On 11/08/2017 09:36 AM, Robert Walz wrote:
Hello coreboot community,
Sup
I'm 23 years old and I'm studying computer science in germany. I want to flash coreboot on my Lenovo T420 with Raspberry Pi's SPI,
You don't need the cumbersome flashing process via a closed source RPI, just get a USB CH341A and a tester clip/cable.
read a lot of content on coreboot.org, but I would have some more questions.
- About VBIOS:
I have Sandy Bridge with integrated graphics (Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller) so it wouldn't be necessary to build the coreboot.rom with a VBIOS, I want to boot with SeaBIOS without graphics. But if I don't add the VBIOS, what is used after the boot? For example I dumped the current vbios.rom of the VGA compatible controller in linux with
Sandy/Ivybridge coreboot features native graphics init, no video bios needed no matter what payload you use.
echo 1 | tee /sys/devices/pci0000:00/0000:00:02.0/rom cat /sys/devices/pci0000:00/0000:00:02.0/rom > vbios.rom
and disassembled it with
ndisasm -k 0,3 vbios.rom | less strings vbios.rom | less
Where is this current vbios stored and for what is it needed? Can I replace it with coreboots VBIOS? Or is it even not necessary and its deleted, if I use coreboot without VBIOS?
- About proprietary BIOS
Is it possible to download a "full" BIOS (with descriptor, me, ...), like it is stored on the mainboard flash chip?, because on the lenovo support webpage I can only find BIOS-Updates, with an empty offset for the descriptor, the intel me and the GbE followed by the BIOS. And this .FL1 file is even biggen then 8 MiB, maybe because it also includes the EC?
I asked this same question many months back, no one could figure it out. I would just update the BIOS, read it from the board and then use the tool to extract the required files (editing the gbe file if you want a new MAC)
- About the EC
Is it possible to create a full EC, which I can flash on the mainboard chip with the raspberry pi?, or does an open source EC already exist for the T420 (I just found one for T400 on libreboot). Is the EC store on another chip?
It is stored on another chip, AFAIK someone made a replacement for the *30 EC but not the *20 EC - which sucks because then you're stuck with the serial number on the T420.