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---
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title: Jobs that need doing
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x-toc-enable: true
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...
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This page contains a curated list of tasks that are to be worked on, or tasks
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that are being worked on. This is intended to complement
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the [issue pages](https://codeberg.org/libreboot/lbmk/issues/).
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General auditing
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================
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Libreboot's build system design is already extremely efficient. See:
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[lbmk build system documentation](../docs/maintain/)
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One of the reasons for this is auditing. The build system is regularly audited.
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In this context, that means reading the code to check for quality, pre-emptively
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fix bugs and generally think about the design of the project. Smaller is better.
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Code equals bugs, so less code yields fewer bugs. For a general idea of how
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audits are done in Libreboot, see:
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* [Libreboot build system audit 1](../news/audit.md)
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* [Libreboot build system audit 2](../news/audit2.md)
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* [Libreboot build system audit 3](../news/audit3.md)
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Auditing can often be pedantic, and seem petty. You might commit a patch that
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reduces the sloccount by only 1 line, maybe 3, but they all add up. Audit 3
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contained hundreds of changes, small changes, that together accounted for
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about 1000 lines of code removed, while not affecting functionality in any way.
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Linuxboot
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=========
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See for inspiration: [Heads project](https://osresearch.net/)
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and [Ownerboot project](https://sr.ht/~amjoseph/ownerboot/), these are other
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coreboot distros similar to Libreboot, but they provide Linux-based payloads.
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Also see more in general, the [Linuxboot](https://www.linuxboot.org/) project.
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Libreboot's build system is documented, see: [lbmk
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documentation](../docs/maintain/).
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It's possible to provide a Linux system that runs from the flash. Linux can
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execute another Linux kernel, using the `kexec` feature. There are bootloaders
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that can make use of it, for example
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the [u-root](https://github.com/u-root/u-root) project.
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Libreboot's current choice of coreboot payloads are:
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* SeaBIOS (x86 only), provides a traditional PC BIOS implementation
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* GNU GRUB (x86 only), provides a multiboot implementation, can boot Linux and
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BSD. This is the preferred default payload on x86, especially for Linux
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distros, because it provides many security features like GPG signature
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checking on Linux kernels, and password protection.
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* U-Boot (ARM only), provides several boot methods, we typically use the UEFI
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implementation but it also provides many different boot methods; the one that
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is most interesting is the SPL (secondary program loader) feature, which is
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essentially the same concept as loading a coreboot payload - together with
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something like the minimal [uefistub](https://review.coreboot.org/c/coreboot/+/78913)
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payload, can provide a complete setup.
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U-Root in particular (not to be confused with U-boot has parsers in it for
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GRUB and Syslinux config files. GRUB also has a parser for syslinux configs.
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This makes it a useful drop-in replacement for the GNU GRUB payload that
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Libreboot currently uses. Linux has much better drivers than GRUB, especially
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for things like LUKS2 and networking.
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Ideas for how to implement in lbmk
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-----------------------------------
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Look at the [lbmk documentation](../docs/maintain/) for context. The most
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logical way to implement Linux payloads in Libreboot's build system, lbmk,
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might be:
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* Re-use the current crossgcc handling in `script/update/trees`, which is used
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for coreboot and u-boot. Coreboot's cross compiler isn't very useful for
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general applications e.g. utilities, but it could compile the Linux kernel
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easily.
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* Separately to crossgcc,
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use [musl-cross-make](https://github.com/richfelker/musl-cross-make) for
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the programs inside initramfs. Use this to provide musl libc, busybox and
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all of the userland applications in general. Musl-cross-make itself would not
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be used as-is, but adapted and integrated into the lbmk build system.
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The design of musl-cross-make is largely compatible with that of lbmk, because
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both build systems are written in shell scripts and with the same minimalist
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mentality. 72 source lines! At least as of musl-cross-make git
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revision `fe915821b652a7fa37b34a596f47d8e20bc72338`.
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* In each package defined under `config/git/` in lbmk, use the current design
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but support specifying, for each one, whether or not to use musl-cross-make.
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The current design in lbmk already permits use of make and cmake, for simple
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projects, otherwise for more complicated setups, a dedicated script is
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written, e.g. `script/build/grub` for building the grub images (which runs
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automake in the grub build system), or `script/build/roms` which builds
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rom images.
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* A script, `script/build/linuxboot` would build the entire payload with u-root
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in it, but `script/update/trees` would actually build each package.
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BONUS: the musl-cross-make logic could also be used to provide static linked
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utilities, so as to provide compiled utilities in Libreboot releases, reliably.
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We currenty only provide source code for utilities, which is not always
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convenient for users, especially for utilities needed alongside vendor scripts.
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If done in the way described above, the current code size in the Libreboot
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build system would not increase much. It's mainly the addition of
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musl-cross-make. Most of the generic build logic already exists in lbmk, for
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projects that use cmake and/or make. It could be done with minimal complexity.
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Flash size limitations
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----------------------
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With a stripped down kernel, and sensible configuration, about 6-8MB of flash
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space would be required in this setup. The Heads setup is just under 8MB.
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Why Linux in flash?
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-------------------
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Linux has better drivers than GRUB, has netboot, and it's much more practical
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when you want to control the boot process. For example, you could more easily
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implement measured boot and make use of TPM-based security mechanisms.
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For the everyday user, it probably doesn't make much difference if they're
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already happy with SeaBIOS, GRUB or SeaBIOS.
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x86 implementation
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------------------
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Coreboot can directly execute it as a payload, but we would also execute it
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from the GRUB payload - if running from the GRUB payload, we could just provide
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it as a vmlinuz and initramfs file.
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ARM implementation
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------------------
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We already standardise on U-Boot, for ARM machines. It's debateable whether
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Linuxboot is even desirable here, U-Boot is quite competent, but the SPL mode
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in U-Boot could be used to provide the Linux payload setup, OR:
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See: [uefistub](https://review.coreboot.org/c/coreboot/+/78913)
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Although currently only under review, not yet merged anywhere, uefistub seems
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like a useful way to provide just the most minimal UEFI implementation, required
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on Linux distros, but all it does it then boot a Linux payload. This is probably
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what should be used, on ARM platforms, instead of U-Boot, if Linux is to be
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provided in flash, but the uefistub will use a lot less space than U-Boot. That
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being said, uefistub does not seem to provide a complete, or even fully
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correct UEFI implementation.
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(then again, linux on bare metal providing kexec as main bootloader method is
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also quite non-standard, at least on x86 and ARM).
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Leah Rowe