Merge pull request #3541 from batocera-linux/uboot-rockpro64

external uboot-rockpro64

configs/batocera-uboot-rockpro64_defconfig

@@ -0,0 +1,32 @@
+# Target definition
+BR2_aarch64=y
+BR2_cortex_a72_a53=y
+BR2_ARM_FPU_NEON_FP_ARMV8=y
+
+# Toolchain definition
+BR2_GCC_VERSION_10_X=y
+BR2_GCC_ENABLE_GRAPHITE=y
+BR2_GCC_ENABLE_LTO=y
+BR2_OPTIMIZE_3=y
+BR2_SHARED_STATIC_LIBS=y
+BR2_TOOLCHAIN_BUILDROOT_GLIBC=y
+# required for utf-8
+BR2_TOOLCHAIN_GLIBC_GCONV_LIBS_COPY=y
+BR2_TOOLCHAIN_BUILDROOT_CXX=y
+
+# BR2_TARGET_ROOTFS_TAR is not set
+
+# Bootloader
+BR2_TARGET_UBOOT=y
+BR2_TARGET_UBOOT_BUILD_SYSTEM_KCONFIG=y
+BR2_TARGET_UBOOT_CUSTOM_VERSION=y
+BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2021.01"
+BR2_TARGET_UBOOT_BOARD_DEFCONFIG="rockpro64-rk3399"
+BR2_TARGET_UBOOT_NEEDS_DTC=y
+BR2_TARGET_UBOOT_NEEDS_PYTHON3=y
+BR2_TARGET_UBOOT_NEEDS_ATF_BL31=y
+BR2_TARGET_UBOOT_NEEDS_ATF_BL31_ELF=y
+BR2_TARGET_UBOOT_FORMAT_CUSTOM=y
+BR2_TARGET_UBOOT_FORMAT_CUSTOM_NAME="u-boot.itb"
+BR2_TARGET_UBOOT_SPL=y
+BR2_TARGET_UBOOT_SPL_NAME="idbloader.img"