信息量好大 --！
神教读物，无人能比：
https://wiki.archlinux.org/index.php/Arch_boot_process
IBM的高质量文档
https://www.ibm.com/developerworks/library/l-linuxboot/
https://www.freedesktop.org/software/systemd/man/bootup.html#
init process： https://en.wikipedia.org/wiki/Linux_startup_process
sysv init script
upstart 与sysv向上兼容
openrc gentoo/freeBSD 等在使用 https://en.wikipedia.org/wiki/OpenRC
systemd。 https://wiki.archlinux.org/index.php/Systemd
https://www.freedesktop.org/wiki/Software/systemd/
http://0pointer.de/blog/projects/systemd-for-admins-1.html
runit。
一个对比：https://wiki.archlinux.org/index.php/Init/Rosetta
process supervison: https://en.wikipedia.org/wiki/Process_supervision
https://wiki.archlinux.org/index.php/Kernel_modules_(%E7%AE%80%E4%BD%93%E4%B8%AD%E6%96%87)