diff options
Diffstat (limited to 'src/arch/i386/boot/gdt.c')
-rw-r--r-- | src/arch/i386/boot/gdt.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/src/arch/i386/boot/gdt.c b/src/arch/i386/boot/gdt.c new file mode 100644 index 0000000000..232502753f --- /dev/null +++ b/src/arch/i386/boot/gdt.c @@ -0,0 +1,59 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2008-2009 coresystems GmbH + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <types.h> +#include <string.h> +#include <cbmem.h> +#include <console/console.h> + +// Global Descriptor Table, defined in c_start.S +extern char gdt; +extern char gdt_end; + +/* i386 lgdt argument */ +struct gdtarg { + u16 limit; + u32 base; +} __attribute__((packed)); + +// Copy GDT to new location and reload it +void move_gdt(void) +{ + void *newgdt; + u16 num_gdt_bytes = &gdt_end - &gdt; + struct gdtarg gdtarg; + + newgdt = cbmem_find(CBMEM_ID_GDT); + if (!newgdt) { + newgdt = cbmem_add(CBMEM_ID_GDT, ALIGN(num_gdt_bytes, 512)); + if (!newgdt) { + printk(BIOS_ERR, "Error: Could not relocate GDT.\n"); + return; + } + 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"); +} + |