26.13. Buildroot vanilla kernel
By default, our build system uses build-linux, and the Buildroot kernel build is disabled: https://stackoverflow.com/questions/52231793/can-buildroot-build-the-root-filesystem-without-building-the-linux-kernel
There are however some cases where we want that ability, e.g.: kernel_modules buildroot package and Benchmark Linux kernel boot.
The build of the kernel can be enabled with the --build-kernel option of build-buildroot.
For example, to build the kernel and then boot it you could do:
./build-buildroot --arch aarch64 --build-linux ./run --arch aarch64 --linux-exec "$(./getvar --arch aarch64 TODO)/vmlinux"
TODO: fails on LKMC d53ffcff18aa26d24ea34b86fb80e4a5694378dch with "ERROR: No hash found for linux-4.19.16.tar.xz": https://github.com/cirosantilli/linux-kernel-module-cheat/issues/115
Note that this kernel is not configured at all by LKMC, and there is no support to do that currently: the Buildroot default kernel configs for a target are used unchanged, e.g. make qemu_aarch64_virt_defconfig,see also; About Buildroot’s kernel configs.
Therefore, this kernel might be missing certain key capabilities, e.g. filesystem support required to boot.