[U-Boot] [PATCH] gpt: Fix the protective MBR partition size
According to the UEFI Spec (Table 16, section 5.2.3 of the version 2.4 Errata B), the protective MBR partition record size must be set to the size of the disk minus one, in LBAs.
However, the current code was setting the size as the total number of LBAs on the disk, resulting in an off-by-one error.
This confused the AM335x ROM code, and will probably confuse other tools as well.
Signed-off-by: Maxime Ripard maxime.ripard@free-electrons.com --- disk/part_efi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/disk/part_efi.c b/disk/part_efi.c index 612f0926b62b..5ca17c138e96 100644 --- a/disk/part_efi.c +++ b/disk/part_efi.c @@ -240,7 +240,7 @@ static int set_protective_mbr(block_dev_desc_t *dev_desc) p_mbr->signature = MSDOS_MBR_SIGNATURE; p_mbr->partition_record[0].sys_ind = EFI_PMBR_OSTYPE_EFI_GPT; p_mbr->partition_record[0].start_sect = 1; - p_mbr->partition_record[0].nr_sects = (u32) dev_desc->lba; + p_mbr->partition_record[0].nr_sects = (u32) dev_desc->lba - 1;
/* Write MBR sector to the MMC device */ if (dev_desc->block_write(dev_desc->dev, 0, 1, p_mbr) != 1) {
(+ Lukasz) Interesting - I'll defer to Lukasz... Thanks, Steve
On 15-01-08 03:26 AM, Maxime Ripard wrote:
According to the UEFI Spec (Table 16, section 5.2.3 of the version 2.4 Errata B), the protective MBR partition record size must be set to the size of the disk minus one, in LBAs.
However, the current code was setting the size as the total number of LBAs on the disk, resulting in an off-by-one error.
This confused the AM335x ROM code, and will probably confuse other tools as well.
Signed-off-by: Maxime Ripard maxime.ripard@free-electrons.com
disk/part_efi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/disk/part_efi.c b/disk/part_efi.c index 612f0926b62b..5ca17c138e96 100644 --- a/disk/part_efi.c +++ b/disk/part_efi.c @@ -240,7 +240,7 @@ static int set_protective_mbr(block_dev_desc_t *dev_desc) p_mbr->signature = MSDOS_MBR_SIGNATURE; p_mbr->partition_record[0].sys_ind = EFI_PMBR_OSTYPE_EFI_GPT; p_mbr->partition_record[0].start_sect = 1;
- p_mbr->partition_record[0].nr_sects = (u32) dev_desc->lba;
p_mbr->partition_record[0].nr_sects = (u32) dev_desc->lba - 1;
/* Write MBR sector to the MMC device */ if (dev_desc->block_write(dev_desc->dev, 0, 1, p_mbr) != 1) {
Hi Steve,
(+ Lukasz) Interesting - I'll defer to Lukasz... Thanks, Steve
Thanks guys for spotting the mistake and sorry for a late reply (holidays time).
I'm glad that this patch was included to v2015.01
On 15-01-08 03:26 AM, Maxime Ripard wrote:
According to the UEFI Spec (Table 16, section 5.2.3 of the version 2.4 Errata B), the protective MBR partition record size must be set to the size of the disk minus one, in LBAs.
However, the current code was setting the size as the total number of LBAs on the disk, resulting in an off-by-one error.
This confused the AM335x ROM code, and will probably confuse other tools as well.
Signed-off-by: Maxime Ripard maxime.ripard@free-electrons.com
disk/part_efi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/disk/part_efi.c b/disk/part_efi.c index 612f0926b62b..5ca17c138e96 100644 --- a/disk/part_efi.c +++ b/disk/part_efi.c @@ -240,7 +240,7 @@ static int set_protective_mbr(block_dev_desc_t *dev_desc) p_mbr->signature = MSDOS_MBR_SIGNATURE; p_mbr->partition_record[0].sys_ind = EFI_PMBR_OSTYPE_EFI_GPT; p_mbr->partition_record[0].start_sect = 1;
- p_mbr->partition_record[0].nr_sects = (u32) dev_desc->lba;
- p_mbr->partition_record[0].nr_sects = (u32) dev_desc->lba
1;
/* Write MBR sector to the MMC device */ if (dev_desc->block_write(dev_desc->dev, 0, 1, p_mbr) !=
- {
On Thu, Jan 08, 2015 at 12:26:44PM +0100, Maxime Ripard wrote:
According to the UEFI Spec (Table 16, section 5.2.3 of the version 2.4 Errata B), the protective MBR partition record size must be set to the size of the disk minus one, in LBAs.
However, the current code was setting the size as the total number of LBAs on the disk, resulting in an off-by-one error.
This confused the AM335x ROM code, and will probably confuse other tools as well.
Signed-off-by: Maxime Ripard maxime.ripard@free-electrons.com
Applied to u-boot/master, thanks!
participants (4)
-
Lukasz Majewski -
Maxime Ripard -
Steve Rae -
Tom Rini