RISC-V ovmf used VirtualRealTimeClockLib but the default epoch is a
compilation time. It causes that the RISC-V ovmf binary image is NOT
reproducible.
This patch added the support of SOURCE_DATE_EPOCH by printenv command.
If SOURCE_DATE_EPOCH be found then we use it as BUILD_EPOCH. Otherwise
we run date command for setting BUILD_EPOCH.
For distributions want a reproducible RISC-V ovmf image, they should
export SOURCE_DATE_EPOCH environment variable before building ovmf.
References: https://reproducible-builds.org/docs/source-date-epoch/
Cc: Pete Batard <pete@akeo.ie>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com>
This is designed to be used on platforms where a a real RTC is not
available and relies on an RtcEpochSeconds variable having been set or,
if that is not the case, falls back to using the epoch embedded at
compilation time.
Note that, in order to keep things simple for the setting of the
compilation time variable, only GCC environments with UNIX-like shells
and where a 'date' command is available are meant to be supported for
now.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Pete Batard <pete@akeo.ie>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Chun-Yi Lee
Michael D Kinney
Pete Batard