configs/stm32f746_disco_sd: new defconfig

The commit adds support for STM32F746G-DISCO board. The discovery kit is
a complete demonstration and development platform for STMicroelectronics
Arm Cortex-M7-core-based STM32F746NG.

Board support package includes the following components:
- mainline Linux kernel 5.15.165
- mainline U-Boot 2024.07
- default packages from buildroot

Link: https://www.st.com/en/evaluation-tools/32f746gdiscovery.html
Co-Developed-by: Waldemar Brodkorb <wbx@openadk.org>
Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

DEVELOPERS

@@ -788,10 +788,12 @@ F:	package/xinetd/
 
 N:	Dario Binacchi <dario.binacchi@amarulasolutions.com>
 F:	board/bsh/
+F:	board/stmicroelectronics/stm32f746-disco/
 F:	board/stmicroelectronics/stm32f769-disco/
 F:	configs/imx6ulz_bsh_smm_m2_defconfig
 F:	configs/imx8mn_bsh_smm_s2_defconfig
 F:	configs/imx8mn_bsh_smm_s2_pro_defconfig
+F:	configs/stm32f746_disco_sd_defconfig
 F:	configs/stm32f769_disco_sd_defconfig
 F:	package/armadillo/
 F:	package/babeld/
@@ -3304,7 +3306,9 @@ F:	package/ngrep/
 
 N:	Waldemar Brodkorb <wbx@openadk.org>
 F:	board/qemu/riscv32-virt/
+F:	board/stmicroelectronics/stm32f746-disco/
 F:	configs/qemu_riscv32_nommu_virt_defconfig
+F:	configs/stm32f746_disco_sd_defconfig
 F:	package/asterisk/
 F:	package/evilwm/
 F:	package/fbv/

board/stmicroelectronics/stm32f746-disco/extlinux.conf

@@ -0,0 +1,4 @@
+label stm32f746-disco-buildroot
+  kernel /boot/zImage
+  devicetree /boot/stm32f746-disco.dtb
+  append console=ttySTM0,115200 root=/dev/mmcblk0p1 rw rootwait consoleblank=0 ignore_loglevel

board/stmicroelectronics/stm32f746-disco/flash_sd.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+if [ $# -eq 0 ]; then
+    OUTPUT_DIR=output
+else
+    OUTPUT_DIR=$1
+fi
+
+if ! test -d "${OUTPUT_DIR}" ; then
+    echo "ERROR: no output directory specified."
+    echo "Usage: $0 OUTPUT_DIR"
+    exit 1
+fi
+
+"${OUTPUT_DIR}"/host/bin/openocd -f board/stm32f746g-disco.cfg \
+    -c "init" \
+    -c "reset init" \
+    -c "flash probe 0" \
+    -c "flash info 0" \
+    -c "flash write_image erase ${OUTPUT_DIR}/images/u-boot.bin 0x08000000" \
+    -c "reset run" \
+    -c "shutdown"

board/stmicroelectronics/stm32f746-disco/genimage.cfg

@@ -0,0 +1,10 @@
+image sdcard.img {
+	hdimage {
+	}
+
+	partition rootfs {
+		partition-type = 0x83
+		image = "rootfs.ext2"
+		size = 32M
+	}
+}

board/stmicroelectronics/stm32f746-disco/linux.fragment

@@ -0,0 +1,13 @@
+# CONFIG_PREEMPT is not set
+# CONFIG_MULTIUSER is not set
+# CONFIG_TIMERFD is not set
+CONFIG_SET_MEM_PARAM=y
+CONFIG_DRAM_BASE=0xC0000000
+CONFIG_DRAM_SIZE=0x01000000
+# CONFIG_GCC_PLUGINS is not set
+# CONFIG_XIP_KERNEL is not set
+# CONFIG_BLK_DEV is not set
+# CONFIG_COMPAT_BRK is not set
+# CONFIG_PROC_SYSCTL is not set
+# CONFIG_CRYPTO is not set
+CONFIG_RCU_TRACE=y

board/stmicroelectronics/stm32f746-disco/patches/linux-headers/linux-headers.hash

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

board/stmicroelectronics/stm32f746-disco/patches/linux/linux.hash

@@ -0,0 +1,2 @@
+# Locally calculated
+sha256  a36dd3e82ceb634afded31f2656568f57c4d9c4b399859f298b18116df11c6fe  linux-5.15.165.tar.xz

board/stmicroelectronics/stm32f746-disco/patches/uboot/uboot.hash

@@ -0,0 +1,2 @@
+# Locally calculated
+sha256  f591da9ab90ef3d6b3d173766d0ddff90c4ed7330680897486117df390d83c8f  u-boot-2024.07.tar.bz2

board/stmicroelectronics/stm32f746-disco/post-build.sh

@@ -0,0 +1,4 @@
+#!/bin/sh
+BOARD_DIR="$(dirname "$0")"
+
+install -m 0644 -D "${BOARD_DIR}"/extlinux.conf "${TARGET_DIR}"/boot/extlinux/extlinux.conf

board/stmicroelectronics/stm32f746-disco/readme.txt

@@ -0,0 +1,31 @@
+STM32F746-DISCO
+===================
+
+This tutorial describes how to use the predefined Buildroot
+configuration for the STM32F746-DISCO evaluation platform.
+
+Building
+--------
+
+  make stm32f746_disco_sd_defconfig
+  make
+
+Flashing
+--------
+
+  ./board/stmicroelectronics/stm32f746-disco/flash_sd.sh output/
+
+It will flash the U-boot bootloader.
+
+Creating SD card
+----------------
+
+Buildroot prepares an "sdcard.img" image in the output/images/ directory,
+ready to be dumped on a SD card. Launch the following command as root:
+
+  dd if=output/images/sdcard.img of=/dev/<your-sd-device>
+
+*** WARNING! This will destroy all the card content. Use with care! ***
+
+For details about the medium image layout and its content, see the
+definition in board/stmicroelectronics/stm32f746-disco/genimage.cfg.

configs/stm32f746_disco_sd_defconfig

@@ -0,0 +1,31 @@
+BR2_arm=y
+BR2_cortex_m7=y
+BR2_BINFMT_FDPIC=y
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_5_15=y
+BR2_GLOBAL_PATCH_DIR="board/stmicroelectronics/stm32f746-disco/patches"
+BR2_DOWNLOAD_FORCE_CHECK_HASHES=y
+BR2_INIT_TINYINIT=y
+BR2_ROOTFS_POST_BUILD_SCRIPT="board/stmicroelectronics/stm32f746-disco/post-build.sh"
+BR2_ROOTFS_POST_IMAGE_SCRIPT="support/scripts/genimage.sh"
+BR2_ROOTFS_POST_SCRIPT_ARGS="-c board/stmicroelectronics/stm32f746-disco/genimage.cfg"
+BR2_LINUX_KERNEL=y
+BR2_LINUX_KERNEL_CUSTOM_VERSION=y
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.15.165"
+BR2_LINUX_KERNEL_DEFCONFIG="stm32"
+BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES="board/stmicroelectronics/stm32f746-disco/linux.fragment"
+BR2_LINUX_KERNEL_IMAGE_TARGET_CUSTOM=y
+BR2_LINUX_KERNEL_IMAGE_TARGET_NAME="zImage"
+BR2_LINUX_KERNEL_DTS_SUPPORT=y
+BR2_LINUX_KERNEL_INTREE_DTS_NAME="stm32f746-disco"
+BR2_LINUX_KERNEL_INSTALL_TARGET=y
+BR2_TARGET_ROOTFS_EXT2=y
+BR2_TARGET_ROOTFS_EXT2_SIZE="32M"
+# BR2_TARGET_ROOTFS_TAR is not set
+BR2_TARGET_UBOOT=y
+BR2_TARGET_UBOOT_BUILD_SYSTEM_KCONFIG=y
+BR2_TARGET_UBOOT_CUSTOM_VERSION=y
+BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2024.07"
+BR2_TARGET_UBOOT_BOARD_DEFCONFIG="stm32f746-disco"
+BR2_TARGET_UBOOT_NEEDS_OPENSSL=y
+BR2_PACKAGE_HOST_GENIMAGE=y
+BR2_PACKAGE_HOST_OPENOCD=y