configs/sipeed_licheepi_4a: add new board

Add support for the LicheePi 4A with mainline component:
 - Linux Kernel 6.12

The following components are provided by vendor:
 - U-Boot 2020.01
 - OpenSBI v0.9

Board homepage and more usable wiki:
 - https://wiki.sipeed.com/hardware/en/lichee/th1520/lpi4a/1_intro.html

th1520-boot-firmware is selected from the package sipeed-lpi4abin.
This is inspired from lone0's fork of buildroot for th1520.[1]

[1] https://github.com/lone0/buildroot-th1520

Signed-off-by: Kanak Shilledar <kanakshilledar@gmail.com>
[Julien: Tested on cpu board version 51601
  on base board version 51602]
Tested-by: Julien Olivain <ju.o@free.fr>
[Julien:
  - add Signed-off-by line in commit log
  - reorder defconfig entries with "make savedefconfig"
  - fixed post-image.sh shellcheck warnings
    (found with "make check-package")
  - add extra info in readme.txt
  - change linux-headers.hash to a symlink
  - change linux.hash comment to take hash from upstream
]
Signed-off-by: Julien Olivain <ju.o@free.fr>

DEVELOPERS

@@ -2056,6 +2056,8 @@ F:	package/libqb/
 F:	package/usbguard/
 
 N:	Kanak Shilledar <kanakshilledar@gmail.com>
+F:	board/sipeed/licheepi_4a/
+F:	configs/sipeed_licheepi_4a_defconfig
 F:	package/sipeed-lpi4abin/
 
 N:	Karoly Kasza <kaszak@gmail.com>

board/sipeed/licheepi_4a/extlinux/extlinux.conf

@@ -0,0 +1,4 @@
+label linux
+  kernel /Image
+  devicetree /th1520-lichee-pi-4a.dtb
+  append console=ttyS0,115200 root=/dev/mmcblk0p4 rootfstype=ext4 rootwait rw earlycon clk_ignore_unused init=/sbin/init

board/sipeed/licheepi_4a/genimage.cfg

@@ -0,0 +1,7 @@
+image boot.ext4 {
+	ext4 {
+		label = "boot"
+	}
+
+	size = 64M
+}

board/sipeed/licheepi_4a/patches/linux-headers/linux-headers.hash

@@ -0,0 +1 @@
+../linux/linux.hash

board/sipeed/licheepi_4a/patches/linux/linux.hash

@@ -0,0 +1,2 @@
+# From https://www.kernel.org/pub/linux/kernel/v6.x/sha256sums.asc
+sha256  beb902a5f69d9e57710112203db38111dad6d30556ea8ce389284c8077fe944d  linux-6.12.18.tar.xz

board/sipeed/licheepi_4a/patches/opensbi/opensbi.hash

@@ -0,0 +1,2 @@
+# Locally computed
+sha256  2510c0e867b4f8c28579def9a21e97fa2e8de95b8c7d66bb8b6642202bcee3b4  opensbi-61d7484c752a5e4c464d5dc18e21d9ac67fbbefa-git4.tar.gz

board/sipeed/licheepi_4a/patches/uboot/uboot.hash

@@ -0,0 +1,2 @@
+# Locally computed
+sha256  6158b9c6faee41a1e790ad4ba2e1b3e18a122ecdb5749fa77c7495a2d1c56262  uboot-b5ee6e549a7b5ff382a14021a5d6a3c94017bddd-git4.tar.gz

board/sipeed/licheepi_4a/post-image.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+
+set -e
+
+BOARD_DIR="$(dirname "$0")"
+GENIMAGE_CFG="${BOARD_DIR}/genimage.cfg"
+GENIMAGE_TMP="${BUILD_DIR}/genimage.tmp"
+
+trap 'rm -rf "${ROOTPATH_TMP}"' EXIT
+ROOTPATH_TMP="$(mktemp -d)"
+rm -rf "${GENIMAGE_TMP}"
+
+cp "${BINARIES_DIR}"/Image "${BINARIES_DIR}"/*.dtb "${BINARIES_DIR}"/fw_dynamic.bin "${ROOTPATH_TMP}"
+cp -a "${BINARIES_DIR}"/bootbins/* "${ROOTPATH_TMP}"
+cp -a "${BOARD_DIR}"/extlinux "${ROOTPATH_TMP}"
+
+genimage \
+	--rootpath "${ROOTPATH_TMP}"   \
+	--tmppath "${GENIMAGE_TMP}"    \
+	--inputpath "${BINARIES_DIR}"  \
+	--outputpath "${BINARIES_DIR}" \
+	--config "${GENIMAGE_CFG}"
+
+exit $?

board/sipeed/licheepi_4a/readme.txt

@@ -0,0 +1,97 @@
+Intro
+=====
+
+This directory contains a Buildroot configuration for building a
+LicheePi 4A image. For more information, see the board wiki page [1].
+
+
+How to build it
+===============
+
+
+Configure Buildroot
+-------------------
+
+    make sipeed_licheepi_4a_defconfig
+
+
+Build the boot and rootfs
+-------------------------
+
+Note: you will need to have access to the network, since Buildroot
+will download the packages' sources.
+
+You may now build your rootfs with:
+
+    make
+
+(This may take a while, consider getting yourself a coffee ;-) )
+
+
+Result of the build
+-------------------
+
+After building, you should obtain this tree:
+
+    output/images/
+    +-- boot.ext4
+    +-- rootfs.ext2
+    +-- rootfs.ext4 -> rootfs.ext2
+    +-- rootfs.tar
+    +-- u-boot.bin
+    +-- u-boot-with-spl.bin
+    +-- fw_dynamic.bin
+    `-- Image
+
+
+How to flash the board
+======================
+
+Once the build process is finished you will have to flash the
+correspoding images to the respective partitions in the eMMC.
+LicheePi 4A uses fastboot to flash the images.
+
+The board needs to be booted in "Burning Mode". For that, check first
+the boot switches (SW1, SW2) on the base board are set up on the
+"eMMC" mode (this is the factory default). Then, boot the board while
+pressing the "BOOT" button. See [2].
+
+Note that the board can be booted by either:
+- attaching the USB-C power cable, or
+- pressing the "RESET" button (near the USB-C power connector) if the
+  power cable is already connected to the host computer.
+
+The board should be enumerated from the host computer. This can be
+confirmed with "lsusb". The board should be listed as:
+
+    ID 2345:7654 T-HEAD USB download gadget
+
+The device should also be listed by the "fastboot devices" command:
+
+    ????????????         Android Fastboot
+
+The board can be flashed with the commands:
+
+    fastboot flash ram output/images/u-boot-with-spl.bin
+    fastboot reboot
+    fastboot flash uboot output/images/u-boot-with-spl.bin
+    fastboot flash boot output/images/boot.ext4
+    fastboot flash root output/images/rootfs.ext2
+
+
+Boot the board
+==============
+
+Connect the console on the System Serial Port on pins
+U0-RX, U0-TX and GND. For more details, see [3].
+
+When resetting or powering up the board on the USB-C port, the U-Boot
+prompt and Linux console will appear on this System Serial Port.
+
+
+References
+==========
+
+[1] https://wiki.sipeed.com/hardware/en/lichee/th1520/lpi4a/1_intro.html
+[2] https://wiki.sipeed.com/hardware/en/lichee/th1520/lpi4a/4_burn_image.html#How-to-enter-burning-mode
+[3] https://wiki.sipeed.com/hardware/en/lichee/th1520/lpi4a/6_peripheral.html#System-Serial-Port

configs/sipeed_licheepi_4a_defconfig

@@ -0,0 +1,42 @@
+BR2_riscv=y
+BR2_RISCV_ISA_RVC=y
+BR2_RISCV_ISA_RVV=y
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_6_12=y
+BR2_GLOBAL_PATCH_DIR="board/sipeed/licheepi_4a/patches"
+BR2_DOWNLOAD_FORCE_CHECK_HASHES=y
+BR2_TARGET_GENERIC_HOSTNAME="licheepi4a"
+BR2_TARGET_GENERIC_ISSUE="Welcome to Buildroot for the LicheePi 4A"
+BR2_TARGET_GENERIC_GETTY_PORT="ttyS0"
+BR2_TARGET_GENERIC_GETTY_BAUDRATE_115200=y
+BR2_ROOTFS_POST_IMAGE_SCRIPT="board/sipeed/licheepi_4a/post-image.sh"
+BR2_LINUX_KERNEL=y
+BR2_LINUX_KERNEL_CUSTOM_VERSION=y
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="6.12.18"
+BR2_LINUX_KERNEL_USE_ARCH_DEFAULT_CONFIG=y
+BR2_LINUX_KERNEL_DTS_SUPPORT=y
+BR2_LINUX_KERNEL_INTREE_DTS_NAME="thead/th1520-lichee-pi-4a"
+BR2_PACKAGE_LINUX_FIRMWARE=y
+BR2_PACKAGE_LINUX_FIRMWARE_RTL_RTW88=y
+BR2_PACKAGE_SIPEED_LPI4ABIN=y
+BR2_PACKAGE_IW=y
+BR2_PACKAGE_WIRELESS_REGDB=y
+BR2_PACKAGE_WIRELESS_TOOLS=y
+BR2_PACKAGE_WPA_SUPPLICANT=y
+BR2_PACKAGE_WPA_SUPPLICANT_CLI=y
+BR2_PACKAGE_WPA_SUPPLICANT_PASSPHRASE=y
+BR2_TARGET_ROOTFS_EXT2=y
+BR2_TARGET_ROOTFS_EXT2_4=y
+BR2_TARGET_OPENSBI=y
+BR2_TARGET_OPENSBI_CUSTOM_GIT=y
+BR2_TARGET_OPENSBI_CUSTOM_REPO_URL="https://github.com/revyos/thead-opensbi.git"
+BR2_TARGET_OPENSBI_CUSTOM_REPO_VERSION="61d7484c752a5e4c464d5dc18e21d9ac67fbbefa"
+BR2_TARGET_OPENSBI_PLAT="generic"
+BR2_TARGET_UBOOT=y
+BR2_TARGET_UBOOT_BOARDNAME="light_lpi4a"
+BR2_TARGET_UBOOT_CUSTOM_GIT=y
+BR2_TARGET_UBOOT_CUSTOM_REPO_URL="https://github.com/revyos/thead-u-boot.git"
+BR2_TARGET_UBOOT_CUSTOM_REPO_VERSION="b5ee6e549a7b5ff382a14021a5d6a3c94017bddd"
+BR2_TARGET_UBOOT_SPL=y
+BR2_TARGET_UBOOT_SPL_NAME="u-boot-with-spl.bin"
+BR2_PACKAGE_HOST_GENIMAGE=y
+BR2_PACKAGE_HOST_MTOOLS=y