Howto | Setup an ARM Linux system for QEMU

I've been playing with QEMU lately and found that it's really awesome. To get started all you need is to create a root filesystem and cross compile a Kernel
which is quite easy to set up on a Debian/Ubuntu based system. Here is what I did:

0 prerequisites

sudo apt-get install debootstrap qemu-user-static qemu-system git gcc-arm-linux-gnueabihf

1 create the rootfs

# create the hard disk file

fallocate -l 2GiB ubuntu-armhf.ext3

mkfs.ext3 ubuntu-armhf.ext3

# mount the hard disk file

mkdir mnt

sudo mount -o loop ubuntu-armhf.ext3 mnt

# create an initial rootfs using debootstrap

HOSTNAME=ubuntu-armhf sudo debootstrap --variant=minbase --foreign --arch armhf precise ./mnt

# copy the statically linked QEMU binary into the rootfs

sudo cp /usr/bin/qemu-arm-static mnt/usr/bin/

# chroot into the rootfs and start a shell using qemu-arm-static

LANG=C sudo chroot mnt /usr/bin/qemu-arm-static -cpu cortex-a9 /bin/sh

# run the debootstrap second stage from within the chroot:

/debootstrap/debootstrap --second-stage

# create the sources.list files for apt:

echo "deb http://ports.ubuntu.com precise
main restricted universe

deb-src http://ports.ubuntu.com precise
main restricted universe" > /etc/apt/sources.list

echo "deb http://ddebs.ubuntu.com precise
main restricted universe multiverse" > /etc/apt/sources.list.d/ddebs.list

apt-key adv --keyserver keyserver.ubuntu.com --recv-keys
428D7C01

# install some fundamental packages

apt-get update

apt-get install sudo apt-utils dialog less wget

# create configuration for the serial console

cp /etc/init/tty1.conf /etc/init/ttyAMA0.conf

sed -i "s/tty1/ttyAMA0/" /etc/init/ttyAMA0.conf

# add a user

adduser myuser

# add user to the sudo group

usermod -aG sudo myuser

# exit the chroot env

exit

# unmount the rootfs

sudo umount mnt

rmdir mnt

2 cross compile the Kernel

# check out the sources

git clone -depth=1 git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

mkdir linux-build

cd linux

# create a .config based on the versatile express default configuration

make ARCH=arm O=../linux-build vexpress_defconfig

# compile the kernel

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- O=../linux-build -j`getconf _NPROCESSORS_ONLN` zImage

cd ..

3 boot the image using QEMU

qemu-system-arm \

-M vexpress-a9 -m 1024 \

-serial stdio -no-reboot \

-kernel linux-build/arch/arm/boot/zImage \

-drive file=ubuntu-armhf.ext3,if=sd,cache=writeback \

--append "rw console=ttyAMA0,38400n8 console=tty root=/dev/mmcblk0" -s -S

之后，你就可以用gdb 或者eclipse 调试了