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HP 50g bootloader binary blob format
06-28-2017, 03:26 PM
Post: #1
HP 50g bootloader binary blob format
When I bought my HP 50g I used a lot userRPL and did some experiments with systemRPL and HPGCC. I'm not using my calculator since few years, so I decided to recycle it to do some other stuff not necessarily related with calculators business.

I saw the amazing newRPL project and now I know it is possible to flash HP 50g with a custom binary blob using built-in bootloader, keeping the option to flash it back again with the official firmware.

I have one problem that prevents me using this approach: I can't reverse engineer nor find information about firmware binary blob format. I only know it starts with "KINPOUPDATEIMAGE" string. Probably there will be a header, maybe sections, an entry point, and some ARM code in ARM or THUMB mode to execute.

Can somebody help me?

Thanks,
Marcial.
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06-28-2017, 07:38 PM
Post: #2
RE: HP 50g bootloader binary blob format
Finally I found the solution. Firmware binary blob must start with the string "KINPOUPDATEIMAGE", followed by 8 bytes with value 0, and followed by executable code in ARM mode (normally a branch instruction to an entry point). Simple.
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06-29-2017, 03:45 AM
Post: #3
RE: HP 50g bootloader binary blob format
Thanks for sharing

Wikis are great, Contribute :)
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