On Wed, Oct 15, 2008 at 06:12:23PM +0200, Robert Millan wrote: > On Wed, Oct 15, 2008 at 03:16:56AM +0100, Ben Hutchings wrote: > > It's for a Motorola 56000 (aka DSP56000 or DSP56K) processor, which is a > > different architecture but maybe with some similarities. I doubt we > > have any of the necessary tools but the code is short enough to hand- > > assemble. > > I found an assembler, "a56" (see http://www.zdomain.com/a56.html), which seems > to be DFSG-free (BSD-style license). I'll see about packaging it.
Gah, there's a bit more to this:
- First I had to run "frodos" on bootstrap.asm to cleanup the CRLF.
- Attached patch fixes a few errors spit by a56. I think my other two fixes
are correct, but I have no idea what the '<' / '>' candy is supposed to do
(hints?).
- Resulting offsets doen't match with the blob. I still haven't figured out
how are program code offsets mapped to the output file, but some parts
don't match. For example, the blob has a jump (0C 00 40) to 0x40
(and so does a56 output, at offset 0x0 in both cases), but then code
from the blob continues at 0xc0, unlike code from a56 which continues at
0x40. Is there some trick to this?
Attached as well is tobin.c, a small parser I've written to test this (it
reads a56 output and writes it to output file in binary form).
Also attaching the blob in binary form for convenience.
--
Robert Millan
The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
how) you may access your data; but nobody's threatening your freedom: we
still allow you to remove your data and not access it at all."
- Remove '<' and '>' candy (FIXME: find out why)
- Replace 'move' with 'movem' when accessing program memory
- Rename a few labels to avoid duplicates (which a56 can't handle)
--- ../bootstrap.asm.old 2008-10-15 18:22:56.000000000 +0200
+++ ../bootstrap.asm 2008-10-15 19:08:26.000000000 +0200
@@ -51,19 +51,20 @@
; Copy DSP program control
move #real,r0
move #upload,r1
- do #upload_end-upload,<_copy
- move P:(r0)+,x0
- move x0,P:(r1)+
-_copy movep #>4,X:<<M_HCR
- movep #>$c00,X:<<M_IPR
+ do #upload_end-upload,_copy
+ movem P:(r0)+,x0
+ movem x0,P:(r1)+
+ movep X:<<M_HRX,Y:(r0)+
+_copy movep #4,X:<<M_HCR
+ movep #$c00,X:<<M_IPR
and #<$fe,mr
jmp upload
real
org P:$7ea9
upload
- movep #>1,X:<<M_PBC
- movep #>0,X:<<M_BCR
+ movep #1,X:<<M_PBC
+ movep #0,X:<<M_BCR
next jclr #0,X:<<M_HSR,*
movep X:<<M_HRX,A
@@ -81,18 +82,18 @@
cmp x0,A
jeq load_Y
-load_P do y0,_load
+load_P do y0,_load_P
jclr #0,X:<<M_HSR,*
movep X:<<M_HRX,P:(r0)+
-_load jmp next
-load_X do y0,_load
+_load_P jmp next
+load_X do y0,_load_X
jclr #0,X:<<M_HSR,*
movep X:<<M_HRX,X:(r0)+
-_load jmp next
-load_Y do y0,_load
+_load_X jmp next
+load_Y do y0,_load_Y
jclr #0,X:<<M_HSR,*
movep X:<<M_HRX,Y:(r0)+
-_load jmp next
+_load_Y jmp next
upload_end
end
#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <fcntl.h>
#include <sys/types.h>
main (int argc, char *argv[])
{
uint8_t type;
off_t offset;
uint32_t native_value;
uint8_t value[3];
int fd;
if (argc != 2)
{
fprintf (stderr, "Usage: %s output < input\n", argv[0]);
exit (1);
}
fd = open (argv[1], O_WRONLY | O_CREAT | O_TRUNC, 0644);
while (scanf ("%c %x %x\n", &type, &offset, &native_value) != EOF)
{
if (type != 'P')
continue;
value[0] = (native_value >> 16) & 0xff;
value[1] = (native_value >> 8) & 0xff;
value[2] = native_value & 0xff;
pwrite (fd, value, 3, offset);
}
}
blob.bin
Description: Binary data
