coreboot™: fast, flexible and reproducible Open Source firmware!

Reproducible Coreboot

Reproducible builds enable anyone to reproduce bit by bit identical binary packages from a given source, so that anyone can verify that a given binary derived from the source it was said to be derived. There is more information about reproducible builds on the Debian wiki and on These pages explain in more depth why this is useful, what common issues exist and which workarounds and solutions are known.

Reproducible Coreboot is an effort to apply this to coreboot. Thus each coreboot.rom is build twice (without payloads), with a few variations added and then those two ROMs are compared using diffoscope. Please note that the toolchain is not varied at all as the rebuild happens on exactly the same system. More variations are expected to be seen in the wild.

There is a weekly run jenkins job to test the master branch of coreboot.git. The jenkins job is running in a Debian environment and this script is solely responsible for creating this page. Feel invited to join #reproducible-builds (on to request job runs whenever sensible. Patches and other feedback are very much appreciated - if you want to help, please start by looking at the ToDo list for coreboot, you might find something easy to contribute.
Thanks to IONOS for donating the virtual machines this is running on!

183 (100.0%) out of 183 built coreboot images were reproducible in our test setup ! These tests were last run on 2021-12-06 for version 4.15-392-gdf808f3619 using diffoscope 195.

variationfirst buildsecond build
hostname osuosl169-amd64 or osuosl170-amd64the other one
domainname is not yet varied between rebuilds of coreboot.
env CAPTURE_ENVIRONMENTnot setCAPTURE_ENVIRONMENT="I capture the environment"
env TZTZ="/usr/share/zoneinfo/Etc/GMT+12"TZ="/usr/share/zoneinfo/Etc/GMT-14"
env LANGLANG="en_GB.UTF-8"LANG="et_EE.UTF-8"
env LC_ALLnot setLC_ALL="et_EE.UTF-8"
env PATHPATH="/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:"PATH="/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/i/capture/the/path"
env USER is not yet varied between rebuilds of coreboot.
uid is not yet varied between rebuilds of coreboot.
gid is not yet varied between rebuilds of coreboot.
UTS namespace is not yet varied between rebuilds of coreboot.
kernel version, modified using /usr/bin/linux64 --uname-2.6Linux 5.10.0-9-amd64Linux 2.6.70-9-amd64
CPU type Intel(R) Xeon(R) CPU E5-2660 0 @ 2.20GHzsame for both builds
/bin/sh is not yet varied between rebuilds of coreboot.
year, month, datetoday (2021-12-06)same for both builds (currently, work in progress)
hour, minutehour and minute will probably vary between two builds...the future system actually runs 398 days, 6 hours and 23 minutes ahead...
Filesystemtmpfssame for both builds (currently, this could be varied using disorderfs)
everything likely the same. There will be more variations in the wild.

commit df808f36190a99013a9687ea5c4aa0c70da5dd40
Author: Patrick Georgi 
Date:   Thu Nov 25 22:53:26 2021 +0100

    Documentation: Add template for deprecation notices
    Change-Id: Ia2cc4f799804c7d56db572823246c487cd19a726
    Signed-off-by: Patrick Georgi 
    Reviewed-by:  Felix Singer 
    Tested-by: build bot (Jenkins)      

cross toolchain sourcesha256sum
acpica-unix2-20210331.tar.gz 3dab326c262d4f3eaf380bbbbd7aa8c2eb5f2697f7821659222cf898d8be28c1
binutils-2.37.tar.xz 820d9724f020a3e69cb337893a0b63c2db161dadcb0e06fc11dc29eb1e84a32c
gcc-11.2.0.tar.xz d08edc536b54c372a1010ff6619dd274c0f1603aa49212ba20f7aa2cda36fa8b
gmp-6.2.1.tar.xz fd4829912cddd12f84181c3451cc752be224643e87fac497b69edddadc49b4f2
mpc-1.2.1.tar.gz 17503d2c395dfcf106b622dc142683c1199431d095367c6aacba6eec30340459
mpfr-4.1.0.tar.xz 0c98a3f1732ff6ca4ea690552079da9c597872d30e96ec28414ee23c95558a7f
Debian 11.1 package on amd64installed version
gcc 4:10.2.1-1
g++ 4:10.2.1-1
make 4.3-4.1
cmake 3.18.4-2
flex 2.6.4-8
bison 2:3.7.5+dfsg-1