Coldfire support

Rolf Fiedler
Thu Jan 14 00:01:00 GMT 1999

On Wed, 13 Jan 1999, Wynn Rostek wrote:

> Does anyone have experience with the GNU tool chain supporting the Coldfire
> processor?  We've got assemblers but the job would go quicker with a C
> compiler and a debugger.
the gnu binutils (2.9.1 I think, grab the newest) support coldfire 
(target=m68k-coff) -> so you have as, ld, objdump, nm, ar, objcopy...
Disassembler (objdump) has some difficulties with some coldfire
instructions (e.g. halt) but is quite usable.
the gcc 2.8.1. has coldfire support - but is buggy in that respect 
(in rare cases produces instructions that the assembler rejects - illegal
for coldfire)
the egcs-1.1.1 compiler is better, produces code that actually works

use both as and gcc with -m5200

I have written a bdm debugger plus linux kernel module for remote
bdm debugging. this supports low level (asm debugging) operations
like stepping and breakpoint (one hardware breakpoint plus one address or
data breakpoint), up/download, flash programming, mem dump and editing.
Requires no software on the target, works even with a coldfire with power
and clock and nothing else.

This is needed to get a new hardware development up and running and to
debug crt0 stuff.

Furthermore I have written a gdb extended remote stub (via tcp network)
to have m68k-coff-gdb 4.17 (slightly patched) talk to the bdm target.
Connects to the target with 
gdb> target extened-remote hostname.domain:port
gdb> load object-file
gdb> symbol-file object-file
gdb> break main
gdb> continue
The remote stub which talks bdm with target is started from inetd, so you
can choose host and port. The machine needs on unused parallel port for
the bdm adapter (can provide schematics and GAL equation - or you can buy
one from P&E Microsystems for US$99 I think).
I debug software on a target that is in the other office, so I don't have
to see the chaos I create.

There is no need for any software on the target, but breakpoints may
only be set in RAM (gdb patches coldfire halt instructions at
breakpoints, original gdb uses a trap instruction).
I am currently using it and it works ok, should be considered beta.

I will activate my private web page at my ISP soon, then you can get all
the debugging related files from there. the patch for gdb 4.17 is simple:
in a header file change the REMOTE_BREAKPOINT from the trap instruction
to coldfire's halt. I will provide a diff for that file.

> TIA, any info appreciated.
I hope this helps.

|    _____        |  Rolf Fiedler                                    |
|   / ___/        |  Electronic Design Engineer                      |
|  / _/           |  Ferrari electronic AG                           |
| /_/e/r/r/a/r/i/ |  phone: +49 3328 4559 0   fax: +49 3328 4559 60  |
|   electronic    |  E-Mail: Rolf.Fiedler@Ferrari.DE                 |
           "Where do you want to go tomorrow?"

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