which serial device to use in that case respectively to not rely on
the OFW names of the input/output and stdin/stdout devices. Instead
check whether input and output refers to the same device and is of
type serial (uart(4) was already doing this) and for the fallback
to a serial console in case a keyboard is the selected input device
but unplugged do the same for stdin and stdout in case the input
device is nonexistent (PS/2 and USB keyboards) or has a 'keyboard'
property (RS232 keyboards). Additionally also check whether the OFW
did a fallback to a serial console in the same way in case the
output device is nonexistent. While at it save on some variables
and for sys/boot/sparc64/loader/metadata.c move the code in question
to a new function md_bootserial() so it can be kept in sync with
uart_cpu_getdev_console() more easily.
This fixes selecting a serial console and the appropriate device
when using a device path for the 'input-device' and 'output-device'
OFW environment variables instead of an alias for the serial device
to use or when using a screen alias that additionally denotes a
video mode (like e.g. 'screen:r1024x768x60') but no keyboard is
plugged in (amongst others). It also makes the code select a serial
console in case the OFW did the same due to a misconfiguration like
both 'input-device' and 'output-device' set to 'keyboard' or to a
nonexisting device (whether the OFW does a fallback to a serial
console in case of a misconfiguration or one ends up with just no
console at all highly depends on the OBP version however).
- Reduce the size of buffers that only ever need to hold the string
'serial' accordingly. Double the size of buffers that may need to
hold a device path as e.g. '/pci@8,700000/ebus@5/serial@1,400000:a'
exceeds 32 chars.
- Remove the package handle of the '/options' node from the argument
list of uart_cpu_getdev_dbgport() as it's unused there and future
use is also unlikely.
MFC after: 1 week
0ea9db01f0