Re: CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT

[Bart Veer <bartv at ecoscentric dot com>]

>>>>> "Jani" == Jani Monoses <jani@iv.ro> writes:

    Jani> Hello 
    Jani> are there any platforms not implementing virtual vectors?
    Jani> How long is non VV code planned to be supported?

What code in particular are you concerned about? I am not sure if
there any interesting platforms left where virtual vectors are
completely unsupported. However there are certainly platforms where
you may want to disable the virtual vector support.

On some systems the application will boot directly from ROM, and
with no RedBoot in the system there is no point in enabling virtual
vectors. Booting directly from the ROM means that you can keep down
the hardware costs, although it may also mean that some of the
development has to happen on special boards with extra memory.

An important subset are systems where there is just not enough memory
for both RedBoot and an application. For example there are chips like
the MCF5282 with 512K on-chip flash and 64K on-chip RAM, and some
people want the application to run in just those two areas of memory
so that the boards don't have to be populated with any external memory
at all. Fitting just an application into the internal memory can prove
tricky. If you need a ROM monitor as well it becomes impossible.

Another example is when you are debugging via jtag or BDM. Even if
there is a ROM monitor programmed into flash as well it won't get a
chance to execute, so the application must run without virtual
vectors.

Bart

-- 
Bart Veer                       eCos Configuration Architect
http://www.ecoscentric.com/     The eCos and RedBoot experts