On Mon, 19 Feb 2024 at 10:24, Mark Kettenis mark.kettenis@xs4all.nl wrote:
From: Peter Robinson pbrobinson@gmail.com Date: Mon, 19 Feb 2024 09:12:15 +0000
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.
Hi Peter,
Any reason not to include 0x0c as well? That is what we use on OpenBSD/armv7 and OpenBSD/arm64. And as far as I know all UEFI implementations (on arm64 at least) boot from such a partition.
I wasn't 100% the support with LBA so I erred with caution, but no reason I can't add it.
(And yes, we use that partition type because we want to have a bootable image that works on the various Raspberry Pi models).
Yes, that is the same reason for us, plus a few other random other Arm devices that won't recognise EF as VFAT and won't boot.
That said, what problem does this fix? And what happens if we have both a 0xea and a 0x01/0x06/0x0b/0x0c partition? In that case U-Boot should probably prefer the 0xea over the others as the ESP.
The reason is because the support to write EFI vars on ESP, and yes I realise it's got security issues but for most boards it's the least of their problem, as the support won't do that without the flag and you get a bunch of these on boot:
No EFI system partition Failed to persist EFI variables
As for multiple partitions UEFI should handle that and I believe the EFI var support has logic around which partition it chooses.
Oh, and while your're at it, the hex constants are a bit inconsistent (0x1/0x6 vs. 0x0b).
Will fix with v2 when I add 0x0c, I'll await other feedback for a bit.
Thanks, Peter
Cheers,
Mark
Signed-off-by: Peter Robinson pbrobinson@gmail.com
disk/part_dos.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/disk/part_dos.c b/disk/part_dos.c index 567ead7511d..303eb1d13ee 100644 --- a/disk/part_dos.c +++ b/disk/part_dos.c @@ -40,6 +40,12 @@ static int get_bootable(dos_partition_t *p) { int ret = 0;
if (p->sys_ind == 0x1)ret |= PART_EFI_SYSTEM_PARTITION;if (p->sys_ind == 0x6)ret |= PART_EFI_SYSTEM_PARTITION;if (p->sys_ind == 0x0b)ret |= PART_EFI_SYSTEM_PARTITION; if (p->sys_ind == 0xef) ret |= PART_EFI_SYSTEM_PARTITION; if (p->boot_ind == 0x80)-- 2.43.1