package/environment-setup: add variable KERNEL_DIR alongside KERNELDIR

Update host environment setup helper script to incorporate the variable KENREL_DIR alongside the existing KERNELDIR. This adjustment ensures consistency, as some projects utilize KERNELDIR while others use KERNEL_DIR.

Signed-off-by Nayab Sayed<[email protected]>

---
Changes in v2:
- Keep both KERNEL_DIR and KERNELDIR.
- Update commit message
- Link to v1:https://lore.kernel.org/r/[email protected]

---
  package/environment-setup/environment-setup    | 3 ++-
  package/environment-setup/environment-setup.mk | 2 ++
  2 files changed, 4 insertions(+), 1 deletion(-)

package/environment-setup/environment-setup +2 -1

index 84a9843c24..0bae813e1a 100644
@@ -10,7 +10,8 @@ cat <<'EOF'
  Some tips:
  * PATH now contains the SDK utilities
  * Standard autotools variables (CC, LD, CFLAGS) are exported
-* Kernel compilation variables (ARCH, CROSS_COMPILE, KERNELDIR) are exported
+* Kernel compilation variables (ARCH, CROSS_COMPILE, KERNELDIR or KERNEL_DIR)
+  are exported
  * To configure do "./configure $CONFIGURE_FLAGS" or use
    the "configure" alias
  * To build CMake-based projects, use the "cmake" alias

package/environment-setup/environment-setup.mk +2 -1

index 29ec5a9a95..4a71f18f3a 100644
@@ -35,6 +35,8 @@ define HOST_ENVIRONMENT_SETUP_INSTALL_CMDS
 
  	$(if $(BR2_LINUX_KERNEL),\
  		printf "export \"KERNELDIR=$(LINUX_BUILDDIR)\"\n" \
+			>> $(ENVIRONMENT_SETUP_FILE)
+		printf "export \"KERNEL_DIR=$(LINUX_BUILDDIR)\"\n" \
  			>> $(ENVIRONMENT_SETUP_FILE),)
  endef
 
 
---

base-commit: 04dfeff6242516a1061973fc7af2cc9c5e3dd4e2
change-id: 20240124-kernel_dir-41a48fd97b75

Best regards,

Update host environment setup helper script to incorporate the variable KENREL_DIR alongside the existing KERNELDIR. This adjustment ensures consistency, as some projects utilize KERNELDIR while others use KERNEL_DIR.

Signed-off-by Nayab Sayed <[email protected]>

Hello Nayab,

Quoted 5 lines · On Wed, 31 Jan 2024 23:48:28 +0530 Nayab Sayed via buildroot…

Update host environment setup helper script to incorporate the variable KENREL_DIR alongside the existing KERNELDIR. This adjustment ensures consistency, as some projects utilize KERNELDIR while others use KERNEL_DIR.

Signed-off-by Nayab Sayed <[email protected]>

Thanks for this new iteration, but on my side, I'm tempted to reject this patch, and actually to remove the support for KERNELDIR as well.

Indeed, even Angelo, who added the environment-setup script was not able to provide a solid reason for exporting KERNELDIR in the first place. I don't think there is any standard, or somewhat standard variable to point to the Linux kernel source directory.

I'm fine with environment-setup exposing CC, LD, CFLAGS, LDFLAGS, or even CROSS_COMPILE as these are reasonably standardized by various build systems. But KERNELDIR or KERNEL_DIR are not, and the simple fact that both would be needed/useful is a clear hint of that. The whole thing I didn't like in the first place with environment-setup is the fact that it exports a mixed bag of somewhat random environment variables, and exposing both KERNELDIR and KERNEL_DIR clearly goes further into this direction in my opinion.

Quoted 8 lines

Hello Nayab,

Quoted 3 lines · On Wed, 31 Jan 2024 23:48:28 +0530 Nayab Sayed via buildroot…

Update host environment setup helper script to incorporate the variable KENREL_DIR alongside the existing KERNELDIR. This adjustment ensures consistency, as some projects utilize KERNELDIR while others use

KERNEL_DIR.

Quoted 11 lines

Quoted 2 lines

Signed-off-by Nayab Sayed <[email protected]>

Thanks for this new iteration, but on my side, I'm tempted to reject this patch, and actually to remove the support for KERNELDIR as well.

Indeed, even Angelo, who added the environment-setup script was not able to provide a solid reason for exporting KERNELDIR in the first place. I don't think there is any standard, or somewhat standard variable to point to the Linux kernel source directory.

Quoted 8 lines

I'm fine with environment-setup exposing CC, LD, CFLAGS, LDFLAGS, or even CROSS_COMPILE as these are reasonably standardized by various build systems. But KERNELDIR or KERNEL_DIR are not, and the simple fact that both would be needed/useful is a clear hint of that. The whole thing I didn't like in the first place with environment-setup is the fact that it exports a mixed bag of somewhat random environment variables, and exposing both KERNELDIR and KERNEL_DIR clearly goes further into this direction in my opinion.

Well, without an exported KERNELDIR, it will be very hard to build
kernel
modules outside of buildroot (and the whole point of this environment-setup
thing is to make it easier to build stuff outside of buildroot). Indeed, output/build/linux-* will match stuff like linux-pam as well.

bit
over the top.

Regards,
Arnout