Re: diagnostic output to custom handler

[Bart Veer <bartv@ecoscentric.com>]

>>>>> "Simon" == Simon Kallweit <simon.kallweit@intefo.ch> writes:

    Simon> Bart Veer schrieb:
    >>>>>>> "Simon" == Simon Kallweit <simon.kallweit@intefo.ch> writes:
    >>>>>>> 
    >> 
    Simon> This patch adds the possibility to override the
    Simon> diag_write_char function at run-time, allowing diagnostic
    Simon> output to be redirected to a custom handler. I need this
    Simon> functionality as I want the diagnostic output to be written
    Simon> into a ring buffer in flash. I think this function may be
    Simon> useful to others too?!?

    >> What is the point of this, given that you can already insert
    >> your own putc function using diag_init_putc()?

    Simon> This won't change the output function for some of the
    Simon> diagnostic output calls, but on a second glance it would
    Simon> probably cover most of the diagnostic output and might be
    Simon> just fine for my purpose.

    >> The only gain appears to be that your custom write_char
    >> function would not need to worry about carriage return/linefeed
    >> handling, whereas a custom putc may need to do so - depending
    >> on the output destination. That is not worth imposing a bit
    >> more code and data bloat on everybody.

    Simon> Would it make sense to allow overriding the write_char
    Simon> INSTEAD of the putc call?

I think it would be better to stick with _putc, and fix any diagnostic
calls that currently don't use _putc to make them consistent with the
rest of the diag code.

An alternative approach is to tackle things at a lower level: fix the
HAL so that HAL_DIAG_WRITE_CHAR() does the right thing for your
platform, e.g. write data into flash. That may or may not be easy,
depending on the target hardware and the HAL packages involved.

Bart

-- 
Bart Veer                                   eCos Configuration Architect
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