[ECOS] Debugging from ROM

[Bart Veer]

>>>>> "Rich" == Rich LeGrand <rich@charmedlabs.com> writes:

    Rich> Thanks for the information!
    Rich> The reason we are considering this is because there is some
    Rich> flexibility in our target system. i.e. the flash is mapped
    Rich> into the processor's address space through some fpga logic
    Rich> so we can intercept writes to the flash address space,
    Rich> remember the address, store the result and return the result
    Rich> when a read. Surprisingly it is only about 20 lines of HDL
    Rich> code (and simple enough for me to write :) Currently, it can
    Rich> "alias" 16 words in flash (do you think this is enough?) A
    Rich> control bit in a register can enable or disable the aliasing
    Rich> (when disabled the flash contents are "restored")

    Rich> Agreed this is probably not mainstream, but not too many
    Rich> assumptions are made -- only that the target system has some
    Rich> programmable logic and that the CE to the flash device is
    Rich> provided by the programmable logic. (and that the logic has
    Rich> access to the address and data signals -- but this is
    Rich> usually the intent with onboard programmable logic) And it
    Rich> seems like fpgas are becoming more popular for even
    Rich> lower-end systems.

16 breakpoints should be fine for normal usage. This approach to
implementing breakpoints certainly sounds interesting, but there is
still the problem of getting the code into the flash quickly for the
normal development cycle. Do you have any plans for that?

Bart

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

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