Le jeudi 08 mai 2014 à 00:23, Stefan Tauner a écrit:
We could add a programmer parameter and let the user decide/override until we understand this better. Does the DDC tunnel still work with a broken firmware or is an external programmer needed if the first try to modify the firmware fails and the SoC inside the device is reset?
Well, it seems it depends. One user of this mstarddc programmer had an error during the write operation due to (it seems) an I2C driver working at less than half of the normal 100kb/s I2Cspeed, but even after power-cycling the screen, he managed to successfully reflash it using another laptop.
But in the mean time, the screen was not working properly, and I'm guessing it was maybe in some kind of emergency mode, maybe an in-silicon bootloader that allows access to the ISP port.
OTOH, another person, using the "official" MSTAR tool was unable to reflash his screen after the initial failure. But I didn't get him to try the programmer I wrote, so I don't know for sure what his problem was (maybe even just a bug in the official tool).
Anyway, I slightly modified the programmer in the patch revision I sent this morning. It does not send the reset command (which causes the screen to exit ISP mode and re-read the flash firmware) if an error occured. So, as long as the screen remains powered, another attempt can be made.
But then, with the limited amount of info I had, most of it is just guesses.
Best regards, Alex