Re: [flashrom] [PATCH] Add programmer for the MSTAR I2C ISP protocol

[Stefan Tauner]

On Mon, 9 Feb 2015 00:53:40 +0100
Idwer Vollering  wrote:
> 2014-05-04 18:20 GMT+02:00 Alexandre Boeglin :
> > 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.

[PATCH] Add programmer for the MSTAR I2C ISP protocol

[Alexandre Boeglin]

Hi,

Le samedi 14 février 2015 à 23:09, Stefan Tauner a écrit:
> hm... I wonder if that is a bug in how we do it... but the write
> routine looks really trivial.

Yes, all it does is encapsulating and forwarding data, so I don't really
understand why some bytes are rotated on some models.
> Maybe it would be a good idea to start a list with monitors, SoC
> revisions... (whatever ID data is accessible) that require this hack.

Well, to my knowledge, the BenQ XL2411Z, XL2420Z and XL2720Z were the
only monitors for which a manufacturer released an updated firmware
without providing a tool to flash it.

And I haven't heard either of people attempting to mod LCD firmwares.

Best regards,
Alex