[yocto] meta-cedartrail - serial console

[Darren Hart]

On 06/01/2012 05:51 PM, Bodke, Kishore K wrote:
> 
> 
>> -----Original Message-----
>> From: Hart, Darren
>> Sent: Friday, June 01, 2012 2:17 PM
>> To: Bodke, Kishore K
>> Cc: jfabernathy; yocto at yoctoproject.org
>> Subject: Re: [yocto] meta-cedartrail - serial console
>>
>> On 06/01/2012 02:02 PM, Bodke, Kishore K wrote:
>>>
>>>
>>>> -----Original Message-----
>>>> From: Hart, Darren
>>>> Sent: Friday, June 01, 2012 11:12 AM
>>>> To: Bodke, Kishore K
>>>> Cc: jfabernathy; yocto at yoctoproject.org
>>>> Subject: Re: [yocto] meta-cedartrail - serial console
>>>>
>>>> On 06/01/2012 11:03 AM, Bodke, Kishore K wrote:
>>>>>
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: Hart, Darren
>>>>>> Sent: Thursday, May 31, 2012 12:43 PM
>>>>>> To: jfabernathy
>>>>>> Cc: Bodke, Kishore K; yocto at yoctoproject.org
>>>>>> Subject: Re: [yocto] meta-cedartrail - serial console
>>>>>>
>>>>>> On 05/31/2012 12:32 PM, jfabernathy wrote:
>>>>>>> On 05/31/2012 02:18 PM, Bodke, Kishore K wrote:
>>>>>>>>
>>>>>>>>> -----Original Message-----
>>>>>>>>> From: yocto-bounces at yoctoproject.org [mailto:yocto-
>>>>>>>>> bounces at yoctoproject.org] On Behalf Of jfabernathy
>>>>>>>>> Sent: Thursday, May 31, 2012 9:12 AM
>>>>>>>>> To: yocto at yoctoproject.org
>>>>>>>>> Subject: [yocto] meta-cedartrail - serial console
>>>>>>>>>
>>>>>>>>> Using a DN2800MT (Marshalltown) Intel board, I'm testing the
>>>>>>>>> meta-cedartrail using edison branch and noticed an issues with the
>>>>>>>>> serial console.
>>>>>>>>>
>>>>>>>>> The cedartrail.conf in the machine directory has the following
>>>> statements:
>>>>>>>>>
>>>>>>>>> SYSLINUX_OPTS = "serial 0 115200"
>>>>>>>>> SERIAL_CONSOLE = "115200 ttyS0"
>>>>>>>>> APPEND += "console=ttyS0,115200 console=tty0"
>>>>>>>>>
>>>>>>>> I just saw that Edison branch has ttyS3 enabled.
>>>>>>>>
>>>>>>>> SYSLINUX_OPTS = "serial 3 115200"
>>>>>>>> SERIAL_CONSOLE = "115200 ttyS3"
>>>>>>>> APPEND += "console=ttyS3,115200 console=tty3"
>>>>>>>>
>>>>>>>> Are you looking into right branch?
>>>>>>>>
>>>>>>>> Thanks
>>>>>>>> -Kishore.
>>>>>>>>
>>>>>>>
>>>>>>> So how do you get changes in the cedartrail.conf file to take affect??
>>>>>>> I edited the file and did the bitbake again, but nothing changed.  I'm
>>>>>>> guessing I need a bitbake -c cleansstate "somthing"  But I don't know
>>>>>>> what to put there to make rebuild with ttyS0.
>>>>>>>
>>>>>>
>>>>>> Ah yes, this rebuild is a bit frustrating. I believe it is the
>>>>>> task_core* tasks you need to rebuild. bitbake -u depexp -g
>>>>>> core-image-base (whatever your image is) will allow you to view which
>>>>>> task_ tasks it is building, try cleansstate'ing those and rebuilding the
>>>>>> image.
>>>>>
>>>>> I had to remove the above 3 lines from cedartrail.conf and
>>>>> SERIAL_CONSOLE ?= "115200 ttyS0" line from conf/machine/include/ia32-
>>>> base.inc
>>>>> rebuild the image.
>>>>> It is disabled now.
>>>>
>>>> Did you try with SERIAL_CONSOLE="" in cedartrail.conf ?
>>>
>>> Yes. I tried this.  It is disabled.
>>>
>>
>> Meaning you do not have to modify ia32-base.inc?
> 
> I removed the  SERIAL_CONSOLE ?= "115200 ttyS0" from ia32-base.inc too.
> 
>>
>>> I again added back in the grub.cfg, serial console hangs.
>>
>> Added what back in grub.cfg?
> 
> I added back console=ttyS0,115200 console=tty0 to the grub.cfg file and rebooted 
> to see if I can get the serial console back, but after below boot messages the serial
> console hangs.
> 
> Freeing unused kernel memory: 496k freed
> udev[77]: starting version 164
> EXT3-fs: barriers not enabled
> kjournald starting.  Commit interval 5 seconds
> EXT3-fs (loop0): using internal journal
> EXT3-fs (loop0): recovery complete
> EXT3-fs (loop0): mounted filesystem with ordered data mode
> udev[487]: starting version 164
> NET: Registered protocol family 10
> ADDRCONF(NETDEV_UP): eth0: link is not ready
> ip_tables: (C) 2000-2006 Netfilter Core Team
> nf_conntrack version 0.5.0 (16384 buckets, 65536 max)
> 
>>
>> I thought you were disabling the serial port...
> 
> I wanted to enable and disable the serial console through grub.cfg file.
> 

You can control the kernel logging to the serial console, but not the
login prompt over the serial port, via grub.cfg. The serial login is
managed by /etc/inittab which is dictated by the SERIAL_CONSOLE variable.

-- 
Darren Hart
Intel Open Source Technology Center
Yocto Project - Linux Kernel