--- /dev/null
+image boot.vfat {
+ vfat {
+ files = {
+ "bcm2711-rpi-4-b.dtb",
+ "rpi-firmware/cmdline.txt",
+ "rpi-firmware/config.txt",
+ "rpi-firmware/fixup4.dat",
+ "rpi-firmware/start4.elf",
+ "rpi-firmware/overlays",
+ "zImage"
+ }
+ }
+ size = 32M
+}
+
+image sdcard.img {
+ hdimage {
+ }
+
+ partition boot {
+ partition-type = 0xC
+ bootable = "true"
+ image = "boot.vfat"
+ }
+
+ partition rootfs {
+ partition-type = 0x83
+ image = "rootfs.ext4"
+ }
+}
- the "enhanced" models A+ and B+,
- the model B2 (aka Raspberry Pi 2)
- the model B3 (aka Raspberry Pi 3).
+ - the model B4 (aka Raspberry Pi 4).
How to build it
===============
$ make raspberrypi3_defconfig
+For model 4 B:
+
+ $ make raspberrypi4_defconfig
+
Build the rootfs
----------------
+-- bcm2709-rpi-2-b.dtb [1]
+-- bcm2710-rpi-3-b.dtb [1]
+-- bcm2710-rpi-3-b-plus.dtb [1]
+ +-- bcm2711-rpi-4-b.dtb [1]
+-- boot.vfat
+-- rootfs.ext4
+-- rpi-firmware/
[1] Not all of them will be present, depending on the RaspberryPi
model you are using.
-[2] Only for the Raspberry Pi 3 Model (overlay pi3-miniuart-bt is needed
+[2] Only for the Raspberry Pi 3/4 Models (overlay pi3-miniuart-bt is needed
to enable the RPi3 serial console otherwise occupied by the bluetooth
chip). Alternative would be to disable the serial console in cmdline.txt
and /etc/inittab.
--- /dev/null
+BR2_arm=y
+BR2_cortex_a72=y
+BR2_ARM_FPU_NEON_VFPV4=y
+
+BR2_TOOLCHAIN_BUILDROOT_CXX=y
+
+BR2_SYSTEM_DHCP="eth0"
+
+# Linux headers same as kernel, a 4.19 series
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_19=y
+
+BR2_LINUX_KERNEL=y
+BR2_LINUX_KERNEL_CUSTOM_TARBALL=y
+BR2_LINUX_KERNEL_CUSTOM_TARBALL_LOCATION="$(call github,raspberrypi,linux,eb0360356344d8ba633e61936c794aa46a02397f)/linux-eb0360356344d8ba633e61936c794aa46a02397f.tar.gz"
+BR2_LINUX_KERNEL_DEFCONFIG="bcm2711"
+
+# Build the DTB from the kernel sources
+BR2_LINUX_KERNEL_DTS_SUPPORT=y
+BR2_LINUX_KERNEL_INTREE_DTS_NAME="bcm2711-rpi-4-b"
+
+BR2_LINUX_KERNEL_NEEDS_HOST_OPENSSL=y
+
+BR2_PACKAGE_RPI_FIRMWARE=y
+BR2_PACKAGE_RPI_FIRMWARE_VARIANT_PI4=y
+
+# 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_SIZE="120M"
+# BR2_TARGET_ROOTFS_TAR is not set
+BR2_ROOTFS_POST_BUILD_SCRIPT="board/raspberrypi4/post-build.sh"
+BR2_ROOTFS_POST_IMAGE_SCRIPT="board/raspberrypi4/post-image.sh"
+BR2_ROOTFS_POST_SCRIPT_ARGS="--add-pi3-miniuart-bt-overlay"