APBUART Driver for Sparc

manish jain manish8886 at gmail.com
Thu May 30 16:10:21 UTC 2013

I am looking in code of RTEMS and SPARC BSP from quite a few days . And I
do have these following questions:
1. How does a driver selected when there are more than one driver available
for one device?
2. Is there some difference between uart for console and raw uart? I saw in
RTEMS 4.10 that there are two drivers for UART one is simply apbuart.c and
other is apbuart_cons.c. I am currently opening the uart through open
system call described in GAISLER document with device name as
/dev/apbuart[0|1|2|3|4|5]. And I also read that I should use
3. Is there any RTEMS method for debugging purpose which can tell me the
drivers registered and all devices on a bus? Does it depend on a particular
4. Which makefile is used for adding a new device driver for building?

Can somebody help me out with the answers to above question?


On Tue, May 28, 2013 at 9:43 PM, manish jain <manish8886 at gmail.com> wrote:

> Hi,
> I was looking at the code of UART driver for sparc in
> "/c/src/lib/libbsp/sparc/shared/uart/apbuart.c". I just want to know why in
> the code  member variable "tx_cnt" of apbuart_stats has not been changed.
> Shouldn't it be modified when a "character" has been put  in the "Hardware
> Fifo" from the software "transmission Fifo buffer"?
> Actually, in my code I need to know whether the Software Fifo buffer for
> transmission has any space left or not. I was thinking I can do that by
> knowing the "tx_cnt" after querying the status of the UART. Can somebody
> tell other method by which I can accomplish this?
> Thanks
> Manish
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