Porting advice

["Svein E. Seldal" <Svein.Seldal@solidas.com>]

Hello,

I'm working on porting a new target for gdb, the tic4x, or Texas 
Instruments TMS320C3x and TMS320C4x (DSP's). I have been looking into 
the gdb sources and I have a couple of questions regarding the porting job.

The configuration patch is done, and since tic4x exists already in 
binutils, bfd and opcodes are also done. The only work needed, it seems 
like, is gdb and sim.

- What approach is the best when doing a new port? I have read the gdb 
internals manual, but I must admit that I dont quite get the overall 
picture from it.

- Are there any other targets which serve good as a "template"? I see 
references in the gdbint manual to d10v. Please note that the tic4x 
target will always be a cross target, never native.

- For a cross target what is required?

I have written a TCP gdbserver which accepts the standard gdb remote 
commands which talks to actual hardware. My primary use of gdb is to be 
able to talk to this gdbserver and to examine the runtime code, set 
breakpoints, etc. My second (distant) use of gdb is to use a simulator.

My problem is that I cannot find any references to any cross targets not 
linking in a simulator. Is this the case? If I edit my local 
gdb/config/tic4x/tic4x.mt and remove the "SIM = " line, compilation of 
gdb croaks and dies because of missing sim symbols. Is it possible to 
build a target gdb without the usage of a simulator?

- What does the "SIM_OBS =" line in the gdb/config/tic4x/tic4x.mt file do?

- Should I enable multi-arch support now? I mean, this being a totally 
new target and all?

- What "struct gdbarch" methods do I need to have implemented in 
gdb/tic4x-tdep.c? Is there a collected documentation of the methods 
somewhere? (I've read gdbarch.sh, but more detailed examples would be 
very nice.)


Hmmm.. Too many questions to get any consistent answer... Well, lets try 
anyway...

Regards,
Svein Seldal