Add fast-reboot support for Aboot based images (sonic-net#214)

Author: Staphylo

scripts/fast-reboot

@@ -16,9 +16,18 @@ fi
 
 # Kernel and initrd image
 NEXT_SONIC_IMAGE=$(sonic_installer list | grep "Next: " | cut -d ' ' -f 2)
-KERNEL_OPTIONS=$(cat /host/grub/grub.cfg | sed "/$NEXT_SONIC_IMAGE'/,/}/"'!'"g" | grep linux)
-KERNEL_IMAGE="/host$(echo $KERNEL_OPTIONS | cut -d ' ' -f 2)"
-BOOT_OPTIONS="$(echo $KERNEL_OPTIONS | sed -e 's/\s*linux\s*/BOOT_IMAGE=/') fast-reboot"
+if grep -q aboot_platform= /host/machine.conf; then
+    IMAGE_PATH="/host/image-${NEXT_SONIC_IMAGE#SONiC-OS-}"
+    KERNEL_IMAGE="$(ls $IMAGE_PATH/boot/vmlinuz-*)"
+    BOOT_OPTIONS="$(cat "$IMAGE_PATH/kernel-cmdline" | tr '\n' ' ') fast-reboot"
+elif grep -q onie_platform= /host/machine.conf; then
+    KERNEL_OPTIONS=$(cat /host/grub/grub.cfg | sed "/$NEXT_SONIC_IMAGE'/,/}/"'!'"g" | grep linux)
+    KERNEL_IMAGE="/host$(echo $KERNEL_OPTIONS | cut -d ' ' -f 2)"
+    BOOT_OPTIONS="$(echo $KERNEL_OPTIONS | sed -e 's/\s*linux\s*/BOOT_IMAGE=/') fast-reboot"
+else
+    echo "Unknown bootloader. fast-reboot is not supported."
+    exit 1
+fi
 INITRD=$(echo $KERNEL_IMAGE | sed 's/vmlinuz/initrd.img/g')
 
 sonic_asic_type=$(sonic-cfggen -y /etc/sonic/sonic_version.yml -v asic_type)