[coreboot] CBFS mounting failure

[Gailu Singh]

Hi Experts,

We are using grub2 payload.

When we configure coreboot with CONFIG_CBFS_SIZE and CONFIG_ROM_SIZE to be
same, grub fails to mount cbfsdisk. We added prints and found that it fails
at following check in grub-core/fs/cbfs.c

ptr = grub_cpu_to_le32 (ptr);
  header_off = (grub_disk_get_size (disk) << GRUB_DISK_SECTOR_BITS)
    + (grub_int32_t) ptr;

if (grub_disk_read (disk, 0, header_off,
      sizeof (head), &head))
    goto fail;

However if we keep margin of min 64KB between CONFIG_ROM_SIZE and
CONFIG_CBFS_SIZE it works perfectly.

Is there any possibility that coreboot mess up cbfs layout when both rom
size and cbfs size are same

Thank you