1997 F-Body Tools

[Tom H]

It should cover both banks, from checksum address to end of bin. 16 bit byte sum.

Thanks! I found my problem in an unexpected place. The loader I planned to use to prevent bricking puts the EEPROM in the upper memory at $FE00. Since it overlays the flash, my checksum is wrong. Worse, it will prevent the programming of the upper flash.

Now I just need to see if I can find a solution. I can't move it because it supplies the vectors. Can't turn it off because that's in the config which is protected. HMMMmmm, Kind of makes me think of the first rule of holes...

-Tom

[Tom H]

I can't move it because it supplies the vectors. Can't turn it off because that's in the config which is protected. HMMMmmm, Kind of makes me think of the first rule of holes...
-Tom

Use of the EEPROM as a loader is not workable. In expanded mode there is no way to move or remove the EEPROM from the memory map. It hides the last 512 bytes of flash. I have looked hard, there is no workaround that I can find. In fact the EEPROM used as a loader works a treat for everything but those last few bytes on both pages.

I need to look further into the solutions already in place for the earlier PCMs OR ??
-Tom

[kur4o]

If it doesn`t work as expected you can always put it on hold for now, and focus on actual writing, reading operation. Than when that is nailed, we can look for brick safe solution.

[steveo]

yeah you really need to stop the scope creep and just get a working full reprogram even an unreliable one. eehack never had any of the extra safety measures and it was everyones favorite flash tool for like half a decade. it barely bricked anything. we can definitely help you with the logic that we've put into flashhack. it's insanely reliable, like there is a less than 10 second window where if you disconnect power from the ECM it would be unbootable, outside of that it's recoverable.

[Tom H]

Not sure if it is scope creep... Loader used all the same OBDII structure for commands. Most of the time spent is still of value. Target changes from my loader to GM's code and the module Kur4o provided. For sure I learned good lessons about my assembler and the way it mishandles the S9 record. In this case mishandles=not what I expected, function of S9 isn't well documented. Assembler isn't well supported as the author passed away.

Currently, I have the module loading and doing some prelim stuff, turn on/off vpp, measure voltages. Task at hand is creating the code that can be loaded via bootstrap, morph into special test mode and run that programming module. That way when the FLASH goes away... zeroed, erased and so on I can still step through the programming and/or recover the PCM if I need to.

I am close... probably even try programming TSide later this week.

-Tom