[yocto] meta-cedartrail - serial console

[Darren Hart]

On 06/01/2012 10:39 AM, jfabernathy wrote:
> On 06/01/2012 01:01 PM, Darren Hart wrote:
>>
>> On 06/01/2012 08:45 AM, jfabernathy wrote:
>>> On 05/31/2012 03:41 PM, Darren Hart wrote:
>>>> On 05/31/2012 11:54 AM, jfabernathy wrote:
>>>>> On 05/31/2012 02:13 PM, Darren Hart wrote:
>>>>>> On 05/31/2012 09:11 AM, jfabernathy wrote:
>>>>>>> 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"
>>>>>>>
>>>>>>> However, when the image booted, I had no serial console on ttyS0.  I
>>>>>>> checked /etc/inittab and noticed that the following line existed:
>>>>>>>
>>>>>>> S:2345:respawn:/sbin/getty 115200 ttyS3
>>>>>>>
>>>>>>> I changed the ttyS3 to ttyS0 and then I have a serial console on the
>>>>>>> next reboot.  So it appears the override in the .conf file is not
>>>>>>> working.  Also I only have the console from getty, and not the kernel
>>>>>>> logging console.
>>>>>>>
>>>>>>> Anyone have a solution??
>>>>>>>
>>>>>>> If this is considered a bug I can put it on bugzilla.
>>>>>> Lets make sure your environment is what we expect. Please provide the
>>>>>> output of:
>>>>>>
>>>>>> $ bitbake core-image-minimal -e | grep SERIAL_CONSOLE=
>>>>>>
>>>>>> If it is not "115200 ttyS0" then it is getting overwritten somewhere
>>>>>> either in your config, or possibly by an inappropriate selection of an
>>>>>> assignment operator (=, ?=, etc.) in edison.
>>>>> okay now I'm confused.  while the cedartrail.conf file has the following:
>>>>> SYSLINUX_OPTS = "serial 3 115200"
>>>>> SERIAL_CONSOLE = "115200 ttyS3"
>>>>> APPEND += "console=ttyS3,115200 console=tty3"
>>>>>
>>>>>
>>>>> The output of the bitbake command you suggested above gives:
>>>>> jim at ubuntu-x64:~/poky/build$ bitbake core-image-minimal -e | grep
>>>>> SERIAL_CONSOLE=
>>>>>
>>>>> # SERIAL_CONSOLE=115200 ttyS0
>>>>> SERIAL_CONSOLE="115200 ttyS0"
>>>>> jim at ubuntu-x64:~/poky/build$
>>>>>
>>>>> So is the bitbake command showing the results before the cedartrail.conf
>>>>> options take affect??
>>>> variable assignments can be tricky, and are not the easiest things to
>>>> track down. I suggest looking through your configured layers and looking
>>>> for all the SERIAL_CONSOLE assignments using ttyS3 and ttyS0 and see if
>>>> you can determine what is overriding your cedartrail.conf setting.
>>>>
>>> What I found out is the only variable that matters for login console in
>>> my situation is SERIAL_CONSOLE because I have to use grub and the boot
>>> from hard drive method because my image can't be put on a USB Flash for
>>> some reason.  So I manually have to edit the grub.cfg file as documented
>>> on the wiki "How Do I" section of putting Yocto on a hard drive.  Adding
>>> console=ttyS0,115200 on the linux statement takes care of the boot console.
>> I believe this is a manual process currently. Please open an enhancement
>> in bugzilla for your specific situation and I'll incporporate into the
>> larger boot process and image revamp we're doing for 1.3.
>>
> I'll make the entry.
>>> So the question is has there been any thought about automating the
>>> choice of boot loader and the parameters that are needed or optional?
>>> In the case of meta-cedartrail, the cedartrail.conf assumes syslinux is
>>> the boot loader. When I could use a USB Flash key, creating a boot
>>> device was a trivial dd statement.  Because I have to use a hard drive
>>> now, I have to do a number of manual steps.  Or is there a way to create
>>> a boot-able hard drive with syslinux so the cedartrail.conf parameters
>>> are all that is needed to adjust?
>> This is all good feedback to consider as we work through making more
>> universally bootable images. This is becoming a hot topic as people are
>> using Yocto in more and more situations and as things like EFI become
>> more commonplace.
>>
>> There is no reason you can't just dd (have a look at
>> scripts/contrib/ddimage) the image to a hard disk instead of a usb
>> stick. You may need a USB to SATA adapter for your host (this is what I
>> use). If you have a USB port, you could just use the install option.
> This script does not eliminate the boot error I get with syslinux on USB 
> flash keys.  I noticed the script is not in edison but is in denzil, so 
> I got it there and tried to run it against an image created with 
> edison.  I still get the same boot error I get with dd, which is 
> understandable since that's what the script uses.  Not sure if this is a 
> size issue because my image is over a 1GB.  I'm guessing this this will 
> still fail on a hard drive with the dd'ing of the .hddimg, but I'll test 
> it anyway.

Sorry, ddimage wasn't meant to fix the issue, just as a slightly more
convenient/safe wrapper around dd.

I'm not familiar with the error you are seeing with the live image. Can
you point me to the thread or the bug?

--
Darren

>> The integration between the boot loader options is something that needs
>> work. At some point I hope to replace GRUB with syslinux in all possible
>> situations in order simplify the option handling and present a
>> consistent boot interface between live images, iso limages, and disk images.
>>
> 

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