coreboot

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 https://reproducible-builds.org. 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 reproducible_coreboot.sh in a Debian environment and this script is solely responsible for creating this page. Feel invited to join #reproducible-builds (on irc.oftc.net) 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!

155 (100.0%) out of 155 built coreboot images were reproducible in our test setup ! These tests were last run on 2026-07-17 for version 26.06-409-g1129aed124 using diffoscope 324.

variationfirst buildsecond build
hostname osuosl1-amd64 or osuosl2-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 6.12.95+deb13-amd64Linux 2.6.72+deb13-amd64
umask00220002
CPU type Intel Xeon Processor (Cascadelake)same for both builds
/bin/sh is not yet varied between rebuilds of coreboot.
year, month, datetoday (2026-07-17)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 else...is likely the same. There will be more variations in the wild.

commit 1129aed124abe7fd2826f537429827904bf0e456
Author: Subrata Banik 
Date:   Thu Jul 16 10:43:09 2026 +0530

    mb/google/bluey: Power off AP on AC loss during low-power
    
    During low-power or off-mode charging boot, the AP should not continue
    executing if the user disconnects the AC power source. Checking this
    early prevents a visual glitch where the lightbar is turned off and
    then back on when an AC unplug is eventually detected downstream inside
    the `launch_charger_applet` API.
    
    Add a raw (non-debounced) check using detect_ac_unplug_event() in
    handle_low_power_charging_boot() prior to calling
    launch_charger_applet().
    
    If an AC unplug event is detected:
    1. Trigger an EC off-mode heartbeat to sync the power state.
    2. Force an immediate AP shutdown via google_chromeec_ap_poweroff().
    
    Additionally, expose the detect_ac_unplug_event() prototype in board.h.
    
    TEST=Boot bluey/mica to the low-power charging screen, unplug the
         charger, and verify the AP shuts down immediately. This bypasses
         a 15-second loop waiting to detect charger presence.
    
    Change-Id: Id0087c91980327fe786cb9ca6cb8503ddabadaa7
    Signed-off-by: Subrata Banik 
    Reviewed-on: https://review.coreboot.org/c/coreboot/+/94139
    Tested-by: build bot (Jenkins) 
    Reviewed-by: Kapil Porwal

cross toolchain sourcesha256sum
acpica-unix-20251212.tar.gz 486423245f8154dd0bb5ada9ae057d670210dcbbc4386e62aeccdf5bfdad5f19
binutils-2.46.1.tar.xz e127a709cba24c76de8936cb7083dd768f28cd37eb010492e2f19b71eb1294e4
gcc-15.2.0.tar.xz 438fd996826b0c82485a29da03a72d71d6e3541a83ec702df4271f6fe025d24e
gmp-6.3.0.tar.xz a3c2b80201b89e68616f4ad30bc66aee4927c3ce50e33929ca819d5c43538898
mpc-1.4.1.tar.xz 91204cd32f164bd3b7c992d4a6a8ce6519511aadab30f78b6982d0bf8d73e931
mpfr-4.2.2.tar.xz b67ba0383ef7e8a8563734e2e889ef5ec3c3b898a01d00fa0a6869ad81c6ce01
Debian 13.6 package on amd64installed version
gcc 4:14.2.0-1
g++ 4:14.2.0-1
make 4.4.1-2
cmake 3.31.6-2
flex 2.6.4-8.2+b4
bison 2:3.8.2+dfsg-1+b2
pkg-config 1.8.1-4

There is more information about jenkins.debian.net and about reproducible builds of Debian available elsewhere.
Please send technical feedback about this setup to the Debian jenkins development list, or as a bug report against the jenkins.debian.org package. Feedback about specific job results should go to their respective lists and/or the BTS.
The code of jenkins.debian.net is mostly GPL-2 licensed. The weather icons are public domain and were taken from the Tango Icon Library. Copyright 2014-2024 Holger Levsen and many others.
Last update: 2026-07-17 14:58 UTC