Arch Linux User Repository

The PKGBUILD file supports a few different configurable build-time options:

• _makenconfig Tweak kernel options prior to a build via nconfig. Pseudo-graphical menu based on ncurses. 1 2
• _localmodcfg Only compile active modules to VASTLY reduce the number of modules built and the build time.
• Please read arch wiki page for detailed explanation on how to use it.
• _subarch Enable additional optimization/tuning for kernel builds by adding more micro-architectures options. Default is Generic-x86-64 number 36 if nothing else is selected.
• PKGBUILD file with the list of architectures
• graysky kernel_compiler_patch
• _use_current Use the current kernel's .config file. Enabling this option will use the .config of the RUNNING kernel rather than the ARCH defaults. Useful when the package gets updated and you already went through the trouble of customizing your config options. NOT recommended when a new kernel is released, but again, convenient for package bumps.
• _use_llvm_lto Compile the kernel with LLVM/Clang.
• _debug Enable y some additional debug features present in arch kernel, but not in Clear upstream. n to force disable or leave empty to ignore.

Lastly, build the kernel by setting your environment variable env _subarch=40 _localmodcfg=y.

1. Binaries available in my repo: http://download.opensuse.org/repositories/home:/metakcahura:/kernel/Arch_Extra_standard/x86_64/

[home_metakcahura_kernel_Arch_Extra_standard]
SigLevel = Never
Server = http://download.opensuse.org/repositories/home:/metakcahura:/kernel/Arch_Extra_standard/$arch

THIS IS OPTIONAL:

2. After install adjust your boot cmd line. ClearLinux uses clr-boot-manager which takes care of that. This is upstream default:

quiet console=tty0 console=ttyS0,115200n8 cryptomgr.notests initcall_debug intel_iommu=igfx_off kvm-intel.nested=1 no_timer_check noreplace-smp page_alloc.shuffle=1 rcupdate.rcu_expedited=1 rootfstype=ext4,btrfs,xfs,f2fs tsc=reliable rw 

@metak thanks for your work, having the options listed is very helpful. For somebody new coming to this project, it will be very beneficial.

Regarding _debug it looks like you check if it is set, and then enable the proper debug kernel flags. As far as I understand, the issue with btfids is because the default arch kernel has these on, and when we use _use_current it is pulling in those options even if they aren't enabled in clear. Because those are set, you need to run resolve_btfids.

I am thinking that this is one of those 'tradeoffs' of debug vs performance. I might want to disable these. If I pass _debug=n do you think you could disable these kernel flags instead of enabling them if it is set?

I know I could use _makenconfig to disable these, but then if I ever have to boot standard arch kernel and compile linux-clear I will likely forget and miss them again.

@rayzorben resolve_btfids should be resolved with the latest update where I've added _debug option which enables some basic debug options.

Those are the default Clear linux boot parameters. I pasted it here for refference only, the kernel should boot just fine without any modifications. SERIAL_8250

The PKGBUILD file supports a few different configurable build-time options:

• _makenconfig Tweak kernel options prior to a build via nconfig. Pseudo-graphical menu based on ncurses. 1 2
• _localmodcfg Only compile active modules to VASTLY reduce the number of modules built and the build time.
• Please read arch wiki page for detailed explanation on how to use it.
• _subarch Enable additional optimization/tuning for kernel builds by adding more micro-architectures options. Default is Generic-x86-64 number 36 if nothing else is selected.
• PKGBUILD file with the list of architectures
• graysky kernel_compiler_patch
• _use_current Use the current kernel's .config file. Enabling this option will use the .config of the RUNNING kernel rather than the ARCH defaults. Useful when the package gets updated and you already went through the trouble of customizing your config options. NOT recommended when a new kernel is released, but again, convenient for package bumps.
• _use_llvm_lto Compile the kernel with LLVM/Clang.
• _debug Enable y some additional debug features present in arch kernel, but not in Clear upstream. n to force disable or leave empty to ignore.

Lastly, build the kernel by setting your environment variable env _subarch=40 _localmodcfg=y.

I also had the resolve_btfids issue. I had it working, but when upgrading the kernel I forgot to modify the PKGBUILD and next thing you know, no dkms modules were installing.

Would be nice to have a _use_resolve_btfids option, or check for the correct kernel option if it is enabled and call it.

Also to note, what is the console=tty0 console=ttyS0,115200n8 line about? I had an issue with fstab, and nothing was being output during boot even with quiet removed. When I removed those I was able to see what it was outputting. This may make boot faster because its not dumping what it is doing to the screen but it made it a pain to debug.

@rayzorben You should boot the default arch kernel, plug in all your devices so it loads appropriate modules and then create modprobe.db. It seems like something might be missing in your build and that's why bluetooth is not working? As for the options, I'll add some description in the future.

Would love to see some basic instructions pinned with what the options are. I discovered them through the PKGBUILD but still wasn't sure what to do with them.

That being said, I had a few trial and errors regardless. I felt like env _subarch=35 _localmodcfg=y _use_current=y would be the best combo while running my fully functioning system. However it seems that _localmodcfg for some reason is causing issues with bluetooth. Bluetooth was there, it could see devices, it said my mouse was connected, but it would not work. Rebuilding without _localmodcfg works though.

OK, turning debug info off works.

(Maybe because I have CONFIG_DEBUG_INFO_BTF turned on in my kernel config which causes resolve_btfids to be called during DKMS build. Let me try turning most debug options off.)

@xuanruiqi After testing nvidia-dkms I couldn't reproduce it. It builds fine (gcc & llvm). It's definitely something on your system that's causing this. Try building in clean environment?

I was building nvidia-dkms. Some modules like nvidia need btf info to build properly, so maybe you want to put it under an option or something like that. AFAIK a lot of people use nvidia-dkms.