[Buildroot] ADEOS patch and kernel override

[Michael Nazzareno Trimarchi]

Hi Thomas

On Fri, Sep 7, 2018 at 2:03 PM Michael Nazzareno Trimarchi
<michael at amarulasolutions.com> wrote:
>
> Hi
>
> On Fri, Sep 7, 2018 at 1:31 PM Thomas Petazzoni
> <thomas.petazzoni at bootlin.com> wrote:
> >
> > Hello Michael,
> >
> > On Fri, 7 Sep 2018 12:44:43 +0200, Michael Nazzareno Trimarchi wrote:
> >
> > > I'm trying to understand if I can override the kernel and let apply
> > > the adeos patch on top of it. Seems that PREHOOK is not called
> > > in the linux kernel override directory. Is there some semantic to use?
> >
> > When you said "override the kernel", I will assume you talking about
> > using LINUX_OVERRIDE_SRCDIR. If that is the case, then no, Buildroot
> > will not patch it for you.
> >

diff --git a/linux/linux.mk b/linux/linux.mk
index 675e790..085801d 100644
--- a/linux/linux.mk
+++ b/linux/linux.mk
@@ -351,6 +351,10 @@ define LINUX_KCONFIG_FIXUP_CMDS
                $(call KCONFIG_DISABLE_OPT,CONFIG_MXC_GPU_VIV,$(@D)/.config))
 endef

+ifneq ($(BR2_LINUX_KERNEL_EXT_XENOMAI_ADEOS_PATCH),)
+LINUX_DEPENDENCIES += xenomai
+endif
+
 ifeq ($(BR2_LINUX_KERNEL_DTS_SUPPORT),y)
 # Starting with 4.17, the generated dtc parser code is no longer
 # shipped with the kernel sources, so we need flex and bison. For

Is this fit anyway? I mean if I have a kernel patched with xenomai and
I'm working with it I need to tell that xenomai is needed.
Now another problem is that xenomai create symlink to the linux kernel
source. Another idea is to make both part of overlay development.

Michael
> > Let me give a few more details about this, and explain why it is done
> > like this.
> >
> > In a normal situation (i.e without OVERRIDE_SRCDIR), a package goes
> > through the following steps:
> >
> >  (1) download
> >  (2) extract
> >  (3) patch
> >  (4) configure
> >  (5) build
> >  (6) install
> >
> > When you switch to using OVERRIDE_SRCDIR for that package, the first
> > three steps are skipped and replaced by a "rsync" step, while the three
> > last steps remain the same:
> >
> >  (1) rsync
> >  (2) configure
> >  (3) build
> >  (4) install
> >
> > The reason is that if you do an override source directory:
> >
> >  * Buildroot has no idea what is the state of the source code in here,
> >    so it has no idea if the patches it has will apply. Most likely not.
> >
> >  * More importantly, it means that you own/control the source code,
> >    so you can simply apply whatever changes are needed on the source
> >    code located in the OVERRIDE_SRCDIR location.
> >
> > Does that help ?
> >
> Thomas is perfect description and I can see from the Makefile and make
> sense. So patch should be done as a script over the kernel override. I
> will proceed this way
>
> Michael
>
> > Best regards,
> >
> > Thomas
> > --
> > Thomas Petazzoni, CTO, Bootlin
> > Embedded Linux and Kernel engineering
> > https://bootlin.com
>
>
>
> --
> | Michael Nazzareno Trimarchi                     Amarula Solutions BV |
> | COO  -  Founder                                      Cruquiuskade 47 |
> | +31(0)851119172                                 Amsterdam 1018 AM NL |
> |                  [`as] http://www.amarulasolutions.com               |



-- 
| Michael Nazzareno Trimarchi                     Amarula Solutions BV |
| COO  -  Founder                                      Cruquiuskade 47 |
| +31(0)851119172                                 Amsterdam 1018 AM NL |
|                  [`as] http://www.amarulasolutions.com               |