Gentoo 5.15.x generic kernel configuration

Source

The 5.15.11 Linux kernel has been marked as stable in Gentoo a few weeks ago and I've wanted to put out a new generic kernel configuration but I kept struggling with a really silly issue adapting it. As with my previous posts this configuration is largely based on the Fedora kernel with some Gentoo-specific tweaks. It supports practically every bit of hardware in existence and enables a lot of bleeding-edge kernel functionality.

The only few notable changes compared to the Fedora kernel are the following:

  • The binfmt_misc module is baked in for convenience

  • The NVMe core modules are baked in so you can boot from an NVMe drive without having to use an initrd

  • The CONFIG_ACPI_EXTLOG option is enabled. This is useful if you're using rasdaemon to monitor ECC memory

  • The boot logo is disabled

  • Kernel debugging is disabled

  • The CONFIG_GENTOO_KERNEL_SELF_PROTECTION option is enabled. This implicitly enables an additional set of security features for hardening the kernel

  • The CONFIG_GENTOO_PRINT_FIRMWARE_INFO option is enabled, it prints out the firmwares that are loaded into various bits of hardware. This is useful if you want to reduce the amount of files installed sys-kernel/linux-firmware package

Note that the RTC time based on NTP synchronization is enabled (and it's finally become the default in many other Linux distros) so you don't need the hwclock service (but you can use osclock instead if some other service requires the clock facility).

Additionally note that this kernel configuration is for use with OpenRC. If you're using systemd you'll have to remove the CONFIG_GENTOO_LINUX_INIT_SCRIPT=y line from the configuration file and add CONFIG_GENTOO_LINUX_INIT_SYSTEMD=y instead.

For maximum compatibility I haven't enabled kernel compression in this configuration, but I suggest using CONFIG_MODULE_COMPRESS_ZSTD=y as it provides significant space savings while having effectively no impact on load times. Just make sure that the sys-apps/kmod package has the zstd USE flag set so that it can handle the compressed modules.

To use this configuration file install the latest stable sys-kernel/gentoo-sources package (5.15.x), copy the configuration file under /usr/src/linux/ and rename it to .config then proceed to build and install the kernel as usual.

Gentoo 5.15.x kernel configuration file