arch/x86/kernel/head32-xen.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/trampoline.h>
  17 #include <asm/apic.h>
  18 #include <asm/io_apic.h>
  19 #include <asm/tlbflush.h>
  20
  21 static void __init i386_default_early_setup(void)
  22 {
  23         /* Initialize 32bit specific setup functions */
  24         x86_init.resources.reserve_resources = i386_reserve_resources;
  25 #ifndef CONFIG_XEN
  26         x86_init.mpparse.setup_ioapic_ids = setup_ioapic_ids_from_mpc;
  27
  28         reserve_ebda_region();
  29 #endif
  30 }
  31
  32 void __init i386_start_kernel(void)
  33 {
  34 #ifdef CONFIG_XEN
  35         struct xen_platform_parameters pp;
  36
  37         WARN_ON(HYPERVISOR_vm_assist(VMASST_CMD_enable,
  38                                      VMASST_TYPE_4gb_segments));
  39
  40         init_mm.pgd = swapper_pg_dir = (pgd_t *)xen_start_info->pt_base;
  41
  42         if (HYPERVISOR_xen_version(XENVER_platform_parameters, &pp) == 0) {
  43                 hypervisor_virt_start = pp.virt_start;
  44                 reserve_top_address(0UL - pp.virt_start);
  45         }
  46
  47         BUG_ON(pte_index(hypervisor_virt_start));
  48 #endif
  49
  50         memblock_reserve(__pa_symbol(&_text),
  51                          __pa_symbol(&__bss_stop) - __pa_symbol(&_text));
  52
  53 #ifndef CONFIG_XEN
  54 #ifdef CONFIG_BLK_DEV_INITRD
  55         /* Reserve INITRD */
  56         if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
  57                 /* Assume only end is not page aligned */
  58                 u64 ramdisk_image = boot_params.hdr.ramdisk_image;
  59                 u64 ramdisk_size  = boot_params.hdr.ramdisk_size;
  60                 u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
  61                 memblock_reserve(ramdisk_image, ramdisk_end - ramdisk_image);
  62         }
  63 #endif
  64
  65         /* Call the subarch specific early setup function */
  66         switch (boot_params.hdr.hardware_subarch) {
  67         case X86_SUBARCH_MRST:
  68                 x86_mrst_early_setup();
  69                 break;
  70         case X86_SUBARCH_CE4100:
  71                 x86_ce4100_early_setup();
  72                 break;
  73         default:
  74                 i386_default_early_setup();
  75                 break;
  76         }
  77 #else
  78 #ifdef CONFIG_BLK_DEV_INITRD
  79         BUG_ON(xen_start_info->flags & SIF_MOD_START_PFN);
  80         if (xen_start_info->mod_start)
  81                 xen_initrd_start = __pa(xen_start_info->mod_start);
  82 #endif
  83         {
  84                 int max_cmdline;
  85
  86                 if ((max_cmdline = MAX_GUEST_CMDLINE) > COMMAND_LINE_SIZE)
  87                         max_cmdline = COMMAND_LINE_SIZE;
  88                 memcpy(boot_command_line, xen_start_info->cmd_line, max_cmdline);
  89                 boot_command_line[max_cmdline-1] = '\0';
  90         }
  91
  92         i386_default_early_setup();
  93         xen_start_kernel();
  94 #endif
  95
  96         /*
  97          * At this point everything still needed from the boot loader
  98          * or BIOS or kernel text should be early reserved or marked not
  99          * RAM in e820. All other memory is free game.
 100          */
 101
 102         start_kernel();
 103 }