http://ncmiller.github.io/2016/05/14/linux-and-qemu.html
Fast linux kernel testing with qemu This is the process I followed on my Fedora 23 host machine to build a small/minimal vanilla Linux kernel and test in Qemu (based on this blog post). This will provide a safe sandbox in which to test kernel changes, and is generally faster than developing natively on the host machine. Qemu will boot the kernel image directly in the emulated system.
sudo apt-get install qemu-system
Install required build tools on host machine dnf install ncurses-devel kernel-devel kernel-headers openssl-devel dnf install gcc dnf install gcc-c++ glibc-static dnf install git dnf install qemu Prepare a working space for kernel development cd $HOME mkdir kdev TOP=$HOME/kdev Download source code Download stable busybox, which will provide a basic set of tools for the kernel-under-test:
wget http://busybox.net/downloads/busybox-1.24.2.tar.bz2 tar xvf busybox-1.24.2.tar.bz2 rm busybox-1.24.2.tar.bz2 Clone Linux kernel:
git clone https://github.com/torvalds/linux.git Configure busybox cd $TOP/busybox-1.24.2 mkdir -p $TOP/build/busybox-x86 make O=$TOP/build/busybox-x86 defconfig make O=$TOP/build/busybox-x86 menuconfig Enable building BusyBox as a static binary:
- -> Busybox Settings
- -> Build Options
[*] Build BusyBox as a static binary (no shared libs) [] Support RPC services - disable it if you get compilation error due to some bindport Build and install busybox (local install, no sudo required) cd $TOP/build/busybox-x86 make -j2 make install Create minimal filesystem mkdir -p $TOP/build/initramfs/busybox-x86 cd $TOP/build/initramfs/busybox-x86 mkdir -pv {bin,sbin,etc,proc,sys,usr/{bin,sbin}} cp -av $TOP/build/busybox-x86/_install/* . Create simple init script Create a file called init with the following contents:
#!/bin/sh
mount -t proc none /proc mount -t sysfs none /sys
echo -e "nBoot took $(cut -d' ' -f1 /proc/uptime) secondsn"
exec /bin/sh Make it executable:
chmod +x init Generate initramfs find . -print0
cpio --null -ov --format=newcgzip -9 > $TOP/build/initramfs-busybox-x86.cpio.gz
Configure Linux using simple defconfig and kvm options cd $TOP/linux make O=$TOP/build/linux-x86-basic x86_64_defconfig make O=$TOP/build/linux-x86-basic kvmconfig Build Linux make O=$TOP/build/linux-x86-basic -j2 Boot with Qemu in seconds! cd $TOP qemu-system-x86_64
-kernel build/linux-x86-basic/arch/x86_64/boot/bzImage -initrd build/initramfs-busybox-x86.cpio.gz -nographic -append "console=ttyS0 nokaslr" -enable-kvm