mirror of https://gitee.com/openkylin/linux.git
94 lines
2.3 KiB
C
94 lines
2.3 KiB
C
/*
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* linux/arch/x86_64/kernel/head64.c -- prepare to run common code
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*
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* Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
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*/
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#include <linux/init.h>
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#include <linux/linkage.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/percpu.h>
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#include <asm/processor.h>
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#include <asm/proto.h>
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#include <asm/smp.h>
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#include <asm/bootsetup.h>
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#include <asm/setup.h>
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#include <asm/desc.h>
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#include <asm/pgtable.h>
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#include <asm/tlbflush.h>
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#include <asm/sections.h>
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static void __init zap_identity_mappings(void)
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{
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pgd_t *pgd = pgd_offset_k(0UL);
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pgd_clear(pgd);
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__flush_tlb();
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}
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/* Don't add a printk in there. printk relies on the PDA which is not initialized
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yet. */
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static void __init clear_bss(void)
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{
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memset(__bss_start, 0,
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(unsigned long) __bss_stop - (unsigned long) __bss_start);
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}
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#define NEW_CL_POINTER 0x228 /* Relative to real mode data */
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#define OLD_CL_MAGIC_ADDR 0x20
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#define OLD_CL_MAGIC 0xA33F
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#define OLD_CL_OFFSET 0x22
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static void __init copy_bootdata(char *real_mode_data)
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{
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unsigned long new_data;
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char * command_line;
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memcpy(x86_boot_params, real_mode_data, BOOT_PARAM_SIZE);
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new_data = *(u32 *) (x86_boot_params + NEW_CL_POINTER);
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if (!new_data) {
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if (OLD_CL_MAGIC != *(u16 *)(real_mode_data + OLD_CL_MAGIC_ADDR)) {
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return;
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}
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new_data = __pa(real_mode_data) + *(u16 *)(real_mode_data + OLD_CL_OFFSET);
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}
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command_line = __va(new_data);
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memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
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}
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void __init x86_64_start_kernel(char * real_mode_data)
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{
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int i;
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/*
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* Make sure kernel is aligned to 2MB address. Catching it at compile
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* time is better. Change your config file and compile the kernel
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* for a 2MB aligned address (CONFIG_PHYSICAL_START)
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*/
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BUILD_BUG_ON(CONFIG_PHYSICAL_START & (__KERNEL_ALIGN - 1));
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/* clear bss before set_intr_gate with early_idt_handler */
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clear_bss();
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/* Make NULL pointers segfault */
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zap_identity_mappings();
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for (i = 0; i < IDT_ENTRIES; i++)
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set_intr_gate(i, early_idt_handler);
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asm volatile("lidt %0" :: "m" (idt_descr));
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early_printk("Kernel alive\n");
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for (i = 0; i < NR_CPUS; i++)
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cpu_pda(i) = &boot_cpu_pda[i];
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pda_init(0);
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copy_bootdata(__va(real_mode_data));
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#ifdef CONFIG_SMP
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cpu_set(0, cpu_online_map);
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#endif
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start_kernel();
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}
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