GDB and Dragonball EZ.

David Williams (davidwilliams@ozemail.com.au)
Mon, 22 Nov 1999 16:05:32 +1100
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Hi All,

I need some help to get started in modifying the appropriate parts of GDB 
so that I can remotely debug my system.
I am using the Motorola MC68EZ328 (Dragonball EZ). It has a hardware 
breakpoint capability built in (not BDM as Dragonball is a 68000 core not 
CPU32). The hardware breakpoint capability would seem to be peculiar to 
this processor so I believe I will have to modify some parts(drivers etc) 
of GDB to use it. The processors breakpoint facility allows you to define a 
single address (and mask for ranges) to set a break-point on for either 
instruction or data accesses - read or write. This is great as can then set 
break-points in code without having to have code in RAM! A small problem is 
it only allows one hardware breakpoint to be set at a time.

Another "small" problem is that I don't have a spare RS-232 port to 
communicate to GDB with. I have only one on my system. I have two options, 
as I see it. Firstly I could share the serial port between GDB and my 
application. One problem with this approach is will make debugging the IrDA 
part of my application more difficult. Secondly I could try and implement a 
software UART using the handshaking lines. Currently I think this second 
option may be better as long as a simple half duplex software UART can be 
implemented and provide adequate communications.

Anyway what I would like to know is which parts of GDB to look at and what 
existing drivers/stubs etc I should use as templates for modification? Are 
DLDT drivers appropriate? Is GDB stub ("remote target") appropriate?

Please point me in the right direction I am currently lost in a sea of 
documentation and source code with no maps!

Note: I am currenty using ECGS 1.1.2 and have downloaded GDB 4.18 
distribution.

TIA
David Williams
davidwilliams@ozemail.com.au

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