void-packages/srcpkgs/runit-kdump/files
..
07-kdump.sh
README.voidlinux

README.voidlinux

To enable loading the crash kernel, append crashkernel=128M to the
Linux command line.

By default, crash dumping will use the default initrd and dump in
runit stage 1 to /var/crash.

You can place a custom initrd used for crash dumping as
/boot/initramfs-${KERNELVERSION}kdump.img.