TianoCore

TianoCore is an open source implementation of UEFI, the Unified Extensible Firmware Interface. UEFI (formerly EFI) is intended to replace the traditional PC BIOS. TianoCore as in implementation cannot do that, as it lacks the code to do hardware initalization. Since hardware initialization is exactly what coreboot does, the combination of coreboot + TianoCore is the most straightforward option to provide a complete, opensource UEFI environment.

There are various approaches for loading TianoCore. One is to use SeaBIOS' floppy mechanism to load DUET, a TianoCore-on-BIOS. The other is to make TianoCore a true coreboot payload.

DUET

Howto DuetPkg

• Setup edk2 for compilation:
• First compile DuetPkg:

cd BaseTools
export EDK_TOOLS_PATH=$(pwd)
cd ../
. ./edksetup.sh BaseTools
build -p DuetPkg/DuetPkgIa32.dsc

• Then package it in a floppy file:

Go in the edk2 directory, then run the following commands:

cd BaseTools
export EDK_TOOLS_PATH=$(pwd)
cd ../
. ./edksetup.sh BaseTools
./DuetPkg/PostBuild.sh IA32 GCC44
./DuetPkg/CreateBootDisk.sh file ./floppy.img ./floppy.img FAT12 IA32 GCC44
lzma -zc floppy.img > myfloppy.img.lzma

• Then add it to cbfs:

Go into the coreboot directory and do:

./build/cbfstool coreboot.rom add -f /path/to/myfloppy.img.lzma -n floppyimg/MyFloppy.lzma -t raw
./build/cbfstool coreboot.rom print

• reflash coreboot and reboot.
• Then while booting press F12 and choose it:

Press F12 for boot menu.

Select boot device:

1. Ramdisk [MyFloppy]
2. ata1-0: Hitachi HDP725050GLA360 ATA-8 Hard-Disk (465 GiByte

Result

M4A785T-M => fails with an interrupt issue

Qemu => way too slow

x60 => seem to work,no media to test

TianoCore as coreboot payload

http://www.phisch.org/website/efiboot/ reports on a first implementation, but for various reasons there is no source code.

https://github.com/pgeorgi/edk2/tree/coreboot-pkg hosts an attempt to do an published open source implementation of such a payload. It boots, but still lacks many features. Graphics output is possible by integrating SeaBIOS as CSM, but various native components (such as a GOP driver that piggybacks on the coreboot framebuffer) are planned.