[ECOS] on gdb and exception handlers..

[gopi at india dot tejasnetworks dot com]

hi..

  I am currently using cygmon(and plan to move to redboot once the
platform support is available) on IXP1200EB with IXP1200 n/w
processor.  I took the cygmon code from netwinder.com provided by
the intel guys.

  In the source code, they said they had some problems with
using gdb.  Hence I am not able to use the singlestep etc features
on cygmon.  Before fixing the problem,  I wanted to know the
following things(on using gdb over a serial line)

  + Which part of the boot loader(or cygmon) can I single step
    using gdb?
  + is gdb used to debug cygmon or applications running over cygmon?

Another question regarding exception handlers:
  In our case, cygmon is started by some other code sitting in
  flash(@0x0).  The exception handlers put by the other code is
  not accessible to cygmon.   But cygmon is still able to receive
  interrupts(uart code is working with interrupts enabled).
  Even the MMU is disabled.

  So, when an uart interrupt comes and an exception is raised,
  who is calling the exception handlers of cygmon?

  What is the link between the actual exception vectors(@0x0, 0x8,
  0x12 ..) and the cygmon exception handlers?

thanx in advance
gopi


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