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coreboot-kgpe-d16
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Relocate the GDT to reserved memory, so it won't get clobbered by elfboot(), etc. 

git-svn-id: svn://svn.coreboot.org/coreboot/trunk@2024 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
This commit is contained in:
Steven J. Magnani 2005-09-12 18:41:30 +00:00
parent 9b945c7cd8
commit d94e1d6e9d
1 changed files with 30 additions and 0 deletions
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30
src/arch/i386/boot/tables.c
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@ -7,6 +7,32 @@
#include <arch/acpi.h> #include <arch/acpi.h>
#include "linuxbios_table.h" #include "linuxbios_table.h"
// Global Descriptor Table, defined in c_start.S
extern uint8_t gdt;
extern uint8_t gdt_end;
/* i386 lgdt argument */
struct gdtarg {
unsigned short limit;
unsigned int base;
} __attribute__((packed));
// Copy GDT to new location and reload it
// 2003-07 by SONE Takeshi
// Ported from Etherboot to LinuxBIOS 2005-08 by Steve Magnani
void move_gdt(unsigned long newgdt)
{
uint16_t num_gdt_bytes = &gdt_end - &gdt;
struct gdtarg gdtarg;
printk_debug("Moving GDT to %#lx...", newgdt);
memcpy((void*)newgdt, &gdt, num_gdt_bytes);
gdtarg.base = newgdt;
gdtarg.limit = num_gdt_bytes - 1;
__asm__ __volatile__ ("lgdt %0\n\t" : : "m" (gdtarg));
printk_debug("ok\n");
}
struct lb_memory *write_tables(void) struct lb_memory *write_tables(void)
{ {
unsigned long low_table_start, low_table_end; unsigned long low_table_start, low_table_end;
@ -45,6 +71,10 @@ struct lb_memory *write_tables(void)
low_table_end = 0x500; low_table_end = 0x500;
} }
// Relocate the GDT to reserved memory, so it won't get clobbered
move_gdt(low_table_end);
low_table_end += &gdt_end - &gdt;
/* The linuxbios table must be in 0-4K or 960K-1M */ /* The linuxbios table must be in 0-4K or 960K-1M */
write_linuxbios_table( write_linuxbios_table(
low_table_start, low_table_end, low_table_start, low_table_end,