This document provides instructions to create a disk image with
hack_back_ckpt.rcS script (located in
gem5/configs/boot/) installed. This script creates a checkpoint once the Linux system boots up. Using environment variables the script makes sure that the checkpoint is not created if one already exists. On restoring the simulation from the checkpoint, a new script can be provided to execute the desired applications.
Note: The instructions in this README are based on experiments with gem5-20.
We assume the following directory structure while following the instructions in this README file:
npb/ |___ gem5/ # gem5 source code | |___ disk-image/ | |___ shared/ # Auxiliary files needed for disk creation | |___ hack-back/ | |___ hack-back-image/ # Will be created once the disk is generated | | |___ hack-back # The generated disk image | |___ hack-back.json # The Packer script to build the disk image | |___ hack_back_ckpt.rcS # Main script responsible for checkpointing | |___ post-installation.sh # Moves hack_back_ckpt.rcS to guest's .bashrc | | |___ README.md # This README file
Assuming that you are in the
src/hack-back/ directory (the directory containing this README), first build
m5 (which is needed to create the disk image):
git clone https://gem5.googlesource.com/public/gem5 cd gem5/util/m5 scons build/x86/out/m5
cd disk-image # if packer is not already installed wget https://releases.hashicorp.com/packer/1.6.0/packer_1.6.0_linux_amd64.zip unzip packer_1.6.0_linux_amd64.zip # validate the packer script ./packer validate hack-back/hack-back.json # build the disk image ./packer build hack-back/hack-back.json
Once this process succeeds, the created disk image can be found on
The details of how to use this disk image are following:
exit_eventand take a checkpoint using
system.readfile=[path to the script]in your gem5 run script.