Adding upstream version 4.19.249.upstream/4.19.249

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

1 files changed, 182 insertions, 0 deletions

diff --git a/arch/x86/boot/main.c b/arch/x86/boot/main.c
new file mode 100644
index 000000000..9bcea386d
--- /dev/null
+++ b/arch/x86/boot/main.c
@@ -0,0 +1,182 @@
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ *   This file is part of the Linux kernel, and is made available under
+ *   the terms of the GNU General Public License version 2.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Main module for the real-mode kernel code
+ */
+
+#include "boot.h"
+#include "string.h"
+
+struct boot_params boot_params __attribute__((aligned(16)));
+
+char *HEAP = _end;
+char *heap_end = _end;		/* Default end of heap = no heap */
+
+/*
+ * Copy the header into the boot parameter block.  Since this
+ * screws up the old-style command line protocol, adjust by
+ * filling in the new-style command line pointer instead.
+ */
+
+static void copy_boot_params(void)
+{
+	struct old_cmdline {
+		u16 cl_magic;
+		u16 cl_offset;
+	};
+	const struct old_cmdline * const oldcmd =
+		(const struct old_cmdline *)OLD_CL_ADDRESS;
+
+	BUILD_BUG_ON(sizeof boot_params != 4096);
+	memcpy(&boot_params.hdr, &hdr, sizeof hdr);
+
+	if (!boot_params.hdr.cmd_line_ptr &&
+	    oldcmd->cl_magic == OLD_CL_MAGIC) {
+		/* Old-style command line protocol. */
+		u16 cmdline_seg;
+
+		/* Figure out if the command line falls in the region
+		   of memory that an old kernel would have copied up
+		   to 0x90000... */
+		if (oldcmd->cl_offset < boot_params.hdr.setup_move_size)
+			cmdline_seg = ds();
+		else
+			cmdline_seg = 0x9000;
+
+		boot_params.hdr.cmd_line_ptr =
+			(cmdline_seg << 4) + oldcmd->cl_offset;
+	}
+}
+
+/*
+ * Query the keyboard lock status as given by the BIOS, and
+ * set the keyboard repeat rate to maximum.  Unclear why the latter
+ * is done here; this might be possible to kill off as stale code.
+ */
+static void keyboard_init(void)
+{
+	struct biosregs ireg, oreg;
+	initregs(&ireg);
+
+	ireg.ah = 0x02;		/* Get keyboard status */
+	intcall(0x16, &ireg, &oreg);
+	boot_params.kbd_status = oreg.al;
+
+	ireg.ax = 0x0305;	/* Set keyboard repeat rate */
+	intcall(0x16, &ireg, NULL);
+}
+
+/*
+ * Get Intel SpeedStep (IST) information.
+ */
+static void query_ist(void)
+{
+	struct biosregs ireg, oreg;
+
+	/* Some older BIOSes apparently crash on this call, so filter
+	   it from machines too old to have SpeedStep at all. */
+	if (cpu.level < 6)
+		return;
+
+	initregs(&ireg);
+	ireg.ax  = 0xe980;	 /* IST Support */
+	ireg.edx = 0x47534943;	 /* Request value */
+	intcall(0x15, &ireg, &oreg);
+
+	boot_params.ist_info.signature  = oreg.eax;
+	boot_params.ist_info.command    = oreg.ebx;
+	boot_params.ist_info.event      = oreg.ecx;
+	boot_params.ist_info.perf_level = oreg.edx;
+}
+
+/*
+ * Tell the BIOS what CPU mode we intend to run in.
+ */
+static void set_bios_mode(void)
+{
+#ifdef CONFIG_X86_64
+	struct biosregs ireg;
+
+	initregs(&ireg);
+	ireg.ax = 0xec00;
+	ireg.bx = 2;
+	intcall(0x15, &ireg, NULL);
+#endif
+}
+
+static void init_heap(void)
+{
+	char *stack_end;
+
+	if (boot_params.hdr.loadflags & CAN_USE_HEAP) {
+		asm("leal %P1(%%esp),%0"
+		    : "=r" (stack_end) : "i" (-STACK_SIZE));
+
+		heap_end = (char *)
+			((size_t)boot_params.hdr.heap_end_ptr + 0x200);
+		if (heap_end > stack_end)
+			heap_end = stack_end;
+	} else {
+		/* Boot protocol 2.00 only, no heap available */
+		puts("WARNING: Ancient bootloader, some functionality "
+		     "may be limited!\n");
+	}
+}
+
+void main(void)
+{
+	/* First, copy the boot header into the "zeropage" */
+	copy_boot_params();
+
+	/* Initialize the early-boot console */
+	console_init();
+	if (cmdline_find_option_bool("debug"))
+		puts("early console in setup code\n");
+
+	/* End of heap check */
+	init_heap();
+
+	/* Make sure we have all the proper CPU support */
+	if (validate_cpu()) {
+		puts("Unable to boot - please use a kernel appropriate "
+		     "for your CPU.\n");
+		die();
+	}
+
+	/* Tell the BIOS what CPU mode we intend to run in. */
+	set_bios_mode();
+
+	/* Detect memory layout */
+	detect_memory();
+
+	/* Set keyboard repeat rate (why?) and query the lock flags */
+	keyboard_init();
+
+	/* Query Intel SpeedStep (IST) information */
+	query_ist();
+
+	/* Query APM information */
+#if defined(CONFIG_APM) || defined(CONFIG_APM_MODULE)
+	query_apm_bios();
+#endif
+
+	/* Query EDD information */
+#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
+	query_edd();
+#endif
+
+	/* Set the video mode */
+	set_video();
+
+	/* Do the last things and invoke protected mode */
+	go_to_protected_mode();
+}