gem5: namespace checkpoints by arch

Also refactor common gem5 x86 and arm command parts

run

@@ -74,35 +74,37 @@ out_dir="${root_dir}/buildroot/output.${arch_dir}~"
 if "$gem5"; then
   build_dir="${out_dir}/build/gem5-1.0"
   gem5_dir="${build_dir}/gem5"
+  if [ "$arch" = x86_64 ]; then
+    gem5_arch=X86
+  else
+    gem5_arch=ARM
+  fi
+  gem5_cpt_dir="./m5out/cpts/${arch}"
+  mkdir -p "$gem5_cpt_dir"
+  gem5_common="\
+M5_PATH='${build_dir}/system' \
+$debug_vm \
+'${gem5_dir}/build/${gem5_arch}/gem5.opt' \
+${gem5opts} \
+'${gem5_dir}/configs/example/fs.py' \
+--checkpoint-dir='${gem5_cpt_dir}' \
+--disk-image='${out_dir}/images/rootfs.ext2' \
+--kernel='${out_dir}/build/linux-custom/vmlinux' \
+--num-cpus='${cpus}' \
+"
   if [ "$arch" = x86_64 ]; then
     if "$kvm"; then
       extra_flags="$extra_flags --cpu-type=X86KvmCPU"
     fi
-    cmd="\
-M5_PATH='${build_dir}/system' \
-$debug_vm \
-'${gem5_dir}/build/X86/gem5.opt' \
-${gem5opts} \
-'${gem5_dir}/configs/example/fs.py' \
+    cmd="${gem5_common} \
 --command-line='earlyprintk=ttyS0 console=ttyS0 lpj=7999923 root=/dev/hda $extra_append' \
---disk-image='${out_dir}/images/rootfs.ext2' \
---kernel='${out_dir}/build/linux-custom/vmlinux' \
---num-cpus=${cpus} \
 $extra_flags \
 "
   elif [ "$arch" = arm ] || [ "$arch" = aarch64 ]; then
-    cmd="\
-M5_PATH='${build_dir}/system' \
-$debug_vm \
-'${gem5_dir}/build/ARM/gem5.opt' \
-${gem5opts} \
-'${gem5_dir}/configs/example/fs.py' \
+    cmd="${gem5_common} \
 --command-line='earlyprintk=pl011,0x1c090000 console=ttyAMA0 lpj=19988480 rw loglevel=8 mem=512MB root=/dev/sda $extra_append' \
---disk-image='${out_dir}/images/rootfs.ext2' \
 --dtb-file='${gem5_dir}/system/arm/dt/$([ "$arch" = arm ] && echo "armv7_gem5_v1_${cpus}cpu" || echo "armv8_gem5_v1_${cpus}cpu").dtb' \
---kernel='${out_dir}/build/linux-custom/vmlinux' \
 --machine-type=VExpress_GEM5_V1 \
---num-cpus='${cpus}' \
 $extra_flags \
 "
   fi