This page is about the notebook HP EliteBook 820 G2.
HP EliteBook 820 G2 was released in 2015 and is now end of life. It can be bought from a secondhand market like Taobao or eBay.
The following blobs are required to operate the hardware:
HP EliteBook 820 G2 uses SMSC MEC1324 as its embedded controller. The EC firmware is stored in the flash chip, but we don't need to touch it or use it in the coreboot build process.
Intel ME firmware is in the flash chip. It is not needed when building coreboot.
The Broadwell memory reference code binary and reference code blob is needed when building coreboot. Read the document Blobs used in Intel Broadwell boards on how to get these blobs.
Before flashing, remove the battery and the hard drive cover according to the Maintenance and Service Guide of this laptop.
HP EliteBook 820 G2 has two flash chips, a 16MiB system flash, and a 2MiB private flash. To install coreboot, we need to program both flash chips. Read HP Sure Start for detailed information.
To access the system flash, we need to connect the AC adapter to the machine, then clip on the flash chip with an SOIC-8 clip. An STM32-based flash programmer made with an STM32 development board is tested to work.
To access the private flash chip, we can use a ch341a based flash programmer and flash the chip with the AC adapter disconnected.
To flash coreboot on a board running OME firmware, create a backup for both flash chips, then do the following:
To erase the private flash chip, attach it with the flash programmer via the SOIC-8 clip, then run:
flashrom -p <programmer> --erase
To modify the IFD, write the following flash layout to a file:
00000000:00000fff fd 00001000:00002fff gbe 00003000:005fffff me 00600000:00bfffff bios 00eb5000:00ffffff pd
Suppose the above layout file is layout.txt
and the origin content of the system flash is in factory-sys.rom
, run:
ifdtool -n layout.txt factory-sys.rom
Then a flash image with a new IFD will be in factory-sys.rom.new
.
Flash the IFD of the system flash:
flashrom -p <programmer> --ifd -i fd -w factory-sys.rom.new
Then flash the coreboot image:
# first extend the 12M coreboot.rom to 16M fallocate -l 16M build/coreboot.rom flashrom -p <programmer> --ifd -i bios -w build/coreboot.rom
After coreboot is installed, the coreboot firmware can be updated with internal flashing:
flashrom -p internal --ifd -i bios --noverify-all -w build/coreboot.rom
The board can be debugged with EHCI debug. The EHCI debug port is the USB port on the left.
+------------------+-----------------------------+ | SoC | Intel Broadwell | +------------------+-----------------------------+ | EC | SMSC MEC1324 | +------------------+-----------------------------+ | Coprocessor | Intel Management Engine | +------------------+-----------------------------+