[ECOS] Problem with serial setup

Jonathan Larmour jifl@eCosCentric.com
Thu May 1 02:03:00 GMT 2003

Daniel Lidsten wrote:
>>Yes, I have done this successfully on the PowerPC (QUICC) 
>>hardware that you are using.  Be sure and get up-to-date 
>>sources, as I fixed a bug in the HAL/QUICC serial serial 
>>drivers about a month ago.
> When you use the two serial drivers together, how have you setup all
> options in the configTool?

I think trying to do both is a recipe for confusion. You say you set:
HAL/diag serial device driver: /dev/ser1
but assuming you are referring to  CYGDAT_IO_SERIAL_TTY_CONSOLE, this is 
just the name of the device that the io/serial layer _exports_ as a tty 
device based on top of haldiag. It doesn't actually change anything about 
where haldiag goes *to*.

Instead this option should be left as /dev/ttydiag, otherwise you will get 
two entries in the device table that claim to be /dev/ser1 which would be bad.

But even then haldiag isn't really intended to be used with the 
interrupt-driven serial drivers. You can maybe let it share the same 
device but with haldiag still using its own driver in the HAL - that might 
not be too bad, although obviously output may overlap. You'll also 
probably get bogus tx complete interrupts, although hopefully whatever 
serial driver you are using should ignore those.

If you really want to use the interrupt-driven driver for diagnostic 
output, you could try editting infra/current/src/diag.cxx, specifically 
diag_write_char, to do this. Although some care is needed - you will have 
to eliminate anything that tries to do any diag output before the serial 
driver is initialized and interrupts enabled, otherwise it may jam waiting 
for an interrupt that never happens, or if the driver isn't initialized 
yet, it may do who knows what depending on what your hardware requires to 
be set up (you could of course cheat by just testing in your serial driver 
if the device has been initialized and interrupts enabled).

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