Serial console only works after reboot?
ambrisko at ambrisko.com
Sun Jan 4 19:49:08 PST 2004
Nate Lawson writes:
| I have a laptop (IBM T23) and use sio0 as my console/gdb port. One thing
| I noticed is if I power up the laptop and boot -h, I get garbage out the
| serial port. However, if I boot fully and then just warm reboot, the
| serial console works fine. I'm only using 9600 bps. Ideas?
| sio0 port 0x3f8-0x3ff irq 4 on acpi0
| sio0: type 16550A
I use this patch on a lot of systems to force it to CONSPEED and not try
to auto-detect what the prior boot-loaders etc. had set it up.
In my case a lot of the time nothing ever set the port up and it gets
random junk the messes up the speed etc.
RCS file: /cvs/src/sys/dev/sio/sio.c,v
retrieving revision 1.417
diff -c -r1.417 sio.c
*** sio.c 24 Dec 2003 04:11:10 -0000 1.417
--- sio.c 5 Jan 2004 03:46:27 -0000
*** 2832,2838 ****
--- 2832,2841 ----
/* XXX there should be more sanity checking. */
if (divisor == 0)
+ /* DJA
return (rclk / (16UL * divisor));
+ return (CONSPEED);
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