[Feature request] autoexec.bin should dump serial flash

[WalterSchulz]

According to kitor dumping serial flash may be useful for unbricking. It is a requirement for emulation in QEMU.

But our standard autoexec.bin only dumps ROM0 and ROM1.
Dumping serial flash to SFDATA.BIN is included in "Portable ROM Dumper" autoexec.bin. Link: https://www.magiclantern.fm/forum/index.php?topic=16534.0

Request: Make standard autoexec.bin dumping serial flash (if any)

[reticulatedpines]

I've often thought this would make sense. The fact that Alex never did it makes me wonder if there is some good reason. Probably not speed? It should only happen on first boot - we only create ROM files if they don't exist on disk.

If you can find any evidence on why we never did it before, that would be helpful.

[WalterSchulz]

No idea.
I thought about why a1ex never implemented it, too. Makes no sense to me.
Asking Indy or g3gg0 maybe?

[WalterSchulz]

Just tested 5D2 and 550D: No serial flash in these cams. At least none found by portable ROM dumper autoexec.bin.
So ... maybe they just got sloppy and missed to update dump procedure to include Digic 5 with serial flash?

[WalterSchulz]

After some sleep:
With our current file structure it will have impact formatting a card in cam when using "keep ML" option, which is default. The routine copies ML directory + autoexec.bin + ML-SETUP.FIR into some memory area. If autoexec.bin saves SFDATA..BIN, too it will require additional space.

But hear me out: I was always quite unhappy with ROMO.BIN and ROM1.BIN location in ML/LOGs.

• IMO it makes little sense to save/restore those files
• It makes sharing configurations (= zipping ML directory + autoexec.bin) sharing ROM content, too. Which we do not like because of IP. Which we do not like because it disables users having their own ROM content saved. This is a constant issue with Zeek's tutorials. Sharing ZIPs with preconfigured settings. ROMs are included.

So ... why not using the same routine as Portable ROM Dumper autoexec.bin and store the whole shebang in card root directory?
Consequences:

• Bin files in root will not be written into memory before formatting.
• After formatting with "keep ML" option ROM/serial flash will get written to card root. First start after format will take a bit longer. But this should be seen (IMO) as part of the format process and should get tolerated by users.
• Users - and we - stay clear more easily from unintentionally sharing Canon's IP.
• Editing some wiki entries and such ...

[reticulatedpines]

The last part makes some sense to me, but could be made safer. As you describe it I think there's a small possibility of a new problem: a user formats with keep ML, the roms get deleted, then properties (or whatever) gets corrupted, cam crashes. No roms available to diagnose / reflash.

If we instead copy old saved ROMs to mem, format, write old ROMs to a different location (ML/old/ROM0.BIN or similar), then the next boot the cam will make new backups of ROMs and SFDATA (in the normal location). ML can detect this when it has finished initialising, then delete old/ROM files.