On Sun, 4 May 2014 18:20:04 +0200 Alexandre Boeglin email@example.com wrote:
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...)
I only read code from Linux kernel archives published by Acer to figure out the protocol (for a touchscreen controller and a NFC chip, both by MSTAR, that shared the same ISP protocol), so I don't think there are any legal problems with it.
Please let me know what you think about this patch, and whether you're interested in including it.
that's a hilarious story, thanks for sharing! I just skimmed through your blog post but it really looks like an awesome RE experience, and the whole tunnel flash access is just insane :) I would really love to include this just because of that... I am not so sure if it would be useful to many... OTOH one of our community members immediately popped up his screen after reading your story... and found a MSTAR chip and a flash and already got it to probe successfully, so... :)
I did not carefully review the patch yet, just a few remarks: - We need a proper sign-off from you to include the patch, see http://www.coreboot.org/Development_Guidelines#Sign-off_Procedure - I'd like to have at least a dedicated paragraph in the manpage that gives some background information, and some explanation regarding the dev syntax of course. - The coding style does not completely follow ours, e.g. the braces after ifs should be on the same line. - The progress print needs to go, I think. It has been decided long ago that we either do this right(tm) or not at all. flashrom should never go into infinite loops and it should also not be interrupted, hence a progress bar is only a placebo, he just have to be patient.