<div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote">On Tue, May 3, 2016 at 11:13 AM, Robert P. J. Day <span dir="ltr"><<a href="mailto:rpjday@crashcourse.ca" target="_blank">rpjday@crashcourse.ca</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">On Tue, 3 May 2016, Bruce Ashfield wrote:<br>
<br>
</span><span class="">> If you are not supplying a defconfig, and are inheriting the<br>
> standard kernel options, then yes, you'd be getting those fragments<br>
> as well.<br>
<br>
</span> ah, this actually leads me into my next question -- what is magic<br>
about a "defconfig" file that changes the normal processing?\<br></blockquote><div><br></div><div>It's the existing kernel.bbclass mechanism, and a well known convention</div><div>used in the kernel. So it is used to trigger the core kernel configuration,</div><div>and when I was extending things for kernel fragments it was similarly used</div><div>as a sentinel value.</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
in the YP kernel dev manual, section 2.2.3, one reads:<br>
<br>
"If you have a complete, working Linux kernel .config file you want to<br>
use for the configuration, as before, copy that file to the<br>
appropriate ${PN} directory in your layer's recipes-kernel/linux<br>
directory, and rename the copied file to "defconfig". Then, add the<br>
following lines to the linux-yocto .bbappend file in your layer:<br>
<br>
FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"<br>
SRC_URI += "file://defconfig"<br>
<br>
so the idea here is that a "defconfig" file is, in some sense, a<br>
"complete, working" config file that requires no extra processing, is<br>
that correct? does that mean that if you explicitly use a SRC_URI<br>
"defconfig" reference, all that extra normal processing won't be done?<br></blockquote><div><br></div><div>Nope. Everything is still processed, the kernel version you are using,</div><div>patches, etc, all make a difference to what ends up in the .config. The</div><div>phrasing there is to point out that it is what the mainline kernel considers</div><div>a defconfig, and it is typically a complete configuration of the kernel (that</div><div>is expected to boot your target).</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
also, that same section in the YP manual is slightly confusing -- if<br>
your SRC_URI refers to a defconfig file *and* some .cfg fragment<br>
files, is it necessarily true that the defconfig file is consulted<br>
first (no matter where it shows up in SRC_URI), after which all .cfg<br>
files are applied on top of that in order? it's not entirely clear<br>
from the manual if that's what happens.<br></blockquote><div><br></div><div>Yep. If you mix the two techniques, the defconfig is first (and taken</div><div>as the settings), and then fragments are applied on top.</div><div><br></div><div>Note: There are some changes in defconfig that are related to features</div><div>I'm doing for the fall 2.2 release, but nothing that changes the basic </div><div>processing (so compatibility is maintained). </div><div><br></div><div>Bruce</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
predictably, a couple more kernel config questions coming ...<br>
<div class="HOEnZb"><div class="h5"><br>
rday<br>
<br>
--<br>
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Robert P. J. Day Ottawa, Ontario, CANADA<br>
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<br>
</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature">"Thou shalt not follow the NULL pointer, for chaos and madness await thee at its end"</div>
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