Added support for reComputer J2012

Makefile

+recomputer-j2012: grub.efiarm64
 aws: grub.bios
 kvm64: grub.bios
 phenom: grub.bios
@@ -90,6 +91,22 @@ grub.efi: grub-config
 	umount /dev/$(DISK)1
 	rm -rf grub-2.06
 
+grub.efiarm64: grub-config-arm
+	tar xf grub-2.06.tar.xz
+	cd grub-2.06 && ./configure --prefix=/usr --sbindir=/sbin --sysconfdir=/etc --with-platform=efi --disable-werror
+	$(MAKE) -C grub-2.06
+	$(MAKE) -C grub-2.06 install
+	rm /etc/bash_completion.d/grub
+	mkdir -p /boot/efi
+	mkfs -t vfat -n EFIBOOT /dev/$(DISK)1
+	sed -i "/\/dev\/root/a \/dev\/disk\/by-label\/EFIBOOT \/boot/efi    vfat   defaults,sync,auto       0     0" /etc/fstab
+	mount /dev/$(DISK)1 /boot/efi
+	mkdir -p /boot/efi/EFI/BOOT
+	grub-mkimage -p /efi/boot -o /boot/efi/EFI/BOOT/bootaa64.efi -O arm64-efi part_gpt fat ext2 normal linux efi_gop test loadenv reboot hashsum echo halt gcry_sha256
+	@echo "$$GRUB_CONFIG_ARM" > /boot/efi/EFI/BOOT/grub.cfg
+	umount /dev/$(DISK)1
+	rm -rf grub-2.06
+
 grub-config:
 define GRUB_CONFIG
 # Begin /boot/grub/grub.cfg
@@ -103,3 +120,18 @@ linux /boot/zImage console=tty1 root=/dev/disk/by-label/CLFS rootfstype=ext4 roo
 boot
 endef
 export GRUB_CONFIG
+
+grub-config-arm:
+define GRUB_CONFIG_ARM
+# Begin /boot/grub/grub.cfg
+set default=0
+set timeout=5
+
+insmod ext2
+set root=(hd1,2)
+
+linux /boot/Image console=tty1 root=/dev/disk/by-label/CLFS rootfstype=ext4 rootflags=discard rw rootwait quiet loglevel=3 systemd.show_status=1 net.ifnames=0
+devicetree /boot/machine.dtb
+boot
+endef
+export GRUB_CONFIG_ARM