[E3-hacking] previous amstrad emailer

David Given e3-hacking@earth.li
Wed, 06 Apr 2005 17:04:42 +0100

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.

+- David Given --McQ-+ "Under communism, man exploits man. Under
|  dg@cowlark.com    | capitalism, it's just the opposite." --- John
| (dg@tao-group.com) | Kenneth Galbrith
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