minimal linux
What's this?
This is the stripped version of linux kernel for learning.
Features are
- fast compilation (only takes 20 seconds on Xeon E3-1275 v5 @ 3.60GHz)
- less source files (almost 900 .c files)
Limitations are
- only works on x86_64 QEMU
- only supports 8250 serial driver
compilation
use 'minimalconfig' for configuration. DO NOT GENERATE '.config' FROM 'make' COMMANDS!
$ cp minimalconfig .config
$ make -j8 bzImage
make rootfs
$ cd (project_root)
$ wget http://busybox.net/downloads/busybox-1.27.2.tar.bz2
$ tar xf busybox-1.27.2.tar.bz2
$ cd busybox
$ make menuconfig
Busybox Settings ---> Build Options --->Build BusyBox as a static binary (no shared libs)
$ make -j8
$ make install
$ mv _install ../rootfs
$ cd ../rootfs
$ find . | cpio -o --format=newc > ../rootfs.img
$ cd ..
run
qemu-system-x86_64 -kernel arch/x86/boot/bzImage -initrd (project_root)/rootfs.img -append "console=tty0 console=ttyS0,115200 root=/dev/ram rdinit=/bin/sh" -curses
You must switch to the serial console monitor with Ctrl+Alt+3.