Re: [PATCH]serial: make early_uart to use early_prarm instead of console_initcall

[Andrew Morton <akpm@linux-foundation.org>]

On Fri, 18 May 2007 19:00:16 -0700 Yinghai Lu <Yinghai.Lu@Sun.COM> wrote:

> [PATCH]serial: make early_uart to use early_prarm instead of console_initcall
> 
> Make early_uart to use early_param, so uart console can be used earlier.
> Make it to be bootconsole with CON_BOOT flag, so can use console handover
> feature. and it will switch to corresponding normal serial console automatically.
> new command line will be
> 
> earlycon=uart,io,0x3f8,9600n8
> earlycon=uart,io,0x3f8,9600n8 console=tty0
> 
> it will print in very early stage
> Early serial console at I/O port 0x3f8 (options '9600n8')
> later for console it will print
> console handover: boot [uart0] -> real [ttyS0]

I'll queue this up for some testing, but I'd be a bit reluctant to send it
into Linus due to my poor understanding of what it actually does.  What
_is_ an early console, and how does it differ from a non-early one?

Someone help, please.

Coudl you please provide a patch against
Documentation/kernel-parameters.txt as well?