configs/raspberrypicm4io_64_uboot_defconfig: new defconfig

The new config deviates from the existing
configs/raspberrypicm4io_64_defconfig only as far as necessary to
demonstrate booting through U-Boot instead of having the firmware load
the kernel directly. The sample boot script loads the kernel from the
rootfs and uses the device tree provided by the firmware, and should
be compatible with any RPi device that runs U-Boot.

Signed-off-by: Fiona Klute (WIWA) <fiona.klute@gmx.de>
[Arnout: update kernel to same as raspberrypicm4io_64_defconfig]
Signed-off-by: Arnout Vandecappelle <arnout@rnout.be>

board/raspberrypi/boot.scr.in

@@ -0,0 +1,18 @@
+# Please note that this is only a sample, we recommend you to change
+# it to fit your needs. You should override this file using
+# BR2_PACKAGE_HOST_UBOOT_TOOLS_BOOT_SCRIPT_SOURCE.
+
+# On most Raspberry Pi boards UART0 is ttyAMA0, Raspberry Pi 5 is
+# different.
+if test "$board_name" = "5 Model B"; then
+    env set serial_uart "ttyAMA10,115200"
+else
+    env set serial_uart "ttyAMA0,115200"
+fi
+env set bootargs "root=/dev/mmcblk0p2 rootwait console=tty1 console=${serial_uart}"
+
+# load kernel from the root partition
+load mmc 0:2 ${kernel_addr_r} boot/Image
+
+# boot using the FDT provided by firmware
+booti ${kernel_addr_r} - ${fdt_addr}

board/raspberrypi/config_cm4io_64bit_uboot.txt

@@ -0,0 +1,23 @@
+# Please note that this is only a sample, we recommend you to change it to fit
+# your needs.
+# You should override this file using BR2_PACKAGE_RPI_FIRMWARE_CONFIG_FILE.
+# See http://buildroot.org/manual.html#rootfs-custom
+# and http://elinux.org/RPiconfig for a description of config.txt syntax
+
+start_file=start4.elf
+fixup_file=fixup4.dat
+
+kernel=u-boot.bin
+
+# Enable UART0 for serial console on ttyAMA0
+dtoverlay=miniuart-bt
+
+# enable RTC
+dtparam=i2c_vc=on
+dtoverlay=i2c-rtc,pcf85063a,i2c_csi_dsi
+
+# enable dwc2 USB controller (USB 2.0)
+dtoverlay=dwc2,dr_mode=host
+
+# enable 64bits support
+arm_64bit=1

board/raspberrypi/readme.txt

@@ -83,6 +83,10 @@ or for CM4 (on IO Board - 64 bit):
 
   $ make raspberrypicm4io_64_defconfig
 
+or to boot CM4 (on IO Board - 64 bit) using U-Boot:
+
+  $ make raspberrypicm4io_64_uboot_defconfig
+
 For model 5 B and 500:
 
   $ make raspberrypi5_defconfig

configs/raspberrypicm4io_64_uboot_defconfig

@@ -0,0 +1,40 @@
+BR2_aarch64=y
+BR2_cortex_a72=y
+BR2_ARM_FPU_VFPV4=y
+BR2_TOOLCHAIN_EXTERNAL=y
+BR2_TOOLCHAIN_EXTERNAL_BOOTLIN=y
+BR2_TOOLCHAIN_EXTERNAL_BOOTLIN_AARCH64_GLIBC_STABLE=y
+BR2_GLOBAL_PATCH_DIR="board/raspberrypi/patches"
+BR2_DOWNLOAD_FORCE_CHECK_HASHES=y
+BR2_SYSTEM_DHCP="eth0"
+BR2_ROOTFS_POST_BUILD_SCRIPT="board/raspberrypicm4io-64/post-build.sh"
+BR2_ROOTFS_POST_IMAGE_SCRIPT="board/raspberrypicm4io-64/post-image.sh"
+BR2_LINUX_KERNEL=y
+BR2_LINUX_KERNEL_CUSTOM_TARBALL=y
+BR2_LINUX_KERNEL_CUSTOM_TARBALL_LOCATION="$(call github,raspberrypi,linux,21b410140c47ffab5668399f6f143c7d7b935c8b)/linux-21b410140c47ffab5668399f6f143c7d7b935c8b.tar.gz"
+BR2_LINUX_KERNEL_DEFCONFIG="bcm2711"
+BR2_LINUX_KERNEL_DTS_SUPPORT=y
+BR2_LINUX_KERNEL_INTREE_DTS_NAME="broadcom/bcm2711-rpi-cm4"
+BR2_LINUX_KERNEL_INSTALL_TARGET=y
+BR2_LINUX_KERNEL_NEEDS_HOST_OPENSSL=y
+BR2_PACKAGE_BUSYBOX_SHOW_OTHERS=y
+BR2_PACKAGE_XZ=y
+BR2_PACKAGE_RPI_FIRMWARE=y
+BR2_PACKAGE_RPI_FIRMWARE_VARIANT_PI4=y
+BR2_PACKAGE_RPI_FIRMWARE_CONFIG_FILE="board/raspberrypicm4io-64/config_cm4io_64bit_uboot.txt"
+BR2_PACKAGE_KMOD=y
+BR2_PACKAGE_KMOD_TOOLS=y
+BR2_TARGET_ROOTFS_EXT2=y
+BR2_TARGET_ROOTFS_EXT2_4=y
+BR2_TARGET_ROOTFS_EXT2_SIZE="120M"
+# BR2_TARGET_ROOTFS_TAR is not set
+BR2_TARGET_UBOOT=y
+BR2_TARGET_UBOOT_BOARD_DEFCONFIG="rpi_arm64"
+BR2_PACKAGE_HOST_DOSFSTOOLS=y
+BR2_PACKAGE_HOST_GENIMAGE=y
+BR2_PACKAGE_HOST_KMOD_XZ=y
+BR2_PACKAGE_HOST_MTOOLS=y
+BR2_PACKAGE_HOST_RASPBERRYPI_USBBOOT=y
+BR2_PACKAGE_HOST_UBOOT_TOOLS=y
+BR2_PACKAGE_HOST_UBOOT_TOOLS_BOOT_SCRIPT=y
+BR2_PACKAGE_HOST_UBOOT_TOOLS_BOOT_SCRIPT_SOURCE="board/raspberrypicm4io-64/boot.scr.in"