Apparently the ttyS0 console doesn't exist but ttyS1 does:
raccoon% sudo stty -F /dev/ttyS0
stty: /dev/ttyS0: Input/output error
raccoon% sudo stty -F /dev/ttyS1
speed 9600 baud; line = 0;
-brkint -imaxbel
The dmesg line agrees:
00:03: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a 16550A
The console configuration is then moved from base to xeon to allow
changing it for the raccoon machine.
To accomodate the raccoon knights workstation, some of the configuration
pulled by m/common/main.nix has to be removed. To solve it, the xeon
specific parts are placed into m/common/xeon.nix and only the common
configuration is at m/common/base.nix.
Reviewed-by: Aleix Roca Nonell <aleix.rocanonell@bsc.es>