mirror of
https://github.com/team-infusion-developers/android_kernel_samsung_msm8976.git
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6a50a664ca
o X86_64 kernel should run from 2MB aligned address for two reasons. - Performance. - For relocatable kernels, page tables are updated based on difference between compile time address and load time physical address. This difference should be multiple of 2MB as kernel text and data is mapped using 2MB pages and PMD should be pointing to a 2MB aligned address. Life is simpler if both compile time and load time kernel addresses are 2MB aligned. o Flag the error at compile time if one is trying to build a kernel which does not meet alignment restrictions. Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
93 lines
2.3 KiB
C
93 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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