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

[Gedare Bloom]

On Mon, Feb 22, 2021 at 6:41 AM <Jan.Sommer at dlr.de> wrote:
>
>
>
> > -----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.
>
Can you update this patch to reflect the baud rate selection?

> Best regards,
>
>     Jan
>
> > Chris