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glaucus

initramfs

  • https://github.com/glaucuslinux/initramfs-generator

  • No need for network or wireless drivers inside initramfs because we won’t live boot over network (at least for now)

  • tinycorelinux is run entirely in the initramfs (no switch_root)

  • kiss provides a minimal initramfs, and packages as .tar.xz then extracts them instead of changing root upon booting

  • tinyramfs does support hardware detection at boot as long as you include all modules necessary for booting. As of how to make this all work, there is the kiss-live project which uses tinyramfs to generate initramfs for live iso.

  • initramfs is newer compared to initrd

  • The file /init must exist in an initramfs

  • All daemons started by the initramfs must be killed, as the kernel reserves PID 1 for the init system

  • pivot_root is older than switch_root and was used by the old initrd, while the latter is used by the newer initramfs

  • Some init setups require proc, sys and dev to be mounted before starting up with switch_root in init, in this case is better to use mount --move instead of cleaning up with umount before switch_root, otherwise it is better overall to use umount to boot in a clean state.

  • /run needs to exist for some applications like cryptsetup, but for the ISO we do not need it

  • /mnt/root is the accepted mountpoint for the root filesystem

  • We can make use of findfs from util-linux to detect the label glaucus instead of using /dev/sr0 directly

  • When using find . -print0 the option -0 or --null should be used with cpio

  • insmod does not consider dependencies, unlike modprobe

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