serial console

[KokHow Teh]

Hi;
      I have tried with 4 types of command lines with my linux kernel with
devfs and serial device compiled in and none gives me the desired results:

(1)   console=tts/0,115200n8 OR console=ttyCPM0,115200n8

      no serial console output at all during boot time but it gives me
login prompt at the end.

(2)   without "console=" OR console=ttyS0,115200n8

      serial console output fine during bootup but only until the point
when it prints out "Freeing unused kernel memory: 232k init 4k prep". After
that, the serial console output is garbled. No login prompt.

      So this has not solved my problem. I need more advice. Here are some
more questions and observations:

(1)   David Jander's comment:

I don't know exactly what I am talking about right now, but the string
"tts/0"
in the console-line sounds suspicious to me. AFAIK when using devfs still
device names on the kernel-commandline have to be old-style.
Just a guess: try using "console=ttyS0,115200n8" and see if this helps.

      Is it confirmed that kernel-commandline has to be old-style even
though the kernel is using devfs?

(2)   Vitaly Bordug's suggestion of using "console=ttyCPM0". May I know
where is ttyCPM0 defined and how is it bound to the serial console device
driver in the source?

      Thanks for any input and pointer.

Regards,
TEH