Flashed coreboot_edk2-phaser-mrchromebox_20260709.rom on a Lenovo C340-11 and now it seams to bootloop

Support General Device Support
1

System Details

  • Device: [Lenovo C340-11]
  • Firmware Type: [UEFI Full ROM]
  • Internal storage type: [eMMC or UFS] (if applicable)

Flashed coreboot_edk2-phaser-mrchromebox_20260709.rom on a Lenovo C340-11 and now it seams to bootloop( flashing backlight every few seconds for a second or so) no image i removed write protect with my CH341 and deleted the contents of the W25Q128FW 1.8V verified it to be empty then flashed the file and verified again put the laptop back together and got this result. I dont have a battery in the laptop the one i own is broken i think before i flashed the bios it didnt boot into chrome os because of a tpm failure.

Expected Behavior

[Coreboot working]

2

flashed how?

you can’t just flash a device with stock firmware using a ch341a and expect it to work. I have documentation for a reason. You likely didn’t disable software WP.

3

I can flash it back to stock, but I can’t get it booting except in a broken recovery mode, which doesn’t accept USB drives. It also can’t boot because of the TPM, which I am assuming is due to the removed battery that was dead. So, I thought I could flash the UEFI directly. I didn’t know there was a write-protect in the software, but since I can’t boot into the software, I can’t disable it. So, I’m kinda stuck.

4

that’s not correct, you simply need to disable software WP using flashrom as per the instructions on my site.

you also didn’t answer my question on how and what you flashed. you’re not supposed to flash the entire chip, again per the docs on my site

5

I flashed coreboot_edk2-phaser-mrchromebox_20260709.rom onto the bios chip i made a backup disabled the write protect the chip had and wiped it and wrote that and verified it got written didnt know it wasnt possible to manually flash the chip.

6

if you didn’t also disable SW WP via flashrom, that was/is your problem.

8

Do you mean the Sreg: 00000000(0x00), 00000000(0x00), 01100000(0x60) with SW WP i set them to that

9

I don’t know why you’d do this manually when flashrom --wp-disable and --wp-range exist

10

Cause i did it on windows for some reason and AsProgrammers function didnt work cause the board was sucking away the power I think for writing the sreg didn’t know that yet so i tried manually then figured out why powered the board with usb then set the Sreg manually and didn’t go back to the automatic but Sreg: 00000000(0x00), 00000000(0x00), 01100000(0x60) seams to have it at least made it possible to write to the chip

11

well, flash your backup back, and flash the UEFI ROM properly under linux using flashrom per my instructions. only write the bios region, not the whole chip