configs: add raspberrypi3 64bits defconfig

This configuration builds a 64bit image for RaspberryPi 3.

The size of the ext4 filesystem has to be extended to fit the large amount
(~60MB) of kernel modules enabled in the defconfig.

[Peter: drop gcc version selection / glibc, explain ext4 size requirement]
Signed-off-by: Gaël PORTAY <gael.portay@savoirfairelinux.com>
Tested-by: Ricardo Martincoski <ricardo.martincoski@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

board/raspberrypi/genimage-raspberrypi3-64.cfg

@@ -0,0 +1,31 @@
+image boot.vfat {
+  vfat {
+    files = {
+      "bcm2710-rpi-3-b.dtb",
+      "bcm2837-rpi-3-b.dtb",
+      "rpi-firmware/bootcode.bin",
+      "rpi-firmware/cmdline.txt",
+      "rpi-firmware/config.txt",
+      "rpi-firmware/fixup.dat",
+      "rpi-firmware/start.elf",
+      "Image"
+    }
+  }
+  size = 32M
+}
+
+image sdcard.img {
+  hdimage {
+  }
+
+  partition boot {
+    partition-type = 0xC
+    bootable = "true"
+    image = "boot.vfat"
+  }
+
+  partition rootfs {
+    partition-type = 0x83
+    image = "rootfs.ext4"
+  }
+}

board/raspberrypi/post-image.sh

@@ -13,6 +13,26 @@ case "${2}" in
 
 # fixes rpi3 ttyAMA0 serial console
 dtoverlay=pi3-miniuart-bt
+__EOF__
+	fi
+	;;
+	--aarch64)
+	# Run a 64bits kernel (armv8)
+	sed -e '/^kernel=/s,=.*,=Image,' -i "${BINARIES_DIR}/rpi-firmware/config.txt"
+	if ! grep -qE '^arm_control=0x200' "${BINARIES_DIR}/rpi-firmware/config.txt"; then
+		cat << __EOF__ >> "${BINARIES_DIR}/rpi-firmware/config.txt"
+
+# enable 64bits support
+arm_control=0x200
+__EOF__
+	fi
+
+	# Enable uart console
+	if ! grep -qE '^enable_uart=1' "${BINARIES_DIR}/rpi-firmware/config.txt"; then
+		cat << __EOF__ >> "${BINARIES_DIR}/rpi-firmware/config.txt"
+
+# enable rpi3 ttyS0 serial console
+enable_uart=1
 __EOF__
 	fi
 	;;

board/raspberrypi3-64

@@ -0,0 +1 @@
+raspberrypi

configs/raspberrypi3_64_defconfig

@@ -0,0 +1,37 @@
+BR2_aarch64=y
+BR2_cortex_a53=y
+BR2_ARM_FPU_VFPV4=y
+
+BR2_TOOLCHAIN_BUILDROOT_CXX=y
+
+BR2_SYSTEM_DHCP="eth0"
+
+# Linux headers same as kernel, a 4.9 series
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_9=y
+
+BR2_LINUX_KERNEL=y
+BR2_LINUX_KERNEL_CUSTOM_GIT=y
+BR2_LINUX_KERNEL_CUSTOM_REPO_URL="https://github.com/raspberrypi/linux.git"
+BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION="5e4ee836560d4c0371e109bf469e1ad808ae7a44"
+BR2_LINUX_KERNEL_DEFCONFIG="bcmrpi3"
+
+# Build the DTB from the kernel sources
+BR2_LINUX_KERNEL_DTS_SUPPORT=y
+BR2_LINUX_KERNEL_INTREE_DTS_NAME="broadcom/bcm2710-rpi-3-b broadcom/bcm2837-rpi-3-b"
+
+BR2_PACKAGE_RPI_FIRMWARE=y
+# BR2_PACKAGE_RPI_FIRMWARE_INSTALL_DTB_OVERLAYS is not set
+
+# Required tools to create the SD image
+BR2_PACKAGE_HOST_DOSFSTOOLS=y
+BR2_PACKAGE_HOST_GENIMAGE=y
+BR2_PACKAGE_HOST_MTOOLS=y
+
+# Filesystem / image
+BR2_TARGET_ROOTFS_EXT2=y
+BR2_TARGET_ROOTFS_EXT2_4=y
+BR2_TARGET_ROOTFS_EXT2_BLOCKS=120000
+# BR2_TARGET_ROOTFS_TAR is not set
+BR2_ROOTFS_POST_BUILD_SCRIPT="board/raspberrypi3-64/post-build.sh"
+BR2_ROOTFS_POST_IMAGE_SCRIPT="board/raspberrypi3-64/post-image.sh"
+BR2_ROOTFS_POST_SCRIPT_ARGS="--aarch64"