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/trampoline.h>
  18 #include <asm/apic.h>
  19 #include <asm/io_apic.h>
  20 #include <asm/bios_ebda.h>
  21 #include <asm/tlbflush.h>
  22
  23 static void __init i386_default_early_setup(void)
  24 {
  25         /* Initialize 32bit specific setup functions */
  26         x86_init.resources.probe_roms = probe_roms;
  27         x86_init.resources.reserve_resources = i386_reserve_resources;
  28         x86_init.mpparse.setup_ioapic_ids = setup_ioapic_ids_from_mpc;
  29
  30         reserve_ebda_region();
  31 }
  32
  33 void __init i386_start_kernel(void)
  34 {
  35         memblock_init();
  36
  37 #ifdef CONFIG_X86_TRAMPOLINE
  38         /*
  39          * But first pinch a few for the stack/trampoline stuff
  40          * FIXME: Don't need the extra page at 4K, but need to fix
  41          * trampoline before removing it. (see the GDT stuff)
  42          */
  43         memblock_x86_reserve_range(PAGE_SIZE, PAGE_SIZE + PAGE_SIZE, "EX TRAMPOLINE");
  44 #endif
  45
  46         memblock_x86_reserve_range(__pa_symbol(&_text), __pa_symbol(&__bss_stop), "TEXT DATA BSS");
  47
  48 #ifdef CONFIG_BLK_DEV_INITRD
  49         /* Reserve INITRD */
  50         if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
  51                 /* Assume only end is not page aligned */
  52                 u64 ramdisk_image = boot_params.hdr.ramdisk_image;
  53                 u64 ramdisk_size  = boot_params.hdr.ramdisk_size;
  54                 u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
  55                 memblock_x86_reserve_range(ramdisk_image, ramdisk_end, "RAMDISK");
  56         }
  57 #endif
  58
  59         /* Call the subarch specific early setup function */
  60         switch (boot_params.hdr.hardware_subarch) {
  61         case X86_SUBARCH_MRST:
  62                 x86_mrst_early_setup();
  63                 break;
  64         default:
  65                 i386_default_early_setup();
  66                 break;
  67         }
  68
  69         /*
  70          * At this point everything still needed from the boot loader
  71          * or BIOS or kernel text should be early reserved or marked not
  72          * RAM in e820. All other memory is free game.
  73          */
  74
  75         start_kernel();
  76 }