On 10/8/25 16:08, Peter Robinson wrote:
The EFI spec states that the ESP can be any of FAT12/16/32 but for
compatibility doesn't necssarily require the partition to be the
EFI partition table ID of 0xef. A number of arm devices will not
find their firmware on a FAT partition with an ID of 0xef so also
allow the original FAT12/16/32 partition IDs as they are also
permissable for an ESP.
Signed-off-by: Peter Robinson <[email protected]>
Reviewed-by: Mark Kettenis <[email protected]>
Reviewed-by: Ilias Apalodimas <[email protected]>
Hello Peter,
Please, read the Microsoft documentation:
"The Extensible Firmware Interface System Partitions on an MBR disk is
identified by partition type 0xEF." [1]
The other partition types like 0x06 have non-ESP use and should never be
taken for an ESP.
Updating partition tables is trivial. Just fix the buggy partition table
entry on your ARM devices instead of this cumbersome patch.
Best regards
Heinrich
[1]
https://learn.microsoft.com/en-us/troubleshoot/windows-server/backup-and-storage/guid-partitioning-table-disk-faq
---
v2:
- Add 0x0c option
- Make hex constants consistent
- Move from if to switch statement
v3:
- Fix switch brain fart
v4:
- Drop boot_ind out of switch
This is just a resend, it fell off my radar, and there was a CI failure.
disk/part_dos.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/disk/part_dos.c b/disk/part_dos.c
index 18dd35c9b98..92d6fa6e028 100644
--- a/disk/part_dos.c
+++ b/disk/part_dos.c
@@ -39,10 +39,21 @@ static int get_bootable(dos_partition_t *p)
{
int ret = 0;
- if (p->sys_ind == 0xef)
+ switch (p->sys_ind) {
+ case 0x01:
+ case 0x06:
+ case 0x0b:
+ case 0x0c:
+ case 0xef:
ret |= PART_EFI_SYSTEM_PARTITION;
+ break;
+ default:
+ break;
+ }
+
if (p->boot_ind == 0x80)
ret |= PART_BOOTABLE;
+
return ret;
}
