[U-Boot-Users] Serial Port Configuration on MPC8xx

[Wolfgang Denk]

In message <D96E2AFA0DF3D211B139009027454948034CBEB1 at helios.gnv.tcc.thomson-csf.com> you wrote:
>
> In fact when I change the baudrate of SMC1 in UBoot, I see that the same
> baudrate remains used in the linux console ( am I getting mad ?? :-)) )

This is just lucky coincidence if you happen to use the  same  serial
port  for cosole in U-Boot and Linux. Normally, you will have to pass
the required information to the Linux kernel as a boot argument, like
"console=ttyS2,115200"

> So I thought that the IO Connfiguration & The BRG settings was done only by
> UBoot.

No, the philosophy is that each part of the software, each driver, is
responsible to initialize the hardware it accesses. So the LInux UART
driver will initialize the serial port(s) itself.

> BTW, depending on the hardware the IO pins ( and the IO Config ) are not the
> same and nothing in the linux config allow to choose that... So it should

There are some de-facto standard configurations, which are  supported
by the Linux driver.

> mean that the Linux Uart Driver should be patched depending on your
> hardware.

Indeed. If your hardware guys decided to build some different  confi-
guration,  this  may require to add some #ifdef's to the Linux kernel
code. If you have a look at the UART drivers in our kernel treee  you
will see what I mean :-(


Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
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