Kernel message missing characters!

Kernel message missing characters!

[Yonghao Wang]

Hello experts,

Help needed! I am trying porting linux on our MPC8260 board using
ppcboot as boot loader and kernel 2.4.7. The console is set up on serial

SMC2. I've changed little bit code on arch/ppc/boot/mbx/m8260_tty.c to
enable it supports SMC2. But when I boot kernel,  the console output
seems missing characters like below:

=> bootm a00000
bootm a00000
## Booting image at 00a00000 ...
   Image Name:   2.4.7-01 for initrd on ATMC8260
   Image Type:   PowerPC Linux Kernel Image (gzip compressed)
   Data Size:    503628 Bytes = 491 kB = 0 MB
   Load Address: 00000000
   Entry Point:  00000000
   Verifying Checksum ... OK
   Uncompressing Kernel Image ... OK

Ttlmmr  2M;uig0Bfrhs al a 0000
Lnxvrin247 wn@ihmr.tlc.k gcvrin30 1FiMr1 53:7GT20
oe0:378pgs:378
oe2:0pgs.
Kre omn ie ot/e/f wnsot121..4:epr/p-f-oti=7.61.1:7.6213121..1:5.5..:iuAM

airtn ea op. 3.9BgMP
eoy 268 vial 82 enlcd,28 aa 2 nt khgmm

etyccehs al nre:134(re:5 302bts
nd-ah ahtbeetis 12(re:4 53 ye)Mutccehs al nre:24 odr ,134bts
ufrccehs al nre:89 odr ,378bts
aeccehs al nre:378(re:5 302bts
OI ofrac etn yUII
ae pnSasaUiest optrSceyNT.3
Satn sadv.
CMUR rvrvrin00

tS0a x00i  M

Does anybody can give me some clue how to fix it?

I'm new in embedded area. Thanks a lot!

Wang Yonghao


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Re: Kernel message missing characters!

[Wolfgang Denk]

In message <3C9B393E.4958C98E@ftel.co.uk> you wrote:
>
> ppcboot as boot loader and kernel 2.4.7. The console is set up on serial
>
> SMC2. I've changed little bit code on arch/ppc/boot/mbx/m8260_tty.c to
> enable it supports SMC2. But when I boot kernel,  the console output

Seems you didn't do this right, then.

> seems missing characters like below:
...
> Ttlmmr  2M;uig0Bfrhs al a 0000
> Lnxvrin247 wn@ihmr.tlc.k gcvrin30 1FiMr1 53:7GT20
> oe0:378pgs:378
> oe2:0pgs.
> Kre omn ie ot/e/f wnsot121..4:epr/p-f-oti=7.61.1:7.6213121..1:5.5..:iuAM

Well known problem, every second character is missing.

> Does anybody can give me some clue how to fix it?

Make sure to enable SMC1 as serial port, too. If the  console  is  on
SMC2,  _both_ SMC1 and SMC2 must be enabled as a serial ports, or you
have to adjust the uart driver a bit.


Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
Nobody trips over mountains. It is the small pebble that  causes  you
to  stumble.  Pass all the pebbles in your path and you will find you
have crossed the mountain.

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Re: Kernel message missing characters!

[Yonghao Wang]

Thank you very much, Wolfgang.  You are right. We need to modify both
arch/ppc/boot/mbx/m8260_tty.c and rch/ppc/8260_io/uart.c to enable linux
support SMC2 as console for MPC8260. Ppcboot1.0.4 support it, but latest
linux kernel hasn't made SMC2 easy to configuration, although the uart.c
seems already has most code there.

Now I am finished my degree project as porting linux to custom MPC8260 board!
Thank you for your help during this period.

Wang Yonghao

Wolfgang Denk wrote:

> In message <3C9B393E.4958C98E@ftel.co.uk> you wrote:
> >
> > ppcboot as boot loader and kernel 2.4.7. The console is set up on serial
> >
> > SMC2. I've changed little bit code on arch/ppc/boot/mbx/m8260_tty.c to
> > enable it supports SMC2. But when I boot kernel,  the console output
>
> Seems you didn't do this right, then.
>
> > seems missing characters like below:
> ...
> > Ttlmmr  2M;uig0Bfrhs al a 0000
> > Lnxvrin247 wn@ihmr.tlc.k gcvrin30 1FiMr1 53:7GT20
> > oe0:378pgs:378
> > oe2:0pgs.
> > Kre omn ie ot/e/f wnsot121..4:epr/p-f-oti=7.61.1:7.6213121..1:5.5..:iuAM
>
> Well known problem, every second character is missing.
>
> > Does anybody can give me some clue how to fix it?
>
> Make sure to enable SMC1 as serial port, too. If the  console  is  on
> SMC2,  _both_ SMC1 and SMC2 must be enabled as a serial ports, or you
> have to adjust the uart driver a bit.
>
> Wolfgang Denk
>
> --
> Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
> Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
> Nobody trips over mountains. It is the small pebble that  causes  you
> to  stumble.  Pass all the pebbles in your path and you will find you
> have crossed the mountain.


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/