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<!DOCTYPE bugzilla SYSTEM "https://bugzilla.yoctoproject.org/page.cgi?id=bugzilla.dtd">

<bugzilla version="5.0.6"
          urlbase="https://bugzilla.yoctoproject.org/"
          
          maintainer="it-coreprojects-helpdesk@linuxfoundation.org"
>

    <bug>
          <bug_id>8595</bug_id>
          
          <creation_ts>2015-10-28 09:34:35 +0000</creation_ts>
          <short_desc>Document how to change kernel version</short_desc>
          <delta_ts>2016-04-13 04:08:37 +0000</delta_ts>
          <reporter_accessible>1</reporter_accessible>
          <cclist_accessible>1</cclist_accessible>
          <classification_id>9</classification_id>
          <classification>Documentation</classification>
          <product>Mega Manual</product>
          <component>mega-manual</component>
          <version>2.1</version>
          <rep_platform>x86</rep_platform>
          <op_sys>Multiple</op_sys>
          <bug_status>VERIFIED</bug_status>
          <resolution>FIXED</resolution>
          
          
          <bug_file_loc></bug_file_loc>
          <status_whiteboard>11 April 2016: RESOLVED</status_whiteboard>
          <keywords></keywords>
          <priority>Medium+</priority>
          <bug_severity>normal</bug_severity>
          <target_milestone>2.1 M4</target_milestone>
          
          
          <everconfirmed>1</everconfirmed>
          <reporter name="Bogdan Alexandru Voiculescu">bogdanx.a.voiculescu</reporter>
          <assigned_to name="Scott Rifenbark">srifenbark</assigned_to>
          <cc>bluelightning</cc>
    
    <cc>richard.purdie</cc>
    
    <cc>srifenbark</cc>
          
          <qa_contact name="Bogdan Alexandru Voiculescu">bogdanx.a.voiculescu</qa_contact>
          <cf_os>---</cf_os>
          <cf_regression_type>---</cf_regression_type>
          
          <cf_docchange>Done (doc changes complete)</cf_docchange>

      

      

      

          <comment_sort_order>oldest_to_newest</comment_sort_order>  
          <long_desc isprivate="0" >
    <commentid>55880</commentid>
    <comment_count>0</comment_count>
    <who name="Bogdan Alexandru Voiculescu">bogdanx.a.voiculescu</who>
    <bug_when>2015-10-28 09:34:35 +0000</bug_when>
    <thetext>Recently I needed to override a variable: kernel version.
Founding in manual the indication for this was not an easy task. 

Intuitively PREFERRED_VERSION should be used: 
http://www.yoctoproject.org/docs/1.9/ref-manual/ref-manual.html#var-PREFERRED_VERSION

Still, if this variable is changed in local conf, new value will not override 
PREFERRED_VERSION_linux-yocto ?= &quot;4.1% from poky/meta-yocto/distro/poky.conf 

(See https://bugzilla.yoctoproject.org/show_bug.cgi?id=4204)

On method is to use &apos;forcevariable&apos; like: 
PREFERRED_VERSION_linux-yocto_forcevariable = &quot;3.4%&quot;
or 
use a machine override
PREFERRED_VERSION_linux-yocto_qemux86 = &quot;3.4%&quot; - we need to specify in which conf files using this variable will work or from command line.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>55923</commentid>
    <comment_count>1</comment_count>
    <who name="Scott Rifenbark">srifenbark</who>
    <bug_when>2015-10-28 14:18:11 +0000</bug_when>
    <thetext>Setting target to 2.1 and state to ACCEPTED.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>60694</commentid>
    <comment_count>2</comment_count>
    <who name="Scott Rifenbark">srifenbark</who>
    <bug_when>2016-04-01 17:11:37 +0000</bug_when>
    <thetext>Hi, 

See http://www.yoctoproject.org/docs/2.1/ref-manual/ref-manual.html#var-PREFERRED_VERSION for an updated description of this variable.  I do not know what .conf files apply for forcing this.  If you could tell me then I can further update the description to include that information.

Thanks, 
Scott</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>60724</commentid>
    <comment_count>3</comment_count>
    <who name="Bogdan Alexandru Voiculescu">bogdanx.a.voiculescu</who>
    <bug_when>2016-04-04 06:35:14 +0000</bug_when>
    <thetext>Hi Scott,
I believe Richard knows best the design (See https://bugzilla.yoctoproject.org/show_bug.cgi?id=4204).</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>60750</commentid>
    <comment_count>4</comment_count>
    <who name="Richard Purdie">richard.purdie</who>
    <bug_when>2016-04-04 19:54:22 +0000</bug_when>
    <thetext>I&apos;d word this as:

&quot;&quot;&quot;
Sometimes the PREFERRED_VERSION can be set by configuration files in a way which is hard to change. You can use OVERRIDES to help with this, e.g. a machine specific override as follows:

     PREFERRED_VERSION_linux-yocto_qemux86 = &quot;3.4%&quot;

Although not recommended, worst case, you can also use &quot;forcevariable&quot; override, the strongest override there is as follows:

     PREFERRED_VERSION_linux-yocto_forcevariable = &quot;3.4%&quot;
&quot;&quot;&quot;</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>60755</commentid>
    <comment_count>5</comment_count>
    <who name="Scott Rifenbark">srifenbark</who>
    <bug_when>2016-04-04 20:35:09 +0000</bug_when>
    <thetext>Hi, 

I have implemented Richard&apos;s feedback.  I will leave the bug at IN PROGRESS REVIEW for a while and then if there is no further feedback will close it. 

Scott

http://www.yoctoproject.org/docs/2.1/ref-manual/ref-manual.html#var-PREFERRED_VERSION</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>60785</commentid>
    <comment_count>6</comment_count>
    <who name="Bogdan Alexandru Voiculescu">bogdanx.a.voiculescu</who>
    <bug_when>2016-04-05 07:30:33 +0000</bug_when>
    <thetext>Hi Scott,
It is still unclear in which this should be set: in poky.conf or in local.conf? 
My initial problem was: 
&quot;If this variable is changed in local conf, new value will not override 
PREFERRED_VERSION_linux-yocto ?= &quot;4.1% from poky/meta-yocto/distro/poky.conf&quot;

Should we specify in manual that setting &quot;PREFERRED_VERSION_linux-yocto ?= &quot;4.1%&quot; in local.conf will NOT overwrite the poky.conf value? Or this is a bug?</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>60788</commentid>
    <comment_count>7</comment_count>
    <who name="Richard Purdie">richard.purdie</who>
    <bug_when>2016-04-05 08:45:37 +0000</bug_when>
    <thetext>We need to keep the manual a little bit generic, not specific. You could have a conflict with PREFERRED_VERSION in any two config files and you could want this setting in site.conf or auto.conf or local.conf or a distro config or a machine config. We therefore can&apos;t be entirely specific as it could vary for other kernels or change location in future :/.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>60789</commentid>
    <comment_count>8</comment_count>
    <who name="Paul Eggleton">bluelightning</who>
    <bug_when>2016-04-05 08:50:15 +0000</bug_when>
    <thetext>I think it&apos;s not unreasonable to have a documented way to accomplish this task though, with pointers as to how to debug it for people with custom setups where the instructions don&apos;t have the desired effect. You could view this as part of us offering more task-oriented documentation rather than reference.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>60826</commentid>
    <comment_count>9</comment_count>
    <who name="Scott Rifenbark">srifenbark</who>
    <bug_when>2016-04-05 23:12:33 +0000</bug_when>
    <thetext>This sounds like a good candidate for a &quot;cookbook&quot; topic on &quot;How to Change the Kernel Version.&quot;  

Maybe we should open a new doc bug requesting a procedure be documented for this task.  We could close this bug as it was against the variable description.  

Thoughts?</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>60835</commentid>
    <comment_count>10</comment_count>
    <who name="Bogdan Alexandru Voiculescu">bogdanx.a.voiculescu</who>
    <bug_when>2016-04-06 05:48:22 +0000</bug_when>
    <thetext>Scott, I vote for the cookbook.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>61111</commentid>
    <comment_count>11</comment_count>
    <who name="Scott Rifenbark">srifenbark</who>
    <bug_when>2016-04-12 18:31:05 +0000</bug_when>
    <thetext>Closing this bug for the variable description.  I am opening a new bug to capture a &quot;cookbook&quot; item to address the concerns in Comment 8. See Bug 9451 for the new bug requesting a procedure be documented. 

Scott</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>61126</commentid>
    <comment_count>12</comment_count>
    <who name="Bogdan Alexandru Voiculescu">bogdanx.a.voiculescu</who>
    <bug_when>2016-04-13 04:08:37 +0000</bug_when>
    <thetext>Verified</thetext>
  </long_desc>
      
      

    </bug>

</bugzilla>