Byte-order problems with GDB and BDM driver

[Chris Johns]

Dario Alcocer wrote:
> 
> However, it now appears that there's something *definitely* wrong with
> how bdmReadMemory() works, at least with my Coldfire setup using the
> P&E Coldfire pod.
> 
> [snip]
> 
> Any ideas why the order of short and byte reads would be significant?
> 

I have modified the chk program to write bytes, then verify (read bytes,
words, and longs), then write words (16bits), verify, write longs,
verify, and write a buffer then verify.

I will upload a snapshot of this code and the driver tomorrow (Sydney
time) to :

  ftp://www.cybertec.com.au/pub/bdm/

This test passes on the 5206e and 5307. I then went back to gdb and did
not get the problem you showed (see the trace below).

Are you accessing DRAM ?
If so are you sure you have the DRAM controller is setup correctly ?

Could try this test where only the internal SRAM is being accessed not
any DRAM or hardware which requires a setup parameter :

 $ m68k-bdm-elf-gdb
GNU gdb 5.0
Copyright 2000 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you
are
welcome to change it and/or distribute copies of it under certain
conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for
details.
This GDB was configured as "--host=i686-pc-linux-gnu
--target=m68k-bdm-elf".
(gdb) target bdm kea:/dev/bdmcf1
Remote bdm connected to kea:/dev/bdmcf1
(gdb) bdm_setdebug 1
(gdb) set $rambar=0x20000001
BDM: Read system register RPC: 0xffe01cb8
BDM: Read system register RAMBAR: 0x20000000
BDM: Write system register RAMBAR: 0x20000001
(gdb) set *(0x20000000)=0x11223344
BDM: Read 0x822a0000 @ 0x20000000
BDM: Write 0x11223344 @ 0x20000000
(gdb) x /10b 0x20000000
BDM: Read 0x11 @ 0x20000000
BDM: Read 0x22 @ 0x20000001
BDM: Read 0x33 @ 0x20000002
BDM: Read 0x44 @ 0x20000003
BDM: Read 00 @ 0x20000004
BDM: Read 00 @ 0x20000005
BDM: Read 0x14 @ 0x20000006
BDM: Read 0x04 @ 0x20000007
0x20000000:     0x11    0x22    0x33    0x44    0x00    0x00    0x14   
0x04
BDM: Read 00 @ 0x20000008
BDM: Read 0x7c @ 0x20000009
0x20000008:     0x00    0x7c
(gdb) q
BDM: Status 0x2 


-- 
 Chris Johns, mailto:cjohns at cybertec.com.au mailto:ccj at acm.org