Re: [ECOS] Stepping problem with GDB

[Jonathan Larmour <jifl at eCosCentric dot com>]

George Sosnowski wrote:
> I'm running ecos on a powerpc 860 MBX-based board.
> I boot up to redboot and connect to the serial port via
> Gdb and load my ecos application image. 
>
> When I run and hit a breakpoint, I use "step" to try to step
> into the function call. Instead of actually stepping into the function
> it hits another breakpoint further in the function. It appears to
> behave as "cont" instead of "step". 
>
> Is this something someone else has seen or knows
> what I could be doing wrong?

Probably nothing as such: sometimes it fails because GDB's heuristics 
about where to place the next breakpoint fail; sometimes it fails because 
something in the eCos stub for that architecture fails, for example a 
branch opcode it doesn't understand. See 
hal/powerpc/arch/current/src/ppc_stub.c for where this magic lives. You'd 
be able to tell using stepi instead of step and seeing if it still 
hyperspaces then.

But my guess is actually the former - GDB's heuristics, and the best 
workaround is to make GDB's job a bit easier and don't try and debug 
optimised code. Instead compile without -O2.

Jifl
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