+---------------------+--------------------+ | Type | Value | +=====================+====================+ | Socketed flash | no | +---------------------+--------------------+ | Size | 8 MiB | +---------------------+--------------------+ | In circuit flashing | Yes | +---------------------+--------------------+ | Package | SOIC-8 | +---------------------+--------------------+ | Write protection | No | +---------------------+--------------------+ | Dual BIOS feature | No | +---------------------+--------------------+ | Internal flashing | Yes | +---------------------+--------------------+
Flashing coreboot for the first time needs to be done using an external programmer, because vendor firmware prevents rewriting the BIOS region.
Please also have a look at the flashing tutorial
There's one 8MiB flash which contains IFD, GBE, ME and BIOS regions. On Lenovo's UEFI the EC firmware update is placed at the start of the BIOS region. The update is then written into the EC once.
It is possible to reduce the Intel ME firmware size to free additional space for the bios
region. This is usually referred to as cleaning the ME or stripping the ME. After reducing the Intel ME firmware size you must modify the original IFD and then write a full ROM using an external programmer. Have a look at me_cleaner for more information.
Tests on Lenovo X220 showed no issues with a stripped ME firmware.
Modified flash layout:
The overall size of the gbe
, me,
ifd
region is less than 128KiB, leaving the remaining space for the bios
partition.