On Wed, 2005-04-06 at 12:52 +0100, Matt Evans wrote: [...]
(I was aiming for What I'd Like PBL To Have Been, i.e. give you a shell & let you YMODEM things into DRAM/flash etc. More of a 2ndstage bootloader for uCLinux more than anything else.)
Hmm.
Yes, indeed.
Mine seems to be insisting on turning into what would seem to be one of the very few microkernel-based CP/M clones ever made. (Although it's more inspired by CP/M rather than a straight copy.) The idea is that you should be able to get something useful on a new platform by simply implementing serial read and write routines; it doesn't even need interrupts --- but it ought to be scalable to do a lot more than that.
The next tricky bit is a file system driver. I have a read-only MinixFS driver, but I need a block driver for it... accessing the NAND flash is trickier than it looks, particularly if you want to write to it. (NAND flash is notoriously unreliable and you need to be able to do ECC, bad block remapping, and wear levelling in order to avoid killing it.)
Ideally I'd like to skip all that completely and go straight to USB. Yeah, right.