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linux-next/arch/x86_64/kernel/head64.c
Vivek Goyal 069f11f9d6 x86_64: display more intuitive error message if kernel is not 2MB aligned
o x86_64 kernel needs to be compiled for 2MB aligned addresses. Currently
  we are using BUILD_BUG_ON() to warn the user if he has not done so. But
  looks like folks are not finding message very intutive and don't open
  the respective c file to find problem source. (Bug 8439)

arch/x86_64/kernel/head64.c: In function 'x86_64_start_kernel':
arch/x86_64/kernel/head64.c:70: error: size of array 'type name' is negative

o Using preprocessor directive #error to print a better message if
  CONFIG_PHYSICAL_START is not aligned to 2MB boundary.

Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 08:29:32 -07:00

87 lines
2.0 KiB
C

/*
* 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/tlbflush.h>
#include <asm/sections.h>
static void __init zap_identity_mappings(void)
{
pgd_t *pgd = pgd_offset_k(0UL);
pgd_clear(pgd);
__flush_tlb();
}
/* 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 0x20
#define OLD_CL_MAGIC 0xA33F
#define OLD_CL_OFFSET 0x22
static void __init copy_bootdata(char *real_mode_data)
{
unsigned long new_data;
char * command_line;
memcpy(x86_boot_params, real_mode_data, BOOT_PARAM_SIZE);
new_data = *(u32 *) (x86_boot_params + NEW_CL_POINTER);
if (!new_data) {
if (OLD_CL_MAGIC != *(u16 *)(real_mode_data + OLD_CL_MAGIC_ADDR)) {
return;
}
new_data = __pa(real_mode_data) + *(u16 *)(real_mode_data + OLD_CL_OFFSET);
}
command_line = __va(new_data);
memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
}
void __init x86_64_start_kernel(char * real_mode_data)
{
int i;
/* clear bss before set_intr_gate with early_idt_handler */
clear_bss();
/* Make NULL pointers segfault */
zap_identity_mappings();
for (i = 0; i < IDT_ENTRIES; i++)
set_intr_gate(i, early_idt_handler);
asm volatile("lidt %0" :: "m" (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));
#ifdef CONFIG_SMP
cpu_set(0, cpu_online_map);
#endif
start_kernel();
}