configs/visionfive_defconfig: new defconfig

Add a defconfig for the Starfive VisionFive board, a board built around the
Starfive JH7100 RISC-V 64bit SoC (same as Beaglev).

This board comes with functional lowlevel and U-Boot bootloaders in SPI
flash.  The defconfig reuses these and only builds a (6.0 based) kernel and
rootfs.

The factory shipped U-Boot is hard coded to look at MMC partition 3 and
misses some variables, so we provide a uEnv.txt to fix that up, based on
what is done in provided Fedora image.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

DEVELOPERS

@@ -2310,6 +2310,7 @@ F:	board/openblocks/a6/
 F:	board/orangepi/
 F:	board/pandaboard/
 F:	board/roseapplepi/
+F:	board/visionfive/
 F:	boot/shim/
 F:	boot/sun20i-d1-spl/
 F:	configs/avenger96_defconfig
@@ -2324,6 +2325,7 @@ F:	configs/orangepi_r1_defconfig
 F:	configs/pandaboard_defconfig
 F:	configs/roseapplepi_defconfig
 F:	configs/sheevaplug_defconfig
+F:	configs/visionfive_defconfig
 F:	package/bats-core/
 F:	package/docker-compose/
 F:	package/dump1090/

board/visionfive/genimage.cfg

@@ -0,0 +1,21 @@
+# Minimal SD card image for the Starfive VisionFive board
+
+image sdcard.img {
+	hdimage {
+	}
+
+	# u-boot is hard coded to look at 3rd partition
+	partition dummy1 {
+		size = 512
+	}
+
+	partition dummy2 {
+		size = 512
+	}
+
+	partition rootfs {
+		partition-type = 0x83
+		image = "rootfs.ext4"
+		bootable = "true"
+	}
+}

board/visionfive/overlay/boot/extlinux/extlinux.conf

@@ -0,0 +1,4 @@
+label linux
+  kernel /boot/Image
+  devicetree /boot/jh7100-starfive-visionfive-v1.dtb
+  append console=ttyS0,115200 root=/dev/mmcblk0p3

board/visionfive/overlay/boot/uEnv.txt

@@ -0,0 +1,15 @@
+fdt_high=0xffffffffffffffff
+initrd_high=0xffffffffffffffff
+
+scriptaddr=0x88100000
+script_offset_f=0x1fff000
+script_size_f=0x1000
+
+kernel_addr_r=0x84000000
+kernel_comp_addr_r=0x90000000
+kernel_comp_size=0x10000000
+
+fdt_addr_r=0x88000000
+ramdisk_addr_r=0x88300000
+
+bootcmd=devnum=0; run mmc_boot

board/visionfive/readme.txt

@@ -0,0 +1,32 @@
+Starfive VisionFive
+===================
+
+The VisionFive is a low-cost RISC-V 64-bit based platform, powered by a
+Starfive JH7100 processor.
+
+https://doc-en.rvspace.org/Doc_Center/visionfive.html
+
+How to build
+============
+
+$ make visionfive_defconfig
+$ make
+
+How to write the SD card
+========================
+
+Once the build process is finished you will have an image called "sdcard.img"
+in the output/images/ directory.
+
+Copy the bootable "sdcard.img" onto an SD card with "dd":
+
+  $ sudo dd if=output/images/sdcard.img of=/dev/sdX
+
+Preparing the board
+===================
+
+Connect a TTL UART cable to pin 6 (GND), 8 (TX) and 10 (RX).
+
+Insert your SD card.
+
+Power-up the board using an USB-C cable.

configs/visionfive_defconfig

@@ -0,0 +1,17 @@
+BR2_riscv=y
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_6_0=y
+BR2_SYSTEM_DHCP="eth0"
+BR2_ROOTFS_OVERLAY="board/visionfive/overlay"
+BR2_ROOTFS_POST_IMAGE_SCRIPT="support/scripts/genimage.sh"
+BR2_ROOTFS_POST_SCRIPT_ARGS="-c board/visionfive/genimage.cfg"
+BR2_LINUX_KERNEL=y
+BR2_LINUX_KERNEL_CUSTOM_TARBALL=y
+BR2_LINUX_KERNEL_CUSTOM_TARBALL_LOCATION="$(call github,starfive-tech,linux,cfcb617265422c0af0ae5bc9688dceba2d10b27a)/linux-cfcb617265422c0af0ae5bc9688dceba2d10b27a.tar.gz"
+BR2_LINUX_KERNEL_DEFCONFIG="visionfive"
+BR2_LINUX_KERNEL_DTS_SUPPORT=y
+BR2_LINUX_KERNEL_INTREE_DTS_NAME="starfive/jh7100-starfive-visionfive-v1"
+BR2_LINUX_KERNEL_INSTALL_TARGET=y
+BR2_TARGET_ROOTFS_EXT2=y
+BR2_TARGET_ROOTFS_EXT2_4=y
+# BR2_TARGET_ROOTFS_TAR is not set
+BR2_PACKAGE_HOST_GENIMAGE=y