Re: [PATCH v7 4/8] x86/kexec: Add 8250 serial port output

[Ingo Molnar <mingo@kernel.org>]

* David Woodhouse <dwmw2@infradead.org> wrote:

> From: David Woodhouse <dwmw@amazon.co.uk>
> 
> If a serial port was configured for early_printk, use it for debug output
> from the relocate_kernel exception handler too.

Does the early console output something once it's initialized? If not 
then I'd go one step further here: if early_printk serial debugging was 
configured, let's output some sort of message as early as it's expected 
to work. That way if any of this debug codepath regresses for 
relocate_kernel, the discovery of that regression won't be delayed 
until something nasty triggers within relocate_kernel that would 
necessitate a working debug mechanism ...

Also, printing something to the early console using these new 
relocate_kernel printing functions would be an additional bonus as 
well, for similar reasons.

Thanks,

	Ingo