Add sysutils/u-boot-qemu-arm64: U-Boot build for QEMU aarch64

Reviewed by:	manu
Sponsored by:	DARPA
Differential Revision:	https://reviews.freebsd.org/D24726

sysutils/Makefile

@@ -1335,6 +1335,7 @@
     SUBDIR += u-boot-pinebook
     SUBDIR += u-boot-pinebookpro
     SUBDIR += u-boot-qemu-arm
+    SUBDIR += u-boot-qemu-arm64
     SUBDIR += u-boot-riotboard
     SUBDIR += u-boot-rock64
     SUBDIR += u-boot-rockpro64

sysutils/u-boot-qemu-arm64/Makefile

@@ -0,0 +1,12 @@
+# $FreeBSD$
+
+MASTERDIR=	${.CURDIR}/../u-boot-master
+
+MODEL=		qemu-arm64
+BOARD_CONFIG=	qemu_arm64_defconfig
+FAMILY=		qemu
+UBOOT_ARCH=	aarch64
+
+UBOOT_PLIST=	u-boot.bin
+
+.include "${MASTERDIR}/Makefile"

sysutils/u-boot-qemu-arm64/pkg-descr

@@ -0,0 +1,8 @@
+U-Boot loader for QEMU arm64
+
+To use this bootloader to boot a FreeBSD aarch64 image, install emulators/qemu
+and execute it as eg:
+
+qemu-system-aarch64 -M virt -cpu cortex-a57 -m 512m -nographic -bios /usr/local/share/u-boot/u-boot-qemu-arm64/u-boot.bin -hda FreeBSD-13.0-CURRENT-arm64-aarch64-RPI3-20200409-r359731.img
+
+For general information about U-Boot see WWW: https://www.denx.de/wiki/U-Boot