[PATCH rtems-docs] user/bsps: Mention fixed console baud rate for zynq

[Jan.Sommer at dlr.de]

> -----Original Message-----
> From: Chris Johns <chrisj at rtems.org>
> Sent: Saturday, February 20, 2021 11:57 PM
> To: Gedare Bloom <gedare at rtems.org>; Sommer, Jan
> <Jan.Sommer at dlr.de>
> Cc: devel at rtems.org
> Subject: Re: [PATCH rtems-docs] user/bsps: Mention fixed console baud rate
> for zynq
> 
> On 20/2/21 3:59 am, Gedare Bloom wrote:
> > On Fri, Feb 19, 2021 at 1:21 AM Jan Sommer <jan.sommer at dlr.de> wrote:
> >>
> >> ---
> >>  user/bsps/arm/xilinx-zynq.rst | 14 ++++++++++++++
> >>  1 file changed, 14 insertions(+)
> >>
> >> diff --git a/user/bsps/arm/xilinx-zynq.rst
> >> b/user/bsps/arm/xilinx-zynq.rst index 365c336..dcc0649 100644
> >> --- a/user/bsps/arm/xilinx-zynq.rst
> >> +++ b/user/bsps/arm/xilinx-zynq.rst
> >> @@ -37,6 +37,20 @@ to return the peripheral clock. Normally this is
> >> half the CPU  clock. This function is declared ``weak`` so you can
> >> override the  default behaviour by providing it in your application.
> >>
> >> +Console
> >> +-------
> >> +
> >> +The console driver for the UARTs will always be set to a baud rate
> >> +of 115200 with 8 bit characters, 1 stop bit and no parity bits
> >> +during start up.
> >> +Previous configurations programmed into the hardware by the Xilinx
> >> +tools or a bootloader will be overwritten.
> >> +
> >> +The settings for parity and stop bits can be changes by the user
> >> +application. The baud rate is hard coded to 115200 and can not be
> >> +changed.
> >> +
> >> +
> > Only 1 blank line here please. Chris to approve the content, I think
> > he has the most to say on this topic :)
> 
> It is OK for master because it is what we have. Joel and I have been
> discussing the issue of the hardcoded baudrate and the issues it presents. If
> we decide something needs to change this documentation can change.
> 
> The issue is there are 2 UARTs on the zync and if one is used for the console
> the fixed rate is fine however if one is used for another purpose not being
> able to set the baudrate is a bug in RTEMS.
> 

That actually is a use case for us.
I have taken a closer look at the source and I don't see any reason why the baud rate should hard coded.
It looks like it is only missing the switch-case for the termios Baud options.
I will prepare a patch.

Best regards,

    Jan

> Chris