XEN: Timer: Unable to retrieve IRQ 0 from the device tree

System image with XEN enabled for R-Car M3SK was built successfully with the following commands, but error occurred during startup.

1. Build steps
$ repo init -b master -u https://gerrit.automotivelinux.org/gerrit/AGL/AGL-rep
$ repo sync
$ source meta-agl/scripts/aglsetup.sh -m m3ulcb -b build agl-devel agl-demo agl-netboot agl-appfw-smack agl-localdev agl-virt-xen agl-virt agl-virt-xen
$ bitbake agl-demo-platform

2. IPL update

• https://elinux.org/R-Car/Boards/M3SK#Flashing_firmware

3. Startup with new built Images
=> pri
bootargs=console=ttySC0 root=/dev/nfs rw nfsroot=192.168.100.75:/work/kernel/rootfs/core-image-weston-m3ulcb rootwait ip=dhcp
bootcmd=run load_ker; run load_dtb; run load_xen; bootm 0x48080000 – 0x48000000
load_xen=tftpboot 0x48080000 xen-m3ulcb.uImage
load_dtb=tftpboot 0x48000000 r8a7796-m3ulcb-xen.dtb
load_ker=tftpboot 0x7a000000 Image.xen
(snip)
=> run bootcmd
(snip)

1. 1. Booting kernel from Legacy Image at 48080000 ...
      Image Name: XEN
      Image Type: AArch64 Linux Kernel Image (uncompressed)
      Data Size: 755024 Bytes = 737.3 KiB
      Load Address: 48080000
      Entry Point: 48080000
      Verifying Checksum ... OK
   2. Flattened Device Tree blob at 48000000
      Booting using the fdt blob at 0x48000000
      Loading Kernel Image ... OK
      Using Device Tree in place at 0000000048000000, end 0000000048012f79
      Starting kernel ...
      Xen 4.12.0
      (XEN) Xen version 4.12.0 (xen-4.12.0-r0@poky-agl) (aarch64-agl-linux-gcc (GCC) 9.2.0) debug=n 2020-03-10
      (XEN) Latest ChangeSet:
      (XEN) Processor: 411fd073: "ARM Limited", variant: 0x1, part 0xd07, rev 0x3
      (XEN) 64-bit Execution:
      (XEN) Processor Features: 0000000000002222 0000000000000000
      (XEN) Exception Levels: EL3:64+32 EL2:64+32 EL1:64+32 EL0:64+32
      (XEN) Extensions: FloatingPoint AdvancedSIMD
      (XEN) Debug Features: 0000000010305106 0000000000000000
      (XEN) Auxiliary Features: 0000000000000000 0000000000000000
      (XEN) Memory Model Features: 0000000000001124 0000000000000000
      (XEN) ISA Features: 0000000000011120 0000000000000000
      (XEN) 32-bit Execution:
      (XEN) Processor Features: 00000131:00011011
      (XEN) Instruction Sets: AArch32 A32 Thumb Thumb-2 Jazelle
      (XEN) Extensions: GenericTimer Security
      (XEN) Debug Features: 03010066
      (XEN) Auxiliary Features: 00000000
      (XEN) Memory Model Features: 10201105 40000000 01260000 02102211
      (XEN) ISA Features: 02101110 13112111 21232042 01112131 00011142 00011121
      (XEN)
      (XEN) ****************************************
      (XEN) Panic on CPU 0:
      (XEN) Timer: Unable to retrieve IRQ 0 from the device tree
      (XEN) ****************************************
      (XEN)
      (XEN) Reboot in five seconds...

Please correct me if something goes wrong.
Any comments will be appreciated.