Motorola coldfire520X and gcc/gdb

Rolf Fiedler
Thu Jun 5 04:16:00 GMT 1997

hi there,

while trying to build a binutils/gcc/gdb crossdevelopment platform
for an embedded CF5204 system I learned that there is no 
proper coldfire support in the gcc sources.

the coldfire has a instruction set that is a reduced 68000 set with
a couple of 68020 enhancements (VBR, etc..) plus cache control
and MAC (multiply-accumelate) instructions.

Now, the binutils support coldfire, i.e. I can ask gas to detect
unsupported instructions and print nice error messages.

the problem is that I can't get gcc compiled in a way that
gcc only emits instructions supported by coldfires.

the next problem is that the libgcc1.asm for m68k has instructions
missing from coldfires all over it. Well, I can fix that one easily.

 The worst thing is that I can not get gcc to invoke gas with the
proper -m5200, so gas has no chance to detect the unsupported 
instructions (and I feel everything went ok :-(

I haven't done any compiler back-end work for gcc yet, so I have
no clue what to touch in config/m68k/.

For debugging I want to use gdb, and there is a BDM 
(background debugging mode) patch for gdb and a kernel module
for my linux box's parallel port interface cable.
This has been developed for CPU32's with BDM - has anybody tried
it with coldfire?

Now the questions:
has anybody been doing work on the subject?
Are there any patches?
Am I just misunderstanding the whole problem?

thanks for your attention,

|  ||||||   |  Rolf Fiedler                                            |
|  6 6  \   |  Electronic Design Engineer                              |
|  /_  ) |  |  Ferrari electronic GmbH                                 |
|   >   /   |  phone: +49 3328 4559 0  E-Mail: Rolf.Fiedler@Ferrari.DE |
|   |  |    |  fax  : +49 3328 4559 60                                 |

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