diff --git a/device/dell/x86_64-dell_s6000_s1220-r0/installer.conf b/device/dell/x86_64-dell_s6000_s1220-r0/installer.conf
index eb135bee0ff1..a8fef6185912 100644
--- a/device/dell/x86_64-dell_s6000_s1220-r0/installer.conf
+++ b/device/dell/x86_64-dell_s6000_s1220-r0/installer.conf
@@ -1,5 +1,7 @@
 ONIE_PLATFORM_EXTRA_CMDLINE_LINUX="processor.max_cstate=1 intel_idle.max_cstate=0"
 
+if [ "$install_env" = "onie" ]; then
+
 echo "Replace ONIE reboot with Dell reset commands"
 
 # set I2C GPIO mux
@@ -21,3 +23,5 @@ i2cset -y 0 0x31 1 0xfd
 EOF
 
 chmod a+x /sbin/reboot
+
+fi
diff --git a/installer/x86_64/install.sh b/installer/x86_64/install.sh
index 18669893bcb5..f7d1dbb29a6f 100755
--- a/installer/x86_64/install.sh
+++ b/installer/x86_64/install.sh
@@ -36,7 +36,14 @@ if [ $(id -u) -ne 0 ]
 fi
 
 # get running machine from conf file
-[ -r /etc/machine.conf ] && . /etc/machine.conf
+if [ -r /etc/machine.conf ]; then
+    . /etc/machine.conf
+elif [ -r /host/machine.conf ]; then
+    . /host/machine.conf
+else
+    echo "cannot find machine.conf"
+    exit 1
+fi
 
 echo "onie_platform: $onie_platform"
 
@@ -57,9 +64,10 @@ if [ -d "/etc/sonic" ]; then
 else
     echo "Installing SONiC in ONIE"
     install_env="onie"
-    [ -r platforms/$onie_platform ] && source platforms/$onie_platform
 fi
 
+[ -r platforms/$onie_platform ] && . platforms/$onie_platform
+
 # Install demo on same block device as ONIE
 onie_dev=$(blkid | grep ONIE-BOOT | head -n 1 | awk '{print $1}' |  sed -e 's/:.*$//')
 blk_dev=$(echo $onie_dev | sed -e 's/[1-9][0-9]*$//' | sed -e 's/\([0-9]\)\(p\)/\1/')