RES: Is there any change on interrupt catch between RTEMS 4.9.4 and 4.10.0?

Fabrício de Novaes Kucinskis fabricio at
Mon Feb 28 13:42:04 UTC 2011



I'm experiencing the same problem Filipe described, and have some more


I have a simple application that runs on SPARC/SIS. It uses printf to show
the user some info, and gets data through the UART A interrupt.


This application worked fine on RTEMS 4.6.4 through 4.9.4. After upgrading
to 4.10, it stopped working.


What happens, as far as I could go, is the following:


1. The application starts and prints a lot of messages;

2. At some point, it calls 'rtems_interrupt_catch' to install the handler
for UARTA (the same UART used by printf);

3. After the rtems_interrupt_catch, it runs some more instructions, until it
reaches the next printf;

4. When executing this printf, only the first character is printed, and then
the application halts.


Debugging, I could identify that, after step 4 above, the application is
only running the Idle task, as if there were nothing else to run (which is
not true). It seems that the control never returns to the task that called
printf, since any breakpoint after this call is reached.


If I use printk instead of printf, this doesn't happen.


As this didn't occur until RTEMS 4.9.4, what could've changed? Maybe the
change on the interrupt handler type on the Interrupt Extension API?
Something related to printf?


It seems I could change all printf's to printk's to solve the issue, but it
would be important to know the reason of the problem.


Thanks in advance and best regards,


Fabrício de Novaes Kucinskis.

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