Re: PrePiLib's FwVol.c can't handle padding before volume header

[Michael Zimmermann <sigmaepsilon92@gmail.com>]

VolInfo doesn't seem to complain about FVMAIN_COMPACT.Fv:
https://pastebin.com/ueUnepXF

Does VolInfo support Fs's as well? because it fails on mine(even on a
working one).

On Sun, Dec 10, 2017 at 10:49 PM, Ard Biesheuvel
<ard.biesheuvel@linaro.org> wrote:
> On 10 December 2017 at 21:45, Michael Zimmermann
> <sigmaepsilon92@gmail.com> wrote:
>> The layout is basically the same as in ArmVirtQemuKernel.fdf but I've
>> changed the size to 8MB and these are the usage stats:
>> FV Space Information
>> FVMAINDEVICE [99%Full] 57856 total, 57800 used, 56 free
>> FVMAINMSM8960 [99%Full] 222336 total, 222312 used, 24 free
>> FVMAIN_COMPACT [63%Full] 8380416 total, 5305944 used, 3074472 free
>> FVMAIN [99%Full] 17026304 total, 17026264 used, 40 free
>> FVMAINQCOM [99%Full] 37184 total, 37152 used, 32 free
>>
>> and here's an uefitool report:
>> https://pastebin.com/pnHNSFz4
>> The padding in line 13 is the one causing trouble. The interesting
>> part is that it's not zero. it's value is '08 CD 03 01'.
>>
>> PrePiLib fails in this line:
>> https://github.com/tianocore/edk2/blob/5a44a766b597e4c9960ac1936e6d18001c5e7ce2/EmbeddedPkg/Library/PrePiLib/FwVol.c#L682
>> The reason is simply that VolumeHandle is offset by 4 bytes.
>>
>
> That code is identical to PeiFfsFvPpiGetVolumeInfo() in PEI core so
> this does not look specific to PrePiLib.
>
> Does VolInfo complain as well?