Subject: Console Panic after Kernel comes up - in cons.c ...
To: None <port-powerpc@NetBSD.org>
From: netbsd <netbsd@scentech.ch>
List: port-powerpc
Date: 04/30/2004 16:46:30
Hi all,
porting 2.0 current to a 750 PowerPC HW platform we
focus the following problems.
-- actual situation : Kernel comes up but 'panics'
saying "panic: cnopen: no console device" ...
We have a HW that has a minimal BIOS. i.e. we don't
need to initialize any serial port in "com.c". The
Only thing we do is filling up the structure:
-- begin snip from com.c
/*
* Following are all routines needed for COM to act as console
*/
struct consdev comcons = {
NULL, NULL, comcngetc, comcnputc, comcnpollc, NULL, NULL, NULL,
NODEV, CN_NORMAL
};
-- end snip from com.c
however in cons.c the kernel checks if cn_tab->cn_dev ...
-- begin snip from cons.c
cndev = cn_tab->cn_dev;
if (cndev == NODEV) {
/*
* This is most likely an error in the console attach
* code. Panicing looks better than jumping into nowhere
* through cdevsw below....
*/
panic("cnopen: no console device");
-- end snip cons.c
... is being set to "NODEV" .. the initial setting ...
So, we don't wantr to reinitialize the HW - UART ports, is
it sufficient call : cn_tab->cn_dev = makedev(0, 0);
in order to use the very same serial port for the kernel boot
sequence afterwards in the usermode for communication?
Thank's in advance
Markus