[Buildroot] [PATCH 1/1] configs/stm32f429_disco: fix kernel bootup

Dario Binacchi dariobin at libero.it
Sun Jun 6 20:13:39 UTC 2021


As described by [1], the kernel generated by the configuration for the
STM32f469 Discovery board is buggy. Using a newer kernel, as suggested
by [1], increases the dtb and Kernel image size. In particular, the
5.12 version of the kernel generates a dtb and a kernel image whose sum
exceeds the 2 MByte of the flash module.

So I decided to replace the afboot-stm32 bootloader in the flash with
U-boot to easily boot the system from sdcard without having to worry
about the size of dtb, kernel and rootfs generated by the configuration.

This solution allows you to fix the kernel boot issue and makes it
possible to use its future versions.

[1] http://buildroot-busybox.2317881.n4.nabble.com/Bug-11746-New-stm32f469-didn-t-work-correctly-td219644.html

Signed-off-by: Dario Binacchi <dariobin at libero.it>
---
 .../stm32f469-disco/extlinux.conf             |  4 +++
 .../stm32f469-disco/flash.sh                  |  4 +--
 .../stm32f469-disco/genimage.cfg              | 27 +++++++++++++++
 .../stm32f469-disco/linux.fragment            |  1 +
 ...sco-don-t-force-init-in-chosen-boota.patch | 33 -------------------
 .../stm32f469-disco/post-build.sh             |  4 +++
 .../stm32f469-disco/readme.txt                | 16 +++++++--
 configs/stm32f469_disco_defconfig             | 19 ++++++-----
 8 files changed, 62 insertions(+), 46 deletions(-)
 create mode 100644 board/stmicroelectronics/stm32f469-disco/extlinux.conf
 create mode 100644 board/stmicroelectronics/stm32f469-disco/genimage.cfg
 create mode 100644 board/stmicroelectronics/stm32f469-disco/linux.fragment
 delete mode 100644 board/stmicroelectronics/stm32f469-disco/patches/linux/0001-ARM-stm32f249-disco-don-t-force-init-in-chosen-boota.patch
 create mode 100755 board/stmicroelectronics/stm32f469-disco/post-build.sh

diff --git a/board/stmicroelectronics/stm32f469-disco/extlinux.conf b/board/stmicroelectronics/stm32f469-disco/extlinux.conf
new file mode 100644
index 0000000000..1c2db4383b
--- /dev/null
+++ b/board/stmicroelectronics/stm32f469-disco/extlinux.conf
@@ -0,0 +1,4 @@
+label stm32f469-disco-buildroot
+  kernel /zImage
+  devicetree /stm32f469-disco.dtb
+  append console=ttySTM0,115200 root=/dev/mmcblk0p2 rw rootfstype=ext2 rootwait earlyprintk consoleblank=0 ignore_loglevel
diff --git a/board/stmicroelectronics/stm32f469-disco/flash.sh b/board/stmicroelectronics/stm32f469-disco/flash.sh
index 0ec0beb2de..984d2b2599 100755
--- a/board/stmicroelectronics/stm32f469-disco/flash.sh
+++ b/board/stmicroelectronics/stm32f469-disco/flash.sh
@@ -13,8 +13,6 @@ ${OUTPUT_DIR}/host/bin/openocd -f board/stm32f469discovery.cfg \
   -c "reset init" \
   -c "flash probe 0" \
   -c "flash info 0" \
-  -c "flash write_image erase ${OUTPUT_DIR}/images/stm32f469i-disco.bin 0x08000000" \
-  -c "flash write_image erase ${OUTPUT_DIR}/images/stm32f469-disco.dtb 0x08004000" \
-  -c "flash write_image erase ${OUTPUT_DIR}/images/xipImage 0x08008000" \
+  -c "flash write_image erase ${OUTPUT_DIR}/images/u-boot.bin 0x08000000" \
   -c "reset run" \
   -c "shutdown"
diff --git a/board/stmicroelectronics/stm32f469-disco/genimage.cfg b/board/stmicroelectronics/stm32f469-disco/genimage.cfg
new file mode 100644
index 0000000000..bc945955fa
--- /dev/null
+++ b/board/stmicroelectronics/stm32f469-disco/genimage.cfg
@@ -0,0 +1,27 @@
+image boot.vfat {
+	vfat {
+		files = {
+			"zImage",
+			"stm32f469-disco.dtb",
+			"extlinux"
+		}
+	}
+	size = 16M
+}
+
+image sdcard.img {
+	hdimage {
+	}
+
+	partition u-boot {
+		partition-type = 0xC
+                image = "boot.vfat"
+	}
+
+	partition rootfs {
+		partition-type = 0x83
+		image = "rootfs.ext2"
+		size = 32M
+	}
+}
+
diff --git a/board/stmicroelectronics/stm32f469-disco/linux.fragment b/board/stmicroelectronics/stm32f469-disco/linux.fragment
new file mode 100644
index 0000000000..90f5e8a8ff
--- /dev/null
+++ b/board/stmicroelectronics/stm32f469-disco/linux.fragment
@@ -0,0 +1 @@
+# CONFIG_XIP_KERNEL is not set
\ No newline at end of file
diff --git a/board/stmicroelectronics/stm32f469-disco/patches/linux/0001-ARM-stm32f249-disco-don-t-force-init-in-chosen-boota.patch b/board/stmicroelectronics/stm32f469-disco/patches/linux/0001-ARM-stm32f249-disco-don-t-force-init-in-chosen-boota.patch
deleted file mode 100644
index 750e477dfc..0000000000
--- a/board/stmicroelectronics/stm32f469-disco/patches/linux/0001-ARM-stm32f249-disco-don-t-force-init-in-chosen-boota.patch
+++ /dev/null
@@ -1,33 +0,0 @@
-From c8f8f33c2f0460a34c9545b01a7972a7ed2df0e9 Mon Sep 17 00:00:00 2001
-From: Christophe Priouzeau <christophe.priouzeau at st.com>
-Date: Mon, 29 May 2017 13:38:16 +0200
-Subject: [PATCH] ARM: stm32f249-disco: don't force init= in /chosen/bootargs
-
-There is no reason to override the kernel's default init= value, as
-this breaks userspace that assumes the kernel default of /init is
-used. Since stm32 is often used with a minimal bootloader
-(afboot-stm32) that doesn't provide any mechanism to override the DTB,
-we need to adjust the kernel command line in the Device Tree source.
-
-Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
-Signed-off-by: Christophe Priouzeau <christophe.priouzeau at st.com>
----
- arch/arm/boot/dts/stm32f469-disco.dts | 2 +-
- 1 file changed, 1 insertion(+), 1 deletion(-)
-
-diff --git a/arch/arm/boot/dts/stm32f469-disco.dts b/arch/arm/boot/dts/stm32f469-disco.dts
-index 0dd56ef..93ee1b2 100644
---- a/arch/arm/boot/dts/stm32f469-disco.dts
-+++ b/arch/arm/boot/dts/stm32f469-disco.dts
-@@ -53,7 +53,7 @@
- 	compatible = "st,stm32f469i-disco", "st,stm32f469";
- 
- 	chosen {
--		bootargs = "root=/dev/ram rdinit=/linuxrc";
-+		bootargs = "root=/dev/ram";
- 		stdout-path = "serial0:115200n8";
- 	};
- 
--- 
-2.7.4
-
diff --git a/board/stmicroelectronics/stm32f469-disco/post-build.sh b/board/stmicroelectronics/stm32f469-disco/post-build.sh
new file mode 100755
index 0000000000..ec20fca7d9
--- /dev/null
+++ b/board/stmicroelectronics/stm32f469-disco/post-build.sh
@@ -0,0 +1,4 @@
+#!/bin/sh
+BOARD_DIR="$(dirname $0)"
+
+install -m 0644 -D $BOARD_DIR/extlinux.conf $BINARIES_DIR/extlinux/extlinux.conf
diff --git a/board/stmicroelectronics/stm32f469-disco/readme.txt b/board/stmicroelectronics/stm32f469-disco/readme.txt
index 888bff08a1..c1e1d30e69 100644
--- a/board/stmicroelectronics/stm32f469-disco/readme.txt
+++ b/board/stmicroelectronics/stm32f469-disco/readme.txt
@@ -15,5 +15,17 @@ Flashing
 
   ./board/stmicroelectronics/stm32f469-disco/flash.sh output/
 
-It will flash the minimal bootloader, the Device Tree Blob, and the
-kernel image which includes the root filesystem as initramfs.
+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/stm32f469-disco/genimage.cfg.
diff --git a/configs/stm32f469_disco_defconfig b/configs/stm32f469_disco_defconfig
index 9760d51878..8701ccbc02 100644
--- a/configs/stm32f469_disco_defconfig
+++ b/configs/stm32f469_disco_defconfig
@@ -1,19 +1,22 @@
 BR2_arm=y
 BR2_cortex_m4=y
-BR2_GLOBAL_PATCH_DIR="board/stmicroelectronics/stm32f469-disco/patches"
-BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_11=y
-BR2_ROOTFS_POST_BUILD_SCRIPT="board/stmicroelectronics/common/stm32f4xx/stm32-post-build.sh"
+BR2_ROOTFS_POST_BUILD_SCRIPT="board/stmicroelectronics/common/stm32f4xx/stm32-post-build.sh board/stmicroelectronics/stm32f469-disco/post-build.sh"
+BR2_ROOTFS_POST_IMAGE_SCRIPT="support/scripts/genimage.sh"
+BR2_ROOTFS_POST_SCRIPT_ARGS="-c board/stmicroelectronics/stm32f469-disco/genimage.cfg"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.11"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.12"
 BR2_LINUX_KERNEL_DEFCONFIG="stm32"
-BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES="$(LINUX_DIR)/arch/arm/configs/dram_0x00000000.config"
+BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES="$(LINUX_DIR)/arch/arm/configs/dram_0x00000000.config board/stmicroelectronics/stm32f469-disco/linux.fragment"
 BR2_LINUX_KERNEL_IMAGE_TARGET_CUSTOM=y
-BR2_LINUX_KERNEL_IMAGE_TARGET_NAME="xipImage"
+BR2_LINUX_KERNEL_IMAGE_TARGET_NAME="zImage"
 BR2_LINUX_KERNEL_DTS_SUPPORT=y
 BR2_LINUX_KERNEL_INTREE_DTS_NAME="stm32f469-disco"
 BR2_PACKAGE_BUSYBOX_CONFIG="package/busybox/busybox-minimal.config"
-BR2_TARGET_ROOTFS_INITRAMFS=y
+BR2_TARGET_ROOTFS_EXT2=y
+BR2_TARGET_ROOTFS_EXT2_SIZE="32M"
 # BR2_TARGET_ROOTFS_TAR is not set
-BR2_TARGET_AFBOOT_STM32=y
+BR2_TARGET_UBOOT=y
+BR2_TARGET_UBOOT_BOARD_DEFCONFIG="stm32f469-discovery"
+BR2_PACKAGE_HOST_GENIMAGE=y
 BR2_PACKAGE_HOST_OPENOCD=y
-- 
2.17.1



More information about the buildroot mailing list