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Juro Bystricky
cf6f3c023c
Setup environment for builds requiring binary reproducibility. Determine and export SOURCE_DATE_EPOCH per each recipe. This is a crucial step to achieve binary reproducibility. The value for this variable (timestamp) is obtained after source code for a recipe has been unpacked, but before it is patched. If the code sources come from a GIT repo, we get the timestamp from the top commit. (GIT repo does not preserve file mktime timestamps). Otherwise, if GIT repo is not present, we try to get mtime from known files such as NEWS, ChangeLog, etc. If this also fails, we go through all files and get the timestamp from the youngest one. We create an individual timestamp for each recipe. The timestamp is stored in the file '__source_date_epoch.txt' (in the folder source-date-epoch_). Later on, each task reads this file and sets the exported value of SOURCE_DATE_EPOCH to the value found in the file. Uasge: INHERIT += "reproducible_build" [YOCTO#11178] [YOCTO#11179] (From OE-Core rev: cc438ac7711dedbe05d654e99af9316c9215b02e) Signed-off-by: Juro Bystricky <juro.bystricky@intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
QEMU Emulation Targets ====================== To simplify development, the build system supports building images to work with the QEMU emulator in system emulation mode. Several architectures are currently supported in 32 and 64 bit variants: * ARM (qemuarm + qemuarm64) * x86 (qemux86 + qemux86-64) * PowerPC (qemuppc only) * MIPS (qemumips + qemumips64) Use of the QEMU images is covered in the Yocto Project Reference Manual. The appropriate MACHINE variable value corresponding to the target is given in brackets.