[Help] Rock 5B (Vendor/Noble) - Unable to set CONFIG_ARM64_VA_BITS=39, config gets overwritten

[加藤惠的老公]

Description:

Hello everyone, I am encountering an issue where kernel configuration changes do not take effect when building an image for the Rock 5B using the Armbian Build system.

 

Environment:

Board: Rock 5B

Kernel: Vendor

Release: Noble

Build Mode: Mini

Build Tag/Branch: v25.11

 

Specific Issue:

To ensure compatibility with Redroid containers, I need to change the kernel's CONFIG_ARM64_VA_BITS from the default 48-bit to 39-bit.

 

What I have tried:

I have attempted the following three methods, but none have worked:

Ran the kernel configuration tool to change CONFIG_ARM64_VA_BITS, then copied the generated .config to userpatches/linux-rk35xx-vendor.config.

Took the default config/kernel/linux-rk35xx-vendor.config, manually modified/added CONFIG_ARM64_VA_BITS=39 and CONFIG_ARM64_VA_BITS_39=y, and copied it to userpatches/linux-rk35xx-vendor.config.

Created a kernel source patch in userpatches targeting arch/arm64/configs/rockchip_linux_defconfig and arch/arm64/configs/defconfig to force CONFIG_ARM64_VA_BITS=39 and CONFIG_ARM64_VA_BITS_39=y.

 

Result:

Regardless of the method used, the final Armbian-generated kernel remains at VA_BITS=48. It seems my configuration changes are being overwritten or ignored during the build process.

 

Request:

Is there specific logic in the Vendor/RK3588 build configuration that forcibly locks VA_BITS? What is the correct way to modify this parameter for this specific board/kernel combination?

Thanks for your help!

[Werner]

Hi

 

While I thiknk your approach should have worked, a quick search revealed that something similar is done for a different family. Perhaps try this way:https://github.com/armbian/build/blob/9aa6e1e29ec2d397bbe223bebaa93bd13ef79818/patch/kernel/archive/filogic-6.16/patches.armbian/0007-build.sh-add-additional-build-script-config-defconfi.patch#L1909