[PATCH] arm64: add support for uart earlyprintk

[catalin.marinas@arm.com (Catalin Marinas)]

On Thu, Feb 28, 2013 at 11:34:17AM +0000, Marc Zyngier wrote:
> On 28/02/13 11:01, Anup Patel wrote:
> > +}
> > +
> > +/*
> >   * PL011 single character TX.
> >   */
> >  static void pl011_printch(char ch)
> > @@ -47,6 +62,7 @@ struct earlycon_match {
> >  
> >  static const struct earlycon_match earlycon_match[] __initconst = {
> >  	{ .name = "pl011", .printch = pl011_printch, },
> > +	{ .name = "uart", .printch = uart_printch, },
> 
> "uart" is way too generic. pl011 is an UART too, and I suspect most of
> the backends that are going to be added here over time will be UARTs.
> 
> "uart8250" would be a possibility (and actually consistent with the rest
> of the kernel, see drivers/tty/serial/8250/8250_early.c.

I think it makes more sense to use the existing 8250_early.c driver. It
has more features than the simple earlyprintk implementation in the
64-bit kernel (like parsing more parameters, initialising the UART). The
only difference is that the early_param is called "earlycon".

-- 
Catalin