VarEMU: An emulation testbed for Variability-Aware Software

Build instructions

VarEMU

• Download VarEMU source code.
• Extract QEMU Linaro snapshot
• Copy VarEMU extensions into QEMU
• Configure QEMU
• Build QEMU with VarEMU extensions

wget https://github.com/nesl/varemu/archive/master.zip
unzip master.zip
cd varemu-master/
tar xjf qemu-linaro-13-03.28.tar.bz2
cp -r varemu/* qemu-linaro/
cd qemu-linaro
./configure --disable-kvm --enable-debug --enable-debug-tcg --target-list=arm-softmmu
make CFLAGS=-DVEMU
cd ..

Linux kernel for versatilepb

• Pre-requisite: Download and install CodeBench for ARM (Linux version, tested with 2011.09-70)
• Download and extract Linux kernel version 3.6.3
• Apply VarEMU kernel extensions to kernel source tree
• Configure Linux kernel for versatilepb platform

cd linux
wget http://www.kernel.org/pub/linux/kernel/v3.0/linux-3.6.3.tar.bz2
tar xjf linux-3.6.3.tar.bz2
export ARCH=arm
export CROSS_COMPILE=arm-none-linux-gnueabi-
cp -r linux-3.6.3-variability/* linux-3.6.3/
cd linux-3.6.3/
make versatile_defconfig
make menuconfig

• Load an alternate config file, select ../linuxconfig
• Save an alternate config file: .config

make
cd ..

Buildroot

cd linux
wget http://buildroot.uclibc.org/downloads/buildroot-2012.11.tar.bz2
tar xjf buildroot-2012.11.tar.bz2 
cd buildroot-2012.11
make menuconfig

• Under Load an Alternate Configuration File, select "buildrootconfig" in the linux directory
• Select any additional apps needed under Package Selection for the Target
• Save an Alternate Configuration file -> "buildroot-2012.11/.config"
• Add your apps and custom configuration files under the "fs" directory. Buildroot will run the "prepare_fs.sh" script to copy these files before preparing the filesystem image

make

Running VarEMU

• From the main varemu directory, start QEMU with VarEMU options

qemu-linaro/arm-softmmu/qemu-system-arm -M versatilepb -m 256M -kernel linux/linux-3.6.3/arch/arm/boot/zImage -initrd linux/buildroot-2012.11/output/images/rootfs.cpio.gz -append "root=/dev/ram rdinit=/sbin/init" -singlestep -variability power_model_data/45nm_nc.txt -net nic -net user  -nographic

VarEMU Power Monitor

• Start QEMU with a monitor socket by adding -qmp unix:qmp-sock_01,server to the command line
• Start the VarEMU Python Monitor

python qemu-linaro/QMP/vemu-power.py qmp-sock_01