120 lines
3.1 KiB
C
120 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* linux/arch/i386/kernel/head32.c -- prepare to run common code
|
|
*
|
|
* Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
|
|
* Copyright (C) 2007 Eric Biederman <ebiederm@xmission.com>
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/start_kernel.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/memblock.h>
|
|
|
|
#include <asm/desc.h>
|
|
#include <asm/setup.h>
|
|
#include <asm/sections.h>
|
|
#include <asm/e820/api.h>
|
|
#include <asm/page.h>
|
|
#include <asm/apic.h>
|
|
#include <asm/io_apic.h>
|
|
#include <asm/bios_ebda.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/bootparam_utils.h>
|
|
|
|
static void __init i386_default_early_setup(void)
|
|
{
|
|
/* Initialize 32bit specific setup functions */
|
|
x86_init.resources.reserve_resources = i386_reserve_resources;
|
|
x86_init.mpparse.setup_ioapic_ids = setup_ioapic_ids_from_mpc;
|
|
}
|
|
|
|
asmlinkage __visible void __init i386_start_kernel(void)
|
|
{
|
|
/* Make sure IDT is set up before any exception happens */
|
|
idt_setup_early_handler();
|
|
|
|
cr4_init_shadow();
|
|
|
|
sanitize_boot_params(&boot_params);
|
|
|
|
x86_early_init_platform_quirks();
|
|
|
|
/* Call the subarch specific early setup function */
|
|
switch (boot_params.hdr.hardware_subarch) {
|
|
case X86_SUBARCH_INTEL_MID:
|
|
x86_intel_mid_early_setup();
|
|
break;
|
|
case X86_SUBARCH_CE4100:
|
|
x86_ce4100_early_setup();
|
|
break;
|
|
default:
|
|
i386_default_early_setup();
|
|
break;
|
|
}
|
|
|
|
start_kernel();
|
|
}
|
|
|
|
/*
|
|
* Initialize page tables. This creates a PDE and a set of page
|
|
* tables, which are located immediately beyond __brk_base. The variable
|
|
* _brk_end is set up to point to the first "safe" location.
|
|
* Mappings are created both at virtual address 0 (identity mapping)
|
|
* and PAGE_OFFSET for up to _end.
|
|
*
|
|
* In PAE mode initial_page_table is statically defined to contain
|
|
* enough entries to cover the VMSPLIT option (that is the top 1, 2 or 3
|
|
* entries). The identity mapping is handled by pointing two PGD entries
|
|
* to the first kernel PMD. Note the upper half of each PMD or PTE are
|
|
* always zero at this stage.
|
|
*/
|
|
void __init mk_early_pgtbl_32(void)
|
|
{
|
|
#ifdef __pa
|
|
#undef __pa
|
|
#endif
|
|
#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET)
|
|
pte_t pte, *ptep;
|
|
int i;
|
|
unsigned long *ptr;
|
|
/* Enough space to fit pagetables for the low memory linear map */
|
|
const unsigned long limit = __pa(_end) +
|
|
(PAGE_TABLE_SIZE(LOWMEM_PAGES) << PAGE_SHIFT);
|
|
#ifdef CONFIG_X86_PAE
|
|
pmd_t pl2, *pl2p = (pmd_t *)__pa(initial_pg_pmd);
|
|
#define SET_PL2(pl2, val) { (pl2).pmd = (val); }
|
|
#else
|
|
pgd_t pl2, *pl2p = (pgd_t *)__pa(initial_page_table);
|
|
#define SET_PL2(pl2, val) { (pl2).pgd = (val); }
|
|
#endif
|
|
|
|
ptep = (pte_t *)__pa(__brk_base);
|
|
pte.pte = PTE_IDENT_ATTR;
|
|
|
|
while ((pte.pte & PTE_PFN_MASK) < limit) {
|
|
|
|
SET_PL2(pl2, (unsigned long)ptep | PDE_IDENT_ATTR);
|
|
*pl2p = pl2;
|
|
#ifndef CONFIG_X86_PAE
|
|
/* Kernel PDE entry */
|
|
*(pl2p + ((PAGE_OFFSET >> PGDIR_SHIFT))) = pl2;
|
|
#endif
|
|
for (i = 0; i < PTRS_PER_PTE; i++) {
|
|
*ptep = pte;
|
|
pte.pte += PAGE_SIZE;
|
|
ptep++;
|
|
}
|
|
|
|
pl2p++;
|
|
}
|
|
|
|
ptr = (unsigned long *)__pa(&max_pfn_mapped);
|
|
/* Can't use pte_pfn() since it's a call with CONFIG_PARAVIRT */
|
|
*ptr = (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
|
|
|
|
ptr = (unsigned long *)__pa(&_brk_end);
|
|
*ptr = (unsigned long)ptep + PAGE_OFFSET;
|
|
}
|
|
|