+ * so code should check against ~0UL first..
+ */
+static inline unsigned long ffz(unsigned long word)
+{
+	unsigned long result;
+
+	result = -1;
+	__asm__("1:\n\t"
+		"shlr.l %1\n\t"
+		"adds #1,%0\n\t"
+		"bcs 1b"
+		: "=r"(result),"=r"(word)
+		: "0"(result), "1"(word));
+	return result;
+}
+
+#define H8300_GEN_BITOP(FNAME, OP)				\
+static inline void FNAME(int nr, volatile unsigned long *addr)	\
+{								\
+	unsigned char *b_addr;					\
+	unsigned char bit = nr & 7;				\
+								\
+	b_addr = (unsigned char *)addr + ((nr >> 3) ^ 3);	\
+	if (__builtin_constant_p(nr)) {				\
+		__asm__(OP " %1,%0" : "+WU"(*b_addr) : "i"(nr & 7));	\
+	} else {						\
+		__asm__(OP " %s1,%0" : "+WU"(*b_addr) : "r"(bit));	\
+	}							\
+}
+
+H8300_GEN_BITOP(set_bit,    "bset")
+H8300_GEN_BITOP(clear_bit,  "bclr")
+H8300_GEN_BITOP(change_bit, "bnot")
+#define __set_bit(nr, addr)    set_bit((nr), (addr))
+#define __clear_bit(nr, addr)  clear_bit((nr), (addr))
+#define __change_bit(nr, addr) change_bit((nr), (addr))
+
+#undef H8300_GEN_BITOP
+
+static inline int test_bit(int nr, const volatile unsigned long *addr)
+{
+	int ret = 0;
+	unsigned char *b_addr;
+	unsigned char bit = nr & 7;
+
+	b_addr = (unsigned char *)addr + ((nr >> 3) ^ 3);
+	if (__builtin_constant_p(nr)) {
+		__asm__("bld %Z2,%1\n\t"
+			"rotxl %0\n\t"
+			: "=r"(ret)
+			: "WU"(*b_addr), "i"(nr & 7), "0"(ret) : "cc");
+	} else {
+		__asm__("btst %w2,%1\n\t"
+			"beq 1f\n\t"
+			"inc.l #1,%0\n"
+			"1:"
+			: "=r"(ret)
+			: "WU"(*b_addr), "r"(bit), "0"(ret) : "cc");
+	}
+	return ret;
+}
+
+#define __test_bit(nr, addr) test_bit(nr, addr)
+
+#define H8300_GEN_TEST_BITOP(FNNAME, OP)				\
+static inline int FNNAME(int nr, void *addr)				\
+{									\
+	int retval = 0;							\
+	char ccrsave;							\
+	unsigned char *b_addr;						\
+	unsigned char bit = nr & 7;					\
+									\
+	b_addr = (unsigned char *)addr + ((nr >> 3) ^ 3);		\
+	if (__builtin_constant_p(nr)) {					\
+		__asm__("stc ccr,%s2\n\t"				\
+			"orc #0x80,ccr\n\t"				\
+			"bld %4,%1\n\t"					\
+			OP " %4,%1\n\t"					\
+			"rotxl.l %0\n\t"				\
+			"ldc %s2,ccr"					\
+			: "=r"(retval), "+WU" (*b_addr), "=&r"(ccrsave)	\
+			: "0"(retval), "i"(nr & 7) : "cc");		\
+	} else {							\
+		__asm__("stc ccr,%t3\n\t"				\
+			"orc #0x80,ccr\n\t"				\
+			"btst %s3,%1\n\t"				\
+			OP " %s3,%1\n\t"				\
+			"beq 1f\n\t"					\
+			"inc.l #1,%0\n\t"				\
+			"1:\n"						\
+			"ldc %t3,ccr"					\
+			: "=r"(retval), "+WU" (*b_addr)			\
+			: "0" (retval), "r"(bit) : "cc");		\
+	}								\
+	return retval;							\
+}									\
+									\
+static inline int __ ## FNNAME(int nr, void *addr)			\
+{									\
+	int retval = 0;							\
+	unsigned char *b_addr;						\
+	unsigned char bit = nr & 7;					\
+									\
+	b_addr = (unsigned char *)addr + ((nr >> 3) ^ 3);		\
+	if (__builtin_constant_p(nr)) {					\
+		__asm__("bld %3,%1\n\t"					\
+			OP " %3,%1\n\t"					\
+			"rotxl.l %0\n\t"				\
+			: "=r"(retval), "+WU"(*b_addr)			\
+			: "0" (retval), "i"(nr & 7));			\
+	} else {							\
+		__asm__("btst %s3,%1\n\t"				\
+			OP " %s3,%1\n\t"				\
+			"beq 1f\n\t"					\
+			"inc.l #1,%0\n\t"				\
+			"1:"						\
+			: "=r"(retval), "+WU"(*b_addr)			\
+			: "0" (retval), "r"(bit));			\
+	}								\
+	return retval;							\
+}
+
+H8300_GEN_TEST_BITOP(test_and_set_bit,	  "bset")
+H8300_GEN_TEST_BITOP(test_and_clear_bit,  "bclr")
+H8300_GEN_TEST_BITOP(test_and_change_bit, "bnot")
+#undef H8300_GEN_TEST_BITOP
+
+#include <asm-generic/bitops/ffs.h>
+
+static inline unsigned long __ffs(unsigned long word)
+{
+	unsigned long result;
+
+	result = -1;
+	__asm__("1:\n\t"
+		"shlr.l %1\n\t"
+		"adds #1,%0\n\t"
+		"bcc 1b"
+		: "=r" (result),"=r"(word)
+		: "0"(result), "1"(word));
+	return result;
+}
+
+#include <asm-generic/bitops/find.h>
+#include <asm-generic/bitops/sched.h>
+#include <asm-generic/bitops/hweight.h>
+#include <asm-generic/bitops/lock.h>
+#include <asm-generic/bitops/le.h>
+#include <asm-generic/bitops/ext2-atomic.h>
+
+#endif /* __KERNEL__ */
+
+#include <asm-generic/bitops/fls.h>
+#include <asm-generic/bitops/__fls.h>
+#include <asm-generic/bitops/fls64.h>
+
+#endif /* _H8300_BITOPS_H */
diff --git a/arch/h8300/include/asm/bug.h b/arch/h8300/include/asm/bug.h
new file mode 100644
index 000000000..00fe5e966
--- /dev/null
+++ b/arch/h8300/include/asm/bug.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _H8300_BUG_H
+#define _H8300_BUG_H
+
+/* always true */
+#define is_valid_bugaddr(addr) (1)
+
+#include <asm-generic/bug.h>
+
+struct pt_regs;
+extern void die(const char *str, struct pt_regs *fp, unsigned long err);
+
+#endif
diff --git a/arch/h8300/include/asm/byteorder.h b/arch/h8300/include/asm/byteorder.h
new file mode 100644
index 000000000..6eaa7ad5f
--- /dev/null
+++ b/arch/h8300/include/asm/byteorder.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __H8300_BYTEORDER_H__
+#define __H8300_BYTEORDER_H__
+
+#include <linux/byteorder/big_endian.h>
+
+#endif
diff --git a/arch/h8300/include/asm/cache.h b/arch/h8300/include/asm/cache.h
new file mode 100644
index 000000000..4243eb319
--- /dev/null
+++ b/arch/h8300/include/asm/cache.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ARCH_H8300_CACHE_H
+#define __ARCH_H8300_CACHE_H
+
+/* bytes per L1 cache line */
+#define        L1_CACHE_SHIFT  2
+#define        L1_CACHE_BYTES  (1 << L1_CACHE_SHIFT)
+
+#define __cacheline_aligned
+#define ____cacheline_aligned
+
+#endif
diff --git a/arch/h8300/include/asm/cmpxchg.h b/arch/h8300/include/asm/cmpxchg.h
new file mode 100644
index 000000000..c64bb38ce
--- /dev/null
+++ b/arch/h8300/include/asm/cmpxchg.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ARCH_H8300_CMPXCHG__
+#define __ARCH_H8300_CMPXCHG__
+
+#include <linux/irqflags.h>
+
+#define xchg(ptr, x) \
+	((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), \
+				    sizeof(*(ptr))))
+
+struct __xchg_dummy { unsigned long a[100]; };
+#define __xg(x) ((volatile struct __xchg_dummy *)(x))
+
+static inline unsigned long __xchg(unsigned long x,
+				   volatile void *ptr, int size)
+{
+	unsigned long tmp, flags;
+
+	local_irq_save(flags);
+
+	switch (size) {
+	case 1:
+		__asm__ __volatile__
+			("mov.b %2,%0\n\t"
+			 "mov.b %1,%2"
+			 : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)));
+		break;
+	case 2:
+		__asm__ __volatile__
+			("mov.w %2,%0\n\t"
+			 "mov.w %1,%2"
+			 : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)));
+		break;
+	case 4:
+		__asm__ __volatile__
+			("mov.l %2,%0\n\t"
+			 "mov.l %1,%2"
+			 : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)));
+		break;
+	default:
+		tmp = 0;
+	}
+	local_irq_restore(flags);
+	return tmp;
+}
+
+#include <asm-generic/cmpxchg-local.h>
+
+/*
+ * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
+ * them available.
+ */
+#define cmpxchg_local(ptr, o, n)					 \
+	((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr),		 \
+						     (unsigned long)(o), \
+						     (unsigned long)(n), \
+						     sizeof(*(ptr))))
+#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
+
+#ifndef CONFIG_SMP
+#include <asm-generic/cmpxchg.h>
+#endif
+
+#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
+
+#endif /* __ARCH_H8300_CMPXCHG__ */
diff --git a/arch/h8300/include/asm/elf.h b/arch/h8300/include/asm/elf.h
new file mode 100644
index 000000000..029647cda
--- /dev/null
+++ b/arch/h8300/include/asm/elf.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_H8300_ELF_H
+#define __ASM_H8300_ELF_H
+
+/*
+ * ELF register definitions..
+ */
+
+#include <asm/ptrace.h>
+#include <asm/user.h>
+
+typedef unsigned long elf_greg_t;
+
+#define ELF_NGREG (sizeof(struct user_regs_struct) / sizeof(elf_greg_t))
+typedef elf_greg_t elf_gregset_t[ELF_NGREG];
+typedef unsigned long elf_fpregset_t;
+
+/*
+ * This is used to ensure we don't load something for the wrong architecture.
+ */
+#define elf_check_arch(x) ((x)->e_machine == EM_H8_300)
+
+/*
+ * These are used to set parameters in the core dumps.
+ */
+#define ELF_CLASS	ELFCLASS32
+#define ELF_DATA	ELFDATA2MSB
+#define ELF_ARCH	EM_H8_300
+#if defined(CONFIG_CPU_H8300H)
+#define ELF_CORE_EFLAGS 0x810000
+#endif
+#if defined(CONFIG_CPU_H8S)
+#define ELF_CORE_EFLAGS 0x820000
+#endif
+
+#define ELF_PLAT_INIT(_r) do { (_r)->er1 = 0; } while (0)
+
+#define ELF_EXEC_PAGESIZE	4096
+
+/* This is the location that an ET_DYN program is loaded if exec'ed.  Typical
+   use of this is to invoke "./ld.so someprog" to test out a new version of
+   the loader.  We need to make sure that it is out of the way of the program
+   that it will "exec", and that there is sufficient room for the brk.  */
+
+#define ELF_ET_DYN_BASE         0xD0000000UL
+
+/* This yields a mask that user programs can use to figure out what
+   instruction set this cpu supports.  */
+
+#define ELF_HWCAP	(0)
+
+/* This yields a string that ld.so will use to load implementation
+   specific libraries for optimization.  This is more specific in
+   intent than poking at uname or /proc/cpuinfo.  */
+
+#define ELF_PLATFORM  (NULL)
+
+#define R_H8_NONE       0
+#define R_H8_DIR32      1
+#define R_H8_DIR32_28   2
+#define R_H8_DIR32_24   3
+#define R_H8_DIR32_16   4
+#define R_H8_DIR32U     6
+#define R_H8_DIR32U_28  7
+#define R_H8_DIR32U_24  8
+#define R_H8_DIR32U_20  9
+#define R_H8_DIR32U_16 10
+#define R_H8_DIR24     11
+#define R_H8_DIR24_20  12
+#define R_H8_DIR24_16  13
+#define R_H8_DIR24U    14
+#define R_H8_DIR24U_20 15
+#define R_H8_DIR24U_16 16
+#define R_H8_DIR16     17
+#define R_H8_DIR16U    18
+#define R_H8_DIR16S_32 19
+#define R_H8_DIR16S_28 20
+#define R_H8_DIR16S_24 21
+#define R_H8_DIR16S_20 22
+#define R_H8_DIR16S    23
+#define R_H8_DIR8      24
+#define R_H8_DIR8U     25
+#define R_H8_DIR8Z_32  26
+#define R_H8_DIR8Z_28  27
+#define R_H8_DIR8Z_24  28
+#define R_H8_DIR8Z_20  29
+#define R_H8_DIR8Z_16  30
+#define R_H8_PCREL16   31
+#define R_H8_PCREL8    32
+#define R_H8_BPOS      33
+#define R_H8_PCREL32   34
+#define R_H8_GOT32O    35
+#define R_H8_GOT16O    36
+#define R_H8_DIR16A8   59
+#define R_H8_DIR16R8   60
+#define R_H8_DIR24A8   61
+#define R_H8_DIR24R8   62
+#define R_H8_DIR32A16  63
+#define R_H8_ABS32     65
+#define R_H8_ABS32A16 127
+
+#endif
diff --git a/arch/h8300/include/asm/flat.h b/arch/h8300/include/asm/flat.h
new file mode 100644
index 000000000..78070f924
--- /dev/null
+++ b/arch/h8300/include/asm/flat.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * arch/h8300/asm/include/flat.h -- uClinux flat-format executables
+ */
+
+#ifndef __H8300_FLAT_H__
+#define __H8300_FLAT_H__
+
+#include <asm/unaligned.h>
+
+/*
+ * on the H8 a couple of the relocations have an instruction in the
+ * top byte.  As there can only be 24bits of address space,  we just
+ * always preserve that 8bits at the top,  when it isn't an instruction
+ * is is 0 (davidm@snapgear.com)
+ */
+
+#define	flat_get_relocate_addr(rel)		(rel & ~0x00000001)
+static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
+					u32 *addr)
+{
+	u32 val = get_unaligned((__force u32 *)rp);
+	if (!(flags & FLAT_FLAG_GOTPIC))
+		val &= 0x00ffffff;
+	*addr = val;
+	return 0;
+}
+
+static inline int flat_put_addr_at_rp(u32 __user *rp, u32 addr, u32 rel)
+{
+	u32 *p = (__force u32 *)rp;
+	put_unaligned((addr & 0x00ffffff) | (*(char *)p << 24), p);
+	return 0;
+}
+
+#endif /* __H8300_FLAT_H__ */
diff --git a/arch/h8300/include/asm/hash.h b/arch/h8300/include/asm/hash.h
new file mode 100644
index 000000000..2960b4c9e
--- /dev/null
+++ b/arch/h8300/include/asm/hash.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_HASH_H
+#define _ASM_HASH_H
+
+/*
+ * The later H8SX models have a 32x32-bit multiply, but the H8/300H
+ * and H8S have only 16x16->32.  Since it's tolerably compact, this is
+ * basically an inlined version of the __mulsi3 code.  Since the inputs
+ * are not expected to be small, it's also simplfied by skipping the
+ * early-out checks.
+ *
+ * (Since neither CPU has any multi-bit shift instructions, a
+ * shift-and-add version is a non-starter.)
+ *
+ * TODO: come up with an arch-specific version of the hashing in fs/namei.c,
+ * since that is heavily dependent on rotates.  Which, as mentioned, suck
+ * horribly on H8.
+ */
+
+#if defined(CONFIG_CPU_H300H) || defined(CONFIG_CPU_H8S)
+
+#define HAVE_ARCH__HASH_32 1
+
+/*
+ * Multiply by k = 0x61C88647.  Fitting this into three registers requires
+ * one extra instruction, but reducing register pressure will probably
+ * make that back and then some.
+ *
+ * GCC asm note: %e1 is the high half of operand %1, while %f1 is the
+ * low half.  So if %1 is er4, then %e1 is e4 and %f1 is r4.
+ *
+ * This has been designed to modify x in place, since that's the most
+ * common usage, but preserve k, since hash_64() makes two calls in
+ * quick succession.
+ */
+static inline u32 __attribute_const__ __hash_32(u32 x)
+{
+	u32 temp;
+
+	asm(   "mov.w	%e1,%f0"
+	"\n	mulxu.w	%f2,%0"		/* klow * xhigh */
+	"\n	mov.w	%f0,%e1"	/* The extra instruction */
+	"\n	mov.w	%f1,%f0"
+	"\n	mulxu.w	%e2,%0"		/* khigh * xlow */
+	"\n	add.w	%e1,%f0"
+	"\n	mulxu.w	%f2,%1"		/* klow * xlow */
+	"\n	add.w	%f0,%e1"
+	: "=&r" (temp), "=r" (x)
+	: "%r" (GOLDEN_RATIO_32), "1" (x));
+	return x;
+}
+
+#endif
+#endif /* _ASM_HASH_H */
diff --git a/arch/h8300/include/asm/io.h b/arch/h8300/include/asm/io.h
new file mode 100644
index 000000000..096d99580
--- /dev/null
+++ b/arch/h8300/include/asm/io.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _H8300_IO_H
+#define _H8300_IO_H
+
+#ifdef __KERNEL__
+
+#include <linux/types.h>
+
+/* H8/300 internal I/O functions */
+
+#define __raw_readb __raw_readb
+static inline u8 __raw_readb(const volatile void __iomem *addr)
+{
+	return *(volatile u8 *)addr;
+}
+
+#define __raw_readw __raw_readw
+static inline u16 __raw_readw(const volatile void __iomem *addr)
+{
+	return *(volatile u16 *)addr;
+}
+
+#define __raw_readl __raw_readl
+static inline u32  __raw_readl(const volatile void __iomem *addr)
+{
+	return *(volatile u32 *)addr;
+}
+
+#define __raw_writeb __raw_writeb
+static inline void __raw_writeb(u8 b, const volatile void __iomem *addr)
+{
+	*(volatile u8 *)addr = b;
+}
+
+#define __raw_writew __raw_writew
+static inline void __raw_writew(u16 b, const volatile void __iomem *addr)
+{
+	*(volatile u16 *)addr = b;
+}
+
+#define __raw_writel __raw_writel
+static inline void __raw_writel(u32 b, const volatile void __iomem *addr)
+{
+	*(volatile u32 *)addr = b;
+}
+
+static inline void ctrl_bclr(int b, void __iomem *addr)
+{
+	if (__builtin_constant_p(b))
+		__asm__("bclr %1,%0" : "+WU"(*(u8 *)addr): "i"(b));
+	else
+		__asm__("bclr %w1,%0" : "+WU"(*(u8 *)addr): "r"(b));
+}
+
+static inline void ctrl_bset(int b, void __iomem *addr)
+{
+	if (__builtin_constant_p(b))
+		__asm__("bset %1,%0" : "+WU"(*(u8 *)addr): "i"(b));
+	else
+		__asm__("bset %w1,%0" : "+WU"(*(u8 *)addr): "r"(b));
+}
+
+#include <asm-generic/io.h>
+
+#endif /* __KERNEL__ */
+
+#endif /* _H8300_IO_H */
diff --git a/arch/h8300/include/asm/irq.h b/arch/h8300/include/asm/irq.h
new file mode 100644
index 000000000..5fc5b436d
--- /dev/null
+++ b/arch/h8300/include/asm/irq.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _H8300_IRQ_H_
+#define _H8300_IRQ_H_
+
+#include <linux/irqchip.h>
+
+#if defined(CONFIG_CPU_H8300H)
+#define NR_IRQS 64
+#define IRQ_CHIP h8300h_irq_chip
+#define EXT_IRQ0 12
+#define EXT_IRQS 6
+#elif defined(CONFIG_CPU_H8S)
+#define NR_IRQS 128
+#define IRQ_CHIP h8s_irq_chip
+#define EXT_IRQ0 16
+#define EXT_IRQS 16
+#endif
+
+static inline int irq_canonicalize(int irq)
+{
+	return irq;
+}
+
+void h8300_init_ipr(void);
+extern struct irq_chip h8300h_irq_chip;
+extern struct irq_chip h8s_irq_chip;
+#endif /* _H8300_IRQ_H_ */
diff --git a/arch/h8300/include/asm/irqflags.h b/arch/h8300/include/asm/irqflags.h
new file mode 100644
index 000000000..48756b7f4
--- /dev/null
+++ b/arch/h8300/include/asm/irqflags.h
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _H8300_IRQFLAGS_H
+#define _H8300_IRQFLAGS_H
+
+#ifdef CONFIG_CPU_H8300H
+typedef unsigned char h8300flags;
+
+static inline h8300flags arch_local_save_flags(void)
+{
+	h8300flags flags;
+
+	__asm__ volatile ("stc ccr,%w0" : "=r" (flags));
+	return flags;
+}
+
+static inline void arch_local_irq_disable(void)
+{
+	__asm__ volatile ("orc  #0xc0,ccr");
+}
+
+static inline void arch_local_irq_enable(void)
+{
+	__asm__ volatile ("andc #0x3f,ccr");
+}
+
+static inline h8300flags arch_local_irq_save(void)
+{
+	h8300flags flags;
+
+	__asm__ volatile ("stc ccr,%w0\n\t"
+		      "orc  #0xc0,ccr" : "=r" (flags));
+	return flags;
+}
+
+static inline void arch_local_irq_restore(h8300flags flags)
+{
+	__asm__ volatile ("ldc %w0,ccr" : : "r" (flags) : "cc");
+}
+
+static inline int arch_irqs_disabled_flags(unsigned long flags)
+{
+	return (flags & 0xc0) == 0xc0;
+}
+#endif
+#ifdef CONFIG_CPU_H8S
+typedef unsigned short h8300flags;
+
+static inline h8300flags arch_local_save_flags(void)
+{
+	h8300flags flags;
+
+	__asm__ volatile ("stc ccr,%w0\n\tstc exr,%x0" : "=r" (flags));
+	return flags;
+}
+
+static inline void arch_local_irq_disable(void)
+{
+	__asm__ volatile ("orc #0x80,ccr\n\t");
+}
+
+static inline void arch_local_irq_enable(void)
+{
+	__asm__ volatile ("andc #0x7f,ccr\n\t"
+		      "andc #0xf0,exr\n\t");
+}
+
+static inline h8300flags arch_local_irq_save(void)
+{
+	h8300flags flags;
+
+	__asm__ volatile ("stc ccr,%w0\n\t"
+		      "stc exr,%x0\n\t"
+		      "orc  #0x80,ccr\n\t"
+		      : "=r" (flags));
+	return flags;
+}
+
+static inline void arch_local_irq_restore(h8300flags flags)
+{
+	__asm__ volatile ("ldc %w0,ccr\n\t"
+		      "ldc %x0,exr"
+		      : : "r" (flags) : "cc");
+}
+
+static inline int arch_irqs_disabled_flags(h8300flags flags)
+{
+	return (flags & 0x0080) == 0x0080;
+}
+
+#endif
+
+static inline int arch_irqs_disabled(void)
+{
+	return arch_irqs_disabled_flags(arch_local_save_flags());
+}
+
+#endif /* _H8300_IRQFLAGS_H */
diff --git a/arch/h8300/include/asm/kgdb.h b/arch/h8300/include/asm/kgdb.h
new file mode 100644
index 000000000..726ff8fdf
--- /dev/null
+++ b/arch/h8300/include/asm/kgdb.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2015 Yoshinori Sato <ysato@users.sourceforge.jp>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#ifndef _ASM_H8300_KGDB_H
+#define _ASM_H8300_KGDB_H
+
+#define CACHE_FLUSH_IS_SAFE	1
+#define BUFMAX			2048
+
+enum regnames {
+	GDB_ER0, GDB_ER1, GDB_ER2, GDB_ER3,
+	GDB_ER4, GDB_ER5, GDB_ER6, GDB_SP,
+	GDB_CCR, GDB_PC,
+	GDB_CYCLLE,
+#if defined(CONFIG_CPU_H8S)
+	GDB_EXR,
+#endif
+	GDB_TICK, GDB_INST,
+#if defined(CONFIG_CPU_H8S)
+	GDB_MACH, GDB_MACL,
+#endif
+	/* do not change the last entry or anything below! */
+	GDB_NUMREGBYTES,		/* number of registers */
+};
+
+#define GDB_SIZEOF_REG		sizeof(u32)
+#if defined(CONFIG_CPU_H8300H)
+#define DBG_MAX_REG_NUM		(13)
+#elif defined(CONFIG_CPU_H8S)
+#define DBG_MAX_REG_NUM		(14)
+#endif
+#define NUMREGBYTES		(DBG_MAX_REG_NUM * GDB_SIZEOF_REG)
+
+#define BREAK_INSTR_SIZE	2
+static inline void arch_kgdb_breakpoint(void)
+{
+	__asm__ __volatile__("trapa #2");
+}
+
+#endif /* _ASM_H8300_KGDB_H */
diff --git a/arch/h8300/include/asm/page.h b/arch/h8300/include/asm/page.h
new file mode 100644
index 000000000..53e037544
--- /dev/null
+++ b/arch/h8300/include/asm/page.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _H8300_PAGE_H
+#define _H8300_PAGE_H
+
+#include <asm-generic/page.h>
+#include <linux/types.h>
+
+#define MAP_NR(addr) (((uintptr_t)(addr)-PAGE_OFFSET) >> PAGE_SHIFT)
+
+#ifndef __ASSEMBLY__
+extern unsigned long rom_length;
+extern unsigned long memory_start;
+extern unsigned long memory_end;
+extern unsigned long _ramend;
+#endif
+
+#endif
diff --git a/arch/h8300/include/asm/page_offset.h b/arch/h8300/include/asm/page_offset.h
new file mode 100644
index 000000000..888576d7c
--- /dev/null
+++ b/arch/h8300/include/asm/page_offset.h
@@ -0,0 +1,2 @@
+
+#define PAGE_OFFSET_RAW		0x00000000
diff --git a/arch/h8300/include/asm/pgtable.h b/arch/h8300/include/asm/pgtable.h
new file mode 100644
index 000000000..ea833a5d8
--- /dev/null
+++ b/arch/h8300/include/asm/pgtable.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _H8300_PGTABLE_H
+#define _H8300_PGTABLE_H
+#include <asm-generic/pgtable-nopud.h>
+extern void paging_init(void);
+#define PAGE_NONE		__pgprot(0)    /* these mean nothing to NO_MM */
+#define PAGE_SHARED		__pgprot(0)    /* these mean nothing to NO_MM */
+#define PAGE_COPY		__pgprot(0)    /* these mean nothing to NO_MM */
+#define PAGE_READONLY	__pgprot(0)    /* these mean nothing to NO_MM */
+#define PAGE_KERNEL		__pgprot(0)    /* these mean nothing to NO_MM */
+#define __swp_type(x)		(0)
+#define __swp_offset(x)		(0)
+#define __swp_entry(typ, off)	((swp_entry_t) { ((typ) | ((off) << 7)) })
+#define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
+#define __swp_entry_to_pte(x)	((pte_t) { (x).val })
+#define kern_addr_valid(addr)	(1)
+#define pgprot_writecombine(prot)  (prot)
+#define pgprot_noncached pgprot_writecombine
+
+static inline int pte_file(pte_t pte) { return 0; }
+#define swapper_pg_dir ((pgd_t *) 0)
+/*
+ * ZERO_PAGE is a global shared page that is always zero: used
+ * for zero-mapped memory areas etc..
+ */
+#define ZERO_PAGE(vaddr)	(virt_to_page(0))
+
+/*
+ * These would be in other places but having them here reduces the diffs.
+ */
+extern unsigned int kobjsize(const void *objp);
+extern int is_in_rom(unsigned long);
+
+/*
+ * All 32bit addresses are effectively valid for vmalloc...
+ * Sort of meaningless for non-VM targets.
+ */
+#define	VMALLOC_START	0
+#define	VMALLOC_END	0xffffffff
+
+#define arch_enter_lazy_cpu_mode()    do {} while (0)
+
+#endif /* _H8300_PGTABLE_H */
diff --git a/arch/h8300/include/asm/processor.h b/arch/h8300/include/asm/processor.h
new file mode 100644
index 000000000..a060b41b2
--- /dev/null
+++ b/arch/h8300/include/asm/processor.h
@@ -0,0 +1,127 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * include/asm-h8300/processor.h
+ *
+ * Copyright (C) 2002 Yoshinori Sato
+ *
+ * Based on: linux/asm-m68nommu/processor.h
+ *
+ * Copyright (C) 1995 Hamish Macdonald
+ */
+
+#ifndef __ASM_H8300_PROCESSOR_H
+#define __ASM_H8300_PROCESSOR_H
+
+#include <linux/compiler.h>
+#include <asm/segment.h>
+#include <asm/ptrace.h>
+#include <asm/current.h>
+
+static inline unsigned long rdusp(void)
+{
+	extern unsigned int	_sw_usp;
+
+	return _sw_usp;
+}
+
+static inline void wrusp(unsigned long usp)
+{
+	extern unsigned int	_sw_usp;
+
+	_sw_usp = usp;
+}
+
+/*
+ * User space process size: 3.75GB. This is hardcoded into a few places,
+ * so don't change it unless you know what you are doing.
+ */
+#define TASK_SIZE	(0xFFFFFFFFUL)
+
+#ifdef __KERNEL__
+#define STACK_TOP	TASK_SIZE
+#define STACK_TOP_MAX	STACK_TOP
+#endif
+
+/*
+ * This decides where the kernel will search for a free chunk of vm
+ * space during mmap's. We won't be using it
+ */
+#define TASK_UNMAPPED_BASE	0
+
+struct thread_struct {
+	unsigned long  ksp;		/* kernel stack pointer */
+	unsigned long  usp;		/* user stack pointer */
+	unsigned long  ccr;		/* saved status register */
+	unsigned long  esp0;            /* points to SR of stack frame */
+	struct {
+		unsigned short *addr;
+		unsigned short inst;
+	} breakinfo;
+};
+
+#define INIT_THREAD  {						\
+	.ksp  = sizeof(init_stack) + (unsigned long)init_stack, \
+	.usp  = 0,						\
+	.ccr  = PS_S,						\
+	.esp0 = 0,						\
+	.breakinfo = {						\
+		.addr = (unsigned short *)-1,			\
+		.inst = 0					\
+	}							\
+}
+
+/*
+ * Do necessary setup to start up a newly executed thread.
+ *
+ * pass the data segment into user programs if it exists,
+ * it can't hurt anything as far as I can tell
+ */
+#if defined(CONFIG_CPU_H8300H)
+#define start_thread(_regs, _pc, _usp)				\
+do {								\
+	(_regs)->pc = (_pc);					\
+	(_regs)->ccr = 0x00;	   /* clear all flags */	\
+	(_regs)->er5 = current->mm->start_data;	/* GOT base */	\
+	(_regs)->sp = ((unsigned long)(_usp)) - sizeof(unsigned long) * 3; \
+} while (0)
+#endif
+#if defined(CONFIG_CPU_H8S)
+#define start_thread(_regs, _pc, _usp)				\
+do {								\
+	(_regs)->pc = (_pc);					\
+	(_regs)->ccr = 0x00;	   /* clear kernel flag */	\
+	(_regs)->exr = 0x78;	   /* enable all interrupts */	\
+	(_regs)->er5 = current->mm->start_data;	/* GOT base */	\
+	/* 14 = space for retaddr(4), vector(4), er0(4) and exr(2) on stack */ \
+	(_regs)->sp = ((unsigned long)(_usp)) - 14;		\
+} while (0)
+#endif
+
+/* Forward declaration, a strange C thing */
+struct task_struct;
+
+/* Free all resources held by a thread. */
+static inline void release_thread(struct task_struct *dead_task)
+{
+}
+
+unsigned long get_wchan(struct task_struct *p);
+
+#define	KSTK_EIP(tsk)	\
+	({			 \
+		unsigned long eip = 0;	      \
+		if ((tsk)->thread.esp0 > PAGE_SIZE &&	\
+		    MAP_NR((tsk)->thread.esp0) < max_mapnr)	 \
+			eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
+		eip; })
+
+#define	KSTK_ESP(tsk)	((tsk) == current ? rdusp() : (tsk)->thread.usp)
+
+#define cpu_relax()    barrier()
+
+#define HARD_RESET_NOW() ({		\
+	local_irq_disable();		\
+	asm("jmp @@0");			\
+})
+
+#endif
diff --git a/arch/h8300/include/asm/ptrace.h b/arch/h8300/include/asm/ptrace.h
new file mode 100644
index 000000000..66d383848
--- /dev/null
+++ b/arch/h8300/include/asm/ptrace.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _H8300_PTRACE_H
+#define _H8300_PTRACE_H
+
+#include <uapi/asm/ptrace.h>
+
+struct task_struct;
+
+#ifndef __ASSEMBLY__
+#ifndef PS_S
+#define PS_S  (0x10)
+#endif
+
+#if defined(CONFIG_CPU_H8300H)
+#define H8300_REGS_NO 11
+#endif
+#if defined(CONFIG_CPU_H8S)
+#define H8300_REGS_NO 12
+#endif
+
+#define arch_has_single_step()	(1)
+
+#define user_mode(regs) (!((regs)->ccr & PS_S))
+#define instruction_pointer(regs) ((regs)->pc)
+#define profile_pc(regs) instruction_pointer(regs)
+#define user_stack_pointer(regs) ((regs)->sp)
+#define current_pt_regs() ((struct pt_regs *) \
+	(THREAD_SIZE + (unsigned long)current_thread_info()) - 1)
+#define signal_pt_regs() ((struct pt_regs *)current->thread.esp0)
+#define current_user_stack_pointer() rdusp()
+#define task_pt_regs(task) \
+	((struct pt_regs *) (task_stack_page(task) + THREAD_SIZE) - 1)
+
+extern long h8300_get_reg(struct task_struct *task, int regno);
+extern int h8300_put_reg(struct task_struct *task, int regno,
+			 unsigned long data);
+
+#endif /* __ASSEMBLY__ */
+#endif /* _H8300_PTRACE_H */
diff --git a/arch/h8300/include/asm/segment.h b/arch/h8300/include/asm/segment.h
new file mode 100644
index 000000000..37950725d
--- /dev/null
+++ b/arch/h8300/include/asm/segment.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _H8300_SEGMENT_H
+#define _H8300_SEGMENT_H
+
+/* define constants */
+#define USER_DATA     (1)
+#ifndef __USER_DS
+#define __USER_DS     (USER_DATA)
+#endif
+#define USER_PROGRAM  (2)
+#define SUPER_DATA    (3)
+#ifndef __KERNEL_DS
+#define __KERNEL_DS   (SUPER_DATA)
+#endif
+#define SUPER_PROGRAM (4)
+
+#ifndef __ASSEMBLY__
+
+typedef struct {
+	unsigned long seg;
+} mm_segment_t;
+
+#define MAKE_MM_SEG(s)	((mm_segment_t) { (s) })
+#define USER_DS		MAKE_MM_SEG(__USER_DS)
+#define KERNEL_DS	MAKE_MM_SEG(__KERNEL_DS)
+
+/*
+ * Get/set the SFC/DFC registers for MOVES instructions
+ */
+
+static inline mm_segment_t get_fs(void)
+{
+	return USER_DS;
+}
+
+#define uaccess_kernel()	(get_fs().seg == KERNEL_DS.seg)
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _H8300_SEGMENT_H */
diff --git a/arch/h8300/include/asm/signal.h b/arch/h8300/include/asm/signal.h
new file mode 100644
index 000000000..a42f32ca5
--- /dev/null
+++ b/arch/h8300/include/asm/signal.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _H8300_SIGNAL_H
+#define _H8300_SIGNAL_H
+
+#include <uapi/asm/signal.h>
+
+/* Most things should be clean enough to redefine this at will, if care
+   is taken to make libc match.  */
+
+#define _NSIG		64
+#define _NSIG_BPW	32
+#define _NSIG_WORDS	(_NSIG / _NSIG_BPW)
+
+typedef unsigned long old_sigset_t;		/* at least 32 bits */
+
+typedef struct {
+	unsigned long sig[_NSIG_WORDS];
+} sigset_t;
+
+#define __ARCH_HAS_SA_RESTORER
+#include <asm/sigcontext.h>
+
+#endif /* _H8300_SIGNAL_H */
diff --git a/arch/h8300/include/asm/smp.h b/arch/h8300/include/asm/smp.h
new file mode 100644
index 000000000..9e9bd7e58
--- /dev/null
+++ b/arch/h8300/include/asm/smp.h
@@ -0,0 +1 @@
+/* nothing required here yet */
diff --git a/arch/h8300/include/asm/string.h b/arch/h8300/include/asm/string.h
new file mode 100644
index 000000000..78e45bb2f
--- /dev/null
+++ b/arch/h8300/include/asm/string.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _H8300_STRING_H_
+#define _H8300_STRING_H_
+
+#ifdef __KERNEL__ /* only set these up for kernel code */
+
+#include <asm/setup.h>
+#include <asm/page.h>
+
+#define __HAVE_ARCH_MEMSET
+extern void *memset(void *s, int c, size_t count);
+
+#define __HAVE_ARCH_MEMCPY
+extern void *memcpy(void *d, const void *s, size_t count);
+
+#endif /* KERNEL */
+
+#endif
diff --git a/arch/h8300/include/asm/switch_to.h b/arch/h8300/include/asm/switch_to.h
new file mode 100644
index 000000000..2b7e9555b
--- /dev/null
+++ b/arch/h8300/include/asm/switch_to.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _H8300_SWITCH_TO_H
+#define _H8300_SWITCH_TO_H
+
+/*
+ * switch_to(n) should switch tasks to task ptr, first checking that
+ * ptr isn't the current task, in which case it does nothing.  This
+ * also clears the TS-flag if the task we switched to has used the
+ * math co-processor latest.
+ */
+/*
+ * switch_to() saves the extra registers, that are not saved
+ * automatically by SAVE_SWITCH_STACK in resume(), ie. d0-d5 and
+ * a0-a1. Some of these are used by schedule() and its predecessors
+ * and so we might get see unexpected behaviors when a task returns
+ * with unexpected register values.
+ *
+ * syscall stores these registers itself and none of them are used
+ * by syscall after the function in the syscall has been called.
+ *
+ * Beware that resume now expects *next to be in d1 and the offset of
+ * tss to be in a1. This saves a few instructions as we no longer have
+ * to push them onto the stack and read them back right after.
+ *
+ * 02/17/96 - Jes Sorensen (jds@kom.auc.dk)
+ *
+ * Changed 96/09/19 by Andreas Schwab
+ * pass prev in a0, next in a1, offset of tss in d1, and whether
+ * the mm structures are shared in d2 (to avoid atc flushing).
+ *
+ * H8/300 Porting 2002/09/04 Yoshinori Sato
+ */
+
+asmlinkage void resume(void);
+#define switch_to(prev, next, last) \
+do {			     \
+	void *_last;					    \
+	__asm__ __volatile__(				    \
+		"mov.l	%1, er0\n\t"			    \
+		"mov.l	%2, er1\n\t"			    \
+		"mov.l	%3, er2\n\t"			    \
+		"jsr @_resume\n\t"			    \
+		"mov.l	er2,%0\n\t"			    \
+		: "=r" (_last)				    \
+		: "r" (&(prev->thread)),		    \
+		  "r" (&(next->thread)),		    \
+		  "g" (prev)				    \
+		: "cc", "er0", "er1", "er2", "er3");	    \
+	(last) = _last;					    \
+} while (0)
+
+#endif /* _H8300_SWITCH_TO_H */
diff --git a/arch/h8300/include/asm/syscall.h b/arch/h8300/include/asm/syscall.h
new file mode 100644
index 000000000..01666b8bb
--- /dev/null
+++ b/arch/h8300/include/asm/syscall.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_H8300_SYSCALLS_32_H
+#define __ASM_H8300_SYSCALLS_32_H
+
+#ifdef __KERNEL__
+
+#include <linux/compiler.h>
+#include <linux/linkage.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <uapi/linux/audit.h>
+
+static inline int
+syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
+{
+	return regs->orig_er0;
+}
+
+static inline void
+syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
+		      unsigned long *args)
+{
+	*args++ = regs->er1;
+	*args++ = regs->er2;
+	*args++ = regs->er3;
+	*args++ = regs->er4;
+	*args++ = regs->er5;
+	*args   = regs->er6;
+}
+
+static inline int
+syscall_get_arch(struct task_struct *task)
+{
+	return AUDIT_ARCH_H8300;
+}
+
+
+/* Misc syscall related bits */
+asmlinkage long do_syscall_trace_enter(struct pt_regs *regs);
+asmlinkage void do_syscall_trace_leave(struct pt_regs *regs);
+
+#endif /* __KERNEL__ */
+#endif /* __ASM_H8300_SYSCALLS_32_H */
diff --git a/arch/h8300/include/asm/thread_info.h b/arch/h8300/include/asm/thread_info.h
new file mode 100644
index 000000000..a518214d4
--- /dev/null
+++ b/arch/h8300/include/asm/thread_info.h
@@ -0,0 +1,105 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* thread_info.h: h8300 low-level thread information
+ * adapted from the i386 and PPC versions by Yoshinori Sato <ysato@users.sourceforge.jp>
+ *
+ * Copyright (C) 2002  David Howells (dhowells@redhat.com)
+ * - Incorporating suggestions made by Linus Torvalds and Dave Miller
+ */
+
+#ifndef _ASM_THREAD_INFO_H
+#define _ASM_THREAD_INFO_H
+
+#include <asm/page.h>
+#include <asm/segment.h>
+
+#ifdef __KERNEL__
+
+/*
+ * Size of kernel stack for each process. This must be a power of 2...
+ */
+#define THREAD_SIZE_ORDER	1
+#define THREAD_SIZE		8192	/* 2 pages */
+
+#ifndef __ASSEMBLY__
+
+/*
+ * low level task data.
+ * If you change this, change the TI_* offsets below to match.
+ */
+struct thread_info {
+	struct task_struct *task;		/* main task structure */
+	unsigned long	   flags;		/* low level flags */
+	int		   cpu;			/* cpu we're on */
+	int		   preempt_count;	/* 0 => preemptable, <0 => BUG */
+	mm_segment_t		addr_limit;
+};
+
+/*
+ * macros/functions for gaining access to the thread information structure
+ */
+#define INIT_THREAD_INFO(tsk)			\
+{						\
+	.task =		&tsk,			\
+	.flags =	0,			\
+	.cpu =		0,			\
+	.preempt_count = INIT_PREEMPT_COUNT,	\
+	.addr_limit	= KERNEL_DS,		\
+}
+
+/* how to get the thread information struct from C */
+static inline struct thread_info *current_thread_info(void)
+{
+	struct thread_info *ti;
+
+	__asm__("mov.l	sp, %0\n\t"
+		"and.w	%1, %T0"
+		: "=&r"(ti)
+		: "i" (~(THREAD_SIZE-1) & 0xffff));
+	return ti;
+}
+
+#endif /* __ASSEMBLY__ */
+
+/*
+ * thread information flag bit numbers
+ */
+#define TIF_SYSCALL_TRACE	0	/* syscall trace active */
+#define TIF_SIGPENDING		1	/* signal pending */
+#define TIF_NEED_RESCHED	2	/* rescheduling necessary */
+#define TIF_SINGLESTEP		3	/* singlestepping active */
+#define TIF_MEMDIE		4	/* is terminating due to OOM killer */
+#define TIF_RESTORE_SIGMASK	5	/* restore signal mask in do_signal() */
+#define TIF_NOTIFY_RESUME	6	/* callback before returning to user */
+#define TIF_SYSCALL_AUDIT	7	/* syscall auditing active */
+#define TIF_SYSCALL_TRACEPOINT	8	/* for ftrace syscall instrumentation */
+#define TIF_POLLING_NRFLAG	9	/* true if poll_idle() is polling TIF_NEED_RESCHED */
+#define TIF_NOTIFY_SIGNAL	10	/* signal notifications exist */
+
+/* as above, but as bit values */
+#define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
+#define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
+#define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
+#define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
+#define _TIF_SINGLESTEP		(1 << TIF_SINGLESTEP)
+#define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
+#define _TIF_SYSCALL_TRACEPOINT	(1 << TIF_SYSCALL_TRACEPOINT)
+#define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
+#define _TIF_NOTIFY_SIGNAL	(1 << TIF_NOTIFY_SIGNAL)
+
+/* work to do in syscall trace */
+#define _TIF_WORK_SYSCALL_MASK	(_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP | \
+				 _TIF_SYSCALL_AUDIT | _TIF_SYSCALL_TRACEPOINT)
+
+/* work to do on any return to u-space */
+#define _TIF_ALLWORK_MASK	(_TIF_SYSCALL_TRACE | _TIF_SIGPENDING      | \
+				 _TIF_NEED_RESCHED  | _TIF_SYSCALL_AUDIT   | \
+				 _TIF_SINGLESTEP    | _TIF_NOTIFY_RESUME   | \
+				 _TIF_SYSCALL_TRACEPOINT | _TIF_NOTIFY_SIGNAL)
+
+/* work to do on interrupt/exception return */
+#define _TIF_WORK_MASK		(_TIF_ALLWORK_MASK & ~(_TIF_SYSCALL_TRACE | \
+				 _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP))
+
+#endif /* __KERNEL__ */
+
+#endif /* _ASM_THREAD_INFO_H */
diff --git a/arch/h8300/include/asm/tlb.h b/arch/h8300/include/asm/tlb.h
new file mode 100644
index 000000000..d8201ca31
--- /dev/null
+++ b/arch/h8300/include/asm/tlb.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __H8300_TLB_H__
+#define __H8300_TLB_H__
+
+#include <asm-generic/tlb.h>
+
+#endif
diff --git a/arch/h8300/include/asm/traps.h b/arch/h8300/include/asm/traps.h
new file mode 100644
index 000000000..1c5a30ec2
--- /dev/null
+++ b/arch/h8300/include/asm/traps.h
@@ -0,0 +1,41 @@
+/*
+ *  linux/include/asm-h8300/traps.h
+ *
+ *  Copyright (C) 2003 Yoshinori Sato <ysato@users.sourceforge.jp>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ */
+
+#ifndef _H8300_TRAPS_H
+#define _H8300_TRAPS_H
+
+extern void _system_call(void);
+extern void _interrupt_entry(void);
+extern void _trace_break(void);
+extern void _nmi(void);
+extern void _interrupt_entry(void);
+
+extern unsigned long *_interrupt_redirect_table;
+
+#define JMP_OP 0x5a000000
+#define JSR_OP 0x5e000000
+#define VECTOR(address) ((JMP_OP)|((unsigned long)address))
+#define REDIRECT(address) ((JSR_OP)|((unsigned long)address))
+#define CPU_VECTOR ((unsigned long *)0x000000)
+#define ADDR_MASK (0xffffff)
+
+#define TRACE_VEC 5
+
+#define TRAP0_VEC 8
+#define TRAP1_VEC 9
+#define TRAP2_VEC 10
+#define TRAP3_VEC 11
+
+extern char _start[], _etext[];
+#define check_kernel_text(addr) \
+	((addr >= (unsigned long)(_start)) && \
+	 (addr <  (unsigned long)(_etext)) && !(addr & 1))
+
+#endif /* _H8300_TRAPS_H */
diff --git a/arch/h8300/include/asm/user.h b/arch/h8300/include/asm/user.h
new file mode 100644
index 000000000..2298909f2
--- /dev/null
+++ b/arch/h8300/include/asm/user.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _H8300_USER_H
+#define _H8300_USER_H
+
+#include <asm/page.h>
+
+/* Core file format: The core file is written in such a way that gdb
+   can understand it and provide useful information to the user (under
+   linux we use the 'trad-core' bfd).  There are quite a number of
+   obstacles to being able to view the contents of the floating point
+   registers, and until these are solved you will not be able to view the
+   contents of them.  Actually, you can read in the core file and look at
+   the contents of the user struct to find out what the floating point
+   registers contain.
+   The actual file contents are as follows:
+   UPAGE: 1 page consisting of a user struct that tells gdb what is present
+   in the file.  Directly after this is a copy of the task_struct, which
+   is currently not used by gdb, but it may come in useful at some point.
+   All of the registers are stored as part of the upage.  The upage should
+   always be only one page.
+   DATA: The data area is stored.  We use current->end_text to
+   current->brk to pick up all of the user variables, plus any memory
+   that may have been malloced.  No attempt is made to determine if a page
+   is demand-zero or if a page is totally unused, we just cover the entire
+   range.  All of the addresses are rounded in such a way that an integral
+   number of pages is written.
+   STACK: We need the stack information in order to get a meaningful
+   backtrace.  We need to write the data from (esp) to
+   current->start_stack, so we round each of these off in order to be able
+   to write an integer number of pages.
+   The minimum core file size is 3 pages, or 12288 bytes.
+*/
+
+/* This is the old layout of "struct pt_regs" as of Linux 1.x, and
+   is still the layout used by user (the new pt_regs doesn't have
+   all registers). */
+struct user_regs_struct {
+	long er1, er2, er3, er4, er5, er6;
+	long er0;
+	long usp;
+	long orig_er0;
+	long ccr;
+	long pc;
+};
+
+/* When the kernel dumps core, it starts by dumping the user struct -
+   this will be used by gdb to figure out where the data and stack segments
+   are within the file, and what virtual addresses to use. */
+struct user {
+/* We start with the registers, to mimic the way that "memory" is returned
+   from the ptrace(3,...) function.  */
+	struct user_regs_struct regs;	/* Where the registers are actually stored */
+/* ptrace does not yet supply these.  Someday.... */
+/* The rest of this junk is to help gdb figure out what goes where */
+	unsigned long int u_tsize;	/* Text segment size (pages). */
+	unsigned long int u_dsize;	/* Data segment size (pages). */
+	unsigned long int u_ssize;	/* Stack segment size (pages). */
+	unsigned long start_code;     /* Starting virtual address of text. */
+	unsigned long start_stack;	/* Starting virtual address of stack area.
+					   This is actually the bottom of the stack,
+					   the top of the stack is always found in the
+					   esp register.  */
+	long int signal;		/* Signal that caused the core dump. */
+	int reserved;			/* No longer used */
+	unsigned long u_ar0;		/* Used by gdb to help find the values for */
+	/* the registers. */
+	unsigned long magic;		/* To uniquely identify a core file */
+	char u_comm[32];		/* User command that was responsible */
+};
+#define NBPG PAGE_SIZE
+#define UPAGES 1
+#define HOST_TEXT_START_ADDR (u.start_code)
+#define HOST_STACK_END_ADDR (u.start_stack + u.u_ssize * NBPG)
+
+#endif
diff --git a/arch/h8300/include/asm/vmalloc.h b/arch/h8300/include/asm/vmalloc.h
new file mode 100644
index 000000000..08a55c1df
--- /dev/null
+++ b/arch/h8300/include/asm/vmalloc.h
@@ -0,0 +1,4 @@
+#ifndef _ASM_H8300_VMALLOC_H
+#define _ASM_H8300_VMALLOC_H
+
+#endif /* _ASM_H8300_VMALLOC_H */
diff --git a/arch/h8300/include/uapi/asm/Kbuild b/arch/h8300/include/uapi/asm/Kbuild
new file mode 100644
index 000000000..e78470141
--- /dev/null
+++ b/arch/h8300/include/uapi/asm/Kbuild
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+generic-y += ucontext.h
diff --git a/arch/h8300/include/uapi/asm/byteorder.h b/arch/h8300/include/uapi/asm/byteorder.h
new file mode 100644
index 000000000..1fe2f9344
--- /dev/null
+++ b/arch/h8300/include/uapi/asm/byteorder.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _H8300_BYTEORDER_H
+#define _H8300_BYTEORDER_H
+
+#include <linux/byteorder/big_endian.h>
+
+#endif /* _H8300_BYTEORDER_H */
diff --git a/arch/h8300/include/uapi/asm/posix_types.h b/arch/h8300/include/uapi/asm/posix_types.h
new file mode 100644
index 000000000..3efc9dd59
--- /dev/null
+++ b/arch/h8300/include/uapi/asm/posix_types.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */
+#ifndef _UAPI_ASM_POSIX_TYPES_H
+#define _UAPI_ASM_POSIX_TYPES_H
+
+/* h8300-unknown-linux required long */
+#define __kernel_size_t __kernel_size_t
+typedef unsigned long	__kernel_size_t;
+typedef long		__kernel_ssize_t;
+typedef long		__kernel_ptrdiff_t;
+
+#include <asm-generic/posix_types.h>
+
+#endif /* _UAPI_ASM_POSIX_TYPES_H */
diff --git a/arch/h8300/include/uapi/asm/ptrace.h b/arch/h8300/include/uapi/asm/ptrace.h
new file mode 100644
index 000000000..78167f517
--- /dev/null
+++ b/arch/h8300/include/uapi/asm/ptrace.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI_H8300_PTRACE_H
+#define _UAPI_H8300_PTRACE_H
+
+#ifndef __ASSEMBLY__
+
+#define PT_ER1	   0
+#define PT_ER2	   1
+#define PT_ER3	   2
+#define PT_ER4	   3
+#define PT_ER5	   4
+#define PT_ER6	   5
+#define PT_ER0	   6
+#define PT_USP	   7
+#define PT_ORIG_ER0	   8
+#define PT_CCR	   9
+#define PT_PC	   10
+#define PT_EXR     11
+
+/* this struct defines the way the registers are stored on the
+   stack during a system call. */
+
+struct pt_regs {
+	long     retpc;
+	long     er4;
+	long     er5;
+	long     er6;
+	long     er3;
+	long     er2;
+	long     er1;
+	long     orig_er0;
+	long	 sp;
+	unsigned short	 ccr;
+	long     er0;
+	long     vector;
+#if defined(__H8300S__)
+	unsigned short	 exr;
+#endif
+	unsigned long  pc;
+} __attribute__((aligned(2), packed));
+
+#endif /* __ASSEMBLY__ */
+#endif /* _UAPI_H8300_PTRACE_H */
diff --git a/arch/h8300/include/uapi/asm/sigcontext.h b/arch/h8300/include/uapi/asm/sigcontext.h
new file mode 100644
index 000000000..f77273c85
--- /dev/null
+++ b/arch/h8300/include/uapi/asm/sigcontext.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _ASM_H8300_SIGCONTEXT_H
+#define _ASM_H8300_SIGCONTEXT_H
+
+struct sigcontext {
+	unsigned long  sc_mask;		/* old sigmask */
+	unsigned long  sc_usp;		/* old user stack pointer */
+	unsigned long  sc_er0;
+	unsigned long  sc_er1;
+	unsigned long  sc_er2;
+	unsigned long  sc_er3;
+	unsigned long  sc_er4;
+	unsigned long  sc_er5;
+	unsigned long  sc_er6;
+	unsigned short sc_ccr;
+	unsigned long  sc_pc;
+};
+
+#endif
diff --git a/arch/h8300/include/uapi/asm/signal.h b/arch/h8300/include/uapi/asm/signal.h
new file mode 100644
index 000000000..e15521037
--- /dev/null
+++ b/arch/h8300/include/uapi/asm/signal.h
@@ -0,0 +1,116 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI_H8300_SIGNAL_H
+#define _UAPI_H8300_SIGNAL_H
+
+#include <linux/types.h>
+
+/* Avoid too many header ordering problems.  */
+struct siginfo;
+
+#ifndef __KERNEL__
+/* Here we must cater to libcs that poke about in kernel headers.  */
+
+#define NSIG		32
+typedef unsigned long sigset_t;
+
+#endif /* __KERNEL__ */
+
+#define SIGHUP		 1
+#define SIGINT		 2
+#define SIGQUIT		 3
+#define SIGILL		 4
+#define SIGTRAP		 5
+#define SIGABRT		 6
+#define SIGIOT		 6
+#define SIGBUS		 7
+#define SIGFPE		 8
+#define SIGKILL		 9
+#define SIGUSR1		10
+#define SIGSEGV		11
+#define SIGUSR2		12
+#define SIGPIPE		13
+#define SIGALRM		14
+#define SIGTERM		15
+#define SIGSTKFLT	16
+#define SIGCHLD		17
+#define SIGCONT		18
+#define SIGSTOP		19
+#define SIGTSTP		20
+#define SIGTTIN		21
+#define SIGTTOU		22
+#define SIGURG		23
+#define SIGXCPU		24
+#define SIGXFSZ		25
+#define SIGVTALRM	26
+#define SIGPROF		27
+#define SIGWINCH	28
+#define SIGIO		29
+#define SIGPOLL		SIGIO
+/*
+#define SIGLOST		29
+*/
+#define SIGPWR		30
+#define SIGSYS		31
+#define	SIGUNUSED	31
+
+/* These should not be considered constants from userland.  */
+#define SIGRTMIN	32
+#define SIGRTMAX	_NSIG
+
+/*
+ * SA_FLAGS values:
+ *
+ * SA_ONSTACK indicates that a registered stack_t will be used.
+ * SA_RESTART flag to get restarting signals (which were the default long ago)
+ * SA_NOCLDSTOP flag to turn off SIGCHLD when children stop.
+ * SA_RESETHAND clears the handler when the signal is delivered.
+ * SA_NOCLDWAIT flag on SIGCHLD to inhibit zombies.
+ * SA_NODEFER prevents the current signal from being masked in the handler.
+ *
+ * SA_ONESHOT and SA_NOMASK are the historical Linux names for the Single
+ * Unix names RESETHAND and NODEFER respectively.
+ */
+#define SA_NOCLDSTOP	0x00000001
+#define SA_NOCLDWAIT	0x00000002 /* not supported yet */
+#define SA_SIGINFO	0x00000004
+#define SA_ONSTACK	0x08000000
+#define SA_RESTART	0x10000000
+#define SA_NODEFER	0x40000000
+#define SA_RESETHAND	0x80000000
+
+#define SA_NOMASK	SA_NODEFER
+#define SA_ONESHOT	SA_RESETHAND
+
+#define SA_RESTORER	0x04000000
+
+#define MINSIGSTKSZ	2048
+#define SIGSTKSZ	8192
+
+#include <asm-generic/signal-defs.h>
+
+#ifndef __KERNEL__
+/* Here we must cater to libcs that poke about in kernel headers.  */
+
+struct sigaction {
+	union {
+	  __sighandler_t _sa_handler;
+	  void (*_sa_sigaction)(int, struct siginfo *, void *);
+	} _u;
+	sigset_t sa_mask;
+	unsigned long sa_flags;
+	void (*sa_restorer)(void);
+};
+
+#define sa_handler	_u._sa_handler
+#define sa_sigaction	_u._sa_sigaction
+
+#endif /* __KERNEL__ */
+
+typedef struct sigaltstack {
+	void *ss_sp;
+	int ss_flags;
+	size_t ss_size;
+} stack_t;
+
+
+#endif /* _UAPI_H8300_SIGNAL_H */
diff --git a/arch/h8300/include/uapi/asm/unistd.h b/arch/h8300/include/uapi/asm/unistd.h
new file mode 100644
index 000000000..eb7bc0012
--- /dev/null
+++ b/arch/h8300/include/uapi/asm/unistd.h
@@ -0,0 +1,8 @@
+#define __ARCH_NOMMU
+
+#define __ARCH_WANT_RENAMEAT
+#define __ARCH_WANT_STAT64
+#define __ARCH_WANT_SET_GET_RLIMIT
+#define __ARCH_WANT_TIME32_SYSCALLS
+
+#include <asm-generic/unistd.h>
diff --git a/arch/h8300/kernel/.gitignore b/arch/h8300/kernel/.gitignore
new file mode 100644
index 000000000..bbb90f92d
--- /dev/null
+++ b/arch/h8300/kernel/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+vmlinux.lds
diff --git a/arch/h8300/kernel/Makefile b/arch/h8300/kernel/Makefile
new file mode 100644
index 000000000..307aa5157
--- /dev/null
+++ b/arch/h8300/kernel/Makefile
@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux kernel.
+#
+
+extra-y := vmlinux.lds
+
+obj-y := process.o traps.o ptrace.o \
+	 signal.o setup.o syscalls.o \
+	 irq.o entry.o
+
+obj-$(CONFIG_ROMKERNEL) += head_rom.o
+obj-$(CONFIG_RAMKERNEL) += head_ram.o
+
+obj-$(CONFIG_MODULES) += module.o h8300_ksyms.o
+obj-$(CONFIG_H8300H_SIM) += sim-console.o
+obj-$(CONFIG_H8S_SIM) += sim-console.o
+
+obj-$(CONFIG_CPU_H8300H) += ptrace_h.o
+obj-$(CONFIG_CPU_H8S) += ptrace_s.o
+
+obj-$(CONFIG_KGDB) += kgdb.o
diff --git a/arch/h8300/kernel/asm-offsets.c b/arch/h8300/kernel/asm-offsets.c
new file mode 100644
index 000000000..d4b53af65
--- /dev/null
+++ b/arch/h8300/kernel/asm-offsets.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This program is used to generate definitions needed by
+ * assembly language modules.
+ *
+ * We use the technique used in the OSF Mach kernel code:
+ * generate asm statements containing #defines,
+ * compile this file to assembler, and then extract the
+ * #defines from the assembly-language output.
+ */
+
+#include <linux/stddef.h>
+#include <linux/sched.h>
+#include <linux/kernel_stat.h>
+#include <linux/ptrace.h>
+#include <linux/hardirq.h>
+#include <linux/kbuild.h>
+#include <asm/irq.h>
+#include <asm/ptrace.h>
+
+int main(void)
+{
+	/* offsets into the task struct */
+	OFFSET(TASK_STATE, task_struct, state);
+	OFFSET(TASK_FLAGS, task_struct, flags);
+	OFFSET(TASK_PTRACE, task_struct, ptrace);
+	OFFSET(TASK_BLOCKED, task_struct, blocked);
+	OFFSET(TASK_THREAD, task_struct, thread);
+	OFFSET(TASK_THREAD_INFO, task_struct, stack);
+	OFFSET(TASK_MM, task_struct, mm);
+	OFFSET(TASK_ACTIVE_MM, task_struct, active_mm);
+
+	/* offsets into the irq_cpustat_t struct */
+	DEFINE(CPUSTAT_SOFTIRQ_PENDING, offsetof(irq_cpustat_t,
+						 __softirq_pending));
+
+	/* offsets into the thread struct */
+	OFFSET(THREAD_KSP, thread_struct, ksp);
+	OFFSET(THREAD_USP, thread_struct, usp);
+	OFFSET(THREAD_CCR, thread_struct, ccr);
+
+	/* offsets into the pt_regs struct */
+	DEFINE(LER0,  offsetof(struct pt_regs, er0)      - sizeof(long));
+	DEFINE(LER1,  offsetof(struct pt_regs, er1)      - sizeof(long));
+	DEFINE(LER2,  offsetof(struct pt_regs, er2)      - sizeof(long));
+	DEFINE(LER3,  offsetof(struct pt_regs, er3)      - sizeof(long));
+	DEFINE(LER4,  offsetof(struct pt_regs, er4)      - sizeof(long));
+	DEFINE(LER5,  offsetof(struct pt_regs, er5)      - sizeof(long));
+	DEFINE(LER6,  offsetof(struct pt_regs, er6)      - sizeof(long));
+	DEFINE(LORIG, offsetof(struct pt_regs, orig_er0) - sizeof(long));
+	DEFINE(LSP,   offsetof(struct pt_regs, sp)       - sizeof(long));
+	DEFINE(LCCR,  offsetof(struct pt_regs, ccr)      - sizeof(long));
+	DEFINE(LVEC,  offsetof(struct pt_regs, vector)   - sizeof(long));
+#if defined(CONFIG_CPU_H8S)
+	DEFINE(LEXR,  offsetof(struct pt_regs, exr)      - sizeof(long));
+#endif
+	DEFINE(LRET,  offsetof(struct pt_regs, pc)       - sizeof(long));
+
+	DEFINE(PT_PTRACED, PT_PTRACED);
+
+	/* offsets in thread_info structure */
+	OFFSET(TI_TASK, thread_info, task);
+	OFFSET(TI_FLAGS, thread_info, flags);
+	OFFSET(TI_CPU, thread_info, cpu);
+	OFFSET(TI_PRE, thread_info, preempt_count);
+#ifdef CONFIG_PREEMPTION
+	DEFINE(TI_PRE_COUNT, offsetof(struct thread_info, preempt_count));
+#endif
+
+	return 0;
+}
diff --git a/arch/h8300/kernel/entry.S b/arch/h8300/kernel/entry.S
new file mode 100644
index 000000000..c6e289b5f
--- /dev/null
+++ b/arch/h8300/kernel/entry.S
@@ -0,0 +1,434 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *
+ *  linux/arch/h8300/kernel/entry.S
+ *
+ *  Yoshinori Sato <ysato@users.sourceforge.jp>
+ *  David McCullough <davidm@snapgear.com>
+ *
+ */
+
+/*
+ *  entry.S
+ *  include exception/interrupt gateway
+ *          system call entry
+ */
+
+#include <linux/sys.h>
+#include <asm/unistd.h>
+#include <asm/setup.h>
+#include <asm/segment.h>
+#include <asm/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/thread_info.h>
+#include <asm/errno.h>
+
+#if defined(CONFIG_CPU_H8300H)
+#define USERRET 8
+INTERRUPTS = 64
+	.h8300h
+	.macro	SHLL2 reg
+	shll.l	\reg
+	shll.l	\reg
+	.endm
+	.macro	SHLR2 reg
+	shlr.l	\reg
+	shlr.l	\reg
+	.endm
+	.macro	SAVEREGS
+	mov.l	er0,@-sp
+	mov.l	er1,@-sp
+	mov.l	er2,@-sp
+	mov.l	er3,@-sp
+	.endm
+	.macro	RESTOREREGS
+	mov.l	@sp+,er3
+	mov.l	@sp+,er2
+	.endm
+	.macro	SAVEEXR
+	.endm
+	.macro	RESTOREEXR
+	.endm
+#endif
+#if defined(CONFIG_CPU_H8S)
+#define USERRET 10
+#define USEREXR 8
+INTERRUPTS = 128
+	.h8300s
+	.macro	SHLL2 reg
+	shll.l	#2,\reg
+	.endm
+	.macro	SHLR2 reg
+	shlr.l	#2,\reg
+	.endm
+	.macro	SAVEREGS
+	stm.l	er0-er3,@-sp
+	.endm
+	.macro	RESTOREREGS
+	ldm.l	@sp+,er2-er3
+	.endm
+	.macro	SAVEEXR
+	mov.w	@(USEREXR:16,er0),r1
+	mov.w	r1,@(LEXR-LER3:16,sp)		/* copy EXR */
+	.endm
+	.macro	RESTOREEXR
+	mov.w	@(LEXR-LER1:16,sp),r1		/* restore EXR */
+	mov.b	r1l,r1h
+	mov.w	r1,@(USEREXR:16,er0)
+	.endm
+#endif
+
+
+/* CPU context save/restore macros. */
+
+	.macro	SAVE_ALL
+	mov.l	er0,@-sp
+	stc	ccr,r0l				/* check kernel mode */
+	btst	#4,r0l
+	bne	5f
+
+	/* user mode */
+	mov.l	sp,@_sw_usp
+	mov.l	@sp,er0				/* restore saved er0 */
+	orc	#0x10,ccr			/* switch kernel stack */
+	mov.l	@_sw_ksp,sp
+	sub.l	#(LRET-LORIG),sp		/* allocate LORIG - LRET */
+	SAVEREGS
+	mov.l   @_sw_usp,er0
+	mov.l   @(USERRET:16,er0),er1           /* copy the RET addr */
+	mov.l   er1,@(LRET-LER3:16,sp)
+	SAVEEXR
+
+	mov.l	@(LORIG-LER3:16,sp),er0
+	mov.l	er0,@(LER0-LER3:16,sp)		/* copy ER0 */
+	mov.w	e1,r1				/* e1 highbyte = ccr */
+	and	#0xef,r1h			/* mask mode? flag */
+	bra	6f
+5:
+	/* kernel mode */
+	mov.l	@sp,er0				/* restore saved er0 */
+	subs	#2,sp				/* set dummy ccr */
+	subs	#4,sp				/* set dummp sp */
+	SAVEREGS
+	mov.w	@(LRET-LER3:16,sp),r1		/* copy old ccr */
+6:
+	mov.b	r1h,r1l
+	mov.b	#0,r1h
+	mov.w	r1,@(LCCR-LER3:16,sp)		/* set ccr */
+	mov.l	@_sw_usp,er2
+	mov.l	er2,@(LSP-LER3:16,sp)		/* set usp */
+	mov.l	er6,@-sp			/* syscall arg #6 */
+	mov.l	er5,@-sp			/* syscall arg #5 */
+	mov.l	er4,@-sp			/* syscall arg #4 */
+	.endm					/* r1 = ccr */
+
+	.macro	RESTORE_ALL
+	mov.l	@sp+,er4
+	mov.l	@sp+,er5
+	mov.l	@sp+,er6
+	RESTOREREGS
+	mov.w	@(LCCR-LER1:16,sp),r0		/* check kernel mode */
+	btst	#4,r0l
+	bne	7f
+
+	orc	#0xc0,ccr
+	mov.l	@(LSP-LER1:16,sp),er0
+	mov.l	@(LER0-LER1:16,sp),er1		/* restore ER0 */
+	mov.l	er1,@er0
+	RESTOREEXR
+	mov.w	@(LCCR-LER1:16,sp),r1		/* restore the RET addr */
+	mov.b	r1l,r1h
+	mov.b	@(LRET+1-LER1:16,sp),r1l
+	mov.w	r1,e1
+	mov.w	@(LRET+2-LER1:16,sp),r1
+	mov.l	er1,@(USERRET:16,er0)
+
+	mov.l	@sp+,er1
+	add.l	#(LRET-LER1),sp			/* remove LORIG - LRET */
+	mov.l	sp,@_sw_ksp
+	andc	#0xef,ccr			/* switch to user mode */
+	mov.l	er0,sp
+	bra	8f
+7:
+	mov.l	@sp+,er1
+	add.l	#10,sp
+8:
+	mov.l	@sp+,er0
+	adds	#4,sp				/* remove the sw created LVEC */
+	rte
+	.endm
+
+.globl _system_call
+.globl ret_from_exception
+.globl ret_from_fork
+.globl ret_from_kernel_thread
+.globl ret_from_interrupt
+.globl _interrupt_redirect_table
+.globl _sw_ksp,_sw_usp
+.globl _resume
+.globl _interrupt_entry
+.globl _trace_break
+.globl _nmi
+
+#if defined(CONFIG_ROMKERNEL)
+	.section .int_redirect,"ax"
+_interrupt_redirect_table:
+#if defined(CONFIG_CPU_H8300H)
+	.rept	7
+	.long	0
+	.endr
+#endif
+#if defined(CONFIG_CPU_H8S)
+	.rept	5
+	.long	0
+	.endr
+	jmp	@_trace_break
+	.long	0
+#endif
+
+	jsr	@_interrupt_entry		/* NMI */
+	jmp	@_system_call			/* TRAPA #0 (System call) */
+	.long	0
+#if defined(CONFIG_KGDB)
+	jmp	@_kgdb_trap
+#else
+	.long	0
+#endif
+	jmp	@_trace_break			/* TRAPA #3 (breakpoint) */
+	.rept	INTERRUPTS-12
+	jsr	@_interrupt_entry
+	.endr
+#endif
+#if defined(CONFIG_RAMKERNEL)
+.globl _interrupt_redirect_table
+	.section .bss
+_interrupt_redirect_table:
+	.space	4
+#endif
+
+	.section .text
+	.align	2
+_interrupt_entry:
+	SAVE_ALL
+/* r1l is saved ccr */
+	mov.l	sp,er0
+	add.l	#LVEC,er0
+	btst	#4,r1l
+	bne	1f
+	/* user LVEC */
+	mov.l	@_sw_usp,er0
+	adds	#4,er0
+1:
+	mov.l	@er0,er0			/* LVEC address */
+#if defined(CONFIG_ROMKERNEL)
+	sub.l	#_interrupt_redirect_table,er0
+#endif
+#if defined(CONFIG_RAMKERNEL)
+	mov.l	@_interrupt_redirect_table,er1
+	sub.l	er1,er0
+#endif
+	SHLR2	er0
+	dec.l	#1,er0
+	mov.l	sp,er1
+	subs	#4,er1				/* adjust ret_pc */
+#if defined(CONFIG_CPU_H8S)
+	orc	#7,exr
+#endif
+	jsr	@do_IRQ
+	jmp	@ret_from_interrupt
+
+_system_call:
+	subs	#4,sp				/* dummy LVEC */
+	SAVE_ALL
+	/* er0: syscall nr */
+	andc	#0xbf,ccr
+	mov.l	er0,er4
+
+	/* save top of frame */
+	mov.l	sp,er0
+	jsr	@set_esp0
+	andc	#0x3f,ccr
+	mov.l	sp,er2
+	and.w	#0xe000,r2
+	mov.l	@(TI_FLAGS:16,er2),er2
+	and.w	#_TIF_WORK_SYSCALL_MASK,r2
+	beq	1f
+	mov.l	sp,er0
+	jsr	@do_syscall_trace_enter
+1:
+	cmp.l	#__NR_syscalls,er4
+	bcc	badsys
+	SHLL2	er4
+	mov.l	#_sys_call_table,er0
+	add.l	er4,er0
+	mov.l	@er0,er4
+	beq	ret_from_exception:16
+	mov.l	@(LER1:16,sp),er0
+	mov.l	@(LER2:16,sp),er1
+	mov.l	@(LER3:16,sp),er2
+	jsr	@er4
+	mov.l	er0,@(LER0:16,sp)		/* save the return value */
+	mov.l	sp,er2
+	and.w	#0xe000,r2
+	mov.l	@(TI_FLAGS:16,er2),er2
+	and.w	#_TIF_WORK_SYSCALL_MASK,r2
+	beq	2f
+	mov.l	sp,er0
+	jsr	@do_syscall_trace_leave
+2:
+	orc	#0xc0,ccr
+	bra	resume_userspace
+
+badsys:
+	mov.l	#-ENOSYS,er0
+	mov.l	er0,@(LER0:16,sp)
+	bra	resume_userspace
+
+#if !defined(CONFIG_PREEMPTION)
+#define resume_kernel restore_all
+#endif
+
+ret_from_exception:
+#if defined(CONFIG_PREEMPTION)
+	orc	#0xc0,ccr
+#endif
+ret_from_interrupt:
+	mov.b	@(LCCR+1:16,sp),r0l
+	btst	#4,r0l
+	bne	resume_kernel:16	/* return from kernel */
+resume_userspace:
+	andc	#0xbf,ccr
+	mov.l	sp,er4
+	and.w	#0xe000,r4		/* er4 <- current thread info */
+	mov.l	@(TI_FLAGS:16,er4),er1
+	and.l	#_TIF_WORK_MASK,er1
+	beq	restore_all:8
+work_pending:
+	btst	#TIF_NEED_RESCHED,r1l
+	bne	work_resched:8
+	/* work notifysig */
+	mov.l	sp,er0
+	subs	#4,er0			/* er0: pt_regs */
+	jsr	@do_notify_resume
+	bra	resume_userspace:8
+work_resched:
+	mov.l	sp,er0
+	jsr	@set_esp0
+	jsr	@schedule
+	bra	resume_userspace:8
+restore_all:
+	RESTORE_ALL			/* Does RTE */
+
+#if defined(CONFIG_PREEMPTION)
+resume_kernel:
+	mov.l	@(TI_PRE_COUNT:16,er4),er0
+	bne	restore_all:8
+need_resched:
+	mov.l	@(TI_FLAGS:16,er4),er0
+	btst	#TIF_NEED_RESCHED,r0l
+	beq	restore_all:8
+	mov.b	@(LCCR+1:16,sp),r0l	/* Interrupt Enabled? */
+	bmi	restore_all:8
+	mov.l	sp,er0
+	jsr	@set_esp0
+	jsr	@preempt_schedule_irq
+	bra	need_resched:8
+#endif
+
+ret_from_fork:
+	mov.l	er2,er0
+	jsr	@schedule_tail
+	jmp	@ret_from_exception
+
+ret_from_kernel_thread:
+	mov.l	er2,er0
+	jsr	@schedule_tail
+	mov.l	@(LER4:16,sp),er0
+	mov.l	@(LER5:16,sp),er1
+	jsr	@er1
+	jmp	@ret_from_exception
+
+_resume:
+	/*
+	 * Beware - when entering resume, offset of tss is in d1,
+	 * prev (the current task) is in a0, next (the new task)
+	 * is in a1 and d2.b is non-zero if the mm structure is
+	 * shared between the tasks, so don't change these
+	 * registers until their contents are no longer needed.
+	 */
+
+	/* save sr */
+	sub.w	r3,r3
+	stc	ccr,r3l
+	mov.w	r3,@(THREAD_CCR+2:16,er0)
+
+	/* disable interrupts */
+	orc	#0xc0,ccr
+	mov.l	@_sw_usp,er3
+	mov.l	er3,@(THREAD_USP:16,er0)
+	mov.l	sp,@(THREAD_KSP:16,er0)
+
+	/* Skip address space switching if they are the same. */
+	/* FIXME: what did we hack out of here, this does nothing! */
+
+	mov.l	@(THREAD_USP:16,er1),er0
+	mov.l	er0,@_sw_usp
+	mov.l	@(THREAD_KSP:16,er1),sp
+
+	/* restore status register */
+	mov.w	@(THREAD_CCR+2:16,er1),r3
+
+	ldc	r3l,ccr
+	rts
+
+_trace_break:
+	subs	#4,sp
+	SAVE_ALL
+	sub.l	er1,er1
+	dec.l	#1,er1
+	mov.l	er1,@(LORIG,sp)
+	mov.l	sp,er0
+	jsr	@set_esp0
+	mov.l	@_sw_usp,er0
+	mov.l	@er0,er1
+	mov.w	@(-2:16,er1),r2
+	cmp.w	#0x5730,r2
+	beq	1f
+	subs	#2,er1
+	mov.l	er1,@er0
+1:
+	and.w	#0xff,e1
+	mov.l	er1,er0
+	jsr	@trace_trap
+	jmp	@ret_from_exception
+
+_nmi:
+	subs	#4, sp
+	mov.l	er0, @-sp
+	mov.l	@_interrupt_redirect_table, er0
+	add.l	#8*4, er0
+	mov.l	er0, @(4,sp)
+	mov.l	@sp+, er0
+	jmp	@_interrupt_entry
+
+#if defined(CONFIG_KGDB)
+_kgdb_trap:
+	subs	#4,sp
+	SAVE_ALL
+	mov.l	sp,er0
+	add.l	#LRET,er0
+	mov.l	er0,@(LSP,sp)
+	jsr	@set_esp0
+	mov.l	sp,er0
+	subs	#4,er0
+	jsr	@h8300_kgdb_trap
+	jmp	@ret_from_exception
+#endif
+
+	.section	.bss
+_sw_ksp:
+	.space	4
+_sw_usp:
+	.space	4
+
+	.end
diff --git a/arch/h8300/kernel/h8300_ksyms.c b/arch/h8300/kernel/h8300_ksyms.c
new file mode 100644
index 000000000..1c6f902e8
--- /dev/null
+++ b/arch/h8300/kernel/h8300_ksyms.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/module.h>
+#include <linux/linkage.h>
+
+/*
+ * libgcc functions - functions that are used internally by the
+ * compiler...  (prototypes are not correct though, but that
+ * doesn't really matter since they're not versioned).
+ */
+asmlinkage long __ucmpdi2(long long, long long);
+asmlinkage long long __ashldi3(long long, int);
+asmlinkage long long __ashrdi3(long long, int);
+asmlinkage long long __lshrdi3(long long, int);
+asmlinkage long __divsi3(long, long);
+asmlinkage long __modsi3(long, long);
+asmlinkage unsigned long __umodsi3(unsigned long, unsigned long);
+asmlinkage long long __muldi3(long long, long long);
+asmlinkage long __mulsi3(long, long);
+asmlinkage long __udivsi3(long, long);
+asmlinkage void *memcpy(void *, const void *, size_t);
+asmlinkage void *memset(void *, int, size_t);
+asmlinkage long strncpy_from_user(void *to, void *from, size_t n);
+
+	/* gcc lib functions */
+EXPORT_SYMBOL(__ucmpdi2);
+EXPORT_SYMBOL(__ashldi3);
+EXPORT_SYMBOL(__ashrdi3);
+EXPORT_SYMBOL(__lshrdi3);
+EXPORT_SYMBOL(__divsi3);
+EXPORT_SYMBOL(__modsi3);
+EXPORT_SYMBOL(__umodsi3);
+EXPORT_SYMBOL(__muldi3);
+EXPORT_SYMBOL(__mulsi3);
+EXPORT_SYMBOL(__udivsi3);
+EXPORT_SYMBOL(memcpy);
+EXPORT_SYMBOL(memset);
+EXPORT_SYMBOL(strncpy_from_user);
diff --git a/arch/h8300/kernel/head_ram.S b/arch/h8300/kernel/head_ram.S
new file mode 100644
index 000000000..dbf8429f5
--- /dev/null
+++ b/arch/h8300/kernel/head_ram.S
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/sys.h>
+#include <linux/init.h>
+#include <asm/unistd.h>
+#include <asm/setup.h>
+#include <asm/segment.h>
+#include <asm/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/thread_info.h>
+#include <asm/errno.h>
+
+#if defined(CONFIG_CPU_H8300H)
+	.h8300h
+#define SYSCR 0xfee012
+#define IRAMTOP 0xffff20
+#endif
+#if defined(CONFIG_CPU_H8S)
+	.h8300s
+#define INTCR 0xffff31
+#define IRAMTOP 0xffc000
+#endif
+
+	__HEAD
+	.global	_start
+_start:
+	mov.l	#IRAMTOP,sp
+	/* .bss clear */
+	mov.l	#_sbss,er5
+	mov.l	#_ebss,er4
+	sub.l	er5,er4
+	shlr	er4
+	shlr	er4
+	sub.l	er2,er2
+1:
+	mov.l	er2,@er5
+	adds	#4,er5
+	dec.l	#1,er4
+	bne	1b
+	jsr	@h8300_fdt_init
+
+	/* linux kernel start */
+#if defined(CONFIG_CPU_H8300H)
+	ldc	#0xd0,ccr	/* running kernel */
+	mov.l	#SYSCR,er0
+	bclr	#3,@er0
+#endif
+#if defined(CONFIG_CPU_H8S)
+	ldc	#0x07,exr
+	bclr	#4,@INTCR:8
+	bset	#5,@INTCR:8	/* Interrupt mode 2 */
+	ldc	#0x90,ccr	/* running kernel */
+#endif
+	mov.l	#init_thread_union,sp
+	add.l	#0x2000,sp
+	jsr	@start_kernel
+
+1:
+	bra	1b
+
+	.end
diff --git a/arch/h8300/kernel/head_rom.S b/arch/h8300/kernel/head_rom.S
new file mode 100644
index 000000000..ab55a9cb2
--- /dev/null
+++ b/arch/h8300/kernel/head_rom.S
@@ -0,0 +1,111 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/init.h>
+#include <asm/thread_info.h>
+
+#if defined(CONFIG_CPU_H8300H)
+	.h8300h
+#define SYSCR 0xfee012
+#define IRAMTOP 0xffff20
+#define NR_INT 64
+#endif
+#if defined(CONFIG_CPU_H8S)
+	.h8300s
+#define INTCR 0xffff31
+#define IRAMTOP 0xffc000
+#define NR_INT 128
+#endif
+
+	__HEAD
+	.global	_start
+_start:
+	mov.l	#IRAMTOP,sp
+#if !defined(CONFIG_H8300H_SIM) && \
+    !defined(CONFIG_H8S_SIM)
+	jsr	@lowlevel_init
+
+	/* copy .data */
+	mov.l	#_begin_data,er5
+	mov.l	#_sdata,er6
+	mov.l	#_edata,er4
+	sub.l	er6,er4
+	shlr.l	er4
+	shlr.l	er4
+1:
+	mov.l	@er5+,er0
+	mov.l	er0,@er6
+	adds	#4,er6
+	dec.l	#1,er4
+	bne	1b
+	/* .bss clear */
+	mov.l	#_sbss,er5
+	mov.l	#_ebss,er4
+	sub.l	er5,er4
+	shlr	er4
+	shlr	er4
+	sub.l	er0,er0
+1:
+	mov.l	er0,@er5
+	adds	#4,er5
+	dec.l	#1,er4
+	bne	1b
+#else
+	/* get cmdline from gdb */
+	jsr	@0xcc
+	;; er0 - argc
+	;; er1 - argv
+	mov.l	#command_line,er3
+	adds	#4,er1
+	dec.l	#1,er0
+	beq	4f
+1:
+	mov.l	@er1+,er2
+2:
+	mov.b	@er2+,r4l
+	beq	3f
+	mov.b	r4l,@er3
+	adds	#1,er3
+	bra	2b
+3:
+	mov.b	#' ',r4l
+	mov.b	r4l,@er3
+	adds	#1,er3
+	dec.l	#1,er0
+	bne	1b
+	subs	#1,er3
+	mov.b	#0,r4l
+	mov.b	r4l,@er3
+4:
+#endif
+	sub.l	er0,er0
+	jsr	@h8300_fdt_init
+	/* linux kernel start */
+#if defined(CONFIG_CPU_H8300H)
+	ldc	#0xd0,ccr	/* running kernel */
+	mov.l	#SYSCR,er0
+	bclr	#3,@er0
+#endif
+#if defined(CONFIG_CPU_H8S)
+	ldc	#0x07,exr
+	bclr	#4,@INTCR:8
+	bset	#5,@INTCR:8	/* Interrupt mode 2 */
+	ldc	#0x90,ccr	/* running kernel */
+#endif
+	mov.l	#init_thread_union,sp
+	add.l	#0x2000,sp
+	jsr	@start_kernel
+
+1:
+	bra	1b
+
+#if defined(CONFIG_ROMKERNEL)
+	/* interrupt vector */
+	.section .vectors,"ax"
+	.long	_start
+	.long	_start
+vector	=	2
+	.rept	NR_INT - 2
+	.long	_interrupt_redirect_table+vector*4
+vector	=	vector + 1
+	.endr
+#endif
+	.end
diff --git a/arch/h8300/kernel/irq.c b/arch/h8300/kernel/irq.c
new file mode 100644
index 000000000..834e4d7b1
--- /dev/null
+++ b/arch/h8300/kernel/irq.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/arch/h8300/kernel/irq.c
+ *
+ * Copyright 2014-2015 Yoshinori Sato <ysato@users.sourceforge.jp>
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/of_irq.h>
+#include <asm/traps.h>
+
+#ifdef CONFIG_RAMKERNEL
+typedef void (*h8300_vector)(void);
+
+static const h8300_vector __initconst trap_table[] = {
+	0, 0, 0, 0,
+	_trace_break,
+	0, 0,
+	_nmi,
+	_system_call,
+	0, 0,
+	_trace_break,
+};
+
+static unsigned long __init *get_vector_address(void)
+{
+	unsigned long *rom_vector = CPU_VECTOR;
+	unsigned long base, tmp;
+	int vec_no;
+
+	base = rom_vector[EXT_IRQ0] & ADDR_MASK;
+
+	/* check romvector format */
+	for (vec_no = EXT_IRQ0 + 1; vec_no <= EXT_IRQ0+EXT_IRQS; vec_no++) {
+		if ((base+(vec_no - EXT_IRQ0)*4) !=
+		    (rom_vector[vec_no] & ADDR_MASK))
+			return NULL;
+	}
+
+	/* ramvector base address */
+	base -= EXT_IRQ0*4;
+
+	/* writerble? */
+	tmp = ~(*(volatile unsigned long *)base);
+	(*(volatile unsigned long *)base) = tmp;
+	if ((*(volatile unsigned long *)base) != tmp)
+		return NULL;
+	return (unsigned long *)base;
+}
+
+static void __init setup_vector(void)
+{
+	int i;
+	unsigned long *ramvec, *ramvec_p;
+	const h8300_vector *trap_entry;
+
+	ramvec = get_vector_address();
+	if (ramvec == NULL)
+		panic("interrupt vector serup failed.");
+	else
+		pr_debug("virtual vector at 0x%p\n", ramvec);
+
+	/* create redirect table */
+	ramvec_p = ramvec;
+	trap_entry = trap_table;
+	for (i = 0; i < NR_IRQS; i++) {
+		if (i < 12) {
+			if (*trap_entry)
+				*ramvec_p = VECTOR(*trap_entry);
+			ramvec_p++;
+			trap_entry++;
+		} else
+			*ramvec_p++ = REDIRECT(_interrupt_entry);
+	}
+	_interrupt_redirect_table = ramvec;
+}
+#else
+void setup_vector(void)
+{
+	/* noting do */
+}
+#endif
+
+void __init init_IRQ(void)
+{
+	setup_vector();
+	irqchip_init();
+}
+
+asmlinkage void do_IRQ(int irq)
+{
+	irq_enter();
+	generic_handle_irq(irq);
+	irq_exit();
+}
diff --git a/arch/h8300/kernel/kgdb.c b/arch/h8300/kernel/kgdb.c
new file mode 100644
index 000000000..602e478af
--- /dev/null
+++ b/arch/h8300/kernel/kgdb.c
@@ -0,0 +1,135 @@
+/*
+ * H8/300 KGDB support
+ *
+ * Copyright (C) 2015 Yoshinori Sato <ysato@users.sourceforge.jp>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/ptrace.h>
+#include <linux/kgdb.h>
+#include <linux/kdebug.h>
+#include <linux/io.h>
+
+struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
+	{ "er0", GDB_SIZEOF_REG, offsetof(struct pt_regs, er0) },
+	{ "er1", GDB_SIZEOF_REG, offsetof(struct pt_regs, er1) },
+	{ "er2", GDB_SIZEOF_REG, offsetof(struct pt_regs, er2) },
+	{ "er3", GDB_SIZEOF_REG, offsetof(struct pt_regs, er3) },
+	{ "er4", GDB_SIZEOF_REG, offsetof(struct pt_regs, er4) },
+	{ "er5", GDB_SIZEOF_REG, offsetof(struct pt_regs, er5) },
+	{ "er6", GDB_SIZEOF_REG, offsetof(struct pt_regs, er6) },
+	{ "sp", GDB_SIZEOF_REG, offsetof(struct pt_regs, sp) },
+	{ "ccr", GDB_SIZEOF_REG, offsetof(struct pt_regs, ccr) },
+	{ "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, pc) },
+	{ "cycles", GDB_SIZEOF_REG, -1 },
+#if defined(CONFIG_CPU_H8S)
+	{ "exr", GDB_SIZEOF_REG, offsetof(struct pt_regs, exr) },
+#endif
+	{ "tick", GDB_SIZEOF_REG, -1 },
+	{ "inst", GDB_SIZEOF_REG, -1 },
+};
+
+char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
+{
+	if (regno >= DBG_MAX_REG_NUM || regno < 0)
+		return NULL;
+
+	switch (regno) {
+	case GDB_CCR:
+#if defined(CONFIG_CPU_H8S)
+	case GDB_EXR:
+#endif
+		*(u32 *)mem = *(u16 *)((void *)regs +
+				       dbg_reg_def[regno].offset);
+		break;
+	default:
+		if (dbg_reg_def[regno].offset >= 0)
+			memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
+			       dbg_reg_def[regno].size);
+		else
+			memset(mem, 0, dbg_reg_def[regno].size);
+		break;
+	}
+	return dbg_reg_def[regno].name;
+}
+
+int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
+{
+	if (regno >= DBG_MAX_REG_NUM || regno < 0)
+		return -EINVAL;
+
+	switch (regno) {
+	case GDB_CCR:
+#if defined(CONFIG_CPU_H8S)
+	case GDB_EXR:
+#endif
+		*(u16 *)((void *)regs +
+			 dbg_reg_def[regno].offset) = *(u32 *)mem;
+		break;
+	default:
+		memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
+		       dbg_reg_def[regno].size);
+	}
+	return 0;
+}
+
+asmlinkage void h8300_kgdb_trap(struct pt_regs *regs)
+{
+	regs->pc &= 0x00ffffff;
+	if (kgdb_handle_exception(10, SIGTRAP, 0, regs))
+		return;
+	if (*(u16 *)(regs->pc) == *(u16 *)&arch_kgdb_ops.gdb_bpt_instr)
+		regs->pc += BREAK_INSTR_SIZE;
+	regs->pc |= regs->ccr << 24;
+}
+
+void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
+{
+	memset((char *)gdb_regs, 0, NUMREGBYTES);
+	gdb_regs[GDB_SP] = p->thread.ksp;
+	gdb_regs[GDB_PC] = KSTK_EIP(p);
+}
+
+void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
+{
+	regs->pc = pc;
+}
+
+int kgdb_arch_handle_exception(int vector, int signo, int err_code,
+				char *remcom_in_buffer, char *remcom_out_buffer,
+				struct pt_regs *regs)
+{
+	char *ptr;
+	unsigned long addr;
+
+	switch (remcom_in_buffer[0]) {
+	case 's':
+	case 'c':
+		/* handle the optional parameters */
+		ptr = &remcom_in_buffer[1];
+		if (kgdb_hex2long(&ptr, &addr))
+			regs->pc = addr;
+
+		return 0;
+	}
+
+	return -1; /* this means that we do not want to exit from the handler */
+}
+
+int kgdb_arch_init(void)
+{
+	return 0;
+}
+
+void kgdb_arch_exit(void)
+{
+	/* Nothing to do */
+}
+
+const struct kgdb_arch arch_kgdb_ops = {
+	/* Breakpoint instruction: trapa #2 */
+	.gdb_bpt_instr = { 0x57, 0x20 },
+};
diff --git a/arch/h8300/kernel/module.c b/arch/h8300/kernel/module.c
new file mode 100644
index 000000000..cd802cc78
--- /dev/null
+++ b/arch/h8300/kernel/module.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/moduleloader.h>
+#include <linux/elf.h>
+#include <linux/vmalloc.h>
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+
+int apply_relocate_add(Elf32_Shdr *sechdrs,
+		       const char *strtab,
+		       unsigned int symindex,
+		       unsigned int relsec,
+		       struct module *me)
+{
+	unsigned int i;
+	Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
+
+	pr_debug("Applying relocate section %u to %u\n", relsec,
+	       sechdrs[relsec].sh_info);
+	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
+		/* This is where to make the change */
+		uint32_t *loc =
+			(uint32_t *)(sechdrs[sechdrs[relsec].sh_info].sh_addr
+					     + rela[i].r_offset);
+		/* This is the symbol it is referring to.  Note that all
+		   undefined symbols have been resolved.  */
+		Elf32_Sym *sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
+			+ ELF32_R_SYM(rela[i].r_info);
+		uint32_t v = sym->st_value + rela[i].r_addend;
+
+		switch (ELF32_R_TYPE(rela[i].r_info)) {
+		case R_H8_DIR24R8:
+			loc = (uint32_t *)((uint32_t)loc - 1);
+			*loc = (*loc & 0xff000000) | ((*loc & 0xffffff) + v);
+			break;
+		case R_H8_DIR24A8:
+			if (ELF32_R_SYM(rela[i].r_info))
+				*loc += v;
+			break;
+		case R_H8_DIR32:
+		case R_H8_DIR32A16:
+			*loc += v;
+			break;
+		case R_H8_PCREL16:
+			v -= (unsigned long)loc + 2;
+			if ((Elf32_Sword)v > 0x7fff ||
+			    (Elf32_Sword)v < -(Elf32_Sword)0x8000)
+				goto overflow;
+			else
+				*(unsigned short *)loc = v;
+			break;
+		case R_H8_PCREL8:
+			v -= (unsigned long)loc + 1;
+			if ((Elf32_Sword)v > 0x7f ||
+			    (Elf32_Sword)v < -(Elf32_Sword)0x80)
+				goto overflow;
+			else
+				*(unsigned char *)loc = v;
+			break;
+		default:
+			pr_err("module %s: Unknown relocation: %u\n",
+			       me->name, ELF32_R_TYPE(rela[i].r_info));
+			return -ENOEXEC;
+		}
+	}
+	return 0;
+ overflow:
+	pr_err("module %s: relocation offset overflow: %08x\n",
+	       me->name, rela[i].r_offset);
+	return -ENOEXEC;
+}
diff --git a/arch/h8300/kernel/process.c b/arch/h8300/kernel/process.c
new file mode 100644
index 000000000..46b1342ce
--- /dev/null
+++ b/arch/h8300/kernel/process.c
@@ -0,0 +1,176 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/arch/h8300/kernel/process.c
+ *
+ * Yoshinori Sato <ysato@users.sourceforge.jp>
+ *
+ *  Based on:
+ *
+ *  linux/arch/m68knommu/kernel/process.c
+ *
+ *  Copyright (C) 1998  D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>,
+ *                      Kenneth Albanowski <kjahds@kjahds.com>,
+ *                      The Silver Hammer Group, Ltd.
+ *
+ *  linux/arch/m68k/kernel/process.c
+ *
+ *  Copyright (C) 1995  Hamish Macdonald
+ *
+ *  68060 fixes by Jesper Skov
+ */
+
+/*
+ * This file handles the architecture-dependent parts of process handling..
+ */
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task.h>
+#include <linux/sched/task_stack.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/ptrace.h>
+#include <linux/user.h>
+#include <linux/interrupt.h>
+#include <linux/reboot.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/rcupdate.h>
+
+#include <linux/uaccess.h>
+#include <asm/traps.h>
+#include <asm/setup.h>
+
+void (*pm_power_off)(void) = NULL;
+EXPORT_SYMBOL(pm_power_off);
+
+asmlinkage void ret_from_fork(void);
+asmlinkage void ret_from_kernel_thread(void);
+
+/*
+ * The idle loop on an H8/300..
+ */
+void arch_cpu_idle(void)
+{
+	raw_local_irq_enable();
+	__asm__("sleep");
+}
+
+void machine_restart(char *__unused)
+{
+	local_irq_disable();
+	__asm__("jmp @@0");
+}
+
+void machine_halt(void)
+{
+	local_irq_disable();
+	__asm__("sleep");
+	for (;;)
+		;
+}
+
+void machine_power_off(void)
+{
+	local_irq_disable();
+	__asm__("sleep");
+	for (;;)
+		;
+}
+
+void show_regs(struct pt_regs *regs)
+{
+	show_regs_print_info(KERN_DEFAULT);
+
+	pr_notice("\n");
+	pr_notice("PC: %08lx  Status: %02x\n",
+	       regs->pc, regs->ccr);
+	pr_notice("ORIG_ER0: %08lx ER0: %08lx ER1: %08lx\n",
+	       regs->orig_er0, regs->er0, regs->er1);
+	pr_notice("ER2: %08lx ER3: %08lx ER4: %08lx ER5: %08lx\n",
+	       regs->er2, regs->er3, regs->er4, regs->er5);
+	pr_notice("ER6' %08lx ", regs->er6);
+	if (user_mode(regs))
+		printk("USP: %08lx\n", rdusp());
+	else
+		printk("\n");
+}
+
+void flush_thread(void)
+{
+}
+
+int copy_thread(unsigned long clone_flags, unsigned long usp,
+		unsigned long topstk, struct task_struct *p, unsigned long tls)
+{
+	struct pt_regs *childregs;
+
+	childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1;
+
+	if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
+		memset(childregs, 0, sizeof(struct pt_regs));
+		childregs->retpc = (unsigned long) ret_from_kernel_thread;
+		childregs->er4 = topstk; /* arg */
+		childregs->er5 = usp; /* fn */
+	}  else {
+		*childregs = *current_pt_regs();
+		childregs->er0 = 0;
+		childregs->retpc = (unsigned long) ret_from_fork;
+		p->thread.usp = usp ?: rdusp();
+	}
+	p->thread.ksp = (unsigned long)childregs;
+
+	return 0;
+}
+
+unsigned long get_wchan(struct task_struct *p)
+{
+	unsigned long fp, pc;
+	unsigned long stack_page;
+	int count = 0;
+
+	if (!p || p == current || p->state == TASK_RUNNING)
+		return 0;
+
+	stack_page = (unsigned long)p;
+	fp = ((struct pt_regs *)p->thread.ksp)->er6;
+	do {
+		if (fp < stack_page+sizeof(struct thread_info) ||
+		    fp >= 8184+stack_page)
+			return 0;
+		pc = ((unsigned long *)fp)[1];
+		if (!in_sched_functions(pc))
+			return pc;
+		fp = *(unsigned long *) fp;
+	} while (count++ < 16);
+	return 0;
+}
+
+/* generic sys_clone is not enough registers */
+asmlinkage int sys_clone(unsigned long __user *args)
+{
+	unsigned long clone_flags;
+	unsigned long  newsp;
+	uintptr_t parent_tidptr;
+	uintptr_t child_tidptr;
+	struct kernel_clone_args kargs = {};
+
+	get_user(clone_flags, &args[0]);
+	get_user(newsp, &args[1]);
+	get_user(parent_tidptr, &args[2]);
+	get_user(child_tidptr, &args[3]);
+
+	kargs.flags		= (lower_32_bits(clone_flags) & ~CSIGNAL);
+	kargs.pidfd		= (int __user *)parent_tidptr;
+	kargs.child_tid		= (int __user *)child_tidptr;
+	kargs.parent_tid	= (int __user *)parent_tidptr;
+	kargs.exit_signal	= (lower_32_bits(clone_flags) & CSIGNAL);
+	kargs.stack		= newsp;
+
+	return kernel_clone(&kargs);
+}
diff --git a/arch/h8300/kernel/ptrace.c b/arch/h8300/kernel/ptrace.c
new file mode 100644
index 000000000..a11db009d
--- /dev/null
+++ b/arch/h8300/kernel/ptrace.c
@@ -0,0 +1,200 @@
+/*
+ *  linux/arch/h8300/kernel/ptrace.c
+ *
+ *  Copyright 2015 Yoshinori Sato <ysato@users.sourceforge.jp>
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License.  See the file COPYING in the main directory of
+ * this archive for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/audit.h>
+#include <linux/tracehook.h>
+#include <linux/regset.h>
+#include <linux/elf.h>
+
+#define CCR_MASK 0x6f    /* mode/imask not set */
+#define EXR_MASK 0x80    /* modify only T */
+
+#define PT_REG(r) offsetof(struct pt_regs, r)
+
+extern void user_disable_single_step(struct task_struct *child);
+
+/* Mapping from PT_xxx to the stack offset at which the register is
+   saved.  Notice that usp has no stack-slot and needs to be treated
+   specially (see get_reg/put_reg below). */
+static const int register_offset[] = {
+	PT_REG(er1), PT_REG(er2), PT_REG(er3), PT_REG(er4),
+	PT_REG(er5), PT_REG(er6), PT_REG(er0), -1,
+	PT_REG(orig_er0), PT_REG(ccr), PT_REG(pc),
+#if defined(CONFIG_CPU_H8S)
+	PT_REG(exr),
+#endif
+};
+
+/* read register */
+long h8300_get_reg(struct task_struct *task, int regno)
+{
+	switch (regno) {
+	case PT_USP:
+		return task->thread.usp + sizeof(long)*2;
+	case PT_CCR:
+	case PT_EXR:
+	    return *(unsigned short *)(task->thread.esp0 +
+				       register_offset[regno]);
+	default:
+	    return *(unsigned long *)(task->thread.esp0 +
+				      register_offset[regno]);
+	}
+}
+
+int h8300_put_reg(struct task_struct *task, int regno, unsigned long data)
+{
+	unsigned short oldccr;
+	unsigned short oldexr;
+
+	switch (regno) {
+	case PT_USP:
+		task->thread.usp = data - sizeof(long)*2;
+	case PT_CCR:
+		oldccr = *(unsigned short *)(task->thread.esp0 +
+					     register_offset[regno]);
+		oldccr &= ~CCR_MASK;
+		data &= CCR_MASK;
+		data |= oldccr;
+		*(unsigned short *)(task->thread.esp0 +
+				    register_offset[regno]) = data;
+		break;
+	case PT_EXR:
+		oldexr = *(unsigned short *)(task->thread.esp0 +
+					     register_offset[regno]);
+		oldccr &= ~EXR_MASK;
+		data &= EXR_MASK;
+		data |= oldexr;
+		*(unsigned short *)(task->thread.esp0 +
+				    register_offset[regno]) = data;
+		break;
+	default:
+		*(unsigned long *)(task->thread.esp0 +
+				   register_offset[regno]) = data;
+		break;
+	}
+	return 0;
+}
+
+static int regs_get(struct task_struct *target,
+		    const struct user_regset *regset,
+		    struct membuf to)
+{
+	int r;
+
+	BUILD_BUG_ON(sizeof(struct user_regs_struct) % sizeof(long) != 0);
+	for (r = 0; r < ELF_NGREG; r++)
+		membuf_store(&to, h8300_get_reg(target, r));
+
+	return 0;
+}
+
+static int regs_set(struct task_struct *target,
+		    const struct user_regset *regset,
+		    unsigned int pos, unsigned int count,
+		    const void *kbuf, const void __user *ubuf)
+{
+	int r;
+	int ret;
+	struct user_regs_struct regs;
+	long *reg;
+
+	/* build user regs in buffer */
+	BUILD_BUG_ON(sizeof(regs) % sizeof(long) != 0);
+	for (reg = (long *)&regs, r = 0; r < sizeof(regs) / sizeof(long); r++)
+		*reg++ = h8300_get_reg(target, r);
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 &regs, 0, sizeof(regs));
+	if (ret)
+		return ret;
+
+	/* write back to pt_regs */
+	for (reg = (long *)&regs, r = 0; r < sizeof(regs) / sizeof(long); r++)
+		h8300_put_reg(target, r, *reg++);
+	return 0;
+}
+
+enum h8300_regset {
+	REGSET_GENERAL,
+};
+
+static const struct user_regset h8300_regsets[] = {
+	[REGSET_GENERAL] = {
+		.core_note_type	= NT_PRSTATUS,
+		.n		= ELF_NGREG,
+		.size		= sizeof(long),
+		.align		= sizeof(long),
+		.regset_get		= regs_get,
+		.set		= regs_set,
+	},
+};
+
+static const struct user_regset_view user_h8300_native_view = {
+	.name = "h8300",
+	.e_machine = EM_H8_300,
+	.regsets = h8300_regsets,
+	.n = ARRAY_SIZE(h8300_regsets),
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+	return &user_h8300_native_view;
+}
+
+void ptrace_disable(struct task_struct *child)
+{
+	user_disable_single_step(child);
+}
+
+long arch_ptrace(struct task_struct *child, long request,
+		 unsigned long addr, unsigned long data)
+{
+	int ret;
+
+	switch (request) {
+	default:
+		ret = ptrace_request(child, request, addr, data);
+		break;
+	}
+	return ret;
+}
+
+asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
+{
+	long ret = 0;
+
+	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
+	    tracehook_report_syscall_entry(regs))
+		/*
+		 * Tracing decided this syscall should not happen.
+		 * We'll return a bogus call number to get an ENOSYS
+		 * error, but leave the original number in regs->regs[0].
+		 */
+		ret = -1L;
+
+	audit_syscall_entry(regs->er1, regs->er2, regs->er3,
+			    regs->er4, regs->er5);
+
+	return ret ?: regs->er0;
+}
+
+asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
+{
+	int step;
+
+	audit_syscall_exit(regs);
+
+	step = test_thread_flag(TIF_SINGLESTEP);
+	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall_exit(regs, step);
+}
diff --git a/arch/h8300/kernel/ptrace_h.c b/arch/h8300/kernel/ptrace_h.c
new file mode 100644
index 000000000..15db45a03
--- /dev/null
+++ b/arch/h8300/kernel/ptrace_h.c
@@ -0,0 +1,256 @@
+/*
+ *    ptrace cpu depend helper functions
+ *
+ *  Copyright 2003, 2015 Yoshinori Sato <ysato@users.sourceforge.jp>
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License.  See the file COPYING in the main directory of
+ * this archive for more details.
+ */
+
+#include <linux/linkage.h>
+#include <linux/sched/signal.h>
+#include <asm/ptrace.h>
+
+#define BREAKINST 0x5730 /* trapa #3 */
+
+/* disable singlestep */
+void user_disable_single_step(struct task_struct *child)
+{
+	if ((long)child->thread.breakinfo.addr != -1L) {
+		*(child->thread.breakinfo.addr) = child->thread.breakinfo.inst;
+		child->thread.breakinfo.addr = (unsigned short *)-1L;
+	}
+}
+
+/* calculate next pc */
+enum jump_type {none,	 /* normal instruction */
+		jabs,	 /* absolute address jump */
+		ind,	 /* indirect address jump */
+		ret,	 /* return to subrutine */
+		reg,	 /* register indexed jump */
+		relb,	 /* pc relative jump (byte offset) */
+		relw,	 /* pc relative jump (word offset) */
+	       };
+
+/* opcode decode table define
+   ptn: opcode pattern
+   msk: opcode bitmask
+   len: instruction length (<0 next table index)
+   jmp: jump operation mode */
+struct optable {
+	unsigned char bitpattern;
+	unsigned char bitmask;
+	signed char length;
+	signed char type;
+} __packed __aligned(1);
+
+#define OPTABLE(ptn, msk, len, jmp)	\
+	{				\
+		.bitpattern = ptn,	\
+		.bitmask    = msk,	\
+		.length	    = len,	\
+		.type	    = jmp,	\
+	}
+
+static const struct optable optable_0[] = {
+	OPTABLE(0x00, 0xff,  1, none), /* 0x00 */
+	OPTABLE(0x01, 0xff, -1, none), /* 0x01 */
+	OPTABLE(0x02, 0xfe,  1, none), /* 0x02-0x03 */
+	OPTABLE(0x04, 0xee,  1, none), /* 0x04-0x05/0x14-0x15 */
+	OPTABLE(0x06, 0xfe,  1, none), /* 0x06-0x07 */
+	OPTABLE(0x08, 0xea,  1, none), /* 0x08-0x09/0x0c-0x0d/0x18-0x19/0x1c-0x1d */
+	OPTABLE(0x0a, 0xee,  1, none), /* 0x0a-0x0b/0x1a-0x1b */
+	OPTABLE(0x0e, 0xee,  1, none), /* 0x0e-0x0f/0x1e-0x1f */
+	OPTABLE(0x10, 0xfc,  1, none), /* 0x10-0x13 */
+	OPTABLE(0x16, 0xfe,  1, none), /* 0x16-0x17 */
+	OPTABLE(0x20, 0xe0,  1, none), /* 0x20-0x3f */
+	OPTABLE(0x40, 0xf0,  1, relb), /* 0x40-0x4f */
+	OPTABLE(0x50, 0xfc,  1, none), /* 0x50-0x53 */
+	OPTABLE(0x54, 0xfd,  1, ret), /* 0x54/0x56 */
+	OPTABLE(0x55, 0xff,  1, relb), /* 0x55 */
+	OPTABLE(0x57, 0xff,  1, none), /* 0x57 */
+	OPTABLE(0x58, 0xfb,  2, relw), /* 0x58/0x5c */
+	OPTABLE(0x59, 0xfb,  1, reg), /* 0x59/0x5b */
+	OPTABLE(0x5a, 0xfb,  2, jabs), /* 0x5a/0x5e */
+	OPTABLE(0x5b, 0xfb,  2, ind), /* 0x5b/0x5f */
+	OPTABLE(0x60, 0xe8,  1, none), /* 0x60-0x67/0x70-0x77 */
+	OPTABLE(0x68, 0xfa,  1, none), /* 0x68-0x69/0x6c-0x6d */
+	OPTABLE(0x6a, 0xfe, -2, none), /* 0x6a-0x6b */
+	OPTABLE(0x6e, 0xfe,  2, none), /* 0x6e-0x6f */
+	OPTABLE(0x78, 0xff,  4, none), /* 0x78 */
+	OPTABLE(0x79, 0xff,  2, none), /* 0x79 */
+	OPTABLE(0x7a, 0xff,  3, none), /* 0x7a */
+	OPTABLE(0x7b, 0xff,  2, none), /* 0x7b */
+	OPTABLE(0x7c, 0xfc,  2, none), /* 0x7c-0x7f */
+	OPTABLE(0x80, 0x80,  1, none), /* 0x80-0xff */
+};
+
+static const struct optable optable_1[] = {
+	OPTABLE(0x00, 0xff, -3, none), /* 0x0100 */
+	OPTABLE(0x40, 0xf0, -3, none), /* 0x0140-0x14f */
+	OPTABLE(0x80, 0xf0,  1, none), /* 0x0180-0x018f */
+	OPTABLE(0xc0, 0xc0,  2, none), /* 0x01c0-0x01ff */
+};
+
+static const struct optable optable_2[] = {
+	OPTABLE(0x00, 0x20,  2, none), /* 0x6a0?/0x6a8?/0x6b0?/0x6b8? */
+	OPTABLE(0x20, 0x20,  3, none), /* 0x6a2?/0x6aa?/0x6b2?/0x6ba? */
+};
+
+static const struct optable optable_3[] = {
+	OPTABLE(0x69, 0xfb,  2, none), /* 0x010069/0x01006d/014069/0x01406d */
+	OPTABLE(0x6b, 0xff, -4, none), /* 0x01006b/0x01406b */
+	OPTABLE(0x6f, 0xff,  3, none), /* 0x01006f/0x01406f */
+	OPTABLE(0x78, 0xff,  5, none), /* 0x010078/0x014078 */
+};
+
+static const struct optable optable_4[] = {
+/* 0x0100690?/0x01006d0?/0140690?/0x01406d0?/
+   0x0100698?/0x01006d8?/0140698?/0x01406d8? */
+	OPTABLE(0x00, 0x78, 3, none),
+/* 0x0100692?/0x01006d2?/0140692?/0x01406d2?/
+   0x010069a?/0x01006da?/014069a?/0x01406da? */
+	OPTABLE(0x20, 0x78, 4, none),
+};
+
+static const struct optables_list {
+	const struct optable *ptr;
+	int size;
+} optables[] = {
+#define OPTABLES(no)                                                   \
+	{                                                              \
+		.ptr  = optable_##no,                                  \
+		.size = sizeof(optable_##no) / sizeof(struct optable), \
+	}
+	OPTABLES(0),
+	OPTABLES(1),
+	OPTABLES(2),
+	OPTABLES(3),
+	OPTABLES(4),
+
+};
+
+const unsigned char condmask[] = {
+	0x00, 0x40, 0x01, 0x04, 0x02, 0x08, 0x10, 0x20
+};
+
+static int isbranch(struct task_struct *task, int reson)
+{
+	unsigned char cond = h8300_get_reg(task, PT_CCR);
+
+	/* encode complex conditions */
+	/* B4: N^V
+	   B5: Z|(N^V)
+	   B6: C|Z */
+	__asm__("bld #3,%w0\n\t"
+		"bxor #1,%w0\n\t"
+		"bst #4,%w0\n\t"
+		"bor #2,%w0\n\t"
+		"bst #5,%w0\n\t"
+		"bld #2,%w0\n\t"
+		"bor #0,%w0\n\t"
+		"bst #6,%w0\n\t"
+		: "=&r"(cond) : "0"(cond) : "cc");
+	cond &= condmask[reson >> 1];
+	if (!(reson & 1))
+		return cond == 0;
+	else
+		return cond != 0;
+}
+
+static unsigned short *decode(struct task_struct *child,
+			      const struct optable *op,
+			      char *fetch_p, unsigned short *pc,
+			      unsigned char inst)
+{
+	unsigned long addr;
+	unsigned long *sp;
+	int regno;
+
+	switch (op->type) {
+	case none:
+		return (unsigned short *)pc + op->length;
+	case jabs:
+		addr = *(unsigned long *)pc;
+		return (unsigned short *)(addr & 0x00ffffff);
+	case ind:
+		addr = *pc & 0xff;
+		return (unsigned short *)(*(unsigned long *)addr);
+	case ret:
+		sp = (unsigned long *)h8300_get_reg(child, PT_USP);
+		/* user stack frames
+		   |   er0  | temporary saved
+		   +--------+
+		   |   exp  | exception stack frames
+		   +--------+
+		   | ret pc | userspace return address
+		*/
+		return (unsigned short *)(*(sp+2) & 0x00ffffff);
+	case reg:
+		regno = (*pc >> 4) & 0x07;
+		if (regno == 0)
+			addr = h8300_get_reg(child, PT_ER0);
+		else
+			addr = h8300_get_reg(child, regno-1 + PT_ER1);
+		return (unsigned short *)addr;
+	case relb:
+		if (inst == 0x55 || isbranch(child, inst & 0x0f))
+			pc = (unsigned short *)((unsigned long)pc +
+						((signed char)(*fetch_p)));
+		return pc+1; /* skip myself */
+	case relw:
+		if (inst == 0x5c || isbranch(child, (*fetch_p & 0xf0) >> 4))
+			pc = (unsigned short *)((unsigned long)pc +
+						((signed short)(*(pc+1))));
+		return pc+2; /* skip myself */
+	default:
+		return NULL;
+	}
+}
+
+static unsigned short *nextpc(struct task_struct *child, unsigned short *pc)
+{
+	const struct optable *op;
+	unsigned char *fetch_p;
+	int op_len;
+	unsigned char inst;
+
+	op = optables[0].ptr;
+	op_len = optables[0].size;
+	fetch_p = (unsigned char *)pc;
+	inst = *fetch_p++;
+	do {
+		if ((inst & op->bitmask) == op->bitpattern) {
+			if (op->length < 0) {
+				op = optables[-op->length].ptr;
+				op_len = optables[-op->length].size + 1;
+				inst = *fetch_p++;
+			} else
+				return decode(child, op, fetch_p, pc, inst);
+		} else
+			op++;
+	} while (--op_len > 0);
+	return NULL;
+}
+
+/* Set breakpoint(s) to simulate a single step from the current PC.  */
+
+void user_enable_single_step(struct task_struct *child)
+{
+	unsigned short *next;
+
+	next = nextpc(child, (unsigned short *)h8300_get_reg(child, PT_PC));
+	child->thread.breakinfo.addr = next;
+	child->thread.breakinfo.inst = *next;
+	*next = BREAKINST;
+}
+
+asmlinkage void trace_trap(unsigned long bp)
+{
+	if ((unsigned long)current->thread.breakinfo.addr == bp) {
+		user_disable_single_step(current);
+		force_sig(SIGTRAP);
+	} else
+		force_sig(SIGILL);
+}
diff --git a/arch/h8300/kernel/ptrace_s.c b/arch/h8300/kernel/ptrace_s.c
new file mode 100644
index 000000000..ee21f37b7
--- /dev/null
+++ b/arch/h8300/kernel/ptrace_s.c
@@ -0,0 +1,44 @@
+/*
+ *  linux/arch/h8300/kernel/ptrace_h8s.c
+ *    ptrace cpu depend helper functions
+ *
+ *  Yoshinori Sato <ysato@users.sourceforge.jp>
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License.  See the file COPYING in the main directory of
+ * this archive for more details.
+ */
+
+#include <linux/linkage.h>
+#include <linux/sched/signal.h>
+#include <linux/errno.h>
+#include <asm/ptrace.h>
+
+#define CCR_MASK  0x6f
+#define EXR_TRACE 0x80
+
+/* disable singlestep */
+void user_disable_single_step(struct task_struct *child)
+{
+	unsigned char exr;
+
+	exr = h8300_get_reg(child, PT_EXR);
+	exr &= ~EXR_TRACE;
+	h8300_put_reg(child, PT_EXR, exr);
+}
+
+/* enable singlestep */
+void user_enable_single_step(struct task_struct *child)
+{
+	unsigned char exr;
+
+	exr = h8300_get_reg(child, PT_EXR);
+	exr |= EXR_TRACE;
+	h8300_put_reg(child, PT_EXR, exr);
+}
+
+asmlinkage void trace_trap(unsigned long bp)
+{
+	(void)bp;
+	force_sig(SIGTRAP);
+}
diff --git a/arch/h8300/kernel/setup.c b/arch/h8300/kernel/setup.c
new file mode 100644
index 000000000..0281f92ee
--- /dev/null
+++ b/arch/h8300/kernel/setup.c
@@ -0,0 +1,218 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/arch/h8300/kernel/setup.c
+ *
+ *  Copyright (C) 2001-2014 Yoshinori Sato <ysato@users.sourceforge.jp>
+ */
+
+/*
+ * This file handles the architecture-dependent parts of system setup
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/console.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/seq_file.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_address.h>
+#include <linux/clk-provider.h>
+#include <linux/memblock.h>
+#include <linux/screen_info.h>
+#include <linux/clocksource.h>
+
+#include <asm/setup.h>
+#include <asm/irq.h>
+#include <asm/sections.h>
+#include <asm/page.h>
+
+#if defined(CONFIG_CPU_H8300H)
+#define CPU "H8/300H"
+#elif defined(CONFIG_CPU_H8S)
+#define CPU "H8S"
+#else
+#define CPU "Unknown"
+#endif
+
+unsigned long memory_start;
+unsigned long memory_end;
+EXPORT_SYMBOL(memory_end);
+static unsigned long freq;
+extern char __dtb_start[];
+
+#ifdef CONFIG_VT
+struct screen_info screen_info;
+#endif
+
+char __initdata command_line[COMMAND_LINE_SIZE];
+
+void sim_console_register(void);
+
+void __init h8300_fdt_init(void *fdt, char *bootargs)
+{
+	if (!fdt)
+		fdt = __dtb_start;
+	else
+		strcpy(command_line, bootargs);
+
+	early_init_dt_scan(fdt);
+	memblock_allow_resize();
+}
+
+static void __init bootmem_init(void)
+{
+	struct memblock_region *region;
+
+	memory_end = memory_start = 0;
+
+	/* Find main memory where is the kernel */
+	memory_start = memblock_start_of_DRAM();
+	memory_end = memblock_end_of_DRAM();
+
+	if (!memory_end)
+		panic("No memory!");
+
+	/* setup bootmem globals (we use no_bootmem, but mm still depends on this) */
+	min_low_pfn = PFN_UP(memory_start);
+	max_low_pfn = PFN_DOWN(memory_end);
+	max_pfn = max_low_pfn;
+
+	memblock_reserve(__pa(_stext), _end - _stext);
+
+	early_init_fdt_reserve_self();
+	early_init_fdt_scan_reserved_mem();
+
+	memblock_dump_all();
+}
+
+void __init setup_arch(char **cmdline_p)
+{
+	unflatten_and_copy_device_tree();
+
+	init_mm.start_code = (unsigned long) _stext;
+	init_mm.end_code = (unsigned long) _etext;
+	init_mm.end_data = (unsigned long) _edata;
+	init_mm.brk = (unsigned long) 0;
+
+	pr_notice("\r\n\nuClinux " CPU "\n");
+	pr_notice("Flat model support (C) 1998,1999 Kenneth Albanowski, D. Jeff Dionne\n");
+
+	if (*command_line)
+		strcpy(boot_command_line, command_line);
+	*cmdline_p = boot_command_line;
+
+	parse_early_param();
+
+	bootmem_init();
+	/*
+	 * get kmalloc into gear
+	 */
+	paging_init();
+}
+
+/*
+ *	Get CPU information for use by the procfs.
+ */
+
+static int show_cpuinfo(struct seq_file *m, void *v)
+{
+	char *cpu;
+
+	cpu = CPU;
+
+	seq_printf(m,  "CPU:\t\t%s\n"
+		   "Clock:\t\t%lu.%1luMHz\n"
+		   "BogoMips:\t%lu.%02lu\n"
+		   "Calibration:\t%lu loops\n",
+		   cpu,
+		   freq/1000, freq%1000,
+		   (loops_per_jiffy*HZ)/500000,
+		   ((loops_per_jiffy*HZ)/5000)%100,
+		   (loops_per_jiffy*HZ));
+
+	return 0;
+}
+
+static void *c_start(struct seq_file *m, loff_t *pos)
+{
+	return *pos < num_possible_cpus() ?
+		((void *) 0x12345678) : NULL;
+}
+
+static void *c_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	++*pos;
+	return c_start(m, pos);
+}
+
+static void c_stop(struct seq_file *m, void *v)
+{
+}
+
+const struct seq_operations cpuinfo_op = {
+	.start	= c_start,
+	.next	= c_next,
+	.stop	= c_stop,
+	.show	= show_cpuinfo,
+};
+
+#if defined(CONFIG_CPU_H8300H)
+#define get_wait(base, addr) ({		\
+	int baddr;			\
+	baddr = ((addr) / 0x200000 * 2);			     \
+	w *= (readw((base) + 2) & (3 << baddr)) + 1;		     \
+	})
+#endif
+#if defined(CONFIG_CPU_H8S)
+#define get_wait(base, addr) ({		\
+	int baddr;			\
+	baddr = ((addr) / 0x200000 * 16);			     \
+	w *= (readl((base) + 2) & (7 << baddr)) + 1;	\
+	})
+#endif
+
+static __init int access_timing(void)
+{
+	struct device_node *bsc;
+	void __iomem *base;
+	unsigned long addr = (unsigned long)&__delay;
+	int bit = 1 << (addr / 0x200000);
+	int w;
+
+	bsc = of_find_compatible_node(NULL, NULL, "renesas,h8300-bsc");
+	base = of_iomap(bsc, 0);
+	w = (readb(base + 0) & bit)?2:1;
+	if (readb(base + 1) & bit)
+		w *= get_wait(base, addr);
+	else
+		w *= 2;
+	return w * 3 / 2;
+}
+
+void __init calibrate_delay(void)
+{
+	struct device_node *cpu;
+	int freq;
+
+	cpu = of_find_compatible_node(NULL, NULL, "renesas,h8300");
+	of_property_read_s32(cpu, "clock-frequency", &freq);
+	loops_per_jiffy = freq / HZ / (access_timing() * 2);
+	pr_cont("%lu.%02lu BogoMIPS (lpj=%lu)\n",
+		loops_per_jiffy / (500000 / HZ),
+		(loops_per_jiffy / (5000 / HZ)) % 100, loops_per_jiffy);
+}
+
+
+void __init time_init(void)
+{
+	of_clk_init(NULL);
+	timer_probe();
+}
diff --git a/arch/h8300/kernel/signal.c b/arch/h8300/kernel/signal.c
new file mode 100644
index 000000000..75a1c36b1
--- /dev/null
+++ b/arch/h8300/kernel/signal.c
@@ -0,0 +1,287 @@
+/*
+ *  linux/arch/h8300/kernel/signal.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ */
+
+/*
+ * uClinux H8/300 support by Yoshinori Sato <ysato@users.sourceforge.jp>
+ *                and David McCullough <davidm@snapgear.com>
+ *
+ * Based on
+ * Linux/m68k by Hamish Macdonald
+ */
+
+/*
+ * ++roman (07/09/96): implemented signal stacks (specially for tosemu on
+ * Atari :-) Current limitation: Only one sigstack can be active at one time.
+ * If a second signal with SA_ONSTACK set arrives while working on a sigstack,
+ * SA_ONSTACK is ignored. This behaviour avoids lots of trouble with nested
+ * signal handlers!
+ */
+
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <linux/mm.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/syscalls.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/highuid.h>
+#include <linux/personality.h>
+#include <linux/tty.h>
+#include <linux/binfmts.h>
+#include <linux/tracehook.h>
+
+#include <asm/setup.h>
+#include <linux/uaccess.h>
+#include <asm/traps.h>
+#include <asm/ucontext.h>
+
+/*
+ * Do a signal return; undo the signal stack.
+ *
+ * Keep the return code on the stack quadword aligned!
+ * That makes the cache flush below easier.
+ */
+
+struct rt_sigframe {
+	long dummy_er0;
+	long dummy_vector;
+#if defined(CONFIG_CPU_H8S)
+	short dummy_exr;
+#endif
+	long dummy_pc;
+	char *pretcode;
+	struct siginfo *pinfo;
+	void *puc;
+	unsigned char retcode[8];
+	struct siginfo info;
+	struct ucontext uc;
+	int sig;
+} __packed __aligned(2);
+
+static inline int
+restore_sigcontext(struct sigcontext *usc, int *pd0)
+{
+	struct pt_regs *regs = current_pt_regs();
+	int err = 0;
+	unsigned int ccr;
+	unsigned int usp;
+	unsigned int er0;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	/* restore passed registers */
+#define COPY(r)  do { err |= get_user(regs->r, &usc->sc_##r); } while (0)
+	COPY(er1);
+	COPY(er2);
+	COPY(er3);
+	COPY(er5);
+	COPY(pc);
+	ccr = regs->ccr & 0x10;
+	COPY(ccr);
+#undef COPY
+	regs->ccr &= 0xef;
+	regs->ccr |= ccr;
+	regs->orig_er0 = -1;		/* disable syscall checks */
+	err |= __get_user(usp, &usc->sc_usp);
+	regs->sp = usp;
+
+	err |= __get_user(er0, &usc->sc_er0);
+	*pd0 = er0;
+	return err;
+}
+
+asmlinkage int sys_rt_sigreturn(void)
+{
+	unsigned long usp = rdusp();
+	struct rt_sigframe *frame = (struct rt_sigframe *)(usp - 4);
+	sigset_t set;
+	int er0;
+
+	if (!access_ok(frame, sizeof(*frame)))
+		goto badframe;
+	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+		goto badframe;
+
+	set_current_blocked(&set);
+
+	if (restore_sigcontext(&frame->uc.uc_mcontext, &er0))
+		goto badframe;
+
+	if (restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
+	return er0;
+
+badframe:
+	force_sig(SIGSEGV);
+	return 0;
+}
+
+static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
+			     unsigned long mask)
+{
+	int err = 0;
+
+	err |= __put_user(regs->er0, &sc->sc_er0);
+	err |= __put_user(regs->er1, &sc->sc_er1);
+	err |= __put_user(regs->er2, &sc->sc_er2);
+	err |= __put_user(regs->er3, &sc->sc_er3);
+	err |= __put_user(regs->er4, &sc->sc_er4);
+	err |= __put_user(regs->er5, &sc->sc_er5);
+	err |= __put_user(regs->er6, &sc->sc_er6);
+	err |= __put_user(rdusp(),   &sc->sc_usp);
+	err |= __put_user(regs->pc,  &sc->sc_pc);
+	err |= __put_user(regs->ccr, &sc->sc_ccr);
+	err |= __put_user(mask,      &sc->sc_mask);
+
+	return err;
+}
+
+static inline void __user *
+get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size)
+{
+	return (void __user *)((sigsp(rdusp(), ksig) - frame_size) & -8UL);
+}
+
+static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
+			  struct pt_regs *regs)
+{
+	struct rt_sigframe *frame;
+	int err = 0;
+	unsigned char *ret;
+
+	frame = get_sigframe(ksig, regs, sizeof(*frame));
+
+	if (!access_ok(frame, sizeof(*frame)))
+		return -EFAULT;
+
+	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
+		err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+
+	/* Create the ucontext.  */
+	err |= __put_user(0, &frame->uc.uc_flags);
+	err |= __put_user(0, &frame->uc.uc_link);
+	err |= __save_altstack(&frame->uc.uc_stack, rdusp());
+	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
+	err |= copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+	if (err)
+		return -EFAULT;
+
+	/* Set up to return from userspace.  */
+	ret = (unsigned char *)&frame->retcode;
+	if (ksig->ka.sa.sa_flags & SA_RESTORER)
+		ret = (unsigned char *)(ksig->ka.sa.sa_restorer);
+	else {
+		/* sub.l er0,er0; mov.b #__NR_rt_sigreturn,r0l; trapa #0 */
+		err |= __put_user(0x1a80f800 + (__NR_rt_sigreturn & 0xff),
+				  (unsigned long *)(frame->retcode + 0));
+		err |= __put_user(0x5700,
+				  (unsigned short *)(frame->retcode + 4));
+	}
+	err |= __put_user(ret, &frame->pretcode);
+
+	if (err)
+		return -EFAULT;
+
+	/* Set up registers for signal handler */
+	regs->sp  = (unsigned long)frame;
+	regs->pc  = (unsigned long)ksig->ka.sa.sa_handler;
+	regs->er0 = ksig->sig;
+	regs->er1 = (unsigned long)&(frame->info);
+	regs->er2 = (unsigned long)&frame->uc;
+	regs->er5 = current->mm->start_data;	/* GOT base */
+
+	return 0;
+}
+
+static void
+handle_restart(struct pt_regs *regs, struct k_sigaction *ka)
+{
+	switch (regs->er0) {
+	case -ERESTARTNOHAND:
+		if (!ka)
+			goto do_restart;
+		regs->er0 = -EINTR;
+		break;
+	case -ERESTART_RESTARTBLOCK:
+		if (!ka) {
+			regs->er0 = __NR_restart_syscall;
+			regs->pc -= 2;
+		} else
+			regs->er0 = -EINTR;
+		break;
+	case -ERESTARTSYS:
+		if (!(ka->sa.sa_flags & SA_RESTART)) {
+			regs->er0 = -EINTR;
+			break;
+		}
+		fallthrough;
+	case -ERESTARTNOINTR:
+do_restart:
+		regs->er0 = regs->orig_er0;
+		regs->pc -= 2;
+		break;
+	}
+}
+
+/*
+ * OK, we're invoking a handler
+ */
+static void
+handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+{
+	sigset_t *oldset = sigmask_to_save();
+	int ret;
+	/* are we from a system call? */
+	if (regs->orig_er0 >= 0)
+		handle_restart(regs, &ksig->ka);
+
+	ret = setup_rt_frame(ksig, oldset, regs);
+
+	signal_setup_done(ret, ksig, 0);
+}
+
+/*
+ * Note that 'init' is a special process: it doesn't get signals it doesn't
+ * want to handle. Thus you cannot kill init even with a SIGKILL even by
+ * mistake.
+ */
+static void do_signal(struct pt_regs *regs)
+{
+	struct ksignal ksig;
+
+	current->thread.esp0 = (unsigned long) regs;
+
+	if (get_signal(&ksig)) {
+		/* Whee!  Actually deliver the signal.  */
+		handle_signal(&ksig, regs);
+		return;
+	}
+	/* Did we come from a system call? */
+	if (regs->orig_er0 >= 0)
+		handle_restart(regs, NULL);
+
+	/* If there's no signal to deliver, we just restore the saved mask.  */
+	restore_saved_sigmask();
+}
+
+asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags)
+{
+	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
+		do_signal(regs);
+
+	if (thread_info_flags & _TIF_NOTIFY_RESUME)
+		tracehook_notify_resume(regs);
+}
diff --git a/arch/h8300/kernel/sim-console.c b/arch/h8300/kernel/sim-console.c
new file mode 100644
index 000000000..03aa35b1a
--- /dev/null
+++ b/arch/h8300/kernel/sim-console.c
@@ -0,0 +1,31 @@
+/*
+ * arch/h8300/kernel/sim-console.c
+ *
+ *  Copyright (C) 2015 Yoshinori Sato <ysato@users.sourceforge.jp>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/serial_core.h>
+
+static void sim_write(struct console *con, const char *s, unsigned n)
+{
+	register const char *_ptr __asm__("er1") = s;
+	register const unsigned _len __asm__("er2") = n;
+
+	__asm__("sub.l er0,er0\n\t"		/* er0 = 1 (stdout) */
+		"inc.l #1,er0\n\t"
+		".byte 0x5e,0x00,0x00,0xc7\n\t" /* jsr @0xc7 (sys_write) */
+		: : "g"(_ptr), "g"(_len):"er0");
+}
+
+static int __init sim_setup(struct earlycon_device *device, const char *opt)
+{
+	device->con->write = sim_write;
+	return 0;
+}
+
+EARLYCON_DECLARE(h8sim, sim_setup);
diff --git a/arch/h8300/kernel/syscalls.c b/arch/h8300/kernel/syscalls.c
new file mode 100644
index 000000000..9022036fb
--- /dev/null
+++ b/arch/h8300/kernel/syscalls.c
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/syscalls.h>
+#include <linux/signal.h>
+#include <linux/unistd.h>
+
+#undef __SYSCALL
+#define __SYSCALL(nr, call) [nr] = (call),
+
+#define sys_mmap2 sys_mmap_pgoff
+
+asmlinkage int sys_rt_sigreturn(void);
+
+void *_sys_call_table[__NR_syscalls] = {
+#include <asm/unistd.h>
+};
diff --git a/arch/h8300/kernel/traps.c b/arch/h8300/kernel/traps.c
new file mode 100644
index 000000000..cf23ccb50
--- /dev/null
+++ b/arch/h8300/kernel/traps.c
@@ -0,0 +1,160 @@
+/*
+ * linux/arch/h8300/boot/traps.c -- general exception handling code
+ * H8/300 support Yoshinori Sato <ysato@users.sourceforge.jp>
+ *
+ * Cloned from Linux/m68k.
+ *
+ * No original Copyright holder listed,
+ * Probable original (C) Roman Zippel (assigned DJD, 1999)
+ *
+ * Copyright 1999-2000 D. Jeff Dionne, <jeff@rt-control.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task.h>
+#include <linux/mm_types.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/bug.h>
+
+#include <asm/irq.h>
+#include <asm/traps.h>
+#include <asm/page.h>
+
+static DEFINE_SPINLOCK(die_lock);
+
+/*
+ * this must be called very early as the kernel might
+ * use some instruction that are emulated on the 060
+ */
+
+void __init base_trap_init(void)
+{
+}
+
+void __init trap_init(void)
+{
+}
+
+asmlinkage void set_esp0(unsigned long ssp)
+{
+	current->thread.esp0 = ssp;
+}
+
+/*
+ *	Generic dumping code. Used for panic and debug.
+ */
+
+static void dump(struct pt_regs *fp)
+{
+	unsigned long	*sp;
+	unsigned char	*tp;
+	int		i;
+
+	pr_info("\nCURRENT PROCESS:\n\n");
+	pr_info("COMM=%s PID=%d\n", current->comm, current->pid);
+	if (current->mm) {
+		pr_info("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
+			(int) current->mm->start_code,
+			(int) current->mm->end_code,
+			(int) current->mm->start_data,
+			(int) current->mm->end_data,
+			(int) current->mm->end_data,
+			(int) current->mm->brk);
+		pr_info("USER-STACK=%08x  KERNEL-STACK=%08lx\n\n",
+			(int) current->mm->start_stack,
+			(int) PAGE_SIZE+(unsigned long)current);
+	}
+
+	show_regs(fp);
+	pr_info("\nCODE:");
+	tp = ((unsigned char *) fp->pc) - 0x20;
+	for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
+		if ((i % 0x10) == 0)
+			pr_info("\n%08x: ", (int) (tp + i));
+		pr_info("%08x ", (int) *sp++);
+	}
+	pr_info("\n");
+
+	pr_info("\nKERNEL STACK:");
+	tp = ((unsigned char *) fp) - 0x40;
+	for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
+		if ((i % 0x10) == 0)
+			pr_info("\n%08x: ", (int) (tp + i));
+		pr_info("%08x ", (int) *sp++);
+	}
+	pr_info("\n");
+	if (STACK_MAGIC != *(unsigned long *)((unsigned long)current+PAGE_SIZE))
+		pr_info("(Possibly corrupted stack page??)\n");
+
+	pr_info("\n\n");
+}
+
+void die(const char *str, struct pt_regs *fp, unsigned long err)
+{
+	static int diecount;
+
+	oops_enter();
+
+	console_verbose();
+	spin_lock_irq(&die_lock);
+	report_bug(fp->pc, fp);
+	pr_crit("%s: %04lx [#%d] ", str, err & 0xffff, ++diecount);
+	dump(fp);
+
+	spin_unlock_irq(&die_lock);
+	make_task_dead(SIGSEGV);
+}
+
+static int kstack_depth_to_print = 24;
+
+void show_stack(struct task_struct *task, unsigned long *esp, const char *loglvl)
+{
+	unsigned long *stack,  addr;
+	int i;
+
+	if (esp == NULL)
+		esp = (unsigned long *) &esp;
+
+	stack = esp;
+
+	printk("%sStack from %08lx:", loglvl, (unsigned long)stack);
+	for (i = 0; i < kstack_depth_to_print; i++) {
+		if (((unsigned long)stack & (THREAD_SIZE - 1)) >=
+		    THREAD_SIZE-4)
+			break;
+		if (i % 8 == 0)
+			printk("%s ", loglvl);
+		pr_cont(" %08lx", *stack++);
+	}
+
+	printk("%s\nCall Trace:\n", loglvl);
+	i = 0;
+	stack = esp;
+	while (((unsigned long)stack & (THREAD_SIZE - 1)) < THREAD_SIZE-4) {
+		addr = *stack++;
+		/*
+		 * If the address is either in the text segment of the
+		 * kernel, or in the region which contains vmalloc'ed
+		 * memory, it *may* be the address of a calling
+		 * routine; if so, print it so that someone tracing
+		 * down the cause of the crash will be able to figure
+		 * out the call path that was taken.
+		 */
+		if (check_kernel_text(addr)) {
+			if (i % 4 == 0)
+				printk("%s       ", loglvl);
+			pr_cont(" [<%08lx>]", addr);
+			i++;
+		}
+	}
+	printk("%s\n", loglvl);
+}
diff --git a/arch/h8300/kernel/vmlinux.lds.S b/arch/h8300/kernel/vmlinux.lds.S
new file mode 100644
index 000000000..6b1afc2f9
--- /dev/null
+++ b/arch/h8300/kernel/vmlinux.lds.S
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#define RO_EXCEPTION_TABLE_ALIGN	16
+
+#include <asm-generic/vmlinux.lds.h>
+#include <asm/page.h>
+#include <asm/thread_info.h>
+
+#define ROMTOP 0x000000
+#define RAMTOP 0x400000
+
+jiffies = jiffies_64 + 4;
+
+ENTRY(_start)
+
+SECTIONS
+{
+#if defined(CONFIG_ROMKERNEL)
+	. = ROMTOP;
+	.vectors :
+	{
+	_vector = . ;
+		*(.vector*)
+	}
+#else
+	. = RAMTOP;
+	_ramstart = .;
+	. = . + CONFIG_OFFSET;
+#endif
+	_text = .;
+	HEAD_TEXT_SECTION
+	.text : {
+	_stext = . ;
+		TEXT_TEXT
+		SCHED_TEXT
+		CPUIDLE_TEXT
+		LOCK_TEXT
+#if defined(CONFIG_ROMKERNEL)
+		*(.int_redirect)
+#endif
+	_etext = . ;
+	}
+	RO_DATA(4)
+	ROMEND = .;
+#if defined(CONFIG_ROMKERNEL)
+	. = RAMTOP;
+	_ramstart = .;
+#define ADDR(x) ROMEND
+#endif
+	_sdata = . ;
+	__data_start = . ;
+	RW_DATA(0, PAGE_SIZE, THREAD_SIZE)
+#if defined(CONFIG_ROMKERNEL)
+#undef ADDR
+#endif
+	. = ALIGN(0x4) ;
+	__init_begin = .;
+	INIT_TEXT_SECTION(4)
+	INIT_DATA_SECTION(4)
+	__init_end = .;
+	_edata = . ;
+	_begin_data = LOADADDR(.data);
+	_sbss =.;
+	BSS_SECTION(0, 0 ,0)
+	_ebss =.;
+	_ramend = .;
+	_end = .;
+	DISCARDS
+}
diff --git a/arch/h8300/lib/Makefile b/arch/h8300/lib/Makefile
new file mode 100644
index 000000000..685fa837c
--- /dev/null
+++ b/arch/h8300/lib/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for H8/300-specific library files..
+#
+
+lib-y  = memcpy.o memset.o abs.o strncpy.o \
+	 mulsi3.o udivsi3.o muldi3.o moddivsi3.o \
+	 ashldi3.o lshrdi3.o ashrdi3.o ucmpdi2.o \
+	 delay.o
diff --git a/arch/h8300/lib/abs.S b/arch/h8300/lib/abs.S
new file mode 100644
index 000000000..6e1a4ed3a
--- /dev/null
+++ b/arch/h8300/lib/abs.S
@@ -0,0 +1,21 @@
+;;; SPDX-License-Identifier: GPL-2.0
+;;; abs.S
+
+#include <asm/linkage.h>
+
+#if defined(CONFIG_CPU_H8300H)
+	.h8300h
+#endif
+#if defined(CONFIG_CPU_H8S)
+	.h8300s
+#endif
+	.text
+.global _abs
+
+;;; int abs(int n)
+_abs:
+	mov.l	er0,er0
+	bpl	1f
+	neg.l	er0
+1:
+	rts
diff --git a/arch/h8300/lib/ashldi3.c b/arch/h8300/lib/ashldi3.c
new file mode 100644
index 000000000..430720c0c
--- /dev/null
+++ b/arch/h8300/lib/ashldi3.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "libgcc.h"
+
+DWtype
+__ashldi3(DWtype u, word_type b)
+{
+	const DWunion uu = {.ll = u};
+	const word_type bm = (sizeof (Wtype) * BITS_PER_UNIT) - b;
+	DWunion w;
+
+	if (b == 0)
+		return u;
+
+	if (bm <= 0) {
+		w.s.low = 0;
+		w.s.high = (UWtype) uu.s.low << -bm;
+	} else {
+		const UWtype carries = (UWtype) uu.s.low >> bm;
+
+		w.s.low = (UWtype) uu.s.low << b;
+		w.s.high = ((UWtype) uu.s.high << b) | carries;
+	}
+
+	return w.ll;
+}
diff --git a/arch/h8300/lib/ashrdi3.c b/arch/h8300/lib/ashrdi3.c
new file mode 100644
index 000000000..2c6cd424e
--- /dev/null
+++ b/arch/h8300/lib/ashrdi3.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "libgcc.h"
+
+DWtype __ashrdi3(DWtype u, word_type b)
+{
+	const DWunion uu = {.ll = u};
+	const word_type bm = (sizeof (Wtype) * BITS_PER_UNIT) - b;
+	DWunion w;
+
+	if (b == 0)
+		return u;
+
+	if (bm <= 0) {
+		/* w.s.high = 1..1 or 0..0 */
+		w.s.high = uu.s.high >> (sizeof (Wtype) * BITS_PER_UNIT - 1);
+		w.s.low = uu.s.high >> -bm;
+	} else {
+		const UWtype carries = (UWtype) uu.s.high << bm;
+
+		w.s.high = uu.s.high >> b;
+		w.s.low = ((UWtype) uu.s.low >> b) | carries;
+	}
+
+	return w.ll;
+}
diff --git a/arch/h8300/lib/delay.c b/arch/h8300/lib/delay.c
new file mode 100644
index 000000000..f4277529a
--- /dev/null
+++ b/arch/h8300/lib/delay.c
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * delay loops
+ *
+ * Copyright (C) 2015 Yoshinori Sato
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <asm/param.h>
+#include <asm/processor.h>
+#include <asm/timex.h>
+
+void __delay(unsigned long cycles)
+{
+	__asm__ volatile ("1: dec.l #1,%0\n\t"
+			  "bne 1b":"=r"(cycles):"0"(cycles));
+}
+EXPORT_SYMBOL(__delay);
+
+void __const_udelay(unsigned long xloops)
+{
+	u64 loops;
+
+	loops = (u64)xloops * loops_per_jiffy * HZ;
+
+	__delay(loops >> 32);
+}
+EXPORT_SYMBOL(__const_udelay);
+
+void __udelay(unsigned long usecs)
+{
+	__const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */
+}
+EXPORT_SYMBOL(__udelay);
+
+void __ndelay(unsigned long nsecs)
+{
+	__const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */
+}
+EXPORT_SYMBOL(__ndelay);
diff --git a/arch/h8300/lib/libgcc.h b/arch/h8300/lib/libgcc.h
new file mode 100644
index 000000000..b8bcf7035
--- /dev/null
+++ b/arch/h8300/lib/libgcc.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __H8300_LIBGCC_H__
+#define __H8300_LIBGCC_H__
+
+#ifdef __ASSEMBLY__
+#define A0 r0
+#define A0L r0l
+#define A0H r0h
+
+#define A1 r1
+#define A1L r1l
+#define A1H r1h
+
+#define A2 r2
+#define A2L r2l
+#define A2H r2h
+
+#define A3 r3
+#define A3L r3l
+#define A3H r3h
+
+#define S0 r4
+#define S0L r4l
+#define S0H r4h
+
+#define S1 r5
+#define S1L r5l
+#define S1H r5h
+
+#define S2 r6
+#define S2L r6l
+#define S2H r6h
+
+#define PUSHP	push.l
+#define POPP	pop.l
+
+#define A0P	er0
+#define A1P	er1
+#define A2P	er2
+#define A3P	er3
+#define S0P	er4
+#define S1P	er5
+#define S2P	er6
+
+#define A0E	e0
+#define A1E	e1
+#define A2E	e2
+#define A3E	e3
+#else
+#define Wtype   SItype
+#define UWtype  USItype
+#define HWtype  SItype
+#define UHWtype USItype
+#define DWtype  DItype
+#define UDWtype UDItype
+#define UWtype  USItype
+#define Wtype   SItype
+#define UWtype  USItype
+#define W_TYPE_SIZE (4 * BITS_PER_UNIT)
+#define BITS_PER_UNIT (8)
+
+typedef          int SItype     __attribute__ ((mode (SI)));
+typedef unsigned int USItype    __attribute__ ((mode (SI)));
+typedef		 int DItype	__attribute__ ((mode (DI)));
+typedef unsigned int UDItype	__attribute__ ((mode (DI)));
+struct DWstruct {
+	Wtype high, low;
+};
+typedef union {
+	struct DWstruct s;
+	DWtype ll;
+} DWunion;
+
+typedef int word_type __attribute__ ((mode (__word__)));
+
+#endif
+
+#endif
diff --git a/arch/h8300/lib/lshrdi3.c b/arch/h8300/lib/lshrdi3.c
new file mode 100644
index 000000000..8dbc861ca
--- /dev/null
+++ b/arch/h8300/lib/lshrdi3.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "libgcc.h"
+
+DWtype __lshrdi3(DWtype u, word_type b)
+{
+	const DWunion uu = {.ll = u};
+	const word_type bm = (sizeof (Wtype) * BITS_PER_UNIT) - b;
+	DWunion w;
+
+	if (b == 0)
+		return u;
+
+	if (bm <= 0) {
+		w.s.high = 0;
+		w.s.low = (UWtype) uu.s.high >> -bm;
+	} else {
+		const UWtype carries = (UWtype) uu.s.high << bm;
+
+		w.s.high = (UWtype) uu.s.high >> b;
+		w.s.low = ((UWtype) uu.s.low >> b) | carries;
+	}
+
+	return w.ll;
+}
diff --git a/arch/h8300/lib/memcpy.S b/arch/h8300/lib/memcpy.S
new file mode 100644
index 000000000..f1cd67d5e
--- /dev/null
+++ b/arch/h8300/lib/memcpy.S
@@ -0,0 +1,86 @@
+;;; SPDX-License-Identifier: GPL-2.0
+;;; memcpy.S
+
+#include <asm/linkage.h>
+
+#if defined(CONFIG_CPU_H8300H)
+	.h8300h
+#endif
+#if defined(CONFIG_CPU_H8S)
+	.h8300s
+#endif
+	.text
+.global memcpy
+
+;;; void *memcpy(void *to, void *from, size_t n)
+memcpy:
+	mov.l	er2,er2
+	bne	1f
+	rts
+1:
+	;; address check
+	bld	#0,r0l
+	bxor	#0,r1l
+	bcs	4f
+	mov.l	er4,@-sp
+	mov.l	er0,@-sp
+	btst	#0,r0l
+	beq	1f
+	;; (aligned even) odd address
+	mov.b	@er1,r3l
+	mov.b	r3l,@er0
+	adds	#1,er1
+	adds	#1,er0
+	dec.l	#1,er2
+	beq	3f
+1:
+	;; n < sizeof(unsigned long) check
+	sub.l	er4,er4
+	adds	#4,er4		; loop count check value
+	cmp.l	er4,er2
+	blo	2f
+	;; unsigned long copy
+1:
+	mov.l	@er1,er3
+	mov.l	er3,@er0
+	adds	#4,er0
+	adds	#4,er1
+	subs	#4,er2
+	cmp.l	er4,er2
+	bcc	1b
+	;; rest
+2:
+	mov.l	er2,er2
+	beq	3f
+1:
+	mov.b	@er1,r3l
+	mov.b	r3l,@er0
+	adds	#1,er1
+	adds	#1,er0
+	dec.l	#1,er2
+	bne	1b
+3:
+	mov.l	@sp+,er0
+	mov.l	@sp+,er4
+	rts
+
+	;; odd <- even / even <- odd
+4:
+	mov.l	er4,er3
+	mov.l	er2,er4
+	mov.l	er5,er2
+	mov.l	er1,er5
+	mov.l	er6,er1
+	mov.l	er0,er6
+1:
+	eepmov.w
+	mov.w	r4,r4
+	bne	1b
+	dec.w	#1,e4
+	bpl	1b
+	mov.l	er1,er6
+	mov.l	er2,er5
+	mov.l	er3,er4
+	rts
+
+	.end
diff --git a/arch/h8300/lib/memset.S b/arch/h8300/lib/memset.S
new file mode 100644
index 000000000..2d1abc37f
--- /dev/null
+++ b/arch/h8300/lib/memset.S
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* memset.S */
+
+#include <asm/linkage.h>
+
+#if defined(CONFIG_CPU_H8300H)
+	.h8300h
+#endif
+#if defined(CONFIG_CPU_H8S)
+	.h8300s
+#endif
+	.text
+
+.global	memset
+.global	clear_user
+
+;;void *memset(*ptr, int c, size_t count)
+;; ptr = er0
+;; c   = er1(r1l)
+;; count = er2
+memset:
+	btst	#0,r0l
+	beq	2f
+
+	;; odd address
+1:
+	mov.b	r1l,@er0
+	adds	#1,er0
+	dec.l	#1,er2
+	beq	6f
+
+	;; even address
+2:
+	mov.l	er2,er3
+	cmp.l	#4,er2
+	blo	4f
+	;; count>=4 -> count/4
+#if defined(CONFIG_CPU_H8300H)
+	shlr.l	er2
+	shlr.l	er2
+#endif
+#if defined(CONFIG_CPU_H8S)
+	shlr.l	#2,er2
+#endif
+	;; byte -> long
+	mov.b	r1l,r1h
+	mov.w	r1,e1
+3:
+	mov.l	er1,@er0
+	adds	#4,er0
+	dec.l	#1,er2
+	bne	3b
+4:
+	;; count % 4
+	and.b	#3,r3l
+	beq	6f
+5:
+	mov.b	r1l,@er0
+	adds	#1,er0
+	dec.b	r3l
+	bne	5b
+6:
+	rts
+
+clear_user:
+	mov.l	er1, er2
+	sub.l	er1, er1
+	bra	memset
+
+	.end
diff --git a/arch/h8300/lib/moddivsi3.S b/arch/h8300/lib/moddivsi3.S
new file mode 100644
index 000000000..9e33ab045
--- /dev/null
+++ b/arch/h8300/lib/moddivsi3.S
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include "libgcc.h"
+
+; numerator in A0/A1
+; denominator in A2/A3
+	.global	__modsi3
+__modsi3:
+	PUSHP	S2P
+	bsr	modnorm
+	bsr	__divsi3
+	mov.l	er3,er0
+	bra	exitdiv
+
+	.global	__umodsi3
+__umodsi3:
+	bsr	__udivsi3:16
+	mov.l	er3,er0
+	rts
+
+	.global	__divsi3
+__divsi3:
+	PUSHP	S2P
+	bsr	divnorm
+	bsr	__udivsi3:16
+
+	; examine what the sign should be
+exitdiv:
+	btst	#3,S2L
+	beq	reti
+
+	; should be -ve
+	neg.l	A0P
+
+reti:
+	POPP	S2P
+	rts
+
+divnorm:
+	mov.l	A0P,A0P		; is the numerator -ve
+	stc	ccr,S2L		; keep the sign in bit 3 of S2L
+	bge	postive
+
+	neg.l	A0P		; negate arg
+
+postive:
+	mov.l	A1P,A1P		; is the denominator -ve
+	bge	postive2
+
+	neg.l	A1P		; negate arg
+	xor.b	#0x08,S2L	; toggle the result sign
+
+postive2:
+	rts
+
+;; Basically the same, except that the sign of the divisor determines
+;; the sign.
+modnorm:
+	mov.l	A0P,A0P		; is the numerator -ve
+	stc	ccr,S2L		; keep the sign in bit 3 of S2L
+	bge	mpostive
+
+	neg.l	A0P		; negate arg
+
+mpostive:
+	mov.l	A1P,A1P		; is the denominator -ve
+	bge	mpostive2
+
+	neg.l	A1P		; negate arg
+
+mpostive2:
+	rts
+
+	.end
diff --git a/arch/h8300/lib/modsi3.S b/arch/h8300/lib/modsi3.S
new file mode 100644
index 000000000..bdc8a0029
--- /dev/null
+++ b/arch/h8300/lib/modsi3.S
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include "libgcc.h"
+
+; numerator in A0/A1
+; denominator in A2/A3
+	.global	__modsi3
+__modsi3:
+	PUSHP	S2P
+	bsr	modnorm
+	bsr	__divsi3
+	mov.l	er3,er0
+	bra	exitdiv
+
+	.global	__umodsi3
+__umodsi3:
+	bsr	__udivsi3
+	mov.l	er3,er0
+	rts
+
+	.global	__divsi3
+__divsi3:
+	PUSHP	S2P
+	jsr	divnorm
+	bsr	__udivsi3
+
+	; examine what the sign should be
+exitdiv:
+	btst	#3,S2L
+	beq	reti
+
+	; should be -ve
+	neg.l	A0P
+
+reti:
+	POPP	S2P
+	rts
+
+divnorm:
+	mov.l	A0P,A0P		; is the numerator -ve
+	stc	ccr,S2L		; keep the sign in bit 3 of S2L
+	bge	postive
+
+	neg.l	A0P		; negate arg
+
+postive:
+	mov.l	A1P,A1P		; is the denominator -ve
+	bge	postive2
+
+	neg.l	A1P		; negate arg
+	xor.b	#0x08,S2L	; toggle the result sign
+
+postive2:
+	rts
+
+;; Basically the same, except that the sign of the divisor determines
+;; the sign.
+modnorm:
+	mov.l	A0P,A0P		; is the numerator -ve
+	stc	ccr,S2L		; keep the sign in bit 3 of S2L
+	bge	mpostive
+
+	neg.l	A0P		; negate arg
+
+mpostive:
+	mov.l	A1P,A1P		; is the denominator -ve
+	bge	mpostive2
+
+	neg.l	A1P		; negate arg
+
+mpostive2:
+	rts
+
+	.end
diff --git a/arch/h8300/lib/muldi3.c b/arch/h8300/lib/muldi3.c
new file mode 100644
index 000000000..9cb11b134
--- /dev/null
+++ b/arch/h8300/lib/muldi3.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "libgcc.h"
+
+#define __ll_B ((UWtype) 1 << (W_TYPE_SIZE / 2))
+#define __ll_lowpart(t) ((UWtype) (t) & (__ll_B - 1))
+#define __ll_highpart(t) ((UWtype) (t) >> (W_TYPE_SIZE / 2))
+
+#define umul_ppmm(w1, w0, u, v) \
+	do {			   \
+		UWtype __x0, __x1, __x2, __x3;	\
+		UHWtype __ul, __vl, __uh, __vh; \
+		__ul = __ll_lowpart(u);	\
+		__uh = __ll_highpart(u);	\
+		__vl = __ll_lowpart(v);	\
+		__vh = __ll_highpart(v);	\
+		__x0 = (UWtype) __ul * __vl;	\
+		__x1 = (UWtype) __ul * __vh;	\
+		__x2 = (UWtype) __uh * __vl;	\
+		__x3 = (UWtype) __uh * __vh;	\
+		__x1 += __ll_highpart(__x0);	\
+		__x1 += __x2;			\
+		if (__x1 < __x2)		\
+			__x3 += __ll_B;		\
+		(w1) = __x3 + __ll_highpart(__x1);	       \
+		(w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0); \
+	} while (0)
+
+#define __umulsidi3(u, v) (			\
+		{				\
+			DWunion __w;		\
+			umul_ppmm(__w.s.high, __w.s.low, u, v);	\
+			__w.ll; }					\
+		)
+
+DWtype __muldi3(DWtype u, DWtype v)
+{
+	const DWunion uu = {.ll = u};
+	const DWunion vv = {.ll = v};
+	DWunion w = {.ll = __umulsidi3(uu.s.low, vv.s.low)};
+
+	w.s.high += ((UWtype) uu.s.low * (UWtype) vv.s.high
+		     + (UWtype) uu.s.high * (UWtype) vv.s.low);
+
+	return w.ll;
+}
diff --git a/arch/h8300/lib/mulsi3.S b/arch/h8300/lib/mulsi3.S
new file mode 100644
index 000000000..5a062fd29
--- /dev/null
+++ b/arch/h8300/lib/mulsi3.S
@@ -0,0 +1,39 @@
+; SPDX-License-Identifier: GPL-2.0
+;
+; mulsi3 for H8/300H - based on Renesas SH implementation
+;
+; by Toshiyasu Morita
+;
+; Old code:
+;
+; 16b * 16b = 372 states (worst case)
+; 32b * 32b = 724 states (worst case)
+;
+; New code:
+;
+; 16b * 16b =  48 states
+; 16b * 32b =  72 states
+; 32b * 32b =  92 states
+;
+
+	.global __mulsi3
+__mulsi3:
+	mov.w	r1,r2   ; ( 2 states) b * d
+	mulxu	r0,er2  ; (22 states)
+
+	mov.w	e0,r3   ; ( 2 states) a * d
+	beq	L_skip1 ; ( 4 states)
+	mulxu	r1,er3  ; (22 states)
+	add.w	r3,e2   ; ( 2 states)
+
+L_skip1:
+	mov.w	e1,r3   ; ( 2 states) c * b
+	beq	L_skip2 ; ( 4 states)
+	mulxu	r0,er3  ; (22 states)
+	add.w	r3,e2   ; ( 2 states)
+
+L_skip2:
+	mov.l	er2,er0	; ( 2 states)
+	rts		; (10 states)
+
+	.end
diff --git a/arch/h8300/lib/strncpy.S b/arch/h8300/lib/strncpy.S
new file mode 100644
index 000000000..8b65d7c47
--- /dev/null
+++ b/arch/h8300/lib/strncpy.S
@@ -0,0 +1,35 @@
+;;; SPDX-License-Identifier: GPL-2.0
+;;; strncpy.S
+
+#include <asm/linkage.h>
+
+	.text
+.global strncpy_from_user
+
+;;; long strncpy_from_user(void *to, void *from, size_t n)
+strncpy_from_user:
+	mov.l	er2,er2
+	bne	1f
+	sub.l	er0,er0
+	rts
+1:
+	mov.l	er4,@-sp
+	sub.l	er3,er3
+2:
+	mov.b	@er1+,r4l
+	mov.b	r4l,@er0
+	adds	#1,er0
+	beq	3f
+	inc.l	#1,er3
+	dec.l	#1,er2
+	bne	2b
+3:
+	dec.l	#1,er2
+4:
+	mov.b	r4l,@er0
+	adds	#1,er0
+	dec.l	#1,er2
+	bne	4b
+	mov.l	er3,er0
+	mov.l	@sp+,er4
+	rts
diff --git a/arch/h8300/lib/ucmpdi2.c b/arch/h8300/lib/ucmpdi2.c
new file mode 100644
index 000000000..9f646885f
--- /dev/null
+++ b/arch/h8300/lib/ucmpdi2.c
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "libgcc.h"
+
+word_type __ucmpdi2(DWtype a, DWtype b)
+{
+	const DWunion au = {.ll = a};
+	const DWunion bu = {.ll = b};
+
+	if ((UWtype) au.s.high < (UWtype) bu.s.high)
+		return 0;
+	else if ((UWtype) au.s.high > (UWtype) bu.s.high)
+		return 2;
+	if ((UWtype) au.s.low < (UWtype) bu.s.low)
+		return 0;
+	else if ((UWtype) au.s.low > (UWtype) bu.s.low)
+		return 2;
+	return 1;
+}
diff --git a/arch/h8300/lib/udivsi3.S b/arch/h8300/lib/udivsi3.S
new file mode 100644
index 000000000..b810aba8e
--- /dev/null
+++ b/arch/h8300/lib/udivsi3.S
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include "libgcc.h"
+
+	;; This function also computes the remainder and stores it in er3.
+	.global	__udivsi3
+__udivsi3:
+	mov.w	A1E,A1E		; denominator top word 0?
+	bne	DenHighNonZero
+
+	; do it the easy way, see page 107 in manual
+	mov.w	A0E,A2
+	extu.l	A2P
+	divxu.w	A1,A2P
+	mov.w	A2E,A0E
+	divxu.w	A1,A0P
+	mov.w	A0E,A3
+	mov.w	A2,A0E
+	extu.l	A3P
+	rts
+
+	; er0 = er0 / er1
+	; er3 = er0 % er1
+	; trashes er1 er2
+	; expects er1 >= 2^16
+DenHighNonZero:
+	mov.l	er0,er3
+	mov.l	er1,er2
+#ifdef CONFIG_CPU_H8300H
+divmod_L21:
+	shlr.l	er0
+	shlr.l	er2		; make divisor < 2^16
+	mov.w	e2,e2
+	bne	divmod_L21
+#else
+	shlr.l	#2,er2		; make divisor < 2^16
+	mov.w	e2,e2
+	beq	divmod_L22A
+divmod_L21:
+	shlr.l	#2,er0
+divmod_L22:
+	shlr.l	#2,er2		; make divisor < 2^16
+	mov.w	e2,e2
+	bne	divmod_L21
+divmod_L22A:
+	rotxl.w	r2
+	bcs	divmod_L23
+	shlr.l	er0
+	bra	divmod_L24
+divmod_L23:
+	rotxr.w	r2
+	shlr.l	#2,er0
+divmod_L24:
+#endif
+	;; At this point,
+	;;  er0 contains shifted dividend
+	;;  er1 contains divisor
+	;;  er2 contains shifted divisor
+	;;  er3 contains dividend, later remainder
+	divxu.w	r2,er0		; r0 now contains the approximate quotient (AQ)
+	extu.l	er0
+	beq	divmod_L25
+	subs	#1,er0		; er0 = AQ - 1
+	mov.w	e1,r2
+	mulxu.w	r0,er2		; er2 = upper (AQ - 1) * divisor
+	sub.w	r2,e3		; dividend - 65536 * er2
+	mov.w	r1,r2
+	mulxu.w	r0,er2		; compute er3 = remainder (tentative)
+	sub.l	er2,er3		; er3 = dividend - (AQ - 1) * divisor
+divmod_L25:
+	cmp.l	er1,er3		; is divisor < remainder?
+	blo	divmod_L26
+	adds	#1,er0
+	sub.l	er1,er3		; correct the remainder
+divmod_L26:
+	rts
+
+	.end
diff --git a/arch/h8300/mm/Makefile b/arch/h8300/mm/Makefile
new file mode 100644
index 000000000..e85b5c91f
--- /dev/null
+++ b/arch/h8300/mm/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the linux h8300-specific parts of the memory manager.
+#
+
+obj-y	 := init.o fault.o memory.o
diff --git a/arch/h8300/mm/fault.c b/arch/h8300/mm/fault.c
new file mode 100644
index 000000000..b465441f4
--- /dev/null
+++ b/arch/h8300/mm/fault.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/arch/h8300/mm/fault.c
+ *
+ *  Copyright (C) 1998  D. Jeff Dionne <jeff@lineo.ca>,
+ *  Copyright (C) 2000  Lineo, Inc.  (www.lineo.com)
+ *
+ *  Based on:
+ *
+ *  linux/arch/m68knommu/mm/fault.c
+ *  linux/arch/m68k/mm/fault.c
+ *
+ *  Copyright (C) 1995  Hamish Macdonald
+ */
+
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/kernel.h>
+#include <linux/ptrace.h>
+
+
+void die(const char *str, struct pt_regs *fp, unsigned long err);
+
+/*
+ * This routine handles page faults.  It determines the problem, and
+ * then passes it off to one of the appropriate routines.
+ *
+ * error_code:
+ *	bit 0 == 0 means no page found, 1 means protection fault
+ *	bit 1 == 0 means read, 1 means write
+ *
+ * If this routine detects a bad access, it returns 1, otherwise it
+ * returns 0.
+ */
+asmlinkage int do_page_fault(struct pt_regs *regs, unsigned long address,
+			      unsigned long error_code)
+{
+#ifdef DEBUG
+	pr_debug("regs->sr=%#x, regs->pc=%#lx, address=%#lx, %ld\n",
+		 regs->sr, regs->pc, address, error_code);
+#endif
+
+/*
+ * Oops. The kernel tried to access some bad page. We'll have to
+ * terminate things with extreme prejudice.
+ */
+	if ((unsigned long) address < PAGE_SIZE)
+		pr_alert("Unable to handle kernel NULL pointer dereference");
+	else
+		pr_alert("Unable to handle kernel access");
+	printk(" at virtual address %08lx\n", address);
+	if (!user_mode(regs))
+		die("Oops", regs, error_code);
+	make_task_dead(SIGKILL);
+
+	return 1;
+}
diff --git a/arch/h8300/mm/init.c b/arch/h8300/mm/init.c
new file mode 100644
index 000000000..1f3b345d6
--- /dev/null
+++ b/arch/h8300/mm/init.c
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/arch/h8300/mm/init.c
+ *
+ *  Copyright (C) 1998  D. Jeff Dionne <jeff@lineo.ca>,
+ *                      Kenneth Albanowski <kjahds@kjahds.com>,
+ *  Copyright (C) 2000  Lineo, Inc.  (www.lineo.com)
+ *
+ *  Based on:
+ *
+ *  linux/arch/m68knommu/mm/init.c
+ *  linux/arch/m68k/mm/init.c
+ *
+ *  Copyright (C) 1995  Hamish Macdonald
+ *
+ *  JAN/1999 -- hacked to support ColdFire (gerg@snapgear.com)
+ *  DEC/2000 -- linux 2.4 support <davidm@snapgear.com>
+ */
+
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/init.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <linux/memblock.h>
+#include <linux/gfp.h>
+
+#include <asm/setup.h>
+#include <asm/segment.h>
+#include <asm/page.h>
+#include <asm/sections.h>
+
+/*
+ * ZERO_PAGE is a special page that is used for zero-initialized
+ * data and COW.
+ */
+unsigned long empty_zero_page;
+
+/*
+ * paging_init() continues the virtual memory environment setup which
+ * was begun by the code in arch/head.S.
+ * The parameters are pointers to where to stick the starting and ending
+ * addresses of available kernel virtual memory.
+ */
+void __init paging_init(void)
+{
+	/*
+	 * Make sure start_mem is page aligned,  otherwise bootmem and
+	 * page_alloc get different views og the world.
+	 */
+	unsigned long start_mem = PAGE_ALIGN(memory_start);
+	unsigned long end_mem   = memory_end & PAGE_MASK;
+
+	pr_debug("start_mem is %#lx\nvirtual_end is %#lx\n",
+		 start_mem, end_mem);
+
+	/*
+	 * Initialize the bad page table and bad page to point
+	 * to a couple of allocated pages.
+	 */
+	empty_zero_page = (unsigned long)memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+	if (!empty_zero_page)
+		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+		      __func__, PAGE_SIZE, PAGE_SIZE);
+
+	/*
+	 * Set up SFC/DFC registers (user data space).
+	 */
+	set_fs(USER_DS);
+
+	pr_debug("before free_area_init\n");
+
+	pr_debug("free_area_init -> start_mem is %#lx\nvirtual_end is %#lx\n",
+		 start_mem, end_mem);
+
+	{
+		unsigned long max_zone_pfn[MAX_NR_ZONES] = {0, };
+
+		max_zone_pfn[ZONE_NORMAL] = end_mem >> PAGE_SHIFT;
+		free_area_init(max_zone_pfn);
+	}
+}
+
+void __init mem_init(void)
+{
+	pr_devel("Mem_init: start=%lx, end=%lx\n", memory_start, memory_end);
+
+	high_memory = (void *) (memory_end & PAGE_MASK);
+	max_mapnr = MAP_NR(high_memory);
+
+	/* this will put all low memory onto the freelists */
+	memblock_free_all();
+
+	mem_init_print_info(NULL);
+}
diff --git a/arch/h8300/mm/memory.c b/arch/h8300/mm/memory.c
new file mode 100644
index 000000000..4a60e2b5e
--- /dev/null
+++ b/arch/h8300/mm/memory.c
@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/arch/h8300/mm/memory.c
+ *
+ *  Copyright (C) 2002  Yoshinori Sato <ysato@users.sourceforge.jp>,
+ *
+ *  Based on:
+ *
+ *  linux/arch/m68knommu/mm/memory.c
+ *
+ *  Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>,
+ *  Copyright (C) 1999-2002, Greg Ungerer (gerg@snapgear.com)
+ *
+ *  Based on:
+ *
+ *  linux/arch/m68k/mm/memory.c
+ *
+ *  Copyright (C) 1995  Hamish Macdonald
+ */
+
+#include <linux/mm.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include <asm/setup.h>
+#include <asm/segment.h>
+#include <asm/page.h>
+#include <asm/traps.h>
+#include <asm/io.h>
+
+void cache_clear(unsigned long paddr, int len)
+{
+}
+
+
+void cache_push(unsigned long paddr, int len)
+{
+}
+
+void cache_push_v(unsigned long vaddr, int len)
+{
+}
+
+/*
+ * Map some physical address range into the kernel address space.
+ */
+
+unsigned long kernel_map(unsigned long paddr, unsigned long size,
+			 int nocacheflag, unsigned long *memavailp)
+{
+	return paddr;
+}