Impossible to open the root console with 2.6.15

Impossible to open the root console with 2.6.15

[Jean-Marie Teuler]

Hi there,

I am trying to use ELDK 4.0 on my TQM860L board.

I have compiled the included 2.6.15 kernel with reasonable options, but
when I try to boot it, I do not get the prompt after the message
"Uncompressing Kernel Image ... OK"

Actually, I know that the system is not hanging because
1) I see there is network traffic between the board and the NFS server
2) There are messages written in /var/log/messages, and I see that the
initialization is completed (even my /etc/rc.local has been executed)

So I suspect that the problem comes from reading/writing on the console.
As my /etc/inittab has the line
...............................................
3:2345:respawn:/sbin/mingetty --noclear console
...............................................
I have put a wrapper around the binary "mingetty" and I have checked
that indeed it is called... only that I do not see anything on the
screen.

I am pretty sure that this problem is related to the kernel because if I
boot on a 2.4 kernel with the same root filesystem everything works
fine.

With the 2.4 kernel I had the following messages in /var/log/messages
.................................................................
Jan 22 12:16:34 tqm kernel: ttyS0 at 0x0280 is on SMC1 using BRG1
Jan 22 12:16:34 tqm kernel: ttyS1 at 0x0380 is on SMC2 using BRG2
.................................................................

and with the 2.6
......................................................................
Jan 26 20:25:26 tqm kernel: ttyCPM0 at MMIO 0xfff00a80 (irq = 20) is a
CPM UART
Jan 26 20:25:26 tqm kernel: ttyCPM1 at MMIO 0xfff00a90 (irq = 19) is a
CPM UART
......................................................................

I have tried to create these devices with the following characteristics:
......................................................................
crw-rw---- 1 root root 204, 46 mai  3 14:43 dev/ttyCPM0
crw-rw---- 1 root root 204, 47 mai  3 14:43 dev/ttyCPM1
......................................................................
but to no avail.

I have seen that there are many new options related to serial lines in
the new kernel, so I guess that I am doing something wrong.

Thanks in advance for any hint.

Jean-Marie Teuler

........................................................................
: Jean-Marie Teuler              :                                     :
: Laboratoire de Chimie Physique :  Téléphone (33) (1) 69 15 42 05     :
: Université de Paris-sud        :  Télécopie (33) (1) 69 15 61 88     :
: Bâtiment 349                   :  Mél       teuler@lcp.u-psud.fr     :
: 91 405 Orsay Cedex             :  Web       http://www.lcp.u-psud.fr :
........................................................................

Re: Impossible to open the root console with 2.6.15

[jfaslist]

Jean-Marie Teuler wrote:

>Hi there,
>
>I am trying to use ELDK 4.0 on my TQM860L board.
>
>I have compiled the included 2.6.15 kernel with reasonable options, but
>when I try to boot it, I do not get the prompt after the message
>"Uncompressing Kernel Image ... OK"
>  
>
It could be a FAQ:
http://www.denx.de/wiki/DULG/LinuxHangsAfterUncompressingKernel

But in fact, wwe had a similar case recently (no console outputs, but 
linux running OK) and I am told that the problem was with  the "virtual 
terminal"  option that needed to be disabled:

Device Drivers
-> Character devices
 -> [ ] Virtual Terminal
	serial drivers->
		<*> CPM SCC/SMC serial port support
 		 <*> Support for console CMP SCC/SMC serial port......

 --

Best regards,
_______________________________________
jean-francois simon - themis computer
5, rue irene joliot curie
38330 eybens - france
+33 (0)870 448 638
+33 (0)4 76 14 77 85


	

	
		
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Re: Impossible to open the root console with 2.6.15

[Wolfgang Denk]

In message <1146663369.2448.25.camel@khnoum.lcp.u-psud.fr> you wrote:
> 
> I am trying to use ELDK 4.0 on my TQM860L board.
> 
> I have compiled the included 2.6.15 kernel with reasonable options, but
> when I try to boot it, I do not get the prompt after the message
> "Uncompressing Kernel Image ... OK"

We do not support Linux 2.6 kernels for MPC8xx systems yet.  For  the
TQM860L please continue to use ELDK 3.1.1 as shipping with the board.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de
Committee, n.:  A group of men who individually can do nothing but as
a group decide that nothing can be done.                 - Fred Allen

Re: Impossible to open the root console with 2.6.15

[Jean-Marie Teuler]

Dear Jean-François,

> But in fact, wwe had a similar case recently (no console outputs, but 
> linux running OK) and I am told that the problem was with  the "virtual 
> terminal"  option that needed to be disabled:
> 
> Device Drivers
> -> Character devices
>  -> [ ] Virtual Terminal
> 	serial drivers->
> 		<*> CPM SCC/SMC serial port support
>  		 <*> Support for console CMP SCC/SMC serial port......

Thanks. This solved the problem. Just by disabling the virtual
terminals!

Jean-Marie

Re: Impossible to open the root console with 2.6.15

[Jean-Marie Teuler]

Dear Mark,

> Are you passing a 'console=' option to the kernel, like 'console=ttyCPM0' or 
> 'console=ttyCPM1'.

No. I was not passing any option (besides the standard NFSROOT options
(root=/dev/nfs rw nfsroot= ip=).

Actually, the trick suggested by Jean-François Simon (disabling the
virtual terminals option in the kernel configuration) solved the problem
(please see my previous post).

Thanks for your interest anyway.

Jean-Marie

Re: Impossible to open the root console with 2.6.15

[Jean-Marie Teuler]

Dear Wolfgang,

> We do not support Linux 2.6 kernels for MPC8xx systems yet.  For  the
> TQM860L please continue to use ELDK 3.1.1 as shipping with the board.

Sorry for the misunderstanding: as the ELDK 4.0 officially supports
MPC8xx systems (as said in the README.html file), and as it is shipped
with a 2.6 kernel, I have jumped to the conclusion that this kernel was
also supported.

Anyway, my present constatation is that, with the help of the tricks
suggested by Jean-François Simon or Mark Chambers, at least the system
starts correctly... I did not make any further check yet.

Best regards,

Jean-Marie