Re: [PATCH] CON_BOOT

[Andrew Morton <akpm@osdl.org>]

Matthew Wilcox <matthew@wil.cx> wrote:
>
>  I think it's doable
>  if we do something like:
> 
>   - Add an int (*takeover)(struct console *); to struct console
>   - Replace the hunk above with:
> 
>  	for (existing = console_drivers; existing; existing = existing->next) {
>  		if (existing->takeover && existing->takeover(console)) {
>  			unregister_console(existing);
>  			console->flags &= ~CON_PRINTBUFFER;
>  		}
>  	}
> 
>  That puts the onus on the early console to be able to figure out
>  whether a registering console is its replacement or not; for the x86_64
>  early_printk, that'd be as simple as comparing the ->name against "ttyS"
>  or "tty".  It'll be a bit more tricky for PA-RISC, but would solve some
>  messiness that we could potentially have.  I think that's doable; want
>  me to try it?

It doesn't sound terribly important - I was just curious, thanks.  We can
let this one be demand-driven.

I'm surprised that more systems don't encounter this - there's potentially
quite a gap between console_init() and the bringup of the first real
console driver.  What happens if we crash in mem_init()?  Am I misreading
the code, or do we just get no info?