[Buildroot] [PATCH] linux: rebuild after reconfiguring kernel

[Buildroot] [PATCH] linux: rebuild after reconfiguring kernel

[H Hartley Sweeten]

Add support for rebuilding the kernel after make linux26-menuconfig.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>

---

diff --git a/linux/linux.mk b/linux/linux.mk
index 593a1b4..a014f55 100644
--- a/linux/linux.mk
+++ b/linux/linux.mk
@@ -139,6 +139,7 @@ linux26: host-module-init-tools $(LINUX26_DEPENDENCIES) $(LINUX26_DIR)/.stamp_in
 
 linux26-menuconfig linux26-xconfig linux26-gconfig: $(LINUX26_DIR)/.stamp_configured
 	$(MAKE) $(LINUX26_MAKE_FLAGS) -C $(LINUX26_DIR) $(subst linux26-,,$@)
+	$(Q)touch $@
 
 # Support for rebuilding the kernel after the initramfs file list has
 # been generated in $(BINARIES_DIR)/rootfs.initramfs.

[Buildroot] [PATCH] linux: rebuild after reconfiguring kernel

[Thomas Petazzoni]

Hello!

On Tue, 6 Jul 2010 11:30:52 -0700
H Hartley Sweeten <hartleys@visionengravers.com> wrote:

> diff --git a/linux/linux.mk b/linux/linux.mk
> index 593a1b4..a014f55 100644
> --- a/linux/linux.mk
> +++ b/linux/linux.mk
> @@ -139,6 +139,7 @@ linux26: host-module-init-tools $(LINUX26_DEPENDENCIES) $(LINUX26_DIR)/.stamp_in
>  
>  linux26-menuconfig linux26-xconfig linux26-gconfig: $(LINUX26_DIR)/.stamp_configured
>  	$(MAKE) $(LINUX26_MAKE_FLAGS) -C $(LINUX26_DIR) $(subst linux26-,,$@)
> +	$(Q)touch $@

Unless I'm missing something, this change is going to create a
linux26-menuconfig file or a linux26-xconfig file, which is not
correct, and is not going to retrigger the build step of the kernel.

We are already handling the fact that the kernel should be rebuilt when
its configuration is changed. This is done through the following
dependency :

$(LINUX26_DIR)/.stamp_compiled: $(LINUX26_DIR)/.stamp_configured $(LINUX26_DIR)/.config

So, when the kernel .config is changed, the build step is restarted.

Which exact issue are you facing ? Can you provide an example ?

Thanks!

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] [PATCH] linux: rebuild after reconfiguring kernel

[H Hartley Sweeten]

On Wednesday, July 07, 2010 5:10 AM, Thomas Petazzoni wrote:
> Hello!
>
> On Tue, 6 Jul 2010 11:30:52 -0700
> H Hartley Sweeten <hartleys@visionengravers.com> wrote:
>
>> diff --git a/linux/linux.mk b/linux/linux.mk
>> index 593a1b4..a014f55 100644
>> --- a/linux/linux.mk
>> +++ b/linux/linux.mk
>> @@ -139,6 +139,7 @@ linux26: host-module-init-tools $(LINUX26_DEPENDENCIES) $(LINUX26_DIR)/.stamp_in
>>  
>>  linux26-menuconfig linux26-xconfig linux26-gconfig: $(LINUX26_DIR)/.stamp_configured
>>  	$(MAKE) $(LINUX26_MAKE_FLAGS) -C $(LINUX26_DIR) $(subst linux26-,,$@)
>> +	$(Q)touch $@
>
> Unless I'm missing something, this change is going to create a
> linux26-menuconfig file or a linux26-xconfig file, which is not
> correct, and is not going to retrigger the build step of the kernel.

Argh... Your correct.  The .stamp_configured file is the one that needs touched.

> We are already handling the fact that the kernel should be rebuilt when
> its configuration is changed. This is done through the following
> dependency :
>
> $(LINUX26_DIR)/.stamp_compiled: $(LINUX26_DIR)/.stamp_configured $(LINUX26_DIR)/.config
>
> So, when the kernel .config is changed, the build step is restarted.
>
> Which exact issue are you facing ? Can you provide an example ?

Your correct, when the .config file is changed the kernel does rebuild.

The strange thing is, yesterday it didn't work and I haven't changed anything.
I would do:

$ make linux26-menuconfig

Change something in the config, then:

$ make

Or

$ make linux26

And the kernel would not rebuild.  But if I did:

$ touch output/build/linux-2.6.34/.stamp_configured
$ make

It would.

Oh well, it's working now...

Regards,
Hartley

[Buildroot] [PATCH] linux: rebuild after reconfiguring kernel

[Thomas Petazzoni]

On Wed, 7 Jul 2010 15:11:50 -0500
H Hartley Sweeten <hartleys@visionengravers.com> wrote:

> > Unless I'm missing something, this change is going to create a
> > linux26-menuconfig file or a linux26-xconfig file, which is not
> > correct, and is not going to retrigger the build step of the kernel.
> 
> Argh... Your correct.  The .stamp_configured file is the one that needs touched.

Right.

> > Which exact issue are you facing ? Can you provide an example ?
> 
> Your correct, when the .config file is changed the kernel does rebuild.
> 
> The strange thing is, yesterday it didn't work and I haven't changed anything.
> I would do:
> 
> $ make linux26-menuconfig
> 
> Change something in the config, then:
> 
> $ make
> 
> Or
> 
> $ make linux26
> 
> And the kernel would not rebuild.  But if I did:
> 
> $ touch output/build/linux-2.6.34/.stamp_configured
> $ make
> 
> It would.
> 
> Oh well, it's working now...

Strange. If you manage to reproduce something like this, don't hesitate
to tell us.

Thanks,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com