We are currently having troubles locating the serial port address
on the JS21.
The machine has two serial ports one at address 2f8 and the other
at 3f8 both off the isa bus.
Those addresses are configurable, actually.
We believe that 3f8 is wired to serial over lan.
The first port goes to SoL, the second goes to the debug port.
Thanks to a very enterprising colleague we have wired the port at
2f8 to a real serial cable.
"Real" serial cable. Have you looked at the wiring diagram? It is...
interesting. It can be auto-detected though, what a normal serial cable
can not; and SLOF is supposed to use that to automatically configure to
use the debug port if a cable is attached, SoL otherwise.
The firmware is SLOF.
When we boot Linux or Xen SLOF declares to be using 2f8 as the
serial device. Booting Xen or linux we see this on the console
--------
has started execution, serial console @ 2f8
---------
Old firmware version.
Both linux and Xen ask OF about its output device. This is the
output from Linux:
OF stdout device is: /ht/isa@8/serial@3f8
...mixed with a new firmware version.
Seems something is broken in our "stable" tree, i'll get it fixed for
you tomorrow.
Xen receives a similar answer. Since Xen uses it as the serial
address we end talking to the wrong port. Linux recovers since it
can be told as boot argument which tty to use. Any ideas as to
what could be going on here?
One thing you can do as a workaround, is type at the OF console:
s" /ht/isa/@2f8" io
to set the second port as the /chosen/stdout and stdin device.
Both Xen and Linux should pick it up correctly then.
Segher
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