Hello coreboot community,
as an open source fan I recently get to know coreboot and really like the idea behind. Sadly I bought my computer HW before learning more on libre friendly hardware that respects your freedom. Now I try to figure out if I could do one or both of a) installing coreboot , b) remove /disable ME from my zotac mini PC, or I had to look out for already supported HW to do so.
I use a zotac CI 640 nano fanless mini PC with kaby lake Intel Core i5-8250U and intel UHD grafics. https://www.zotac.com/product/mini_pcs/ci640-nano#spec
In the process of cleaning FW I got stuck while figuring out, what is the relevant flash IC storing the bios. Form running linux I could read an 8MB flashrom with flashrom tool and internal programmer.
While reading, flashrom reported chipset "Intel Kaby Lake U w/ iHDCP2.2 Prem." and gave the warning "SPI configuration lockdown activated". The programmer flashchip was reported as "Opaque flash chip" 8192kB. At least ME Cleaner worked with not errors on the captured fw image.
Problem: I want to flash the modified image back to the IC using a raspberry 4b with gpio spi setup using a SOIC8 clip. But I could not manage to find the correct IC on the mainboard. I kept looking for SOIC8 200mil with some "25" signature and found only a GD25Q20C(2M-bit)Serial flash chip, that I could successfully read with raspberry spi setup. However, it contains only 256k data. strings showed me lots of HDMI related stuff.
I have created a list of chips I found while disassembling and some pics. I hope that someone more experienced could explain me how the 8MB fw is stored on this zotac and if it is "safely" possible to rewrite it. I it is to difficult or dangerous, as beginner I will stick with new hardware from already supported hw list.
The "promising" IC chips I found were a - 1 piece of "G labeled" AH1815 25Q2 1BT EE455, I think it is related to the GigaDevice GD25Q20C(2M-bit)I found on web. this chip I managed to read out.. b - 12 pieces of SOIC8 150mil (or samller?) : M B07 N03 EKH 1409 (Macronix? could not find anything:/ ) c - 1 piece of Issi IS25LQ020: 256K x 8 (2 Mbit) (maybe related to USB-C extension module) d - 1 piece of RT9059 GSP6E TOC, which I think could be a RichTek ultra low power voltage regulator? e - 4 pieces of "P labeled" 6982 GA9C1E ICs, I do not know what they are, maybe some MOSFET? f - 1 piece of "P labeled" 4435 GL9B2E SOIC8 200mil which I know nothing about
Pics of the mainboard front and back are here: https://pasteboard.co/JJjQqQO.jpg https://pasteboard.co/JJjRjLU.jpg https://pasteboard.co/JJjRCDt.jpg
Any suggestion how to go on or stop it anyway would be appreciated.
kind regards,
Peter Mueller