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-rw-r--r--arch/x86/boot/main.c161
1 files changed, 161 insertions, 0 deletions
diff --git a/arch/x86/boot/main.c b/arch/x86/boot/main.c
new file mode 100644
index 00000000000..0eeef3989a1
--- /dev/null
+++ b/arch/x86/boot/main.c
@@ -0,0 +1,161 @@
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ * Copyright 2007 rPath, Inc. - All Rights Reserved
+ *
+ * This file is part of the Linux kernel, and is made available under
+ * the terms of the GNU General Public License version 2.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * arch/i386/boot/main.c
+ *
+ * Main module for the real-mode kernel code
+ */
+
+#include "boot.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.
+ */
+#define OLD_CL_MAGIC 0xA33F
+#define OLD_CL_ADDRESS 0x20
+
+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;
+ }
+}
+
+/*
+ * Set the keyboard repeat rate to maximum. Unclear why this
+ * is done here; this might be possible to kill off as stale code.
+ */
+static void keyboard_set_repeat(void)
+{
+ u16 ax = 0x0305;
+ u16 bx = 0;
+ asm volatile("int $0x16"
+ : "+a" (ax), "+b" (bx)
+ : : "ecx", "edx", "esi", "edi");
+}
+
+/*
+ * Get Intel SpeedStep (IST) information.
+ */
+static void query_ist(void)
+{
+ asm("int $0x15"
+ : "=a" (boot_params.ist_info.signature),
+ "=b" (boot_params.ist_info.command),
+ "=c" (boot_params.ist_info.event),
+ "=d" (boot_params.ist_info.perf_level)
+ : "a" (0x0000e980), /* IST Support */
+ "d" (0x47534943)); /* Request value */
+}
+
+/*
+ * Tell the BIOS what CPU mode we intend to run in.
+ */
+static void set_bios_mode(void)
+{
+#ifdef CONFIG_X86_64
+ u32 eax, ebx;
+
+ eax = 0xec00;
+ ebx = 2;
+ asm volatile("int $0x15"
+ : "+a" (eax), "+b" (ebx)
+ : : "ecx", "edx", "esi", "edi");
+#endif
+}
+
+void main(void)
+{
+ /* First, copy the boot header into the "zeropage" */
+ copy_boot_params();
+
+ /* End of heap check */
+ if (boot_params.hdr.loadflags & CAN_USE_HEAP) {
+ heap_end = (char *)(boot_params.hdr.heap_end_ptr
+ +0x200-STACK_SIZE);
+ } else {
+ /* Boot protocol 2.00 only, no heap available */
+ puts("WARNING: Ancient bootloader, some functionality "
+ "may be limited!\n");
+ }
+
+ /* 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?) */
+ keyboard_set_repeat();
+
+ /* Set the video mode */
+ set_video();
+
+ /* Query MCA information */
+ query_mca();
+
+ /* Voyager */
+#ifdef CONFIG_X86_VOYAGER
+ query_voyager();
+#endif
+
+ /* 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
+ /* Do the last things and invoke protected mode */
+ go_to_protected_mode();
+}