From: Vincent Tinelli vincent.tinelli@intel.com

On some cases the first 440 bytes of MBR are used to keep an additional information for ROM boot loader. 'gpt write' command doesn't preserve that area and makes boot code gone.

Preserve boot code area when run 'gpt write' command.

Signed-off-by: Vincent Tinelli vincent.tinelli@intel.com Signed-off-by: Brennan Ashton brn@deako.com Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com --- disk/part_efi.c | 7 +++++++ 1 file changed, 7 insertions(+)

diff --git a/disk/part_efi.c b/disk/part_efi.c index 19243380da..fcb267b42a 100644 --- a/disk/part_efi.c +++ b/disk/part_efi.c @@ -324,6 +324,13 @@ static int set_protective_mbr(struct blk_desc *dev_desc) printf("%s: calloc failed!\n", __func__); return -1; } + + /* Read MBR to backup boot code if it exists */ + if (blk_dread(dev_desc, 0, 1, p_mbr) != 1) { + error("** Can't read from device %d **\n", dev_desc->devnum); + return -1; + } + /* Append signature */ p_mbr->signature = MSDOS_MBR_SIGNATURE; p_mbr->partition_record[0].sys_ind = EFI_PMBR_OSTYPE_EFI_GPT;