1 files changed, 111 insertions, 0 deletions
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