x86: Ensure IDT and GDT remain 16-byte aligned post relocation

Some CPUs have strict alignment requirements for these tables

Signed-off-by: Graeme Russ <graeme.russ@gmail.com>
This commit is contained in:
Graeme Russ 2011-11-08 02:33:21 +00:00
parent a76fc70ee1
commit 303418cc97
2 changed files with 13 additions and 6 deletions

View file

@ -174,7 +174,7 @@ struct desc_ptr {
unsigned short segment;
} __packed;
struct idt_entry idt[256];
struct idt_entry idt[256] __attribute__((aligned(16)));
struct desc_ptr idt_ptr;

View file

@ -161,19 +161,26 @@ gd_t *gd;
static int calculate_relocation_address(void)
{
void *text_start = &__text_start;
void *bss_end = &__bss_end;
void *dest_addr;
ulong text_start = (ulong)&__text_start;
ulong bss_end = (ulong)&__bss_end;
ulong dest_addr;
ulong rel_offset;
/* Calculate destination RAM Address and relocation offset */
dest_addr = (void *)gd->ram_size;
dest_addr = gd->ram_size;
dest_addr -= CONFIG_SYS_STACK_SIZE;
dest_addr -= (bss_end - text_start);
/*
* Round destination address down to 16-byte boundary to keep
* IDT and GDT 16-byte aligned
*/
dest_addr &= ~15;
rel_offset = dest_addr - text_start;
gd->start_addr_sp = gd->ram_size;
gd->relocaddr = (ulong)dest_addr;
gd->relocaddr = dest_addr;
gd->reloc_off = rel_offset;
return 0;