Lenovo M920 Tiny

This page describes how to run coreboot on Lenovo M920 Tiny (M920q, M920x).

Technology

CPU

Intel Core 8th Gen or 9th Gen (Coffee Lake (Refresh))

DRAM

2 SO-DIMM slots, DDR4-2400/2666

Chipset

Intel Q370

Super I/O

NCT6686D-L

TPM

Infineon SLB 9670VQ2.0

Boot

USB, SATA (on-board SATA1 port, M.2 ports), NVMe

Power

65-135 W power adapter

More specifications on Lenovo M920 Tiny specifications.

Flashing coreboot

Type

Value

Socketed flash

no

Model

W25Q128JV + W25Q64JV

Size

16 + 8 MiB

Package

SOIC-8 + SOIC-8

Write protection

chipset PRR

Dual BIOS feature

no

Internal flashing

after flashing coreboot

Internal programming

The SPI flash can be accessed using flashrom.

flashrom -p internal -N -w coreboot.rom --ifd -i bios

Internal programming can be used after the coreboot has been flashed externally for the first time. Internal programming when migrating from original UEFI firmware has not been tested.

External programming

The external access to flash chip is available through standard SOP-8 clip. The voltage of both SPI chips is 3.3V.

It is recommended to flash firmware without supplying power from power adapter.

The resulting coreboot.rom file must be split into two binaries, one for each flash chip:

dd if=build/coreboot.rom of=build/coreboot_flash_1.rom bs=16M count=1
dd if=build/coreboot.rom of=build/coreboot_flash_2.rom bs=8M skip=2

The flash chips are marked on the mainboard as BIOS1 and BIOS2 respectively. They can be flashed with following commands:

flashrom -p ch341a_spi -w build/coreboot_flash_1.rom
flashrom -p ch341a_spi -w build/coreboot_flash_2.rom -c "W25Q64JV-.Q"

Known issues

  • front audio jacks do not work

Working

Tested with edk2 payload (mrchromebox) and Ubuntu 22.04 (Linux 6.2.0):

  • Serial adapter from daughter board (COM1 connector)

  • USB 3.0 and 2.0 rear and front ports (edk2 and Linux 6.2.0)

  • USB-C port (charging, data)

  • Gigabit Ethernet

  • SATA

  • internal speaker

  • TPM2.0

  • WiFi slot

  • HDMI

  • NVMe

  • PCIe x8 port

    • PCIe x8 tested using BA7H70 Rev 1.2 riser and Intel X540-T2 10G dual 10GbE card

    • another riser with PCIe x4 connector remains untested - please modify this page if you do test it!