Re: [PATCH] disk: dos: Add all options for EFI System Partitions

[Mark Kettenis <mark.kettenis@xs4all.nl>]

> 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.

(And yes, we use that partition type because we want to have a
bootable image that works on the various Raspberry Pi models).

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.

Oh, and while your're at it, the hex constants are a bit inconsistent
(0x1/0x6 vs. 0x0b).

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
> 
>