169 строки
4.7 KiB
C
169 строки
4.7 KiB
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 <linux/start_kernel.h>
|
|
|
|
#include <asm/processor.h>
|
|
#include <asm/proto.h>
|
|
#include <asm/smp.h>
|
|
#include <asm/setup.h>
|
|
#include <asm/desc.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/sections.h>
|
|
#include <asm/kdebug.h>
|
|
#include <asm/e820.h>
|
|
|
|
static void __init zap_identity_mappings(void)
|
|
{
|
|
pgd_t *pgd = pgd_offset_k(0UL);
|
|
pgd_clear(pgd);
|
|
__flush_tlb_all();
|
|
}
|
|
|
|
/* 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);
|
|
}
|
|
|
|
static void __init copy_bootdata(char *real_mode_data)
|
|
{
|
|
char * command_line;
|
|
|
|
memcpy(&boot_params, real_mode_data, sizeof boot_params);
|
|
if (boot_params.hdr.cmd_line_ptr) {
|
|
command_line = __va(boot_params.hdr.cmd_line_ptr);
|
|
memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
|
|
}
|
|
}
|
|
|
|
#define BIOS_EBDA_SEGMENT 0x40E
|
|
#define BIOS_LOWMEM_KILOBYTES 0x413
|
|
|
|
/*
|
|
* The BIOS places the EBDA/XBDA at the top of conventional
|
|
* memory, and usually decreases the reported amount of
|
|
* conventional memory (int 0x12) too. This also contains a
|
|
* workaround for Dell systems that neglect to reserve EBDA.
|
|
* The same workaround also avoids a problem with the AMD768MPX
|
|
* chipset: reserve a page before VGA to prevent PCI prefetch
|
|
* into it (errata #56). Usually the page is reserved anyways,
|
|
* unless you have no PS/2 mouse plugged in.
|
|
*/
|
|
static void __init reserve_ebda_region(void)
|
|
{
|
|
unsigned int lowmem, ebda_addr;
|
|
|
|
/* To determine the position of the EBDA and the */
|
|
/* end of conventional memory, we need to look at */
|
|
/* the BIOS data area. In a paravirtual environment */
|
|
/* that area is absent. We'll just have to assume */
|
|
/* that the paravirt case can handle memory setup */
|
|
/* correctly, without our help. */
|
|
if (paravirt_enabled())
|
|
return;
|
|
|
|
/* end of low (conventional) memory */
|
|
lowmem = *(unsigned short *)__va(BIOS_LOWMEM_KILOBYTES);
|
|
lowmem <<= 10;
|
|
|
|
/* start of EBDA area */
|
|
ebda_addr = *(unsigned short *)__va(BIOS_EBDA_SEGMENT);
|
|
ebda_addr <<= 4;
|
|
|
|
/* Fixup: bios puts an EBDA in the top 64K segment */
|
|
/* of conventional memory, but does not adjust lowmem. */
|
|
if ((lowmem - ebda_addr) <= 0x10000)
|
|
lowmem = ebda_addr;
|
|
|
|
/* Fixup: bios does not report an EBDA at all. */
|
|
/* Some old Dells seem to need 4k anyhow (bugzilla 2990) */
|
|
if ((ebda_addr == 0) && (lowmem >= 0x9f000))
|
|
lowmem = 0x9f000;
|
|
|
|
/* Paranoia: should never happen, but... */
|
|
if ((lowmem == 0) || (lowmem >= 0x100000))
|
|
lowmem = 0x9f000;
|
|
|
|
/* reserve all memory between lowmem and the 1MB mark */
|
|
reserve_early(lowmem, 0x100000, "BIOS reserved");
|
|
}
|
|
|
|
void __init x86_64_start_kernel(char * real_mode_data)
|
|
{
|
|
int i;
|
|
|
|
/*
|
|
* Build-time sanity checks on the kernel image and module
|
|
* area mappings. (these are purely build-time and produce no code)
|
|
*/
|
|
BUILD_BUG_ON(MODULES_VADDR < KERNEL_IMAGE_START);
|
|
BUILD_BUG_ON(MODULES_VADDR-KERNEL_IMAGE_START < KERNEL_IMAGE_SIZE);
|
|
BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE);
|
|
BUILD_BUG_ON((KERNEL_IMAGE_START & ~PMD_MASK) != 0);
|
|
BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0);
|
|
BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
|
|
BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
|
|
(__START_KERNEL & PGDIR_MASK)));
|
|
|
|
/* clear bss before set_intr_gate with early_idt_handler */
|
|
clear_bss();
|
|
|
|
/* Make NULL pointers segfault */
|
|
zap_identity_mappings();
|
|
|
|
/* Cleanup the over mapped high alias */
|
|
cleanup_highmap();
|
|
|
|
for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) {
|
|
#ifdef CONFIG_EARLY_PRINTK
|
|
set_intr_gate(i, &early_idt_handlers[i]);
|
|
#else
|
|
set_intr_gate(i, early_idt_handler);
|
|
#endif
|
|
}
|
|
load_idt((const struct desc_ptr *)&idt_descr);
|
|
|
|
early_printk("Kernel alive\n");
|
|
|
|
for (i = 0; i < NR_CPUS; i++)
|
|
cpu_pda(i) = &boot_cpu_pda[i];
|
|
|
|
pda_init(0);
|
|
copy_bootdata(__va(real_mode_data));
|
|
|
|
reserve_early(__pa_symbol(&_text), __pa_symbol(&_end), "TEXT DATA BSS");
|
|
|
|
#ifdef CONFIG_BLK_DEV_INITRD
|
|
/* Reserve INITRD */
|
|
if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
|
|
unsigned long ramdisk_image = boot_params.hdr.ramdisk_image;
|
|
unsigned long ramdisk_size = boot_params.hdr.ramdisk_size;
|
|
unsigned long ramdisk_end = ramdisk_image + ramdisk_size;
|
|
reserve_early(ramdisk_image, ramdisk_end, "RAMDISK");
|
|
}
|
|
#endif
|
|
|
|
reserve_ebda_region();
|
|
|
|
/*
|
|
* At this point everything still needed from the boot loader
|
|
* or BIOS or kernel text should be early reserved or marked not
|
|
* RAM in e820. All other memory is free game.
|
|
*/
|
|
|
|
start_kernel();
|
|
}
|