x86: Move coreboot-table detection into common code

To support detecting booting from coreboot, move the code which locates
the coreboot tables into a common place. Adjust the algorithm slightly to
use a word comparison instead of string, since it is faster.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
[bmeng: correct the comments to 960KB]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
This commit is contained in:
Simon Glass 2020-04-26 09:12:58 -06:00 committed by Bin Meng
parent ba974a0137
commit 33139a0bc7
3 changed files with 41 additions and 15 deletions

View File

@ -115,20 +115,11 @@ __weak void cb_parse_unhandled(u32 tag, unsigned char *ptr)
static int cb_parse_header(void *addr, int len, struct sysinfo_t *info)
{
unsigned char *ptr = addr;
struct cb_header *header;
unsigned char *ptr = (unsigned char *)addr;
int i;
for (i = 0; i < len; i += 16, ptr += 16) {
header = (struct cb_header *)ptr;
if (!strncmp((const char *)header->signature, "LBIO", 4))
break;
}
/* We walked the entire space and didn't find anything. */
if (i >= len)
return -1;
header = (struct cb_header *)ptr;
if (!header->table_bytes)
return 0;
@ -231,10 +222,13 @@ static int cb_parse_header(void *addr, int len, struct sysinfo_t *info)
int get_coreboot_info(struct sysinfo_t *info)
{
int ret = cb_parse_header((void *)0x00000000, 0x1000, info);
long addr;
int ret;
if (ret != 1)
ret = cb_parse_header((void *)0x000f0000, 0x1000, info);
addr = locate_coreboot_table();
if (addr < 0)
return addr;
ret = cb_parse_header((void *)addr, 0x1000, info);
return (ret == 1) ? 0 : -1;
return ret == 1 ? 0 : -ENOENT;
}

View File

@ -447,6 +447,31 @@ int x86_cpu_init_f(void)
return 0;
}
long detect_coreboot_table_at(ulong start, ulong size)
{
u32 *ptr, *end;
size /= 4;
for (ptr = (void *)start, end = ptr + size; ptr < end; ptr += 4) {
if (*ptr == 0x4f49424c) /* "LBIO" */
return (long)ptr;
}
return -ENOENT;
}
long locate_coreboot_table(void)
{
long addr;
/* We look for LBIO in the first 4K of RAM and again at 960KB */
addr = detect_coreboot_table_at(0x0, 0x1000);
if (addr < 0)
addr = detect_coreboot_table_at(0xf0000, 0x1000);
return addr;
}
int x86_cpu_reinit_f(void)
{
setup_identity();

View File

@ -343,4 +343,11 @@ void *high_table_malloc(size_t bytes);
*/
void write_coreboot_table(u32 addr, struct memory_area *cfg_tables);
/**
* locate_coreboot_table() - Try to find coreboot tables at standard locations
*
* @return address of table that was found, or -ve error number
*/
long locate_coreboot_table(void);
#endif