tianocore.github.io

It works on the majority of UEFI implementations 1. Just a matter of a boot entry. However adding the boot entry is not trivial: efibootmgr used to have implementation which have been reverted (it was incomplete, works only with full device path unlike just MAC which the original code added). I don't know any utilities to do that, ended patching efibootmgr myself. Learned about it from this talk: https://youtu.be/EtGhHCr3VLE?t=567 2. HTTP Boot is also available as a DHCP option 67 without boot entry: * https://github.com/tianocore/tianocore.github.io/wiki/HTTP-B... * https://documentation.suse.com/sles/15-SP6/html/SLES-all/cha...

There is still support for CSM in the open source https://github.com/tianocore/tianocore.github.io/wiki/Compat... and even nice projects like https://github.com/coreboot/seabiosto fabricate the CSM16 binary, but many vendors have stopped validating this path, including production of legacy BIOS option roms for adapters (net, gfx, etc) https://www.phoronix.com/news/Intel-Legacy-BIOS-EOL-2020. I still believe CSP's maintain some of this support in their hypervisors' guest firmware for legacy OS binaries/ISO boot support? Also since Windows requires UEFI Secure boot enabled by default and CSM has to be disabled for the UEFI secure boot path, this is another reason legacy BIOS boot isn't exercised so much these days. We could have added legacy oroms hashes to UEFI Secure boot implementations https://patents.google.com/patent/US8694761B2/en,

> * Not having a minimal straightforward shell to troubleshoot from There is a shell for UEFI. It feels a lot like a reimplementation of MS-DOS shell, with "FS0:" to change drives etc, but it has directory listings, file copying, etc. The interface is standardized and there's an open source implementation in EDK2. If you build Linux kernels as "EFISTUB", they're simply executables in the UEFI shell. https://github.com/tianocore/tianocore.github.io/wiki/ShellP...

> someone would have to pay a team of engineers to rewrite everything A partial effort has already been made a while back: https://github.com/tianocore/edk2-staging/tree/edkii-rust However, this uses uefi-rs, which is incompatible with TianoCore's BSD+Patent licensing, and therefore cannot be used as reference material, as the wiki page states: https://github.com/tianocore/tianocore.github.io/wiki/Tasks-... More recent efforts have also been mentioned in the mailing list: https://edk2.groups.io/g/devel/search?p=recentpostdate%2Fsti... Rust also has a basic standard library implementation now: https://github.com/rust-lang/rust/pull/105861

NASM is used in Tiano Core / EDK2 - "framework" for UEFI development https://github.com/tianocore/tianocore.github.io/wiki/Gettin...

Intel has opensource training on EFI/UEFI and the whole boot process. https://github.com/tianocore/tianocore.github.io/wiki/Traini... Alot of the other stuff is either outdated or not relevant for current stuff. Tianocore/EDK is pretty much the standard for dev on that level and this directly teaches that.

You would be surprised. For example, this is a guide my colleague wrote to describe his git workflow: https://github.com/tianocore/tianocore.github.io/wiki/Laszlo...

which you have to pay to use in any way, including writing an implementation You may be misleading here, AFAIK the spec is free to implement (which helped spread its adoption) or else things like this would not exist or be sued out of existence: https://github.com/tianocore/tianocore.github.io/wiki/Corebo... On the other hand, I agree with you and Linus on the actual spec itself: https://yarchive.net/comp/linux/efi.html

You could try this: https://github.com/tianocore/tianocore.github.io/wiki/UEFI-E... I don't know of any easily digestible document though.

https://github.com/tianocore/tianocore.github.io/wiki/Gettin... Also, see the "Resources" section of this: https://github.com/tianocore/edk2 Every computer coming out these days should be on EDKII based UEFI Firmware

In case others find it interesting, I tried to look around for any relationship between linuxbios/seabios and uefi - and found some references tianocore and edk/edk II: https://github.com/tianocore/tianocore.github.io/wiki/EDK_II... Looks like seabios is (mostly) happy being a bios (with possible plans to be packaged as an "csm application" (I'm guessing that means being loaded from efi)). But, s far as I can tell, for a free/open uefi toolkit, tianocore is the project to look at. I'm a little disappointed that I couldn't easily find a ready-to-run uefi space invader or tetris clone... ;) [ed: eh, I see tfa links to tianocore's ovmf code for vms... Oh, well... ]

(U)EFI is essentially a little OS that eventually loads the OS that runs the software you care about. Intel sponsors most of the core OS code (mirrored) at: https://github.com/tianocore/edk2 A Bios vendor takes that code, drops in a bunch of hardware init code from Intel (or AMD), adds thier own user interface, "csm16" old-school BIOS implementation, and value-adds like debugging and automation for factory test and provisioning. In order to comprehend anything in the codebase, the first step is probably to get acquainted with the local vernacular. https://github.com/tianocore/tianocore.github.io/wiki/Acrony...