arch/x86/kernel/head32.c

   1 /*
   2  *  linux/arch/i386/kernel/head32.c -- prepare to run common code
   3  *
   4  *  Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
   5  *  Copyright (C) 2007 Eric Biederman <ebiederm@xmission.com>
   6  */
   7
   8 #include <linux/init.h>
   9 #include <linux/start_kernel.h>
  10 #include <linux/mm.h>
  11
  12 #include <asm/setup.h>
  13 #include <asm/sections.h>
  14 #include <asm/e820.h>
  15 #include <asm/page.h>
  16 #include <asm/trampoline.h>
  17 #include <asm/apic.h>
  18 #include <asm/io_apic.h>
  19 #include <asm/bios_ebda.h>
  20
  21 static void __init i386_default_early_setup(void)
  22 {
  23         /* Initialize 32bit specific setup functions */
  24         x86_init.resources.probe_roms = probe_roms;
  25         x86_init.resources.reserve_resources = i386_reserve_resources;
  26         x86_init.mpparse.setup_ioapic_ids = setup_ioapic_ids_from_mpc;
  27
  28         reserve_ebda_region();
  29 }
  30
  31 void __init i386_start_kernel(void)
  32 {
  33 #ifdef CONFIG_X86_TRAMPOLINE
  34         /*
  35          * But first pinch a few for the stack/trampoline stuff
  36          * FIXME: Don't need the extra page at 4K, but need to fix
  37          * trampoline before removing it. (see the GDT stuff)
  38          */
  39         reserve_early_overlap_ok(PAGE_SIZE, PAGE_SIZE + PAGE_SIZE,
  40                                          "EX TRAMPOLINE");
  41 #endif
  42
  43         reserve_early(__pa_symbol(&_text), __pa_symbol(&__bss_stop), "TEXT DATA BSS");
  44
  45 #ifdef CONFIG_BLK_DEV_INITRD
  46         /* Reserve INITRD */
  47         if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
  48                 /* Assume only end is not page aligned */
  49                 u64 ramdisk_image = boot_params.hdr.ramdisk_image;
  50                 u64 ramdisk_size  = boot_params.hdr.ramdisk_size;
  51                 u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
  52                 reserve_early(ramdisk_image, ramdisk_end, "RAMDISK");
  53         }
  54 #endif
  55
  56         /* Call the subarch specific early setup function */
  57         switch (boot_params.hdr.hardware_subarch) {
  58         case X86_SUBARCH_MRST:
  59                 x86_mrst_early_setup();
  60                 break;
  61         default:
  62                 i386_default_early_setup();
  63                 break;
  64         }
  65
  66         /*
  67          * At this point everything still needed from the boot loader
  68          * or BIOS or kernel text should be early reserved or marked not
  69          * RAM in e820. All other memory is free game.
  70          */
  71
  72         start_kernel();
  73 }