[Buildroot] When building the net-next kernel, buildroot is asking for all the kernel config options one by one to enable

[Buildroot] When building the net-next kernel, buildroot is asking for all the kernel config options one by one to enable

[Ganesh]

Hi,

When using buildroot for my project, I am getting the following piece of
prompt.

*ganesh15255 at CHE-LT-I15255:/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot$
make linux-rebuild
rm -f
/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/build/linux-custom/.stamp_rsynced
rm -f
/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/build/linux-custom/.stamp_staging_installed
rm -f
/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/build/linux-custom/.stamp_target_installed
rm -f
/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/build/linux-custom/.stamp_images_installed
rm -f
/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/build/linux-custom/.stamp_host_installed
rm -f
/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/build/linux-custom/.stamp_built
>>> linux custom Syncing from source dir ../../kernel_net-next/net-next
rsync -au --chmod=u=rwX,go=rX  --exclude .svn --exclude .git --exclude .hg
--exclude .bzr --exclude CVS ../../kernel_net-next/net-next/
/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/build/linux-custom
>>> linux custom Building
PATH="/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/host/bin:/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/host/sbin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/mnt/c/Program
Files/WindowsApps/CanonicalGroupLimited.Ubuntu18.04onWindows_2020.1804.7.0_x64__79rhkp1fndgsc:/mnt/c/Program
Files (x86)/Intel/Intel(R) Management Engine Components/iCLS/:/mnt/c/Program
Files/Intel/Intel(R) Management Engine Components/iCLS/:/mnt/c/Program Files
(x86)/Common
Files/Oracle/Java/javapath:/mnt/c/ProgramData/Oracle/Java/javapath:/mnt/c/WINDOWS/system32:/mnt/c/WINDOWS:/mnt/c/WINDOWS/System32/Wbem:/mnt/c/WINDOWS/System32/WindowsPowerShell/v1.0/:/mnt/c/Program
Files (x86)/WebEx/Productivity Tools:/mnt/c/Program Files
(x86)/Microchip/xc32/v1.42/bin:/mnt/c/Program Files (x86)/Microsoft SQL
Server/100/Tools/Binn/:/mnt/c/Program Files/Microsoft SQL
Server/100/Tools/Binn/:/mnt/c/Program Files/Microsoft SQL
Server/100/DTS/Binn/:/mnt/c/Program Files (x86)/Intel/Intel(R) Management
Engine Components/DAL:/mnt/c/Program Files/Intel/Intel(R) Management Engine
Components/DAL:/mnt/c/Program Files (x86)/Intel/Intel(R) Management Engine
Components/IPT:/mnt/c/Program Files/Intel/Intel(R) Management Engine
Components/IPT:/mnt/c/WINDOWS/System32/OpenSSH/:/mnt/c/Program
Files/Perforce:/mnt/c/Program Files
(x86)/Microchip/xc32/v2.20-TC4/bin:/mnt/c/Users/I15255/AppData/Local/Programs/Python/Python37-32/Scripts/:/mnt/c/Users/I15255/AppData/Local/Programs/Python/Python37-32/:/mnt/c/Users/I15255/AppData/Local/Microsoft/WindowsApps:/mnt/c/Python27:/mnt/c/Python27/Scripts:/mnt/c/Users/I15255/AppData/Local/atom/bin:/snap/bin"
PKG_CONFIG="/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/host/bin/pkg-config"
PKG_CONFIG_SYSROOT_DIR="/" PKG_CONFIG_ALLOW_SYSTEM_CFLAGS=1
PKG_CONFIG_ALLOW_SYSTEM_LIBS=1
PKG_CONFIG_LIBDIR="/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/host/lib/pkgconfig:/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/host/share/pkgconfig"
BR_BINARIES_DIR=/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/images
KCFLAGS=-Wno-attribute-alias /usr/bin/make -j5
HOSTCC="/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/host/bin/ccache
/usr/bin/gcc -O2
-I/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/host/include
-L/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/host/lib
-Wl,-rpath,/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/host/lib"
ARCH=arm
INSTALL_MOD_PATH=/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/target
CROSS_COMPILE="/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/host/bin/arm-buildroot-linux-uclibcgnueabihf-"
DEPMOD=/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/host/sbin/depmod
INSTALL_MOD_STRIP=1 -C
/mnt/d/Local_Linux_Repos/Buildroot_Latest/buildroot/output/build/linux-custom
all
scripts/kconfig/conf  --syncconfig Kconfig
*
* Restart config...
*
*
* GCC plugins
*
GCC plugins (GCC_PLUGINS) [Y/n/?] (NEW) *

My board is an SAMA5D3 (ARM ) board.

I have done the following steps before starting the kernel build:

1. Put my defconfig inside the kernel/arch/arm/config 
2. Go to buildroot directory, make <my_project_defconfig>
3. make 

my_project_defconfig has the following lines of concern:

BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="<kernel path of the defconfig>"
BR2_LINUX_KERNEL_DTS_SUPPORT=y
BR2_LINUX_KERNEL_INTREE_DTS_NAME="My_dts.dts"

After giving the make, am getting a series of prompts from the buildroot
like enabling drivers for a specific product, starting with the GCC thing
and most of which I do not know .
What I expected was that I have already specified the defconfig and that
buildroot should be able to enable the necessary things automatically.

Can anyone tell me where I have gone wrong?

P.S: I am a total newbie to linux and this is my first project.

Buildroot download path: $ git clone
https://github.com/linux4sam/buildroot-at91.git
Kernel : net-next

Thanks in advance,
Ganesh



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[Buildroot] When building the net-next kernel, buildroot is asking for all the kernel config options one by one to enable

[Thomas Petazzoni]

On Wed, 29 Apr 2020 07:32:55 -0500 (CDT)
Ganesh <ganesh45in@gmail.com> wrote:

> My board is an SAMA5D3 (ARM ) board.
> 
> I have done the following steps before starting the kernel build:
> 
> 1. Put my defconfig inside the kernel/arch/arm/config 
> 2. Go to buildroot directory, make <my_project_defconfig>
> 3. make 
> 
> my_project_defconfig has the following lines of concern:
> 
> BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
> BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="<kernel path of the defconfig>"
> BR2_LINUX_KERNEL_DTS_SUPPORT=y
> BR2_LINUX_KERNEL_INTREE_DTS_NAME="My_dts.dts"
> 
> After giving the make, am getting a series of prompts from the buildroot
> like enabling drivers for a specific product, starting with the GCC thing
> and most of which I do not know .
> What I expected was that I have already specified the defconfig and that
> buildroot should be able to enable the necessary things automatically.
> 
> Can anyone tell me where I have gone wrong?

This simply means that your kernel configuration file is not
"up-to-date" with the kernel version you're using. Due to this, some
options exist in the kernel for which the values are not specified in
the kernel configuration file you are providing. So the kernel has to
ask you whether you want to enable or disable those options.

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

[Buildroot] When building the net-next kernel, buildroot is asking for all the kernel config options one by one to enable

[Ganesh]

Hi,

>This simply means that your kernel configuration file is not
>"up-to-date" with the kernel version you're using. Due to this, some
>options exist in the kernel for which the values are not specified in
>the kernel configuration file you are providing. So the kernel has to
>ask you whether you want to enable or disable those options.

Thanks Thomas for a quick response. I have few more queries regarding this.

I tried the following today.

1.Without using the buildroot, Inside the kernel root folder tried to build
my config by doing the following:

make ARCH=arm my_kernel_defconfig
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf-

This time, the kernel doesn't prompt for my responses and it directly
builds.

With buildroot, it copies the entire kernel into output/build/linux-custom
directory and tries to build from there. There it misses some config so its
prompting my responses.

So, my question is am using the same kernel defconfig in both the methods, I
am able to build within kernel but not from within buildroot. 
What's the difference that is making buildroot to not recognise the options
to be enabled and it is prompting me configure the kernel?

I think am missing something very basic here. I tried with some other kernel
config which are default inside the kernel too still the same issue.

Also am using Windows subsystem for Linux for the build and the kernel is
git cloned to my local directory.(added local.mk to specify the custom path
too).

Thanks,
Ganesh.



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[Buildroot] When building the net-next kernel, buildroot is asking for all the kernel config options one by one to enable

[Ganesh]

Hi,

This issue is resolved by installing gcc plugins in my host system.

s*udo apt-get install -y gcc-7-plugin-dev*

After this, buildroot does not ask 

GCC plugins (GCC_PLUGINS) [Y/n/?] (NEW)

and the kernel build is proceeding as expected.

But am not sure how this is helping in resolving the issue. Can anyone
explain how installing the gcc plugins in the host system helps ?



--
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[Buildroot] When building the net-next kernel, buildroot is asking for all the kernel config options one by one to enable

[Andreas Ziegler]

> Message: 3
> Date: Wed, 29 Apr 2020 07:32:55 -0500 (CDT)
> From: Ganesh <ganesh45in@gmail.com>
> To: buildroot at busybox.net
> Subject: [Buildroot] When building the net-next kernel, buildroot is
> 	asking for all the kernel config options one by one to enable

Hi Ganesh,

> I have done the following steps before starting the kernel build:
> 
> 1. Put my defconfig inside the kernel/arch/arm/config
> 2. Go to buildroot directory, make <my_project_defconfig>
> 3. make
> 
> my_project_defconfig has the following lines of concern:
> 
> BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
> BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="<kernel path of the defconfig>"
> BR2_LINUX_KERNEL_DTS_SUPPORT=y
> BR2_LINUX_KERNEL_INTREE_DTS_NAME="My_dts.dts"

Just some remarks about your project configuration:

1. Ideally, you should not copy your kernel defconfig to the kernel tree 
manually, it might get overwritten by the rsync() command. Just 
configure the external location in Buildroot via 
"BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE". File locations are relative to 
the Buildroot directory or absolute and may use BR2_* environment 
variables.

2. The rsync() for the kernel tree will copy any existing .config* files 
into the build location, which may be responsible for your strange 
issue. Remove configuration fragments from your source tree or modify 
the rsync() command.

2. To verify that the correct kernel config is picked up, run
   # make linux-nconfig
from the Buildroot directory and check the configuration.

3. An in-tree DTS name is relative to the dts directory 
(arch/arm/boot/dts) and without the file extension (.dts).

Kind regards,
Andreas