Re: [ECOS] MIPS Evalution board boot ROM

[Bart Veer <bartv at redhat dot com>]

>>>>> "Ling" == Ling Su <lingsu@palmmicro.com> writes:

    Ling> I remembered that I have to burn a CygMon ROM to debug eCos
    Ling> on the MIPS evaluation board. I just find the
    Ling> /ecos/loaders/vr4300-4373/stubrom.bin and stubrom.img, is
    Ling> that the CygMON mentioned before? Currently my board is
    Ling> configured by a PMON boot ROM, if I replace it, how could I
    Ling> find the manual for the CygMON, otherwise, I am not sure how
    Ling> could I go ahead to try it.

What is needed on the target hardware is something that implements the
gdb target-side stubs, so that gdb is able to interact sensibly with
the target board. gdb is able to interact with some other rom monitors
but quite possibly at reduced functionality, for example there will be
no thread-aware debugging. Offhand I do not know how well gdb can
interact with pmon. To avoid incompatibility problems between gdb and
the target side code, we recommend installing target-side gdb stubs.
This can be a full-blown cygmon rom monitor, or it can be just a
minimal set of stubs. If you only intend to use gdb then there is no
reason to prefer cygmon over just the stubs.

Looking at the VR4300 documentation at
http://sourceware.cygnus.com/ecos/docs-1.3.1/tutorials/vr4300/ecos-tutorial.d.html#pgfId=2404264
I see the following instructions:

  VR4300 Hardware Setup

  The eCos Developer's Kit package comes with an EPROM which provides
  GDB support for the NEC VRC4373 evaluation board. An image of this
  EPROM is also provided at loaders/vr4300-vrc4373/gdbload.bin under
  the root of your eCos installation.

  The EPROM is installed to socket U12 on the board. Attention should
  be paid to the correct orientation of the EPROM during installation.
  Only replace the board's existing ROM using a proper PLCC extraction
  tool, as the socket would otherwise risk getting damaged.

  The GDB stub in the EPROM allows communication with GDB using the
  serial port at connector J1. The communication parameters are fixed
  at 38400 baud, 8 data bits, no parity bit and 1 stop bit (8-N-1). No
  flow control is employed. Connection to the host computer should be
  made using a straight-through serial cable.

The same page has instructions on the commands needed within gdb to
interact with the board.

Bart Veer // eCos net maintainer