[coreboot] New Subscriber

Taiidan at gmx.com Taiidan at gmx.com
Wed Nov 8 22:33:30 CET 2017

On 11/08/2017 09:36 AM, Robert Walz wrote:

> Hello coreboot community,
> 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.
> 1) 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?
> 2) 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)
> 3) 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.

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