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zardam / qspi_loader

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How to use multiboot #1

Open DSchndr opened 5 years ago

DSchndr commented 5 years ago

How should epsilon be flashed onto the external flash to be used by multiboot?

zardam commented 5 years ago

You can load https://github.com/zardam/qspi_loader/tree/master/qspi_loader in the calculator, then use flashrom (https://www.flashrom.org/Flashrom) to program the external flash with what you want.

DSchndr commented 5 years ago

So i just need to put an (padded) epsilon.elf onto the ext. flash by using qspi_loader and flashrom and then flash multiboot and press home and 1 after reset to boot to load epsilon from extflash?

zardam commented 5 years ago

If my memory is good, I used a 8 MB flash chip, with four 1 MB slots in the last 4 MB of it (see here : https://github.com/zardam/qspi_loader/blob/master/multiboot/multiboot.c#L71). You will need to put your epsilon.bin (not .elf) in one of these "slot" then program the external flash with flashrom/qspi_loader.

Then, you will need to flash and run the "bootloader", (using this Makefile target : https://github.com/zardam/qspi_loader/blob/master/multiboot/Makefile#L39) to copy the ROM from the external flash slot to the internal flash (you need to do so, as the ROM will be patched on the fly to run the bootloader before it, and also not to overwrite it)

DSchndr commented 5 years ago

Ok, thanks.

I've made an little (horrible) script (https://gist.github.com/DSchndr/36320976a535a98100a21929be26b96b) that simplifies this procedure. It should be placed in tools/