Re: [ECOS] GDB and eCos

[Bart Veer <bartv at redhat dot com>]

>>>>> "Sebastien" == andre33  <sebastien.andre@sxb.bsf.alcatel.fr> writes:

    Sebastien>     Hello,
    Sebastien>     So i'm a newbie

    Sebastien>     It seem that GDB can emulate the target !! i'm
    Sebastien>     wrong ?

Partly correct.

Typically when gcc is ported to a new architecture, one of the first
steps is to write an instruction set simulator for that architecture.
This allows the compiler folks to do their development and testing
before any hardware exists. It is also very useful for subsequent
maintenance. However, this is just an instruction set simulator. It
will do enough to support compiler testing. It will provide only
minimal I/O facilities which bear no resemblance to how I/O happens on
real hardware. Hence typically it cannot be used for eCos development.
The simulator gets built into gdb when you configure for the
appropriate target.

During the early days of eCos development, the simulators for two of
the initial targets (AM31 and TX39) were enhanced to support
architectural simulation of specific boards, the stdeval1 board and
the JMR-TX3904 board. This architectural simulation included support
for a system clock, serial I/O, and interrupt handling, but not for
anything more advanced like ethernet or PCI. In addition eCos was
ported to the PowerPC psim simulator. More details of these can be
found at http://sources.redhat.com/ecos/hardware.html and in the
Getting Started guides for those targets.

More recent work on architectural simulators within Red Hat has
happened in the context of the SID project, http://sources.redhat.com/sid/
Unfortunately I do not really have time to track that project closely
but I suggest you take a look through their web pages and
documentation.

Bart