Non-reproducible binaries generated by GenFw


Ross Burton
 

Hi,

As per https://bugzilla.tianocore.org/show_bug.cgi?id=3256, GenFw
writes non-reproducible binaries by embedding a build path. In fact in
a build of ovmf with embedded shell, this one path is the sole source
of non-determinism.

WriteDebug64() is always called in GenFw on output and that embeds
into the NB10 entry the input filename. As build paths change this is
a source of non-determinism. There already exists a --zero option to
wipe out debug paths but this is in release builds so I'm not sure
what the best solution is. I can see several options:

1) Release builds should not call WriteDebug64() at all
2) --zero should wipe the NB10 entry, and release builds should pass that
3) GenFw should support path remapping (like gcc's -ffile-prefix-map)
to turn build paths into something consistent.

Any suggestions?

Cheers,
Ross

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