kernel: multiplexing /dev/console to all console= entries

[dustymabe]

See kernel mailing list discussion

We'd like to augment the kernel to be able to multiplex /dev/console to all console= entries from the kernel command line. The problem this tries to solve is laid out in the mailing list discussion.

The current proposal is that we add:

a flag to the console= option which would mark a console as a /dev/console device too and multiplex only those specified by the user. Then let's see how it goes with userspace logging out in the wild...

Possible options for how we mark a console to be multiplexed are:

• console=ttyS0,primary
• console=ttyS0,mux
• console=ttyS0+
• consolex=ttyS0

Let's see if we can tackle this problem so we can get more reliable output when people have early boot failures and also we can decrease the number of cloud specific grub snippets we need.

[gursewak1997]

Is this issue still relevant?