diff --git a/README.adoc b/README.adoc
index fca92ea..196429e 100644
--- a/README.adoc
+++ b/README.adoc
@@ -1209,7 +1209,7 @@ Instead, we have only chip makers, who keep everything that really works closed,
 
 ....
 ./configure && ./build -a arm -g
-./rungem5 -a arm
+./run -a arm -g
 ....
 
 On another shell:
@@ -1218,32 +1218,32 @@ On another shell:
 ./rungem5-shell
 ....
 
-===== GEM5 Kernel command line arguments
+===== GEM5 kernel command line arguments
 
 E.g., to add `printk.time=y`, run:
 
 ....
-./rungem5 -a arm -- --command-line='earlyprintk=pl011,0x1c090000 console=ttyAMA0 lpj=19988480 norandmaps rw loglevel=8 mem=512MB root=/dev/sda printk.time=y'
+./run -a arm -e 'init=/poweroff.out' -g
 ....
 
-When you use `--command-line=`, it overrides default command lines, which are required to boot properly.
+Internals: when we give `--command-line=` to GEM5, it overrides default command lines, which are required to boot properly.
 
-So if you pass just `--command-line='printk.time=y'`, it removes the required options, and boot fails.
+So if you pass just `--command-line='printk.time=y'` for example, it removes the required options, and boot fails.
 
-An easy way to find the other options is to to an initial boot:
+Our run script hardcodes the require options in the default `--command-line` and appends extra options given by `-e`.
+
+The default options can be found found with:
 
 ....
-./rungem5 -a arm
+./run -a arm -g
 ....
 
-and then look at the line of the linux kernel that starts with
+and then look at the line of the linux kernel that starts with:
 
 ....
 Kernel command line:
 ....
 
-We might copy the default `--command-line` into our startup scripts to make things easier at some point, but it would be fun to debug when the defaults change upstream and we don't notice :-(
-
 ===== QEMU with GEM5 kernel configuration
 
 TODO: QEMU did not work with the GEM5 kernel configurations.
@@ -1271,7 +1271,7 @@ Guest has not initialized the display (yet).
 Test it out with:
 
 ....
-./rungem5 -a arm
+./run -a arm -g
 ....
 
 TODO hangs at:
@@ -1302,7 +1302,7 @@ Analogous to QEMU's <<snapshot>>.
 Documentation: http://gem5.org/Checkpoints
 
 ....
-./rungem5 -a arm
+./rung -a arm -g
 ....
 
 In guest, wait for the boot to end and run:
@@ -1314,7 +1314,7 @@ In guest, wait for the boot to end and run:
 To restore the checkpoint, kill the VM and run:
 
 ....
-./rungem5 -a arm -- -r 1
+./rung -a arm -g -- -r 1
 ....
 
 Let's create a second checkpoint to see how it works, in guest:
@@ -1327,7 +1327,7 @@ date >f
 Kill the VM, and try it out:
 
 ....
-./rungem5 -a arm -- -r 2
+./run -a arm -g -- -r 2
 ....
 
 and now in the guest:
@@ -1343,6 +1343,10 @@ Internals:
 - the checkpoints are stored under `m5out/cpt.*`
 - `m5` is a guest utility present inside the GEM5 tree which we cross-compiled and installed into the guest
 
+===== GEM5 limitations
+
+* networking not working
+
 ==== GEM5 x86
 
 TODO didn't get it working yet.
@@ -1357,7 +1361,7 @@ Related threads:
 
 ....
 ./configure && ./build -a x86_64-gem5
-./rungem5 -a x86_64-gem5
+./run -a x86_64 -g
 ....
 
 telnet:
diff --git a/build b/build
index 94973c1..1c35ea7 100755
--- a/build
+++ b/build
@@ -91,7 +91,7 @@ else
 BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES=\"../kernel_config_fragment\"
 " >> "${outdir}/.config"
 fi
-if $x11; then
+if "$x11"; then
   cat ../buildroot_config_fragment_x11 >> "${outdir}/.config"
 fi
 if ! "$gem5"; then
diff --git a/gem5/external.mk b/gem5/external.mk
index 81f4482..8b6114f 100644
--- a/gem5/external.mk
+++ b/gem5/external.mk
@@ -8,8 +8,14 @@ GEM5_VERSION = 1.0
 GEM5_SITE = $(BR2_EXTERNAL_GEM5_PATH)
 GEM5_SITE_METHOD = local
 
+ifeq ($(ARCH),x86_64)
+ARCH_MAKE = x86
+else
+ARCH_MAKE = $(ARCH)
+endif
+
 define GEM5_BUILD_CMDS
-	cd '$(@D)/gem5/util/m5' && $(MAKE) -f 'Makefile.$(ARCH)' CC='$(TARGET_CC)' LD='$(TARGET_LD)'
+	cd '$(@D)/gem5/util/m5' && $(MAKE) -f 'Makefile.$(ARCH_MAKE)' CC='$(TARGET_CC)' LD='$(TARGET_LD)'
 endef
 
 define GEM5_INSTALL_TARGET_CMDS
diff --git a/run b/run
index 20425ac..693962c 100755
--- a/run
+++ b/run
@@ -13,9 +13,10 @@ nographic=false
 #   Turned on by default since v4.12
 extra_append='nokaslr norandmaps printk.devkmsg=on printk.time=y'
 extra_flags=''
+gem5=false
 initrd=false
 root=''
-while getopts a:de:iknqt:x OPT; do
+while getopts a:de:giknqt:x OPT; do
   case "$OPT" in
     a)
       arch="$OPTARG"
@@ -33,6 +34,9 @@ while getopts a:de:iknqt:x OPT; do
       extra_flags="$extra_flags -serial tcp::1234,server,nowait"
       kgdb=true
       ;;
+    g)
+      gem5=true
+      ;;
     i)
       initrd=true
       ;;
@@ -49,9 +53,35 @@ done
 shift "$(($OPTIND - 1))"
 extra_flags="$extra_flags $@"
 
-buildroot_out_dir="./buildroot/output.${arch}~"
-images_dir="$buildroot_out_dir/images"
-qemu_common="\
+if $gem5; then
+  outdir="$(pwd)/buildroot/output.${arch}-gem5~"
+  gem5_dir="$(pwd)/gem5/gem5"
+  if [ "$arch" = x86_64 ]; then
+    cmd="\
+M5_PATH='$(pwd)/gem5/gem5-system' \
+'${gem5_dir}/build/X86/gem5.opt' \
+'${gem5_dir}/configs/example/fs.py' \
+--disk-image='${outdir}/images/rootfs.ext2' \
+--kernel='${outdir}/build/linux-custom/vmlinux' \
+--root-device=/dev/sda \
+"
+  elif [ "$arch" = arm ]; then
+    cmd="\
+M5_PATH='$(pwd)/gem5/gem5-system' \
+'${gem5_dir}/build/ARM/gem5.opt' \
+'${gem5_dir}/configs/example/fs.py' \
+--command-line='earlyprintk=pl011,0x1c090000 console=ttyAMA0 lpj=19988480 norandmaps rw loglevel=8 mem=512MB root=/dev/sda $extra_append' \
+--disk-image='${outdir}/images/rootfs.ext2' \
+--dtb-file='${gem5_dir}/system/arm/dt/armv7_gem5_v1_1cpu.dtb' \
+--kernel='${outdir}/build/linux-custom/vmlinux' \
+--machine-type=VExpress_GEM5_V1 \
+"
+  fi
+  cmd="$cmd \"\$@\""
+else
+  buildroot_out_dir="./buildroot/output.${arch}~"
+  images_dir="$buildroot_out_dir/images"
+  qemu_common="\
 $debug_qemu \
 $buildroot_out_dir/host/usr/bin/qemu-system-${arch} \
 -m 128M \
@@ -59,20 +89,20 @@ $buildroot_out_dir/host/usr/bin/qemu-system-${arch} \
 -netdev user,hostfwd=tcp::45455-:45455,id=net0 \
 -smp 1 \
 "
-if $initrd; then
-  extra_flags="$extra_flags -initrd '${images_dir}/rootfs.cpio'"
-fi
-# The base QEMU commands are found under board/qemu/*/readme.tx
-case "$arch" in
-  x86_64)
-    if $kgdb; then
-      extra_append="$extra_append kgdboc=ttyS0,115200"
-    fi
-    if ! $initrd; then
-      root='root=/dev/vda'
-      extra_flags="$extra_flags -drive file='${images_dir}/rootfs.ext2.qcow2,if=virtio,format=qcow2'"
-    fi
-    cmd="$qemu_common \
+  if $initrd; then
+    extra_flags="$extra_flags -initrd '${images_dir}/rootfs.cpio'"
+  fi
+  # The base QEMU commands are found under board/qemu/*/readme.tx
+  case "$arch" in
+    x86_64)
+      if $kgdb; then
+        extra_append="$extra_append kgdboc=ttyS0,115200"
+      fi
+      if ! $initrd; then
+        root='root=/dev/vda'
+        extra_flags="$extra_flags -drive file='${images_dir}/rootfs.ext2.qcow2,if=virtio,format=qcow2'"
+      fi
+      cmd="$qemu_common \
 -M pc \
 -append '$root nopat $extra_append' \
 -device edu \
@@ -81,16 +111,16 @@ case "$arch" in
 -kernel ${images_dir}/bzImage \
 $extra_flags \
 "
-  ;;
-  arm)
-    if $kgdb; then
-      extra_append="$extra_append kgdboc=ttyAMA0,115200"
-    fi
-    if ! $initrd; then
-      root='root=/dev/sda'
-      extra_flags="$extra_flags -drive file='${images_dir}/rootfs.ext2.qcow2,if=scsi,format=qcow2'"
-    fi
-    cmd="$qemu_common \
+    ;;
+    arm)
+      if $kgdb; then
+        extra_append="$extra_append kgdboc=ttyAMA0,115200"
+      fi
+      if ! $initrd; then
+        root='root=/dev/sda'
+        extra_flags="$extra_flags -drive file='${images_dir}/rootfs.ext2.qcow2,if=scsi,format=qcow2'"
+      fi
+      cmd="$qemu_common \
 -M versatilepb \
 -append '$root $extra_append' \
 -device rtl8139,netdev=net0 \
@@ -99,12 +129,12 @@ $extra_flags \
 -serial stdio \
 $extra_flags \
 "
-  ;;
-  aarch64)
-    if $kgdb; then
-      extra_append="$extra_append kgdboc=ttyAMA0,115200"
-    fi
-    cmd="$qemu_common \
+    ;;
+    aarch64)
+      if $kgdb; then
+        extra_append="$extra_append kgdboc=ttyAMA0,115200"
+      fi
+      cmd="$qemu_common \
 -M virt \
 -append 'root=/dev/sda $extra_append' \
 -cpu cortex-a57 \
@@ -114,13 +144,13 @@ $extra_flags \
 -serial stdio \
 $extra_flags \
 "
-  ;;
-  mips64)
-    if ! $initrd; then
-      root='root=/dev/hda'
-      extra_flags="$extra_flags -drive file='${images_dir}/rootfs.ext2.qcow2,format=qcow2'"
-    fi
-    cmd="$qemu_common \
+    ;;
+    mips64)
+      if ! $initrd; then
+        root='root=/dev/hda'
+        extra_flags="$extra_flags -drive file='${images_dir}/rootfs.ext2.qcow2,format=qcow2'"
+      fi
+      cmd="$qemu_common \
 -M malta \
 -append 'root=/dev/hda $extra_append' \
 -cpu I6400 \
@@ -129,7 +159,10 @@ $extra_flags \
 -nographic \
 $extra_flags \
 "
-  ;;
-esac
+    ;;
+  esac
+fi
+
+
 echo "$cmd"
 eval "$cmd"
diff --git a/rungem5 b/rungem5
deleted file mode 100755
index fc70c99..0000000
--- a/rungem5
+++ /dev/null
@@ -1,36 +0,0 @@
-#!/usr/bin/env bash
-arch=arm
-while getopts 'a:' OPT; do
-  case "$OPT" in
-    a)
-      arch="$OPTARG"
-      ;;
-  esac
-done
-shift "$(($OPTIND - 1))"
-outdir="$(pwd)/buildroot/output.${arch}-gem5~"
-gem5_dir="$(pwd)/gem5/gem5"
-if [ "$arch" = x86_64 ]; then
-  cmd="\
-M5_PATH='$(pwd)/gem5/gem5-system' \
-'${gem5_dir}/build/X86/gem5.opt' \
-'${gem5_dir}/configs/example/fs.py' \
---disk-image='${outdir}/images/rootfs.ext2' \
---kernel='${outdir}/build/linux-custom/vmlinux' \
---root-device=/dev/sda \
-"
-elif [ "$arch" = arm ]; then
-  cmd="\
-M5_PATH='$(pwd)/gem5/gem5-system' \
-'${gem5_dir}/build/ARM/gem5.opt' \
-'${gem5_dir}/configs/example/fs.py' \
---disk-image='${outdir}/images/rootfs.ext2' \
---dtb-file='${gem5_dir}/system/arm/dt/armv7_gem5_v1_1cpu.dtb' \
---kernel='${outdir}/build/linux-custom/vmlinux' \
---machine-type=VExpress_GEM5_V1 \
---root-device=/dev/sda \
-"
-fi
-cmd="$cmd \"\$@\""
-echo "$cmd"
-eval "$cmd"