FAT32 is likely going to be an insane effort because it's a hack where a file takes up as many 8.3 file entries on top of the original as it would take to store the name.
Yup. But now that I'm using a newer GEMDOS than the initial demo, there is FAT16 support, allegedly, controlled by a flag on the BPB of the drive. So I might try setting that flag and seeing if it works. That will at least get me to a reasonable volume size, certainly more than reasonable by '80s GEM standards...
This probably can happen during the boot loader if you can grow it by a bit, or possibly as part of the BIOS when it is initialized.
It's probably going to be easier to do it in the BIOS—I already have
@stepleton's lisa_profile_io library (stylistically massacred to assemble with the ancient assembler, but programmatically intact) linked into the BIOS, so it would make sense to use that as a basis for this, too. I think squeezing anything else into the bootloader would mean sacrificing the fish, and I like the fish.
This was going to be my first stop, definitely