[ECOS] RedBoot upload memory troubles

[Jakob Kjaer <makob at makob dot dk>]

Hello!

I'm in the process of porting (debugging) RedBoot for our in-house
developed computer for the SSETI-Express satellite ;)

The computer is very much alike the AT91 EB40 eval.board, ie. ARM7,
and has the following memory layout:
	ROM 	0x01000000, 1MB
	FLASH	0x02000000, 4MB
	RAM	0x03000000, 2MB

Timing and chip-selects etc. is setup correctly, and RedBoot has
succesfully been burned to ROM, and gives me the following pleasant and
well-known greeting:

---begin-output---
RedBoot(tm) bootstrap and debug environment [ROM]
Non-certified release, version SSETI-Express OBC v5 - built 16:20:49, Aug
12 204

Platform: Atmel AT91/AAUOBC (ARM7TDMI)
Copyright (C) 2000, 2001, 2002, Red Hat, Inc.

RAM: 0x03000000-0x03200000, [0x030070e8-0x03200000] available
---end-output---

All nice so far, but... The trouble starts if I connect with gdb. It seems
like the GDB protocol stub got the RAM size (workspace_end?) all wrong:

---begin-output---
Remote debugging using /dev/ttyS0
Cannot access memory at address 0xe880e880
0xe880e880 in ?? ()
---end-output---

I can upload programs, but if I try to start them, I get an error. There
is no memory at address 0xe880e880, I know that! :/

The dissassembled RedBoot ROM elf image does not contain any reference to
the above mentioned address...

Redboot also crashes if I try to upload my hello-world program via y-modem
in minicom. Forcing other base-addresses for the upload doesn't help.
I can use all commands in RedBoot, and there are no complaints in s-record
or elf upload - but when the upload is complete, RedBoot crashes and gdb
protocol stuff gets sent, same error as when using gdb uploads.

I don't have access to a JTAG debugger, so I'm pretty lost on what to try
next... The number of ROM chips are somewhat limited (they are
on-time-programmable), so any advice is very welcome! ;)

Kind regards,
Jakob Kjaer

Student Space Exploration and Technology Initiative
European Space Agency

PS: Yes, it's (or at least, going to be) eCos in space! You can find more
about SSETI-Express on the not-yet-finished web-page:

http://sseti.gte.tuwien.ac.at/WSW4/express1.htm

-- 
Jakob Kjaer
makob@makob.dk


-- 
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss