[PATCH v3] disk: dos: Add all options for EFI System Partitions

[Mark Kettenis]

> From: Peter Robinson <pbrobinson at gmail.com>
> Date: Sat,  2 Mar 2024 10:54:36 +0000

Hi Peter,

> 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 <pbrobinson at gmail.com>
> ---
> 
> v2:
> - Add 0x0c option
> - Make hex constants consistent
> - Move from if to switch statement
> v3:
> - Fix switch brain fart

Sorry, still not quite right...

>  disk/part_dos.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/disk/part_dos.c b/disk/part_dos.c
> index 567ead7511d..97f4ce32bed 100644
> --- a/disk/part_dos.c
> +++ b/disk/part_dos.c
> @@ -40,10 +40,21 @@ 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;
> -	if (p->boot_ind == 0x80)

The boot flag is part of p->boot_ind but the switch is for p->sys_ind
(the partition type).  You can't handle the boot flag in the same
switch!  Probably best to keep the if-statement for that bit.

> +		break;
> +	case 0x80:
>  		ret |= PART_BOOTABLE;
> +		break;
> +	default:
> +		break;
> +	}
> +
>  	return ret;
>  }
>  
> -- 
> 2.44.0
> 
>