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% Libreboot Build System Audit 6 % Leah Rowe % 19 July 2024

Heavy amount of code reduction in this audit, and general cleanup. A new Libreboot release is planned, for the early days of August 2024.

Introduction

Libreboot is a free/opensource boot firmware project. It replaces your proprietary BIOS/UEFI firmware, on supported x86 and ARM computers. It does this by providing an automated build system to download, patch and compile the various upstream sources (e.g. coreboot, GRUB, SeaBIOS). Coreboot is used for hardware initialisation, configuring everything from your CPU, memory controller all way to peripherals, readying the hardware so that it can run software, e.g. Linux/BSD operating systems. You can essentially think of lbmk, which is Libreboot's build system, as a source-based package manager. It is what the Libreboot releases are built with. The lbmk build system essentially implements a coreboot distro, the same way you might think of a Linux distribution; it systematically downloads, resets (to specific revisions) and patches various upstream project sources such as coreboot, U-Boot and GRUB, automatically building entire coreboot images. This build system is what creates Libreboot release images and source tarballs.

Extensive auditing has been performed on lbmk, since the Libreboot 20240612 release. These audits fix bugs, reduce code bloat and generally improve the efficiency of lbmk, adding and removing features in a careful, conservative way, with a focus on clean code.

Remember the magic words: code equals bugs. Fewer lines of code will yield fewer bugs.

This article covers changes from Libreboot 20240612, up to revision 31f1e4dadfcc1ceecacec50dd2a14e63a44364bd from 19 July 2024.

You can read about the previous audit in the article for Libreboot Build System Audit 5.

Notable code size reduction

There are 1109 lines of shell script in the build system, versus 1482 in the Libreboot 20240612 release. Libreboot's build system is written entirely in POSIX sh; not BASH, not KSH, not ZSH, jush sh! It is the build system of build systems; the design focuses on re-using (read: abusing) the build systems of the projects it uses, avoiding as much bloat as possible. More information is available in the lbmk build system documentation.

This is a difference of 373 lines, or a 25% reduction. The main focus has been on removing legacy bloat from the build system, vastly increasing the overall code cleanliness and efficiency. Several new safety and redundancy features were added, such as auto-rebuild when configs change(and auto-redownload) for sources, and additional redundant handling of both repositories and file downloads, cached during operation to avoid over-use of internet bandwidth.

Plan for next release

This code reduction has been the main focus; the focus now, at the next release, will be new payloads and boards, in addition to testing newer upstream revisions of projects such as coreboot, on every machine supported by Libreboot. A release is planned for early August 2024.

A lot of work on new ports is planned. There are a number of new mainboards that will be available, in the next Libreboot release.

Summarised list of changes

The most interesting changes are marked in bold. "Interesting" means that the change greatly improves the usefulness/reliability of Libreboot, or that it affects the user in a profound and noticeable way.

Changes are in order per category, from newest to oldest:

Feature changes

Some unused features have been removed, and yet more added. The overall focus of Audit 6 has been to remove legacy cruft from lbmk, and in general to simplify the operation of lbmk, Libreboot's build system. Several new safety features were implementated for this audit, in addition to features that generally improve the redundancy of certain operations, and overall reliability in lbmk.

The changes are as follows:

  • Put the cache directory location in an environmental variable, named XBMK_CACHE. If unset, it defaults to $PWD/cache, where PWD is the current location that the instance of lbmk is running from, otherwise if defined, the location is used. This means that the same cached files are re-used on the lbmk copy created when running ./update release, thus saving on a lot of internet bandwidth if the main instance already has a lot of files cached - it also means that you can re-use another cache from elsewhere, like if you have multiple clones of lbmk on your system.
  • Allow using coreboot's own build system, to build payloads. Libreboot's build system builds and adds payloads, with coreboot configurations enabling CONFIG_PAYLOAD_NONE exclusively. However, advanced users may wish to use something else such as Tianocore, which Libreboot may/will not provide (with Tianocore it's will not). Simply set build_depend="" in the target.cfg file for a given mainboard, and then enable a payload under coreboot's menuconfig interface, or by direct modification of the defconfig file. When CONFIG_PAYLOAD_NONE is not set, lbmk will skip adding a payload, because it's a given that then coreboot's own build system would have done it. Libreboot will always enable CONFIG_PAYLOAD_NONE on all official targets, so this feature is only intended for power users.
  • Unified cache file handling for vendor files, and files defined as modules for specific projects. They are now cached within the same base directory.
  • script/trees: Automatically re-download and re-build a given project, when configuration changes, on any file under specific directories in config/ pertaining to it; this is done by concatenating the sha512sum hashes for each of those files, and then making a sha512sum hash from that. The hash is stored, and compared to the current one; if it differs, then you know something changed. This feature does not track modifications to the actual downloaded source code for a given project, because this change also tracks the patches/ directories; direct modification (by the user) of the source is not assumed, under the lbmk model, but checking for this may be possible. For example, run the same concatenation logic on a file containing the output of commands such as git describe and git status, perhaps git diff. It was decided that the latter would be undesirable, because developers (of Libreboot, working with lbmk) may want to experiment with quick changes, before preparing patch files to go under config/. - the user previously had to know which files and directories to manually remove, when re-running build commands after modifying a given project within lbmk. Now it's automatic.
  • include/git.sh: Don't download multi-tree projects to src/project/project, e.g. src/coreboot/coreboot, when downloading the upstream repository, for later copying to the actual destination e.g. src/coreboot/default - instead, use the same cached location as alluded to in the two changes below. This avoids needing to delet those directories, when preparing release archives.
  • include/git.sh: Complementing the change seen below, also cache files universally, for vendor files and for submodules files (e.g. crossgcc files). This avoids wasting bandwidth when building for multiple coreboot trees, in cases where multiple trees share the same URLs for crossgcc tarballs.
  • include/git.sh: Cache all git downloads, reset to HEAD, before copying to the final location; this is also done on submodules. If a cached repository exists, run git pull on it but without an exit under fault conditions; if a fault occurs, including when trying to reset on a copy of it, fall back to the old logic where the repository is downloaded (online) directly to the destination. This change results in substantially reduced internet bandwidth usage, especially when downloading submodules for multiple coreboot trees, in cases where those trees share common revisions.
  • script/trees: Support -d (flag) for custom build logic; it does the same thing as -b, but with a variable named dry being set to :; this is prefixed on most build-related commands, and can be further prefixed as desired, in mkhelper functions. The result is that you can do dry runs on a given build. This is used, to provide building of coreboot utilities and downloading of vendor files, without needing specific hacks to be hardcoded in script/trees. The ./update trees -b coreboot TREE utils command is no longer available; instead, do ./update trees -d coreboot TREE; if the TREE argument is instead an actual mainboard target, it also does the vendor file download, if required. The ./vendor download command is still available, and multiple board names can now be provided as argument, because for example, ./build roms x220_8mb x230_12mb would run ./update trees -d coreboot x220_8mb x230_12mb, and the trees script already supports running for multiple target names, within multi-tree projects. The result of -d, combined with use of mkhelper functions, permits very flexible use of the trees script, essentially allowing it to be extended on a plugin-type infrastructure, in any number of ways. The reason for implementing this is precisely so that project-specific hacks can be removed; the trees script now contains much more generalised logic, and project-specific logic was moved to mkhelper functions.
  • script/trees: A premake variable is supported in mkhelper.cfg files, defining a function to be executed before running make, on a given project.
  • script/trees: A postmake variable is supported in mkhelper.cfg and target.cfg files, defining a function to be executed immediately after running make, on a given project. This is used during coreboot builds, to add payloads on a given coreboot image. It can be used for any other purpose. More specifically: postmake is executed after handling the defconfig file entirely, rather than just after running make; the latter is handled by mkhelper.
  • script/trees: Support build dependencies, complementing the existing fetch dependencies. The build_depend variable can define which other sources need to be built, before building the current target. This is being used on coreboot targets, to manually and surgically specify which GRUB and SeaBIOS trees should be compiled, per coreboot target. A fallback declaration is specified in config/data/coreboot/mkhelper.cfg, for cases where a target.cfg file does not specify it. This change means that certain hardcoded build dependency logic was then removed, instead relying on this much more generalised build_depend logic.
  • script/trees: Allow global configuration on multi-tree projects, via file config/data/PROJECT/mkhelper.cfg, e.g. config/data/coreboot/mkhelper.cfg. This is loaded before target.cfg. That way, global configuration can be provided and then overridden.
  • script/trees: If a valid flag is passed, but without argument, a loop is now executed with that flag on every defined project, both single- and multi-tree. For example, if -f is passed, it will download every project. If -b is passed, it will build every project. When it passes over multi-tree projects, it operates on every tree within that project. This fact enabled other parts of the build system to be simplified; for example, the logic in mkrelease() no longer needs to implement the same kind of loop, instead simply running ./update trees -f to download every project and tree. Similar changes have been made, on that same basis.
  • script/trees: Support use of a variable named mkhelper, first defined in project target.cfg files. This variable defines the name of a function, to be called immediately after running make for that project, under the run_make_command() function. This was initially implemented, so that GRUB's grub-mkstandalone utility could be called from the trees script, but in a way that doesn't hardcode such execution. This is because part of the audit's main focus is to remove project-specific hacks, generalising a lot more logic. Prior to Audit 6, the trees script contained a lot of hacks for specific projects, notably coreboot and GRUB, to compile them properly.
  • script/trees: Only permit one single-tree project to be built, where an argument is provided. This script previously supported building multiple single-tree projects, defined by argument, but it was quite error prone and there's no clean way to otherwise do it. We don't use the script this way, anywhere in lbmk, and users are advised the same.
  • script/roms: Only Support SeaBIOS and SeaGRUB, on x86 mainboards. SeaGRUB is a configuration whereby SeaBIOS starts first, but immediately tries to load GRUB from the flash. This complements the other change, listed below. We will no longer provide configurations where GRUB is the primary payload, precisely to mitigate the same issue as described below (lbmk issue 216). If GRUB is enabled, on a given mainboard, SeaBIOS-only setups are not provided; only SeaGRUB is provided. You can press ESC in the SeaGRUB menu, to access other boot methods besides GRUB from flash, so you can use it in the same way; additionally, you can remove the bootorder file from CBFS if you wish, or change the bootorder file, in such a way that GRUB does not load first. For example, you might want a BSD installation, and BSD bootloaders should be loaded from SeaBIOS directly. This can be done as follows: cbfstool libreboot.rom remove -n bootorder - then flash it. The SeaBIOS code is much smaller and more robust than GRUB, so it's a safe choice of primary payload, and it's extremely unlikely that SeaBIOS would ever break.
  • script/roms: Removed support for grubonly SeaBIOS. This was a feature where SeaBIOS would try to load GRUB first (from CBFS), but also disable the SeaBIOS menu. We still provide SeaGRUB, but the SeaBIOS menu is always accessible now. This is to mitigate future issues similar to lbmk issue 216. The Libreboot 20240612 already removed actual configs using grubonly, and we will no longer provide them in Libreboot, so this feature in lbmk became legacy cruft that can simply be removed. The idea is simple: safety first. This has implications for GRUB hardening; you can insert the correct bootorder file, to once again disable SeaBIOS, but you must first verify that GRUB is stable. The GRUB hardening guide already documents how to do this.
  • script/roms: Don't insert timeout.cfg. Instead, hardcode the GRUB timeout to a reasonable default (8 seconds). You can still insert your own timeout config as before, and GRUB will honour it.
  • script/roms: Insert the background image in GRUB's memdisk, instead of coreboot's CBFS. This reduces the amount of code, because we use it as an argument on the grub-mkstandalone command, and it means that the GRUB images can be used standalone in other build systems. The image is very small, so it's OK to do it this way.
  • script/roms: Removed extra checks on grub_scan_disk, because we no longer allow it to be overridden, instead relying only on target.cfg files, which are carefully crafted per board. This setting configures the order of which types of devices Libreboot's grub.cfg scans first, between device types: PCI-E/NVMe, SATA/AHCI and IDE/ATA. Mate Kukri added NVMe SSD support no GRUB, in the Libreboot 20240612 release.
  • script/roms: Removed dangerous -p, -s and -d options. Due to lbmk issue 216 (GRUB memory issue) in Libreboot 20240504, several safety mitigations have been made, for anti-brick purposes. These options enabled use of a custom payload and keymap, which meant that users were able to more easily create a setup affected by 216. See: https://codeberg.org/libreboot/lbmk/issues/216 - this was fully mitigated, by virtue of configuration, but the issue itself is not yet fixed as of the day of today's announcement, the one you're reading now, so it's still possible to create such a broken setup. Libreboot mitigates this fact, by avoiding such configurations.

Configuration changes

This pertains to anything under config/, for any changes that are of note, but it does not pertain to revisions for specific projects, nor does it cover specific patches applied to projects; the latter will be covered in other sections of this audit announcement.

The changes are as follows:

  • coreboot: Set postmake in config/data/coreboot/mkhelper.cfg, defining a function that adds payloads to the coreboot image that was just built. This mkhelper config also integrates include/rom.sh, containing these functions. This replicates the functionality originally provided by script/roms.
  • coreboot: Set build_depend on target.cfg files for specific mainboards. This is used to manually specify which GRUB and SeaBIOS trees should be compiled, required when compiling for a specific target, for the next stage where a payload is added to the coreboot image, because lbmk does not use coreboot's own payload logic, instead building and adding everything itself (the coreboot configs all enable CONFIG_PAYLOAD_NONE). For cases where a target.cfg file does not specify mkhelper, a fallback default entry is dictated within config/data/coreboot/mkhelper.cfg.
  • GRUB: Only load the xhci module from grub.cfg; the install_modules variable now defines xhci, instead of modules defining it. This means that the xHCI module is no longer automatically loaded during GRUB machine initialisation, but it's then loaded immediately when the GRUB shell starts, and the grub.cfg file is first parsed, then executed. This mitigates a previous issue where booting into GRUB with a USB device connected sometimes made GRUB hang; this issue affected Libreboot 20240612, on Haswell thinkpads, and revised images (and a revised source tarball) was then issued for that release, containing the very fix described here.
  • coreboot: Define makeargs in config/data/coreboot/mkhelper.cfg. It was not practical to define this, and other settings, in each target.cfg file due to how many targets there are, but the mkhelper feature makes this much easier. To mitigate the previous issue, the trees script hardcoded coreboot makeargs in a special variable, cbmakeargs; this variable has since been removed, because it's no longer used.
  • GRUB: Define common build options in config/data/grub/mkhelper.cfg, instead of repeating them in target.cfg files for each GRUB tree. The mkhelper.cfg feature was added, defined in the Features section above, which is loaded per-project on multi-tree projects, before each target file. It allows easier configuration tree-wide on multi-tree projects.

Bug fixes

There are fewer acute bug fixes in Audit 6, because bugfixes was the primary focus of Audit 5. The word acute is used, referring to triggered bugs, because many of these changes are pre-emptive bug fixes, preventing future bugs that have been foreseen, based on future modification to existing logic. The focus of Audit 6 has been general code reduction, feature simplification and improvements to safety features / error handling (many pre-emptive bugfixes implement newer safety features, but are listed as pre-emptive fixes, not features).

The changes are as follows:

  • script/trees: Hardcode makeargs for crossgcc specifically, by using another variable (within that script) called xgccargs. This prevents the build threads being default (one thread), ensuring that we set it to the value as defined by XBMK_THREADS. The bug was triggered when building the U-Boot images, because U-Boot does not specify CPUS= on makeargs.
  • include/git.sh: Re-try git pull three times, when updating the cache Git repository for a given project or submodule. This mitigates possible instability in the user's internet connection, where it's online but may otherwise experience jitter (the same issue could also occur on the internet connection hooking up whichever server lbmk is interacting with, such as the coreboot web server).
  • U-Boot (patch): Courtesy of Alper Nebi Yasak, a mitigation is provided in U-Boot working around the lack of support for clock timings on eDP displays; the clock setting was removed in the devicetree, because display works without it, but with it, display breaks because drivers do not yet support it.
  • U-Boot (patch): Courtesy of Alper Nebi Yasak, a fix was made that prevents breaking the build process for U-Boot, when building binman images. In lbmk, we do not use the BL31 firmware from U-Boot itself, because coreboot does this, so it's patched out in Libreboot and we defer to coreboot's logic.
  • script/trees: Don't continue, when no argument is given. main() used to be the only funsction that runs, in this script, but now we source a config file afterward, and run the build after that. Whan a flag is provided without OPTARG, this means that we are continuing such action in error; in practise, it meant that nothing was done because the command was set by mkhelpercfg and cmd, which would be empty in this situation, but it might cause issues depending on the sh implementation, so this fix is pre-emptive.
  • include/: Remove +x permissions on these files, because they must never be executed directly; they are stubbed from build and script/trees. This is listed as a bug fix, because having executable permission on these files is a potential security issue, depending on how lbmk might be modified in the future, so it's a pre-emptive fix.
  • include/rom.sh: Only build coreboot utilities before building coreboot itself. This prevents coreboot.rom from being wiped out, when building it, due to idiosyncrasis in coreboot's own build system. This is a pre-emptive fix, because the issue didn't really cause actual trouble in practise, except under certain test conditions that are unlikely in real use.
  • include/vendor.sh: Properly quote the filename, in a check for ec.bin, on the extract_kbc1126ec() function - in practise, this caused no issue, so this is a pre-emptive bug fix, but quotes are now used to prevent globbing. Overlooked in a previous audit, where anti-globbing was actually a priority in that audit.
  • include/vendor.sh: Skip serprog targets, if defined, because these are not coreboot and they are built using separate logic, but they are placed in the same directory within release archives. This prevents an exit under fault conditions, instead causing a regular exit (zero status). This was never triggered during regular builds, because of other conditions checked throughout, but some users may run the inject command, which this fix is for. The issue was previously fixed for download, but overlooked for inject.
  • include/vendor.sh: Don't inject /dev/null into an image. In some cases, a given board may define empty option ROMs which refer to /dev/null. This is used during the coreboot build process, in cases where we want such images inserted, but not handled by vendor scripts. Specifically: PIKE2008 images were inserted empty, for KGPE-D16, by re-using the VGA ROM options in the coreboot build system. The vendor.sh logic also uses that same config item, which was tripping up on these boards. Simply skip insertion (in vendor.sh) file location is /dev/null. This prevents errors during the build process, in some limited cases.
  • include/lib.sh: Much stricter checks in chkvars(); the variable string may have been set, but otherwise empty. This function was only checking +x via variable expansion, which only yields negative if the variable was never declared. The intention is to check both unitialised and empty strings, per variable. This is a pre-emptive bug fix, because this bug did not seemingly cause any issues in practise, but a bug is still a bug.
  • include/vendor.sh: Re-added the modify_gbe() function, seldom used but nonetheless required; it's called when the user specifies a MAC address, during vendorfile insertion on release images. Direct use of nvmutil is still recommended, simply to gain an understanding of how it works; the MAC address feature in vendor.sh simply runs nvmutil.
  • script/roms: Made U-Boot be built before checking ubootelf, instead of after. The check was flawed, because if U-Boot didn't exist, but a given build would be vzerified by the first check, the check would still fail after build, because the check works by first checking the existence of a given U-Boot build file, deferring to another and then exiting if that doesn't exist, with error status. This is a pre-emptive bug fix, because this bug wasn't triggered in practise since actual targets already used the fallback build, not the first one. Therefore, this fix is pre-emptive for future U-Boot targets in lbmk.
  • include/lib.sh: Do not exceed 80 characters on the line that checks the versiondate variable. Such excess is considered a bug.
  • include/vendor.sh: Rename variable release to vrelease. Also remove the inject_vendorfiles() function and merge into vendor_download(). The release variable is included now in some target.cfg files, so we want to avoid conflicting with it. This is a pre-emptive bug fix, because the bug described had not been triggered in practise, but was theoretically possible.
  • script/trees: Exit with error status if target.cfg not provided, on multi-tree projejcts. It was already by design that this should occur, but we previously did not support target.cfg files on single-tree projects. Single-tree target.cfg support was later added, done by making target.cfg optional there, but the change accidentally made it optional on multi-tree projects. In practise, all multi-tree projects included this file per target, so this is a pre-emptive bug fix on the theory that future maintainers might accidentally exclude target.cfg on a given tree, within a multi-tree project.
  • build: Don't delete TMPDIR if it's /tmp. We set it to a subdirectory under /tmp, and subsequent mktemp calls create resources under it, but it's possible in the future that this functionality might be broken; therefore, this is a pre-emptive bug fix, on the (correct) theory that code equals bugs, and that regressions can and will occur in the future. One could say that this is a safety feature; it could just as easily be listed on Feature changes. This is more strongly a pre-emptive bug fix, as opposed to an actual feature. Upon exit from the main parent instance of lbmk, TMPDIR is deleted. It is set to a subdirectory of /tmp, precisely so that we have a unified directory location for all temporary files, which then get deleted in bulk (upon exit).
  • script/trees: Explicitly err if OPTARG is not set, for a given flag. We otherwise rely on -e, but different sh implementations may behave differently. Therefore, this is a emp-emptive bug fix, on the theory that execution may otherwise continue erroneously (depending on the implementation). NOTE: this is only listed for documentary reasons, but the script was later modified to allow a lack of argument, whereby the script would be re-called recursively on all projects with the exact same flag, while defining an argument throughout.
  • script/trees: Call err if multiple flags are provided. The script is only designed for one flag. Exit with error status if multiple flags are provided.
  • script/trees: Explicitly set mode for flag -b, rather than leaving it at the default state (empty). This is to mitigate the possibility (from later code changes) where other flags might set the string. We need the string to be empty, when the -b flag is used; this is a pre-emptive bug fix, fixing a bug that doesn't actually exist, but rather, preventing such a bug later on.
  • include/lib.sh: Make the presence of a projectname file mandatory, with the project name inside. This prevents the theoretical issue where a project is nameless, because this file is used during the build process when naming release tarballs; theoreticaly, because in practise, lbmk would never remove this file, but the build system is designed to be as adaptable as possible.
  • script/trees: If the crossgcc build fails, run it again first, before returning with error status. If the second build passes, don't yield an error. Sometimes the crossgcc build can fail for whatever reason, but a second run will succeed. This avoids having to re-run the rest of lbmk, just to re-run the crossgcc build. In most cases, the first attempt passes. Coreboot's own buildgcc script is quite complex, and error-prone.
  • script/trees: Don't check if crossgcc is already built. The check was done based on whether the xgcc directory exists, but coreboot's build system may have exited with error status before, having not completed all builds. The result was that subsequent runs would result in a permanently broken crossgcc build, unless the user manually intervened. Instead, lbmk always runs the crossgcc build script from coreboot; coreboot itself has a much more thorough set of checks, skipping a given build that was already performed, but the check is a bit slower, adding a few additional seconds to the build time per target. The bug that this fixes was in fact triggered, during random testing, leading to the fix.
  • include/lib.sh: Fixed error when running ./build dependencies. The e() and setvars() functions were declared after the dependencies function, but are now declared before. Also: after calling install_packages, it was doing a return when it should have done an exit. All of this lead to certain temporary files being created; the context here was that the user would be running ./build dependencies as root, which lead to some of those files being created as root, but lbmk exits with not-zero status when you run it as root, except when running the dependencies command. Therefore, this could create situations where the user can longer run lbmk without intervention such as changing permission on certain files. Avoid the issue entirely.

General code cleanup

Extensive code cleanup has been performed, as was the main purpose of Audit 6.

The changes are as follows:

  • Removed util/autoport, because the Haswell support that we merged for it is now included in upstream(coreboot), so it will be included in future coreboot revisions for lbmk.
  • script/trees: Move dependency building (based on build_depend) to a new function, called from configure_project(), instead of including the logic directly within the latter.
  • script/trees: Merge build_targets() into handle_targets().
  • script/trees: Use : as a prefix on certain build commands, when doing try runs (dry builds); the -d flag was initially implemented with a lot of if/else chains, but : does nothing in sh (that's what it's for, to do nothing), including if arguments are provided to it. This change enables much more granually disablement of certain commands, which would otherwise require many more if/else chains. This change reduced the amount of code.
  • script/trees: Remove all project-specific hacks. The coreboot-specific includes were moved to coreboot's mkhelper.cfg file. Serprog and coreboot images are handled by mkhelper functions now.
  • include/rom.sh: It also provides building of serprog images. The mkhelper configuration is provided for pico-serprog and stm32-vserprog. The old ./build roms serprog commands still work, but you are now advised to run ./update trees -b stm32-vserprog or ./update trees -b pico-serprog, which will now result in the same builds being provided under bin/.
  • include/rom.sh: New file, replacing script/roms. It contains the same functions, more or less, for building coreboot images. The trees script already produces coreboot images, and payloads were added by script/roms; now, those same functions (for adding payloads) are stubbed via mkhelper configuration in config/data/coreboot/mkhelper.cfg. The command ./update trees -b coreboot (whether specifying additional targets, or specifying none and thus building all of them), now builds coreboot images with payloads inserted, and never leaves them on-disk without payloads; this removes an existing issue where the user might accidentally use the no-payload images, mitigated by provided a warning but still an issue regardless (for example, what if the user doesn't understand English very well?). The old ./build roms command is now deprecated, but still provided for backward compatibility, but you are now advised to run the trees command. The bin/ directory is still the place where coreboot images go, but they no longer appear(without payloads) under elf/ - only the bin/ images are provided.
  • script/roms: Removed unnecessary calls to ./update trees -b for payloads, because coreboot targets now specify build_depend which is used generically per tree, per multi-tree project, to provide such build dependencies.
  • script/trees: Rename function load_target_config() to configure_project(), because the function also now handles building to some extent (based on build_depend), not just mere loading of config files.
  • include/vendor.sh: Removed mkdirs() and merged its logic into the only calling function, fetch().
  • include/git.sh: Simplified git_am_patches() by condensing several for loops together, into a single for loop performing each task.
  • include/git.sh and script/trees: Tidy up the use of global variables. Some of them were only initialised in git.sh but also used in the trees script, which means they should be initialised in the trees script.
  • include/git.sh: Simplified initialisation of loc (single code line)
  • script/trees: Simplified distclean directory check, by reducing the nesting of if/else statements.
  • include/git.sh: Condensed a few code lines in fetch_targets().
  • include/git.sh: Shorter git_prep command in fetch_targets().
  • script/trees: Simplified multi-tree bare repository cloning. The git_prep function already creates a given directory where source code goes, so we don't need to handle it from the trees script.
  • script/trees: Merged prepare_new_tree() with fetch_targets().
  • script/trees: Simplified distclean handling; condensed a few code lines.
  • script/trees: Further simplified copy_elf(); condensed a few code lines.
  • script/trees: Added explicit return to the end of handle_defconfig().
  • script/trees: Renamed check_config() to check_defconfig(), for clarity.
  • script/trees: Removed variable config_name, because it's only used once, so its value was instead hardcoded, without declaring a variable.
  • script/trees: Renamed variable config to defconfig, for clarity.
  • include/git.sh: Removed redundant xtree variable, already defined in trees.
  • script/trees: Removed various comments that were redundant, because the code that they covered was already simple enough that what they did was obvious.
  • script/trees: Cleaned up handle_makefile() a bit; condensed a few lines.
  • script/trees: Renamed load_project_config() to load_target_config(), for clarity.
  • script/trees: Download multi-tree bare repositories before given trees. When downloading multi-tree projects, revisions can be reset to HEAD instead of the actual revision for a given target. This occurs when the bare repository (e.g. src/coreboot/coreboot) does not exist and has to be fetched first. Bare repository downloading does not rely on target.cfg, only pkg.cfg, but uses the same variables, e.g. rev. So: instead of using a separate variable name, do the bare repository download first. This means that the git.sh logic can be much cleaner, in that it only copies the bare repository and then runs git_prep. The bare repository is closed directly by calling the relevant function from trees, which is therefore the same behaviour as when cloning single-tree projects.
  • script/trees: The _setcfgarg variable was removed, in function load_project_config() because it became disused and thus redundant.
  • script/trees: Unified multi-tree and single-tree configuration handling. The same functions that load configurations for single- and multi-tree have been merged with the one in git.sh, and then that was moved back into the trees script. Now git.sh only handles the actual downloading and patching of sources, but not configuration of them; the latter is handled directly within the trees script. The benefit of this change is that it generally allows far more flexibility; many functions that use such configuration logic can now be unified under this script, for instance using the mkhelper feature mentioned elsewhere on this page - and that is precisely what was later done, in further changes that are detailed above.
  • script/trees: Unified handling of source downloads. Run it from function load_project_config(). The logic used to be split, between single- and multi-tree projects, but now it is consistent throughout.
  • include/git.sh: Rename fetch_project_trees() to fetch_targets().
  • include/git.sh: Rename fetch_project_repo() to fetch_project().
  • script/trees: Add explicit return at the end of check_coreboot_utils().
  • include/vendor.sh: Remove unnecessary check; we don't need to check whether the grub_install_modules and grub_modules variables are set, because they always are, and we may want to have a setup in the future where no such modules are defined anyway, for testing purposes. Remove this check entirely. This pertains to mkpayload_grub(), which produces the grub.elf payload builds.
  • include/vendor.sh: Remove unnecessary check; we don't need to check the existence of the option ROM in extract_e6400vga(), because a command comes right after it that copies it. If the file doesn't exist, cp will yield error status, causing the same kind of error returned from lbmk.
  • include/vendor.sh: Condensed inject() a bit, by simplifying some of the if/else chains and especially the way in which they return.
  • include/vendor.sh: Simplified checks for E6400 VGA config; it was being done in a complicated for loop running eval, but similar functionality is already implemented in chkvars(), which is now used instead.
  • include/vendor.sh: Simplified the otherwise over-engineered path checks, when reading vendor paths from inside coreboot configuration files.
  • include/vendor.sh: Simplified handling of the kbc1126 utility in coreboot. We were checking whether the binary exists, but make already does this. We still check whether the directory exists, because not all coreboot trees contain this utility; where they don't, but it is needed, we can always add it with a patch, but this is currently not required.
  • include/vendor.sh: Simplified utils handling in bootstrap(); a single for loop is now used, for all utilities, when running the trees script.
  • include/vendor.sh: Simplified initialisatino of the _7ztest variable; it is included now in the main call to setvars, under global variables.
  • include/vendor.sh: Condensed a few code lines in detect_board().
  • include/vendor.sh: Condensed a few code lines in patch_rom().
  • include/vendor.sh: Add explicit return at the end of bootstrap().
  • include/vendor.sh: Renamed getcfg() to readkconfig().
  • include/vendor.sh: Merged cfgutils() into readcfg().
  • include/vendor.sh: Merged build_dependencies_inject() into vendor_inject().
  • include/vendor.sh: Tidied up a few variable initialisations, and the handling of cbutils (coreboot utilities) in this context.
  • include/vendor.sh: Clean up GbE region handling; there were actually two separate sets of logic for handling the MAC address. It was unified, so that only modify_gbe() is used throughout.
  • include/vendor.sh: General code simplification. Many variables were declared separately, instead of being declared with setvars, and a lot of for loops were condensed.
  • include/vendor.sh: Simplified the modify_gbe() function. It was re-added, and the function was still using a much older coding style from before all the various lbmk audits. The function is now about half the size, while performing the same task.
  • Generally tidied up a few setvars calls, condensing them them so that they used fewer code lines, while still observing the 80-character rule.
  • script/roms: Explicitly shift by 1 for all targets. The way this script worked, it would go through all arguments populating each one inside a single string containing them, shifting until no arguments were left. We want to make sure it is shiftedh by one, and make this intention clear.
  • script/roms: Add return value for the list command, because we want a specific return value but return passes the value of the previous return, if a given return call does not specify an argument, and there's no way to predict what the previous value would have been. However, this is not a bug fix, pre-emptive or otherwsise, because nothing actually using this command relied in any way on its return value.
  • include/vendor.sh: Remove unnecessary checks. The trees script already checks the existing of binaries and sources, so it didn't need to be done here.
  • include/vendor.sh: Remove unnecessary coreboot tree check. We didn't need to download a coreboot tree, because this script also handled coreboot utilities, which in turn would download the necessary coreboot tree in the same way.
  • include/vendor.sh: Remove unnecessary cbutils variable check; the same check (of coreboot utilities) was already performed in script/trees.
  • include/vendor.sh: Remove unnecessary check; mktemp will never return empty output, and it was used just prior to an mkdir command on that output, which would subsequently return an error if the argument is empty.
  • include/vendor.sh: Condensed a few code lines in check_board().
  • include/vendor.sh: Condensed some code lines handling variable initialisation.
  • include/vendor.sh: Remove unnecessary cbfstool variable check; the same check is also performed in script/trees.
  • include/vendor.sh: Simplified the cbfstoolref variable check; condense a few code lines. This variable refers to cbfstool from coreboot 4.13, used for extraction of the refcode file on HP EliteBook 820 G2, at build time.
  • include/lib.sh: Tidy up err_(); condense a few code lines.
  • include/lib.sh: Add explicit return to the end of chkvars().
  • include/vendor.sh: Unified reading of board configs. The inject and download functions had separate logic for this, which is now implemented in a single function throughout.
  • include/vendor.sh: Simplify variable check in getcfg(); use chkvars() to check the vcfg and tree variables (exit with error status if they were not initialised).
  • include/vendor.sh: Removed unnecessary cbdir check. We don't need to check it, because the trees script already checks it.
  • Remove use of _xm in the build system, which was a variable containing a given prefix as set throughout, for each function. It was included in error messages, when returning from a function under fault conditions, but it was no longer used; a relic of lbmk from several audits ago.
  • script/trees: Simplify single- and multi-tree handling in main(). Use shorthand notation on a single line, initialising it based on single-tree and then checking that the given project is multi-tree.
  • script/trees: Rename build_projects() to build_project(). The script used to support building multiple single-tree projects, but this behaviour was buggy and unused, so it was removed. Rename the function accordingly.
  • script/trees: Set btype if target.cfg doesn't exist; set to auto. The build system assumes multi-tree, if Kconfig files are used. Single-tree projects will not typically define btype, so just default it to auto.
  • include/lib.sh: Removed unused cbdir variable.
  • script/roms: Don't assign cbdir, because it wasn't even used here.
  • script/trees: Don't hardcode skipping kconfig files based on whether the project is GRUB. Instead, define btype in project target.cfg files, and define this in GRUB. Some projects are multi-tree but do not use Kconfig files, and GRUB is one of them; we must avoid commands such as make menuconfig, doing nothing and returning with zero status explicitly, otherwise it would yield an error, which is a problem if you ran the trees script with a flag but no argument (which, as documented elsewhere in this report, was later made to operate that flag on every project in succession).
  • include/git.sh: Don't check that a given source directory exists, because the main trees script already does this before running fetch commands, which are implemented in git.sh.
  • build: Move git_err() here, from include/lib.sh, because it's only used in the main build script.
  • include/lib.sh: Simplify singletree(); condense a few code lines.
  • include/lib.sh: Add an explicit return to the end of check_defconfig().
  • include/lib.sh: condense the e() function a bit (was already done before, and done again).
  • include/lib.sh: Simplified TMPDIR handling; remove the tmpdir variable and use TMPDIR directly. Use a new variable xbmk_parent, which is set to y only on the main instance; child instances of lbmk do not set it, signalling that TMPDIR should not be removed upon exit (it should only be removed upon exit from the main parent instance of lbmk, not child instances executed by it).
  • include/lib.sh: Condense if/else logic in setcfg(). Use shorthand notation instead, on conditional statements.
  • include/lib.sh: Condensed setvars() a bit.
  • include/lib.sh: Simplified lock message, when a lock file exists while trying to run lbmk.
  • include/lib.sh: Simplified reading of version files. A single for loop now initialises all of these variables with a single eval command inside.
  • include/git.sh, include/lib.sh, script/roms and script/trees: Simplify use of environmental variables. The variables themselves were being copied to other variables, of lowercase naming, but this was unnecessary. The environmental variables are now used, directly, while being properly set per each running instance of lbmk.
  • script/roms: Remove the t variable, which was used for temporary ROM images. The script now operates on images more directly, and this variable is no longer used (previously used for storing paths to temporary images).
  • script/roms: Simplified logic for checking U-Boot builds.
  • script/roms: Simplify initmode/displaymode loop, when building multiple coreboot images per target.
  • script/roms: Renamed a few functions and variables for code clarity.
  • script/roms: Build coreboot images earlier on in the process, to avoid duplicate work. It was built per coreboot configuration, but the logic builds all images per target, so it doesn't make sense to run the build twice. The subsequent runs would just skip, because the images already existed.
  • script/roms: Generalised more logic, merging a lot of functions and reducing a lot of code repetition.
  • include/lib.sh: Remove badcmd(), because it's bloat. This function simply write "bad command", followed by a call to the err function. Instead, simply call err with the same string, when required.
  • include/lib.sh, include/git.sh and include/vendor.sh, script/trees and script/roms: More unified handling of project configurations. Remove the function scan_config(), which worked with a specially crafted format that we had for vendor files and project (source repo) configs. Instead, use flat config files. Individual target.cfg files for coreboot now contain a vcfg variable pointing to a directory, containing vendorfile config. This change resulted in a sloccount reduction of about 20, in the build system, and the new config handling is much more robust.
  • script/trees: More robust check for make fetch, when handling source downloads. Don't use shorthand form; instead, use if/else chains to determine whether to skip a target after download.
  • include/vendor.sh: Minor code cleanup (condense a few code lines).
  • include/git.sh: General code cleanup in fetch_submodules(). Several code lines have been condensed.
  • script/roms: Merge mkserprog() into main(), because it was essentially performing the same functions, but for checking serprog targets. Unify the logic, for handling coreboot, stm32 serprog and rp2040 serprog targets.
  • script/roms: Reduced code indentation in build_grub_roms().
  • script/roms: Remove build_payloads() and split it into smaller functions.
  • script/roms: Condense lines together that check for various payloads.
  • script/roms: Removed the mt86bin variable, because it's only used once. Instead, hardcode the path to memtest86plus when building it.
  • script/roms: Merge build_uboot_payload() into build_payloads(), because both functions are very simple and do essentially the same thing.
  • script/roms: Simplified check for u-boot payload; we only need to know whether it's enabled, not whether it's also disabled. If set to enable other than y, set it to n blindly.
  • script/roms: Simplify the check for serprog source directories. Instead of an if/else chain, re-use variables and use a single eval command between the two types; serprog rp2040 and serprog stm32.
  • script/roms: Simplify the loop for building serprog images, by re-using variables more aggressively and removing the if/else chain for serprog type.
  • script/roms: Shorter variable names for serprog build logic.
  • script/roms: Simplified serprog image copy, by using a single eval call referencing stm32src or rp2040src, thus unifying this logic between both types of serprog build.
  • script/roms: Rename picosrc to rp2040src; this is in preparation for the next change, mentioned above.
  • script/roms: Remove confirmation dialog at the end of a serprog build, because the message was overly pedantic and something the user already knows.
  • script/roms: Merge the serprog handling into a single helper function.
  • script/roms: Renamed the x variable to it in a for loop, to avoid possible conflict with another same-named variable elsewhere in this script.
  • script/roms: Don't call x_ when using cproms(), since it never returns with non-zero status anyway.
  • script/roms: Move the U-Boot images, instead of copying. This way, we don't have to clean up the temporary file that was used for it.
  • script/roms: Allow flexible use of mv or cp in cproms().
  • script/roms, include/lib.sh and script/trees: Use a common string for setting elfdir, which is where builds are copied to upon completion.
  • script/roms: Merge mkUbootRom() into build_uboot_roms().
  • script/roms: Remove unused variables in mkSeabiosRom().
  • script/roms: Remove unused variables in mkUbootRom().
  • script/roms: Remove unnecessary variable assignment; cbcfg was already properly initialised as a global variable, so this was re-used instead.
  • script/roms: Removed unnecessary check for payload_uboot; the uboot_config variable, if set, clearly indicates use of U-Boot.
  • build: Remove unused linkpath and linkname variables.
  • script/roms: Make tmpcfg a variable, re-used elsewhere when a temporary file needs to be written. Simply overwrite the file as required, instead of always calling mktemp.
  • script/roms: Simplified timeout/scandisk insertion. We don't need to call mktemp every time. Just use a static temporary file and keep overwriting it, when we need to make a new configuration file inside CBFS.
  • script/roms: Simplified SeaGRUB check in build_grub_roms(); condensed a few code lines.
  • script/roms: Simplify mkserprog(); condensed several code lines and removed unused variables!
  • script/roms: Simplify the Serprog build functions; condensed several code lines and removed unused variables.
  • script/roms: Simplify U-Boot payload check (same change as below).
  • script/roms: Simplify GRUB-only check on SeaGRUB (same change as below).
  • script/roms: Simplify SeaGRUB check in configure_target(); condensed the if/else checks based on which payloads are configured.
  • script/roms: don't use x_() to call build_grub_roms(), since that function never returns non-zero status anyway.
  • script/trees: Simplify copy_elf(); condense the while loop handling file copies, for copying builds to their destination paths once complete.
  • script/trees: Remove unnecessary check in copy_elf(); we don't need to check whether the listfile string is empty, because a check comes after it as to whether the file it defines exists, and checking an empty string there will always yield a negative result, as intended.
  • include/lib.sh: Add generic cbfs() function, which is now used throughout lbmk when adding files to CBFS on coreboot images. This simplifies handling of CBFS in lbmk.
  • script/roms: merged handling of build targets into the main script, simplifying the loop going through them all; each helper function returns with non-zero status if the build is to cease, and the target is skipped.
  • script/roms: Simplified handling of multiple coreboot build targets, when looping through them all during the build process.
  • include/lib.sh: added a unified function chkvars(), now used for checking variable initialisation; if a variable is not initialised, it causes an exit with non-zero status.
  • script/roms: shorter variable names, condensed several functions.

Revision updates

U-Boot

Alper Nebi Yasak is the maintainer of U-Boot, within Libreboot, and submitted a patch updating U-Boot to v2024.07, on the gru_bob and gru_kevin Chromebooks. Several improvements have been merged upstream, like Alper's patches for Qemu, so these patches have been dropped in lbmk because they're now included by default, in the new U-Boot revision.

Alper also tested the latest coreboot revision and it worked fine, on these boards, but revision updates will be done immediately after Audit 6 is announced, as a priority for further work that is to be completed for the next Libreboot release, ETA August 2024.

Git log

This git log covers all changes in this audit, relative to Libreboot 20240612.

* 31f1e4dad vendor.sh: don't use XBMK_CACHE for appdir 
* 2b50b3ea9 put cachedir in environmental variable 
* 0e0b12a63 git.sh: warn when a cached clone fails 
* 9b1b95576 git.sh: fix typo in git command 
* 82bdf2707 git.sh: fix lack of error exits on fault
* 64283a1fb build: remove tmp/ on release archives
* bf85246c4 trees: hardcode makeargs for xgcc 
* c6e6d96ce allow using coreboot's build system to add payload 
* 78cdc56ae trees: remove unnecessary command 
* e69903789 build: remove cache/ on making releases 
* 79f50b379 unify caching of files into cache/ 
* a9f9de885 unified cache file handling for vendorfile/subfile 
* ef867eccc git.sh: remove previous tmprepo if args>5 
* 4d5385a14 git.sh: try direct clone if cached git fails 
* 0cd52fc7f git.sh: re-try git pull three times 
* 0b9cd77fe trees: auto-delete+auto-rebuild if project changes 
* 4438368c0 trees: also remove single-tree repo/p/ 
* 570e3abb2 trees: remove repo/p, not src/p/p 
* 583502027 git.sh: don't download to src/project/project/ 
* 9f09728ac git.sh: cache git downloads to repo/ 
* f367afabc remove util/autoport 
* 373c2eb23 trees: move dependency building to new function 
*   12c3956f5 Merge pull request 'Update U-Boot to v2024.07' (#225) from alpernebbi/lbmk:uboot-v2024.07 into master 
|\  
| * 708fc14c6 u-boot: Fix display initialization on gru boards 
| * 0cc7736b4 u-boot: Avoid breaking build for U-Boot-only binman images 
| * 2ecec55af u-boot: Update to v2024.07 
|/  
* 090cf7ad5 trees: fix bad comparison in configure_project() 
* e37779c11 trees: don't continue if no argument given 
* 3263eeb6b trees: general code cleanup 
* 17f3e61a0 trees: merge build_targets() with handle_targets() 
* c0a4df688 trees: use wrapper for dry-running make commands 
* 459db1cc2 trees: remove project-specific hacks 
* e9f66ec4a remove executable permission on include/ 
* 91994b785 rom.sh: actually say if a cbutil exists 
* 97b777715 rom.sh: avoid re-building cbutils if built 
* 494b94799 rom.sh: only before cbutils before coreboot 
* 469cc64f9 trees: fix bad comparison 
* 5a1d2401c minor cleanup 
* 964617214 trees: support -d (dry run) for custom build logic 
* e850c06bd rom.sh: only make rom tarball if release=y 
* 2f3cc5d37 rom.sh: new file, to replace script/roms 
* 889afe168 roms: remove unnecessary trees checks 
* c241a3ef4 coreboot: set build_depend on target.cfg files 
* 6d4fb200a trees: rename load_target_config() 
* 87df6ae36 trees: support build dependencies, not just fetch 
* 23ca49bee GRUB: only load xhci from grub.cfg 
* 065453b72 trees: just do makeargs on coreboot, not cbmakearg 
* 2ab1d9949 trees: fix bad rm -Rf command (-Rf, not Rf) 
* d6ff009e2 roms: fix bad comparison in configure_target() 
* 3ee045f9a GRUB: use mkhelper.cfg for common variables 
* 3ef84af9f trees: allow global config on multi-tree projects 
* 2b49714a6 trees: handle all projects if project undefined 
* b7f12ade0 vendor.sh: remove mkdirs() 
* 0018600d6 git.sh: simpler for loop in git_am_patches() 
* 5882056a2 git.sh: merge for loops in git_am_patches() 
* 67421a21f trees and git.sh: tidy up global variables 
* 55dbd72aa git.sh: simplified initialisation of "loc" 
* 0cb84a8dd trees: simplified distclean directory check 
* 5ba0433b5 git.sh: condense fetch_targets() a bit 
* 4772186b1 git.sh: short git_prep command in fetch_targets() 
* c62dbdbe8 trees: only do bare multi-tree clone on git 
* 89a81a291 trees: simplified multi-tree bare repo clone 
* 017fd8259 git.sh: merge prepare_new_tree with fetch_targets 
* f937a1142 trees run_make_command: simpler distclean handling 
* 88f741db9 trees: condense copy_elf() a bit 
* d5928c9ba trees: add return to handle_defconfig() 
* 1a7c8acb0 trees: rename check_config to check_defconfig 
* ba7b3a3b2 trees: remove variable "config_name" 
* 030f1afd8 trees: rename variable "config" to defconfig 
* 739496061 git.sh: remove duplicate "xtree" variable 
* 0c4ad24b0 trees: remove unnecessary commonts 
* eacc41e82 trees: condense run_make_command() a bit 
* 563948141 trees: condense handle_makefile() a bit 
* 1ec9fc336 trees: mv load_project_config load_target_config 
* 789631ccb trees, multi: download bare project *before* trees 
* a5e724e51 trees: unified multi-tree configuration handling 
* cfc9f62ff trees: unified handling of source downloads 
* 7bf283520 git.sh: rename Fetch_project_trees fetch_targets 
* e0c244f37 git.sh: rename fetch_project_repo to fetch_project 
* 02f741795 trees: better skip-clean string in handle_src_tree 
* f7ec42d37 trees: add return to check_coreboot_utils() 
* 8d02adfbb trees: simplify "utilmode" variable initialisation 
* d1b7882c5 vendor.sh readcfg: split the -b coreboot command 
* fbe36b01a trees mkpayload_grub: remove unnecessary check 
* 088a79918 vendor.sh: remove unnecessary check 
* 8c5f78d3d vendor.sh: condense inject() a bit 
* 42925ce79 vendor.sh extract_kbc1126: use quote on file check 
* ddcc74777 vendor.sh extract_kbc1126ec: simplify build check 
* 7a12cd770 vendor.sh: simplify e6400 vga rom file check 
* 163bcfcdf vendor.sh: simplify variable checks for e6400vga 
* cbac2087c vendor.sh: condense fetch() a bit more 
* 675d2c037 vendor.sh: remove unnecessary check 
* 5e46b9f43 vendor.sh: simplify kbc1126 util handling 
* 7086b6868 vendor.sh: simplify bootstrap() utils handling 
* 6a05487ef vendor.sh: simplified initialisation of _7ztest 
* 972e61070 vendor.sh: condense detect_board() a bit 
* bf5acedb1 vendor.sh: condense patch_rom() a bit 
* 8b8cf070d vendor.sh: add return to end of bootstrap() 
* d85b9de2d vendor.sh: rename getcfg() to readkconfig() 
* 53b69f673 vendor.sh: merge cfgutils() into readcfg() 
* 55677d821 vendor.sh: remove build_dependencies_inject() 
* c76419861 vendor.sh: simplify initialisation of variables 
* d63da943c vendor.sh inject: skip serprog targets 
* c6df9666a vendor.sh: don't inject /dev/null 
* f7ab70f60 vendor.sh: simplify inject() 
* ee5bab2c9 vendor.sh: clean up GbE handling 
* f2d53eb84 vendor.sh: condense fetch() a bit 
* 85c2eb0f7 vendor.sh: general code cleanup 
* a8f272536 lib.sh: stricter check in chkvars() 
* fa5af956c vendor.sh: simplified modify_gbe handling 
* 155ce49b1 vendor.sh: simplify modify_gbe() 
* 08bce7ad3 vendor.sh: minor code cleanup 
* 636b86237 vendor.sh: re-add modify_gbe() 
* 2eb0163cc Revert "vendor.sh: remove unnecessary check" 
* 3f37c3788 tidy up some setvars lists 
* ed3cce84b roms: explicitly shift by 1 on the "all" target 
* 359d00bd5 roms: add return value for the list command 
* 3f540e756 roms: build u-boot *before* checking ubootelf 
* afc003068 remove more unnecessary checks on trees commands 
* 35c487106 vendor.sh: remove unnecessary checks 
* ce03786f6 vendor.sh: remove unnecessary command 
* e01b5c974 vendor.sh: remove unnecesessary cbutils check 
* 8196ce6dd vendor.sh: remove unnecessary check 
* 8f50131e1 vendor.sh: condense check_board() a bit 
* d12a68601 vendor fetch(): condense variable initialisation 
* 708e306e5 vendor.sh: remove unnecessary cbfstool check 
* 75951c469 vendor.sh: simplified cbfstoolref check 
* d36c07847 lib.sh: keep versiondate check to 80 characters 
* 40d3bb19b lib.sh: condense for loop 
* 5725e3c4e lib.sh: condense err_() a bit 
* e3546f77b lib.sh: add a return to the end of chkvars() 
* d0f68a0fb vendor.sh: rename release to vrelease 
* 473f27784 vendor.sh: unified reading of board configs 
* a2f4eba58 vendor.sh: simplify variable check in getcfg() 
* 4afcbcb64 vendor.sh: remove unnecessary cbdir check 
* fd037722a remove use of _xm variable in the build system 
* 136787185 trees: don't hardcode use of mkpayload_grub 
* c59fbb365 trees: simplify single/multi handling in main() 
* 902b98d1a trees: rename build_projects to build_project 
* e1e04aa80 trees: err if target.cfg not given if multi-tree 
* 93ff80d96 trees: set btype if target.cfg doesn't exist 
* 732c5908d lib.sh: remove unused cbdir variable 
* 119cebc4d roms: remove unnecessary assignment to cbdir 
* 7a15ba18c trees: avoid kconfig make commands generically 
* eb9c1872b git.sh: remove unnecessary check 
* 9aec992ff lib.sh: move git_err() to build 
* 6fc7cd3c1 lib.sh: condense singletree() a bit 
* 35d09e426 lib.sh: add a return to the end of check_defconfig 
* 144b3c93a trees: condense elfcheck() a bit 
* 7b8c2bd41 lib.sh: condense e() a bit 
* ffdecb0ce trees: shorten the final confirmation message 
* ed6acfee8 lib.sh: make elf/coreboot* a dot directory 
* 44fb98736 build: don't rm TMPDIR if it's /tmp 
* fac74cd60 lib.sh: simplified TMPDIR handling 
* 671893a80 lib.sh: condense setcfg() if/else logic 
* 19bc5845a trees: remove redundant space in printf 
* 9154ba5b8 trees: explicitly err if OPTARG is not set 
* f383b1ad7 trees: only permit one single-tree project 
* a64e2db58 trees: call err if multiple flags are provided 
* 0e97e98fe trees: explicitly set mode for -b 
* 7f7b640d3 roms: re-add compression of coreboot images 
* 1ab9189cb roms: build coreboot *after* checking variables 
* 2b4c6ee5c lib.sh: introduce mandatory check of projectname 
* c79fb125e lib.sh: condense setvars() a bit 
* 1387dc0ae simplified lock message 
* 20ac7ec67 lib.sh: simplify reading of version files 
* 4e48fa808 lib.sh: simplify use of environment variables 
* b4fb25100 roms main(): confirm what serprog images are built 
* 5e2308ce0 roms: remove unused variable name 
* 2960abd00 roms: remove redundant printf 
* c661eca6b roms: optimise u-boot elf check 
* 8af9f904c roms: simplify build_roms() 
* c9f26dbc9 roms: make the bin/elf message more polite 
* 9484eda5a roms: re-add final confirmation of targets 
* 2b7df7ab2 roms: rename functions for extra clarity 
* 6753222d0 roms: build coreboot early to avoid duplicate work 
* 19e7c1eab trees: try xgcc build twice if first attempt fails 
* 6468bdb3a trees: don't check if xgcc is already built 
* d5baaff0e lib.sh: fix error running ./build dependencies 
* 0158a0811 roms: general code cleanup 
* e67cd1716 roms: only support SeaBIOS/SeaGRUB on x86 
* 71137b12b roms: remove support for "grubonly" seabios 
* d4d5d2902 use backticks on eval commands, not subshells 
* c1527b611 lib.sh: remove badcmd() 
* fc7ae3e59 lib.sh: more unified config handling 
* ad1602569 trees: more robust check to avoid "make fetch" 
* a6b1a6bdd roms: fix lack of backslash on multi-line command 
* 8c4a91850 vendor.sh: more cleanup 
* 471129684 Revert "roms: remove build_payloads() and split it up" 
* 5a4fc97c6 vendor.sh: correction (s/scancfg/scan_config) 
* d65e4fac1 git.sh: revert modification to for loop 
* bc61c39ec vendor.sh: minor code cleanup 
* 808458ced minor code cleanup in the build system 
* 4ab99d546 git.sh: general code cleanup in fetch_submodule() 
* cd1d84789 git.sh: reduced indentation on repo/file check 
* 4f6dda136 git.sh: simplified repo/backup check 
* 185d76f57 roms: merge mkserprog() into main() 
* 893e88bc8 roms: don't insert timeout.cfg 
* abfc799fd correction 
* a0da8fdef roms: reduce indentation in build_grub_roms() 
* 383433d4f roms: re-introduce accidentally disabled check 
* 3610667e3 roms: remove build_payloads() and split it up 
* 29a7123c0 roms: group some commands that are similar 
* 2d6946775 roms: remove mt86bin variable 
* 920e5ba2d roms: merge build_uboot_payload to build_payloads 
* a96c4b59f roms: simplify payload_uboot y/n check 
* 28682b1a4 roms: simplify the check for serprog srcdir 
* b61dd4c25 roms: simplify the loop for building serprog roms 
* 6df17860e roms: shorten variable serprog_boards_dir 
* ea5b5b072 roms: simplified serprog image copy 
* ea9bdfce4 roms: rename picosrc variable to rp2040src 
* 1a4f97ffd roms: remove useless confirmation in mkserprogfw 
* 1881d34db roms: merge serprog build into one function 
* f7e28964a roms: remind the user about gkb files 
* f928ac5c7 roms: rename x variable to it in for loop 
* 58a451865 roms: don't use x_ to call cproms() 
* bc853fbb8 roms build_uboot_roms(): move rom, don't copy 
* 12b26f207 roms cproms(): allow other commands besides cp 
* e67628c6a unify coreboot elfdir (DO_NOT_FLASH) 
* 8b58c1eac roms: merge mkUbootRom() into build_uboot_roms() 
* c3f0a109c roms: simplify mkSeabiosRom() 
* c8944f1ca roms: simplify mkUbootRom() 
* 92aa83a23 roms: simplify build_roms() 
* d3e788645 roms: remove unnecessary check 
* ef411c596 build: remove unused variables 
* 6dc051558 roms: further clean up build_grub_roms() 
* 0e9b36c58 roms: simplify timeout/scandisk insertion 
* 3a7b3660f roms: simplify seagrub check in build_grub_roms 
* 4b764d26f roms: simplify mkserprog() 
* 167e7447a roms: simplify the serprog build functions 
* 7bc9fcc34 script/roms: fix serprog build commands 
* 0dfe3aed9 roms: simplified ubootelf check 
* a9166898d roms: simplify grubonly check in configure_target 
* 90017cdc5 roms: simplify seagrub check in configure_target 
* 817004e15 roms: don't use x_ to call build_grub_roms 
* 0812d5321 trees: simplify copy_elf() 
* 331c4097f trees: remove unnecessary check in copy_elf 
* 340eea0b1 grub: insert background in memdisk instead 
* ed9c90e59 roms: unify all add-payload commands 
* 26451775d roms: don't add grub keymaps at all 
* af8296ce6 roms: merge handle_coreboot_target into main() 
* d1c0c3464 roms: simplify target check (whether roms built) 
* f626b25db roms: simplify main() again 
* eb9a688ee roms: remove redundant check on grub_scan_disk 
* a4328cb11 roms: remove dangerous runtime p/s/d options 
* 167e1a0fb unified checks for variable initialisation 
* 98724d701 lib.sh: remove the items() function 
* baea03c67 roms: simplify main()

This is 247 changes in total, between 12 June 2024 and 19 July 2024.