Hardware & Software Setup
- Board: Toradex Apalis iMX8QM V1.1
- BSP Version: toradex-bsp-6.7.0 (trying to integrate with toradex-bsp-6.2.0 for Mender)
- Mender Setup: Using meta-mender-community/meta-mender-toradex
- Kernel: Linux 5.15.148-6.7.0-devel
Problem Description
I have a Cortex-M4 firmware that handles CAN communication. It works perfectly without Mender, but stops functioning properly after Mender OTA integration.
What Works:
M4 firmware loads from rootfs via U-Boot
M4 starts successfully (bootaux complete)
M4 sends initialization messages (“hello world”)
RPMSG channel established (/dev/ttyRPMSG30 exists)
Mender OTA updates work correctly
What Doesn’t Work:
M4 appears to stop after sending initial messages
No further RPMSG communication
CAN functionality doesn’t work
Key Observations
1. Memory Reservation Issue:
[ 0.000000] OF: fdt: Reserved memory: failed to reserve memory for node 'm4@88000000': base 0x0000000088000000, size 128 MiB
2. Device Tree has the reservation:
$ cat /sys/firmware/devicetree/base/reserved-memory/m4@88000000/reg | hexdump -C
00000000 00 00 00 00 88 00 00 00 00 00 00 00 08 00 00 00
(Correctly shows: base=0x88000000, size=128MB)
3. Boot logs show M4 working initially:
[ 3.875948] imx_rpmsg_tty virtio3.rpmsg-virtual-tty-channel.-1.30: new channel: 0x400 -> 0x1e!
[ 3.886594] rpmsg_tty_cb68 65 6c 6c 6f 20 77 6f 72 6c 64 21 hello world!
Then silence - no further messages.
My Configuration
U-Boot Environment (working):
/* Boot M4 */
#define M4_BOOT_ENV \
- "m4_0_image=m4_0.bin\0" \
+ "m4_0_image=/home/pixii/Cortex_M4/pixii_lls.bin\0" \
"m4_1_image=m4_1.bin\0" \
- "loadm4image_0=fatload mmc 0:1 ${loadaddr} ${m4_0_image}\0" \
+ "loadm4image_0=ext4load mmc 0:2 ${loadaddr} ${m4_0_image}\0" \
"loadm4image_1=fatload mmc 0:1 ${loadaddr} ${m4_1_image}\0" \
"m4boot_0=run loadm4image_0; dcache flush; bootaux ${loadaddr} 0\0" \
- "m4boot_1=run loadm4image_1; dcache flush; bootaux ${loadaddr} 1\0" \
+ "m4boot_1=run loadm4image_1; dcache flush; bootaux ${loadaddr} 1\0"
/* Enable Distro Boot */
#define BOOT_TARGET_DEVICES(func) \
@@ -39,6 +39,7 @@
/* Initial environment variables */
#define CONFIG_EXTRA_ENV_SETTINGS \
+ "bootcmd=run m4boot_0; run distro_bootcmd\0" \
BOOTENV \
M4_BOOT_ENV \
MEM_LAYOUT_ENV_SETTINGS \
U-Boot defconfig:
CONFIG_ARM=y
CONFIG_ARCH_IMX8=y
CONFIG_SYS_TEXT_BASE=0x80020000
CONFIG_SYS_MALLOC_LEN=0x2800000
CONFIG_SYS_MALLOC_F_LEN=0x8000
CONFIG_NR_DRAM_BANKS=3
CONFIG_SYS_MEMTEST_START=0x88000000
CONFIG_SYS_MEMTEST_END=0x89000000
CONFIG_ENV_SIZE=0x4000
CONFIG_ENV_OFFSET=0x800000
CONFIG_ENV_OFFSET_REDUND=0x1000000
CONFIG_SYS_REDUNDAND_ENVIRONMENT=y
CONFIG_DM_GPIO=y
CONFIG_DEFAULT_DEVICE_TREE="fsl-imx8qm-apalis"
CONFIG_BOOTAUX_RESERVED_MEM_BASE=0x88000000
CONFIG_BOOTAUX_RESERVED_MEM_SIZE=0x08000000
CONFIG_TARGET_APALIS_IMX8=y
CONFIG_IMX_SNVS_SEC_SC=y
CONFIG_IMX_BOOTAUX=y
CONFIG_DISTRO_DEFAULTS=y
CONFIG_REMAKE_ELF=y
CONFIG_SYS_LOAD_ADDR=0x95400000
# CONFIG_FIT is not set
CONFIG_OF_SYSTEM_SETUP=y
CONFIG_BOOTDELAY=0
CONFIG_ZERO_BOOTDELAY_CHECK=y
CONFIG_SILENT_CONSOLE=y
CONFIG_SILENT_CONSOLE_UPDATE_ON_RELOC=y
CONFIG_SYS_DEVICE_NULLDEV=y
CONFIG_SILENT_CONSOLE_UPDATE_ON_SET=y
CONFIG_SILENT_U_BOOT_ONLY=y
CONFIG_USE_PREBOOT=y
CONFIG_PREBOOT="test -n ${fdtfile} || setenv fdtfile ${soc}-apalis${variant}-${fdt_board}.dtb"
CONFIG_LOG=y
# CONFIG_DISPLAY_BOARDINFO is not set
CONFIG_DISPLAY_BOARDINFO_LATE=y
CONFIG_BOARD_EARLY_INIT_F=y
CONFIG_SYS_PROMPT="Apalis iMX8 # "
CONFIG_CMD_CPU=y
# CONFIG_BOOTM_NETBSD is not set
CONFIG_CMD_ASKENV=y
CONFIG_CMD_BMP=y
CONFIG_CMD_MEMTEST=y
CONFIG_CMD_CLK=y
CONFIG_CMD_DM=y
CONFIG_CMD_FUSE=y
#CONFIG_CMD_GPIO is not set
CONFIG_CMD_I2C=y
CONFIG_CMD_MMC=y
# CONFIG_CMD_USB is not set
# CONFIG_CMD_USB_MASS_STORAGE is not set
CONFIG_CMD_CACHE=y
CONFIG_CMD_UUID=y
CONFIG_CMD_EXT4_WRITE=y
CONFIG_ENV_OVERWRITE=y
CONFIG_ENV_IS_IN_MMC=y
CONFIG_SYS_RELOC_GD_ENV_ADDR=y
CONFIG_SYS_MMC_ENV_PART=0
CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
CONFIG_VERSION_VARIABLE=y
CONFIG_IP_DEFRAG=y
# CONFIG_TFTP_BLOCKSIZE is not set
# CONFIG_TFTP_TSIZE is not set
CONFIG_BOOTCOUNT_LIMIT=y
CONFIG_BOOTCOUNT_ENV=y
CONFIG_CLK_IMX8=y
CONFIG_CPU=y
CONFIG_USB_FUNCTION_FASTBOOT=y
CONFIG_FASTBOOT_BUF_ADDR=0x82800000
CONFIG_FASTBOOT_BUF_SIZE=0x08000000
CONFIG_FASTBOOT_FLASH=y
# CONFIG_GPIO_HOG is not set
CONFIG_MXC_GPIO=y
CONFIG_DM_I2C=y
CONFIG_SYS_I2C_IMX_LPI2C=y
CONFIG_MISC=y
CONFIG_SUPPORT_EMMC_BOOT=y
CONFIG_FSL_USDHC=y
CONFIG_PHYLIB=y
CONFIG_PHY_ADDR_ENABLE=y
# CONFIG_PHY_MICREL is not set
# CONFIG_PHY_MICREL_KSZ90X1 is not set
# CONFIG_DM_ETH is not set
# CONFIG_FEC_MXC_SHARE_MDIO is not set
# CONFIG_FEC_MXC_MDIO_BASE is not set
# CONFIG_FEC_MXC is not set
# CONFIG_MII is not set
# CONFIG_PHY is not set
CONFIG_CDNS3_USB_PHY=y
# CONFIG_PINCTRL is not set
# CONFIG_PINCTRL_IMX8 is not set
CONFIG_POWER_DOMAIN=y
CONFIG_IMX8_POWER_DOMAIN=y
CONFIG_DM_REGULATOR=y
CONFIG_DM_REGULATOR_FIXED=y
CONFIG_DM_REGULATOR_GPIO=y
CONFIG_DM_SERIAL=y
CONFIG_FSL_LPUART=y
CONFIG_DM_THERMAL=y
CONFIG_IMX_SCU_THERMAL=y
CONFIG_USB=y
CONFIG_USB_XHCI_HCD=y
CONFIG_USB_CDNS3=y
CONFIG_USB_CDNS3_GADGET=y
CONFIG_USB_GADGET=y
CONFIG_USB_GADGET_MANUFACTURER="Toradex"
CONFIG_USB_GADGET_VENDOR_NUM=0x1b67
CONFIG_USB_GADGET_PRODUCT_NUM=0x4000
CONFIG_CI_UDC=y
CONFIG_USB_PORT_AUTO=y
CONFIG_OF_LIBFDT_OVERLAY=y
# CONFIG_EFI_LOADER is not set
CONFIG_USE_PREBOOT=y
CONFIG_PREBOOT="setenv fdtfile ${mender_dtb_name}"
CONFIG_CMD_BOOTCOUNT=y
CONFIG_BOOTCOUNT_LIMIT=y
CONFIG_BOOTCOUNT_ENV=y
CONFIG_REGMAP=y
CONFIG_SYSCON=y
CONFIG_DM_PWM=y
CONFIG_VIDEO=y
CONFIG_DM_VIDEO=y
CONFIG_BACKLIGHT_GPIO=y
CONFIG_VIDEO_IMXDPUV1=y
CONFIG_VIDEO_IMX8_LVDS=y
CONFIG_VIDEO_LOGO=y
CONFIG_SPLASH_SCREEN=y
CONFIG_SPLASH_SOURCE=y
CONFIG_SPLASH_SCREEN_ALIGN=y
CONFIG_BMP_16BPP=y
CONFIG_BMP_24BPP=y
CONFIG_BMP_32BPP=y
# CONFIG_CFB_CONSOLE is not set
local.conf (Mender settings):
# Mender Artifact name
MENDER_ARTIFACT_NAME = "test-v1.0"
# specify bsp version
TORADEX_BSP_VERSION="toradex-bsp-6.2.0"
#MENDER CONFIGURATIONS
INHERIT += "mender-full"
INHERIT += "mender-toradex"
DISTRO_FEATURES:append = " systemd"
VIRTUAL-RUNTIME_init_manager = "systemd"
DISTRO_FEATURES_BACKFILL_CONSIDERED = "sysvinit"
VIRTUAL-RUNTIME_initscripts = ""
# Comment/remove below to enable GRUB integration instead of U-Boot
MENDER_FEATURES_ENABLE:append = " mender-uboot mender-image mender-image-sd"
MENDER_FEATURES_DISABLE:append = " mender-grub mender-image-uefi"
IMAGE_CLASSES += "image_type_mender_tezi"
IMAGE_FSTYPES:append = " mender_tezi"
IMAGE_FSTYPES:remove = " teziimg"
IMAGE_INSTALL:append = " kernel-image kernel-devicetree"
# Remove files from boot partition that are loaded by Mender
# from the root partitions; this allows the files to be updated OTA
IMAGE_BOOT_FILES:remove:mender-uboot = "zImage ${KERNEL_DEVICETREE} overlays.txt overlays/*;overlays/"
# Settings for apalis-imx8
#
MENDER_IMAGE_BOOTLOADER_BOOTSECTOR_OFFSET:apalis-imx8 = "0"
OFFSET_SPL_PAYLOAD:apalis-imx8 = ""
MENDER_BOOT_PART_SIZE_MB:apalis-imx8 = "32"
MENDER_STORAGE_TOTAL_SIZE_MB:apalis-imx8 = "12288"
KERNEL_DEVICETREE:apalis-imx8 = "freescale/imx8qm-apalis-v1.1-ixora-v1.2.dtb"
MENDER_STORAGE_DEVICE:apalis-imx8 = "/dev/mmcblk0"
MENDER_BOOT_PART = "${MENDER_STORAGE_DEVICE_BASE}1"
MENDER_DATA_PART = "${MENDER_STORAGE_DEVICE_BASE}4"
MENDER_ROOTFS_PART_A = "${MENDER_STORAGE_DEVICE_BASE}2"
MENDER_ROOTFS_PART_B = "${MENDER_STORAGE_DEVICE_BASE}3"
# Append the Mender provided bootargs to tdxargs
# the Toradex boot.scr will overwrite bootargs so we stash the context in tdxargs
MENDER_UBOOT_POST_SETUP_COMMANDS:append = " ; setenv tdxargs \${tdxargs} \${bootargs}; "
# Make sure the Toradex boot script finds the overlays and overlays.txt file in
# the /boot directory of the rootfs partition
MENDER_UBOOT_POST_SETUP_COMMANDS:append = " ; setenv overlays_file /boot/overlays.txt ; setenv overlays_prefix boot/overlays/ "
#meta-mender-validation configuration
MENDER_FEATURES_ENABLE:append = " mender-prepopulate-inactive-partition"
IMAGE_INSTALL:append = " bootloader-validation"
#Mender Update Modules
IMAGE_INSTALL:append = " mender-ipk mender-rootfs-version-check mender-qt"
Questions
-
Is the “failed to reserve memory” warning expected when M4 is loaded by U-Boot? Or does this indicate Linux might be using M4’s memory?
-
Does Mender’s partition layout affect M4 memory regions? The M4 works without Mender, suggesting something in Mender’s configuration interferes.
-
Should I add
no-mapproperty to the M4 reserved-memory node? Would this prevent Linux from accessing M4’s memory? -
Has anyone successfully integrated M4 firmware with Mender on i.MX8? Any specific configurations needed?
What I’ve Tried
- Loading M4 firmware from rootfs using
${mender_uboot_root}(dynamic partition) - Using dedicated M4 load address (0x88000000) separate from kernel
- Running M4 load in
prebootbefore Mender’s bootcmd - Verified device tree overlays load correctly (including CAN overlay)
- Not yet tried: kernel command line
memmap=128M$0x88000000
Additional Information
M4 firmware binary is in rootfs at /home/pixii/Cortex_M4/pixii_lls.bin and loads successfully (74KB file).
Any guidance would be greatly appreciated! Is this a known issue with Toradex + Mender + M4 integration?
References
- meta-mender-community: meta-mender-toradex-nxp
- BSP: toradex-bsp-6.7.0
- Board: apalis-imx8
