On Mon, 9 Feb 2015 00:53:40 +0100 Idwer Vollering vidwer@gmail.com wrote:
2014-05-04 18:20 GMT+02:00 Alexandre Boeglin alex@boeglin.org:
Hi,
Here is a patch, that provides support for the MSTAR ISP protocol.
Basically, among other chips, MSTAR manufactures SoCs that equip TV sets and computer screens, and it seems that all of their products use the same in-system programming protocol. Basically, they use the DDC channel of VGA or DVI connectors, which is actually an I2C bus, to encapsulate SPI frames (the flash chip is connected to the SoC through an SPI bus).
I wrote this patch since the screen I bought had a software bug, and the manufacturer only released a new firmware binary, but no tool or instructions on flashing it.
More details can be found here: http://boeglin.org/blog/index.php?entry=Flashing-a-BenQ-Z-series-for-free(do...)
There seems to be a silicon (=SoC) bug as well.
One can recover by rotating the original image (YOU DO HAVE BACKUPS, RIGHT :) ) _back_wards - the example assumes the read file is 128 kilobyte large: tail -c 1 orig_read.bin > realimage.bin; head -c 131071 orig_read.bin
realimage.bin; flashrom -p mstar -w realimage.bin --noverify
hm... I wonder if that is a bug in how we do it... but the write routine looks really trivial. Maybe it would be a good idea to start a list with monitors, SoC revisions... (whatever ID data is accessible) that require this hack.