Hurrah! My E2 emailer is now printing 'Hello, world!' at roughly 20 second intervals, as the watchdog timer reboots it!
I attach the gas source that produces the bootable image. It turns out I'd misread the disassembly of the boot process, again... here, for reference, is the updated and corrected document of the boot image's magic:
+0000: magic1, 0x3B513B51 +0008: length of chunk +0014: magic2, 0x00544F42 ("BOT") +0064: address of boot vector after relocation +0068: magic3, 0xB513B513 +006c: relocation destination +0070: image type: 0 == plain 2 == compressed (won't go into the details of this now)
The boot vector is:
+0000: unknown, unused +0004: start address after relocation
The maximum length of the boot chunk is 0x30000 bytes, 192kB. The standard firmware gets relocated to 0x40000, so that's the address I've used.
To produce a bootable image from the attached source, do this:
arm-linux-as -o test-e2.o test-e2.s arm-linux-ld --section-start .text=0x40000 -o test-e2.img test-e2.o arm-linux-objcopy -O binary test-e2.img test-e2.pbl pblq bless test-e2.pbl
Yeah, it's a bit convoluted --- blame GNU. The last stage uses pblq to fix the checksum in the boot image, without which PBL will refuse to touch it.
You can then upload it with:
pblq writeflash test-e2.pbl 0
And then do:
pblq term
, power cycle it, and watch the fun!
You can get pblq from my Amstrad Hacking page here:
http://www.cowlark.com/amstrad.html
Be gentle to my web server --- it's not very big.
On Tue, Mar 22, 2005 at 08:27:13PM +0000, David Given wrote:
You can get pblq from my Amstrad Hacking page here:
FWIW, I get the following results with an E3:
[noodles@pot ~/firm/E3/pblq-0.2]$ ./pblq -v ping Waiting for device reset... Handshaking... Switching to 115200 baud... pblq: Protocol error: incorrect packet prefix (got 64, should be 02)
[noodles@pot ~/firm/E3/pblq-0.2]$ ./pblq -v readflash test.flash 0 1024 Waiting for device reset... Handshaking... pblq: Device failed its handshake --- sent F8 when it should have sent 06!
So it does look like it's sufficiently different to not just work.
J.
On Tue, 2005-03-22 at 21:10 +0000, Jonathan McDowell wrote: [...]
FWIW, I get the following results with an E3:
Er, I forgot to mention that you need different options for the E3 because, IIRC, the E3 starts up at 115200 baud rather than the 9600 of the E2.
Try:
pblq -s 115200 ping
...and see what that does.
(-s specifies the baud rate to do the handshaking at, aka slow mode; -f specifies the baud rate to switch to after handshaking, aka fast mode.)
On Tue, Mar 22, 2005 at 09:44:02PM +0000, David Given wrote:
On Tue, 2005-03-22 at 21:10 +0000, Jonathan McDowell wrote: [...]
FWIW, I get the following results with an E3:
Er, I forgot to mention that you need different options for the E3 because, IIRC, the E3 starts up at 115200 baud rather than the 9600 of the E2.
Try:
pblq -s 115200 ping
...and see what that does.
Should have said; I tried that, but it gets even less far:
[noodles@pot ~/firm/E3/pblq-0.2]$ ./pblq -v -s 115200 ping Waiting for device reset...
And then nothing. It slows the E3 boot down, so it appears to do something (I guess it could just be reading the chars), but it eventually finishes booting fully.
J.
On Tue, 2005-03-22 at 21:51 +0000, Jonathan McDowell wrote: [...]
[noodles@pot ~/firm/E3/pblq-0.2]$ ./pblq -v -s 115200 ping Waiting for device reset...
And then nothing.
Hmm.
Well, if it's managing to do the handshake at 9600 baud, try -f 9600 instead. You won't want to up/download much, but at least you might get it working...
On Tue, Mar 22, 2005 at 10:01:19PM +0000, David Given wrote:
On Tue, 2005-03-22 at 21:51 +0000, Jonathan McDowell wrote: [...]
[noodles@pot ~/firm/E3/pblq-0.2]$ ./pblq -v -s 115200 ping Waiting for device reset...
And then nothing.
Hmm.
Well, if it's managing to do the handshake at 9600 baud, try -f 9600 instead. You won't want to up/download much, but at least you might get it working...
No joy; it doesn't seem to want to play with the PBL 3 packet types; switching baud rate doesn't work and if I tell it not to do that then fetching the version doesn't work.
J.
-
David Given -
Jonathan McDowell