linux-stable-rt/arch/x86_64/kernel/head64.c

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/*
* linux/arch/x86_64/kernel/head64.c -- prepare to run common code
*
* Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
*/
#include <linux/init.h>
#include <linux/linkage.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/percpu.h>
#include <asm/processor.h>
#include <asm/proto.h>
#include <asm/smp.h>
#include <asm/bootsetup.h>
#include <asm/setup.h>
#include <asm/desc.h>
#include <asm/pgtable.h>
#include <asm/sections.h>
/* Don't add a printk in there. printk relies on the PDA which is not initialized
yet. */
static void __init clear_bss(void)
{
memset(__bss_start, 0,
(unsigned long) __bss_stop - (unsigned long) __bss_start);
}
#define NEW_CL_POINTER 0x228 /* Relative to real mode data */
#define OLD_CL_MAGIC_ADDR 0x90020
#define OLD_CL_MAGIC 0xA33F
#define OLD_CL_BASE_ADDR 0x90000
#define OLD_CL_OFFSET 0x90022
extern char saved_command_line[];
static void __init copy_bootdata(char *real_mode_data)
{
int new_data;
char * command_line;
memcpy(x86_boot_params, real_mode_data, BOOT_PARAM_SIZE);
new_data = *(int *) (x86_boot_params + NEW_CL_POINTER);
if (!new_data) {
if (OLD_CL_MAGIC != * (u16 *) OLD_CL_MAGIC_ADDR) {
printk("so old bootloader that it does not support commandline?!\n");
return;
}
new_data = OLD_CL_BASE_ADDR + * (u16 *) OLD_CL_OFFSET;
printk("old bootloader convention, maybe loadlin?\n");
}
command_line = (char *) ((u64)(new_data));
memcpy(saved_command_line, command_line, COMMAND_LINE_SIZE);
printk("Bootdata ok (command line is %s)\n", saved_command_line);
}
void __init x86_64_start_kernel(char * real_mode_data)
{
int i;
for (i = 0; i < 256; i++)
set_intr_gate(i, early_idt_handler);
asm volatile("lidt %0" :: "m" (idt_descr));
clear_bss();
/*
* This must be called really, really early:
*/
lockdep_init();
/*
* switch to init_level4_pgt from boot_level4_pgt
*/
memcpy(init_level4_pgt, boot_level4_pgt, PTRS_PER_PGD*sizeof(pgd_t));
asm volatile("movq %0,%%cr3" :: "r" (__pa_symbol(&init_level4_pgt)));
for (i = 0; i < NR_CPUS; i++)
cpu_pda(i) = &boot_cpu_pda[i];
pda_init(0);
copy_bootdata(real_mode_data);
#ifdef CONFIG_SMP
cpu_set(0, cpu_online_map);
#endif
start_kernel();
}