configs/nanopi_neo4: new defconfig

A defconfig for the nanopi_neo4 was added in
d1cd9cdf26, but then removed in
8af7b11bd8 because an ARM32 compiler was
needed to build ATF, and this was not supported back then.

Thanks to the addition of package/arm-gnu-a-toolchain/, we can now
re-introduce this defconfig.

Compared to the previous defconfig, the following changes were done:

- enable BR2_TARGET_ARM_TRUSTED_FIRMWARE_NEEDS_ARM32_TOOLCHAIN
- bump kernel to 5.4
- increase default rootfs size to 70M
- use mainline u-boot
- switch to Marek Belisko as maintainer

Signed-off-by: Marek Belisko <marek.belisko@open-nandra.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

board/friendlyarm/nanopi-neo4/extlinux.conf

@@ -0,0 +1,4 @@
+label NanoPi Neo4 linux
+  kernel /boot/Image
+  devicetree /boot/rk3399-nanopi-neo4.dtb
+  append earlycon=uart8250,mmio32,0xff1a0000 root=/dev/mmcblk1p1 rootwait

board/friendlyarm/nanopi-neo4/genimage.cfg

@@ -0,0 +1,22 @@
+image sdcard.img {
+	hdimage {
+	}
+
+	partition u-boot-tpl-spl-dtb {
+		in-partition-table = "no"
+		image = "idbloader.img"
+		offset = 32K
+	}
+
+	partition u-boot-dtb {
+		in-partition-table = "no"
+		image = "u-boot.itb"
+		offset = 8M
+		size = 30M
+	}
+
+	partition rootfs {
+		partition-type = 0x83
+		image = "rootfs.ext4"
+	}
+}

board/friendlyarm/nanopi-neo4/post-build.sh

@@ -0,0 +1,5 @@
+#!/bin/sh
+
+BOARD_DIR="$(dirname $0)"
+
+install -m 0644 -D $BOARD_DIR/extlinux.conf $TARGET_DIR/boot/extlinux/extlinux.conf

board/friendlyarm/nanopi-neo4/readme.txt

@@ -0,0 +1,53 @@
+Intro
+=====
+
+NanoPi Neo4 is a RK3399 SoC based ARM64 board.
+
+
+Official wiki: http://wiki.friendlyarm.com/wiki/index.php/NanoPi_NEO4
+Mainline wiki: https://wiki.amarulasolutions.com/bsp/rockchip/rk3399/neo4.html
+
+Build
+=====
+
+Run NanoPi Neo4 configuration
+
+  $ make nanopi_neo4_defconfig
+
+To build, run make comamnd.
+
+  $ make
+
+Files created in output directory
+=================================
+
+output/images
+
+├── bl31.bin
+├── bl31.elf
+├── Image
+├── rk3399-nanopi-neo4.dtb
+├── rootfs.ext2
+├── rootfs.ext4 -> rootfs.ext2
+├── rootfs.tar
+├── sdcard.img
+├── u-boot.bin
+├── u-boot.itb
+├── u-boot-spl-dtb.bin
+├── u-boot-tpl-dtb.bin
+├── u-boot-tpl-dtb.img
+└── u-boot-tpl-spl-dtb.img
+
+Creating bootable SD card:
+=========================
+
+Simply invoke (as root)
+
+  # dd if=output/images/sdcard.img of=/dev/sdX && sync
+
+Where X is your SD card device
+
+Serial console
+--------------
+
+Baudrate for this board is 1500000