[U-Boot-Users] Porting UBoot without UART

Wolfgang Denk wd at denx.de
Fri Feb 25 08:51:47 CET 2005

Dear Grant,

in message <528646bc0502242240233e0d7f at mail.gmail.com> you wrote:
> > > Provide our own console functions. See common/console.c and
> > > common/devices.c how it is initialized and used.
> > 
> > Note thatt he "devices"  are  intialized  pretty  late  in  the  boot
> > sequence.  Until  then,  all  of  the  most  of the important console
> > messages have already beeen printed.
> >From the original post: "We're using some emulation box to develop our
> SoC. Somehow the UART will the last component available for firmware
> development."
> I don't think that is the situation that Shawn is describing.  To me
> it sounded like he is starting firmware development before all of the
> functionality is delivered by the hardware engineers.  I don't think

You are right. Then Ladislav Michl suggested to use  special  console
functions   for   output,   which  works,  but  misses  most  of  the
"interesting" startup messages which  are  printed  long  before  the
device funtions are installed.

> that he is refering to initialization order.  Shawn, could you please
> clarify?

Initialization order plays only a  role  here  as  a  console  device
starts working too late. The native console port is the serial port.

Best regards,

Wolfgang Denk

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