Re: ARC no console output (was Re: [PATCH 1/2] init/console: Use ttynull as a fallback when there is no console)

From: Greg Ungerer
Date: Thu Jan 07 2021 - 08:15:12 EST

Hi John,

On 7/1/21 7:02 pm, John Ogness wrote:
On 2021-01-06, Vineet Gupta <vgupta@xxxxxxxxxxxx> wrote:
This breaks ARC booting (no output on console).

Could you provide the kernel boot arguments that you use? This series is
partly about addressing users that have used boot arguments that are
technically incorrect (even if had worked). Seeing the boot arguments of
users that are not experiencing problems may help to reveal some of the
unusual console usages until now.

I can show an example for m68knommu which this change breaks too
(with no console output on boot).

All the ColdFire dev board targets (arch/m68k/configs/m5*) have a compiled in boot argument which is "root=/dev/mtdblock0". They have no
real mechanism to pass boot arguments from their boot loader, so it is
compiled in.

The default mcf serial driver is the console on these and no "console=ttyS0" argument was required in the past.