[ECOS] HAL Diagnostic Output Question

Jeffrey Szczepanski jrs@inscitek.com
Sat Jan 24 19:27:00 GMT 2004

I am relatively new to eCos and have mostly completed and have running a new
platform port for eCos to the ARM7TMDI core on the TI '5471 part. My
question relates to how the COMMS I/O virtual vector support works, when
running an eCos RAM application on top of the RedBoot ROM monitor that
operates the console and channels through a pair of serial ports.

Specifically, when an application thread makes calls to diag_printf() type
functionality that is mapped through the virtual vectors, what happens
relative to thread scheduling? It is not 100% clear to me while the output
is happening, does something in that whole pile of macros and such disable
interrupts/stop task pre-emption, or is the scheduler still running normally
with interrupts enabled while that output is occurring?

Perhaps more to the point, it is clear to me that the output is completely
synchronous relative to the thread making the virtual vector I/O calls, but
do other threads have the opportunity to run while this is happening?

Thanks in advance,

Jeffrey R. Szczepanski, jrs@inscitek.com
Chief Technical Officer and Co-Founder
InSciTek Microsystems, Inc.
635 CrossKeys Office Park
Fairport, NY 14450

InSciTek is home of Allworx 10x

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