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 #include <linux/memblock.h>
  12
  13 #include <asm/setup.h>
  14 #include <asm/sections.h>
  15 #include <asm/e820.h>
  16 #include <asm/page.h>
  17 #include <asm/apic.h>
  18 #include <asm/io_apic.h>
  19 #include <asm/bios_ebda.h>
  20 #include <asm/tlbflush.h>
  21
  22 static void __init i386_default_early_setup(void)
  23 {
  24         /* Initialize 32bit specific setup functions */
  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         memblock_reserve(__pa_symbol(&_text),
  34                          __pa_symbol(&__bss_stop) - __pa_symbol(&_text));
  35
  36 #ifdef CONFIG_BLK_DEV_INITRD
  37         /* Reserve INITRD */
  38         if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
  39                 /* Assume only end is not page aligned */
  40                 u64 ramdisk_image = boot_params.hdr.ramdisk_image;
  41                 u64 ramdisk_size  = boot_params.hdr.ramdisk_size;
  42                 u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
  43                 memblock_reserve(ramdisk_image, ramdisk_end - ramdisk_image);
  44         }
  45 #endif
  46
  47         /* Call the subarch specific early setup function */
  48         switch (boot_params.hdr.hardware_subarch) {
  49         case X86_SUBARCH_MRST:
  50                 x86_mrst_early_setup();
  51                 break;
  52         case X86_SUBARCH_CE4100:
  53                 x86_ce4100_early_setup();
  54                 break;
  55         default:
  56                 i386_default_early_setup();
  57                 break;
  58         }
  59
  60         /*
  61          * At this point everything still needed from the boot loader
  62          * or BIOS or kernel text should be early reserved or marked not
  63          * RAM in e820. All other memory is free game.
  64          */
  65
  66         start_kernel();
  67 }