Running C/C++ Scripts on Non-Volatile Memory Using gem5 and NVmain

author: Sam Thomas, Brown University Contact samuel_thomas@brown.edu to report errors

0. Workspace Setup This document assumes that the host system is running Ubuntu 20.04.1 on an x86_64 machine and will run an ARM configuration of gem5. ~ $ sudo apt-get install build-essential git scons device-tree-compiler bzip2 python-dev mount

• build-essential: general-purpose Ubuntu command-line tools
• git: used to download
• scons: used to build gem5 executables
• bzip2: used to unzip image file for Ubuntu 18.04
• python-dev: used to mount disk image onto directory
• mount: used to unmount disk image from directory

~ $ mkdir workspace

~ $ cd workspace

1. Installing gem5

workspace $ git clone https://gem5.googlesource.com/public/gem5

workspace $ cd gem5

2. Compile gem5

gem5 $ scons build/ARM/gem5.opt (note: scons will create the "build" repository and its children by running this command - this might take some time)

3. Download gem5 Disk Images and Kernel Binaries (note: binaries and images to be downloaded from gem5 recommended Guest Binaries - see https://www.gem5.org/documentation/general_docs/fullsystem/guest_binaries for more details)

gem5 $ mkdir dist

gem5 $ cd dist

dist $ wget http://dist.gem5.org/dist/current/arm/aarch-system-201901106.tar.bz2

dist $ tar xvf aarch-system-201901106.tar.bz2 (this creates two folders: disks and binaries)

dist $ cd disks

disks $ wget http://dist.gem5.org/dist/current/arm/disks/ubuntu-18.04-arm64-docker.img.bz2

disks $ bzip2 -d ubuntu-18.04-arm64-docker.img.bz2

disks $ cd ../../../

workspace $ echo "gem5 installed, configured and ready to roll!"

4. Download NVmain

workspace $ git clone https://github.com/samueltphd/NVmain

5. Apply NVmain Patches to gem5 and recompile gem5

workspace $ cd gem5

gem5 $ git apply ../NVmain/patches/gem5/nvmain2-gem5-11688+

gem5 $ git apply ../NVmain/patches/gem5/nvmain2-gem5-11689+

gem5 $ scons build/ARM/gem5.opt EXTRAS=../NVmain

workspace $ echo "Built NVmain and applied to gem5!"

6. Write C/C++ Script

workspace $ mkdir src

workspace $ cd src

src $ echo "int main(int argc, char* argv[]) { return 0; }" > hello_world.c

src $ cd ..

workspace $ echo "Example C script written, any script can be written here!"

7. Compile C/C++ Script for ARM Target

workspace $ aarch-linux-gnu-gcc ./src/hello_world.c -o hello_world.arm

workspace $ echo "ARM executable produced!"

8. Mount Executable onto Disk Image

workspace $ mkdir mount-directory

workspace $ sudo python gem5/util/gem5img.py mount gem5/dist/disks/ubuntu-18.04-arm64-docker.img mount-directory

workspace $ sudo cp hello_world.arm mount-directory

workspace $ sudo umount mount-directory

workspace $ rmdir mount-directory

workspace $ echo "Executable file mounted onto disk image!"

9. Run C/C++ Script on gem5 with Non-Volatile Main Memory workspace $ gem5/build/ARM/gem5.opt gem5/configs/example/fs.py --disk-image=gem5/dist/disks/ubuntu-18.04-arm64-docker.img --kernel=gem5/dist/binaries/vmlinux.arm64 --bootloader gem5/dist/binaries/boot.arm64 --mem-type=NVMainMemory --nvmain-config=NVmain/Configs/PCM_ISSCC_2012_4GB.config (gem5 system setup output will be visible with several warnings, this is okay)

In a new terminal window

workspace $ telnet localhost 3456 (More system setup output will appear -- eventually a command prompt "#" will appear, and then a normal Ubuntu terminal can be used!)

# ./hello_world.arm