[U-Boot] [PATCH v0 13/20] efi_loader: use proper device-paths for partitions

[Rob Clark]

On Sun, Aug 6, 2017 at 2:47 PM, Rob Clark <robdclark at gmail.com> wrote:
> On Sun, Aug 6, 2017 at 2:37 PM, Mark Kettenis <mark.kettenis at xs4all.nl> wrote:
>>> Date: Sun, 6 Aug 2017 20:21:45 +0200 (CEST)
>>> From: Mark Kettenis <mark.kettenis at xs4all.nl>
>>>
>>> > Mind sending me or pastebin'ing your u-boot .config?  There are some
>>> > different device-path construction depending on legacy vs
>>> > CONFIG_DM+CONFIG_BLK (the legacy case *looks* right to me, and is used
>>> > by vexpress_ca15_tc2.. so I think it should work..)
>>>
>>> See below.  The Banana Pi (and all other sunxi boards) indeed uses the
>>> legacy code path.  And I think there is a bug in the legacy codepath
>>> where it encodes the partition in the "file" path component.
>>
>> If I fix the code to not insert the partition number there, I can boot
>> from SD card and SATA again.
>>
>> diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
>> index b5acf73f98..8ba0db2d7a 100644
>> --- a/lib/efi_loader/efi_device_path.c
>> +++ b/lib/efi_loader/efi_device_path.c
>> @@ -305,8 +305,8 @@ static void *dp_part_fill(void *buf, struct blk_desc *desc, int part)
>>         struct efi_device_path_file_path *fp;
>>         char devname[32] = { 0 }; /* fp->str is u16[32] long */
>>
>> -       snprintf(devname, sizeof(devname), "%d.%d.%d", desc->if_type,
>> -                desc->devnum, part);
>> +       snprintf(devname, sizeof(devname), "%d.%d", desc->if_type,
>> +                desc->devnum);
>>
>>         memcpy(buf, &ROOT, sizeof(ROOT));
>>         buf += sizeof(ROOT);
>
>
> Hmm, that is probably not a good idea, since now the disk object along
> w/ partition objects will have same devicepath.  (One change from
> before is now we have diskobjs for the disk (part=0) and child
> diskobjs for each partition.. fwiw in UEFI terminology a
> efi_device_path_hard_drive_path is actually a partition.. for maximum
> confusion)

Oh, scratch that.. you are right, part shouldn't be in the string..
since it results in the children having different parent device paths.

(It is still probably a bit funny to file-paths for parent of the
partition objects.. I'll try to come up with something a bit better.)

BR,
-R