U-Boot not storing environment in the expected EXT4 partition

I am using Yocto Kirkstone to build a system for an i.MX8 board. I need to access the U-Boot environment variables from Linux userspace. For this, I need to use fw_printenv and fw_setenv from Linux userspace, and have U-Boot also be able to write into the designated EXT4 partition (in my case it should be an EXT4 partition on MMC device 2 partition 2). My problem is that U-Boot successfully persistently stores the environment - it just does not seem to store it in the expected location. When I flash the eMMC for the i.MX8 and power the device on for the first time, I see the following: U-Boot 2022.04-compulab+g7226f0644a (Aug 26 2024 - 01:02:28 +0000) CPU: i.MX8MP rev1.1 at 1200 MHz Reset cause: POR Model: CompuLab IOT-GATE-IMX8PLUS DRAM: 4 GiB Core: 107 devices, 30 uclasses, devicetree: separate WDT: Not starting watchdog@30280000 MMC: FSL_SDHC: 2 Loading Environment from MMC... *** Warning - bad CRC, using default environment ... *** My Debug Print: Saving environment now: rootwait rw quiet console=ttymxc1,115200 cma=64M root=/dev/mapper/encrypted_fs_a usbcore.autosuspend=-1 audit=0 systemd.restore_state=0 rfkill.default_state=1 rauc.slot=rootfs_a ... Saving Environment to MMC... Writing to MMC(2)... OK bootargs=rootwait rw quiet console=ttymxc1,115200 cma=64M root=/dev/mapper/encrypted_fs_a usbcore.autosuspend=-1 audit=0 systemd.restore_state=0 rfkill.default_state=1 rauc.slot=rootfs_a 78297 bytes read in 1 ms (74.7 MiB/s) 117641056 bytes read in 424 ms (264.6 MiB/s) If I interrupt U-Boot and set some new variables, they are persistent across power cycles. Setting a new variable: iot-gate-imx8plus *** My Debug Print U-Boot => setenv name tom iot-gate-imx8plus *** My Debug PrintU-Boot => saveenv Saving Environment to MMC... Writing to MMC(2)... OK iot-gate-imx8plus *** My Debug Print U-Boot => Power cycle and query the new variable: iot-gate-imx8plus *** My Debug Print U-Boot => reset resetting ... U-Boot SPL 2022.04-compulab+g7226f0644a (Aug 26 2024 - 01:02:28 +0000) pca9450@25 [ldo4][u] = 1v8 DDRINFO: EEPROM VALID DATA [ [ cafecafe ] = 1061010 4 DDRINFO(D): Samsung 4096MB @ 3200 MHz DDRINFO: start DRAM init DDRINFO: DRAM rate 3200MTS DDRINFO:ddrphy calibration done DDRINFO: ddrmix config done DDRINFO(M): mr5-8 [ 0x1061010 ] DDRINFO(E): mr5-8 [ 0x1061010 ] Normal Boot WDT: Not starting watchdog@30280000 Boot Stage: Primary boot image offset 0x0, pagesize 0x200, ivt offset 0x0 ... switch to partitions #0, OK mmc2(part 0) is current device flash target is MMC:2 Net: eth0: ethernet@30be0000, eth1: ethernet@30bf0000 [PRIME] Fastboot: Normal starting USB... Bus usb@38100000: Register 2000140 NbrPorts 2 Starting the controller USB XHCI 1.10 Bus usb@38200000: Register 2000140 NbrPorts 2 Starting the controller USB XHCI 1.10 scanning bus usb@38100000 for devices... 1 USB Device(s) found scanning bus usb@38200000 for devices... 3 USB Device(s) found scanning usb for storage devices... 0 Storage Device(s) found Normal Boot Hit any key to stop autoboot: 0 iot-gate-imx8plus *** My Debug Print U-Boot => iot-gate-imx8plus *** My Debug Print U-Boot => printenv name name=tom iot-gate-imx8plus *** My Debug Print U-Boot => So clearly U-Boot is capable of storing my environment across reboots. However, from Linux userspace, fw_printenv does not show the same environment, and does not include this new variable. Furthermore, if I try to overwrite the name with a new value in with fw_setenv, then U-Boot will not show the change reflected from it's perspective. [device ~]$ fw_printenv name name= My fw_env.conf file looks like this: [device ~]$ cat /etc/fw_env.config /bootenv/u-boot-initial-env-sd 0x0000 0x4000 The 'bootenv' mount is on mmc dev 2 partition 2: [device ~]$ mount | grep booten /dev/mmcblk2p2 on /bootenv type ext4 (rw,relatime) No errors are thrown from either U-Boot or Linux fw_setenv/fw_printenv when they read or modify the U-Boot environment, but changes in either are not considered from the other's perspective. Therefore they are somehow not considering the same storage location. So far I have been unable to determine where U-Boot is exactly storing it's environment persistently. I have configured U-Boot to store the environment in the EXT4 partition primarily with the following configuration options: CONFIG_ENV_IS_IN_EXT4=y CONFIG_ENV_EXT4_INTERFACE="mmc" CONFIG_ENV_EXT4_DEVICE_AND_PART="2:2" CONFIG_ENV_EXT4_FILE="/u-boot-initial-env-sd" CONFIG_SYS_REDUNDAND_ENVIRONMENT=n CONFIG_USE_DEFAULT_ENV_FILE="/u-boot-initial-env-sd" CONFIG_ENV_IS_NOWHERE=y" CONFIG_ENV_IS_IN_MMC=y CONFIG_SYS_MMC_ENV_DEV=2 CONFIG_SYS_MMC_ENV_PART=2 Complete U-Boot environment related portion of ".config" file for compilation: # # Environment # CONFIG_ENV_SUPPORT=y CONFIG_ENV_SOURCE_FILE="" CONFIG_SAVEENV=y # CONFIG_ENV_OVERWRITE is not set CONFIG_ENV_IS_NOWHERE=y # CONFIG_ENV_IS_IN_EEPROM is not set # CONFIG_ENV_IS_IN_FAT is not set CONFIG_ENV_IS_IN_EXT4=y # CONFIG_ENV_IS_IN_FLASH is not set CONFIG_ENV_IS_IN_MMC=y # CONFIG_ENV_IS_IN_NAND is not set # CONFIG_ENV_IS_IN_NVRAM is not set # CONFIG_ENV_IS_IN_ONENAND is not set # CONFIG_ENV_IS_IN_REMOTE is not set # CONFIG_ENV_IS_IN_SATA is not set # CONFIG_ENV_IS_IN_SPI_FLASH is not set # CONFIG_SYS_REDUNDAND_ENVIRONMENT is not set CONFIG_ENV_EXT4_INTERFACE="mmc" CONFIG_ENV_EXT4_DEVICE_AND_PART="2:2" CONFIG_ENV_EXT4_FILE="/u-boot-initial-env-sd" CONFIG_SYS_RELOC_GD_ENV_ADDR=y CONFIG_SYS_MMC_ENV_DEV=2 CONFIG_SYS_MMC_ENV_PART=2 # CONFIG_USE_DEFAULT_ENV_FILE is not set CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y # CONFIG_ENV_IMPORT_FDT is not set # CONFIG_ENV_APPEND is not set # CONFIG_ENV_WRITEABLE_LIST is not set # CONFIG_ENV_ACCESS_IGNORE_FORCE is not set # CONFIG_VERSION_VARIABLE is not set CONFIG_NET=y CONFIG_PROT_UDP=y # CONFIG_BOOTP_SEND_HOSTNAME is not set CONFIG_NET_RANDOM_ETHADDR=y # CONFIG_NETCONSOLE is not set # CONFIG_IP_DEFRAG is not set CONFIG_TFTP_BLOCKSIZE=1468 CONFIG_TFTP_WINDOWSIZE=1 # CONFIG_TFTP_TSIZE is not set # CONFIG_SERVERIP_FROM_PROXYDHCP is not set CONFIG_SERVERIP_FROM_PROXYDHCP_DELAY_MS=100 # CONFIG_KEEP_SERVERADDR is not set # CONFIG_UDP_CHECKSUM is not set # CONFIG_BOOTP_SERVERIP is not set How can I determine where U-Boot is storing the persistent environment and debug the disconnect between Linux userspace and U-Boot? UPDATE: I have a hunch that there is some misconfiguration in U-Boot since I am seeing the following: Loading Environment from MMC... OK When I would expect to see this for EXT4: Loading Environment from EXT4... OK The same for 'saveenv' from U-Boot. It refers to MMC and not EXT4: iot-gate-imx8plus *** My Debug U-Boot => saveenv Saving Environment to MMC... Writing to MMC(2)... OK I would expect the following: Saving Environment to EXT4...