[yocto] Problem with applying a patch using default -pnum

[Daniel Lazzari]

> On 2013-03-07 8:11, Jerrod Peach wrote:
> > Hans,
> >
> > Are you sure you're seeing the patch system use $WORKDIR instead of $S
> > as the root for patching?  I've had to do a lot of patching in our own
> > layers recently and I've always seen $S used as the root for the
> > patch.  Are you explicitly setting S = "${WORKDIR}/git"?  That's what
> > we do for our git recipes.  That's how you get the system to recognize
> > the source somewhere other than just $WORKDIR.
> >
> > As for specifying a different -pnum, you absolutely can do that like so:
> >
> > /SRC_URI += "file://my-change.patch*;striplevel=X*"/
> >
> > X is the pnum that you want.  Its default value is 1.
> >
> > You may also find this page useful -- it contains all sorts of hints
> > for setting up your recipes in a Yocto-standard way:
> >
> > https://wiki.yoctoproject.org/wiki/Recipe_&_Patch_Style_Guide
> >
> > That's where I learned about striplevel and the preference for it over
> > the deprecated pnum parameter.
> >
> > Kind regards,
> >
> > Jerrod
> >
> >
> Hi Jarod. Thanks, the pointer you gave will most certainly be of great aid. I will
> try the striplevel approach instead of writing my own do_patch() override.
> Regarding how certain I am that the root folder is ${WORKDIR} when
> patching, not at all ;) In my do_patch() function is simply did `pwd` and it was
> not set to ${S} as I set it to.
> That does not mean that the built-in patch system is using ${WORKDIR}, I am
> aware of that.
> Things here is, even though my patch is placed in ${W} and I set ${S} to eg.
> ${W}/git/some/folder, why would it not work? In another package I set ${S}
> to ${WORKDIR}/git and it works just fine. I can not understand why setting
> ${S} to something else breaks the logic?
> It's not that bitbake can not find the patch file, it definitely does that, but the
> -pnum seems to get messed up. But maybe that is the whole point of having
> the striplevel=X in the first place.
> 
> Hans
> 
> 
> >
> >
> >
> >
> > On Thu, Mar 7, 2013 at 7:33 AM, Hans Beck?rus <hans.beckerus at gmail.com
> > <mailto:hans.beckerus at gmail.com>> wrote:
> >
> >     On Thu, Mar 7, 2013 at 1:12 PM, Hans Beck?rus
> >     <hans.beckerus at gmail.com <mailto:hans.beckerus at gmail.com>>
> wrote:
> >     > Hi. More problems ;)
> >     > I have a patch file that needs to be applied to a source tree
> >     and the
> >     > patch file is copied properly to the ${WORKDIR} directory.
> >     > So far so good. But, the problem with this source tree is that it is
> >     > not built from the traditional root folder of the repo.
> >     > This means I need to change ${S} to point somewhere else. This also
> >     > causes the patch system to fail!
> >     > I did an override of do_patch() in my .bb and that seems to
> >     work, but
> >     > I do not like to use overrides unless I really have to.
> >     > So basically, is there some way to tell the built-in patch system to
> >     > use a different -pnum value?
> >     > If there is, I could stick with the do_patch() as provided by
> >     default.
> >     >
> >     > Hans
> >
> >     Hmm, ok a correction from my side. Forget parts of what I said ;)
> >     The patch system does not seem to use the value of ${S}, it is using
> >     ${WORKDIR} as the root for patching, this is also where the patch file
> >     is placed. The problem in my case does not seem to be that is built
> >     from a non-standard path. The reason why it fails seems to be because
> >     the actual source is not in ${WORKDIR}, it is in ${WORKDIR}/git. The
> >     patch file does include git as part of the source path for obvious
> >     reasons. What am I doing wrong? Having actual source code in
> >     ${WORKDIR}/git I assume is very common for git based downloads.
> >
> >     Hans
> >     _______________________________________________
> >     yocto mailing list
> >     yocto at yoctoproject.org <mailto:yocto at yoctoproject.org>
> >     https://lists.yoctoproject.org/listinfo/yocto
> >
> >

I also found another useful patch param called patchdir that sets the directory from which the patch is applied. This is useful when ${S} is set to a directory deeper than you want to patch from but don't want to mess with setting ${S}. I needed it to apply a patch to wpa_supplicant's src directory.

Ex.
file://gpio-sysfs-power-onoff-change.patch;patchdir=${WORKDIR}/wpa_supplicant-${PV}

Daniel Lazzari Jr.
Firmware Engineer
dlazzari at leapfrog.com