U-Boot errors when trying to enable Falcon mode on BeagleBone Black

I have been having trouble enabling Falcon mode on the BeagleBone Black. I have a working U-Boot (v2019.04) and Linux (Debian 11.5, kernel v5.15.65-bone-rt-r30), but I have been unsuccessful thus far in enabling Falcon mode. There are several errors I have come across. The first is when I attempt to save the environment:

=> saveenv
Saving Environment to EXT4...
** Unable to use mmc 0:1 for saveenv **
Failed (1)

The second is when I try to export the SPL. It correctly reads the uImage header:

=> spl export fdt ${loadaddr} - ${fdtaddr}
## Booting kernel from Legacy Image at 82000000 ...
   Image Name:   Linux kernel
   Created:      2022-10-26  17:38:41 UTC
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    9880064 Bytes = 9.4 MiB
   Load Address: 80008000
   Entry Point:  80008000

But then it has a checksum error and doesn’t finish the process:

Verifying Checksum ... Bad Data CRC
ERROR: can't get kernel image!
   XIP Invalid Image ... OK
data abort

This is my full U-Boot console log:

CPU  : AM335X-GP rev 2.1
I2C:   ready
DRAM:  512 MiB
No match for driver 'omap_hsmmc'
No match for driver 'omap_hsmmc'
Some drivers were not found
Reset Source: Global external warm reset has occurred.
Reset Source: Global warm SW reset has occurred.
Reset Source: Power-on reset has occurred.
RTC 32KCLK Source: External.
MMC:   OMAP SD/MMC: 0, OMAP SD/MMC: 1
Loading Environment from EXT4...
** Unable to use mmc 0:1 for loading the env **
Board: BeagleBone Black
 not set. Validating first E-fuse MAC
BeagleBone Black:
Model: BeagleBone Black Industrial:
BeagleBone Cape EEPROM: no EEPROM at address: 0x54
BeagleBone Cape EEPROM: no EEPROM at address: 0x55
BeagleBone Cape EEPROM: no EEPROM at address: 0x56
BeagleBone Cape EEPROM: no EEPROM at address: 0x57
Net:   eth0: MII MODE
cpsw, usb_ether
Press SPACE to abort autoboot in 2 seconds
=>
=> setenv args_mmc 'setenv bootargs console=${console} ${optargs} root=/dev/mmcblk0p1 ro rootfstype=${mmcrootfstype}'
=> setenv loadfdt 'mmc read ${fdtaddr} 80 180'
=> setenv loadimage 'mmc read ${loadaddr} 900 2000'
=> setenv bootcmd 'run args_mmc; run loadfdt; run loadimage; bootm ${loadaddr} - ${fdtaddr}'
=> saveenv
Saving Environment to EXT4...
** Unable to use mmc 0:1 for saveenv **
Failed (1)
=> run args_mmc
=> run loadimage

MMC read: dev # 0, block # 2304, count 8192 ... 8192 blocks read: OK
=> run loadfdt

MMC read: dev # 0, block # 128, count 384 ... 384 blocks read: OK
=> spl export fdt ${loadaddr} - ${fdtaddr}
## Booting kernel from Legacy Image at 82000000 ...
   Image Name:   Linux kernel
   Created:      2022-10-26  17:38:41 UTC
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    9880064 Bytes = 9.4 MiB
   Load Address: 80008000
   Entry Point:  80008000
   Verifying Checksum ... Bad Data CRC
ERROR: can't get kernel image!
   XIP Invalid Image ... OK
data abort
pc : []          lr : []
reloc pc : []    lr : []
sp : 9df38b88  ip : 00000000     fp : 00000006
r10: 00000003  r9 : 9df38eb8     r8 : 9df38c6c
r7 : 00000000  r6 : 9ffc0238     r5 : 00000000  r4 : 00000000
r3 : 00000020  r2 : 00000000     r1 : 00000000  r0 : 00000000
Flags: Nzcv  IRQs off  FIQs on  Mode SVC_32
Code: f7fe2000 2800fc91 e7f4d0ed 9ff9f6a8 (4a106803)
Resetting CPU ...

resetting ...

I am following the tutorial https://embetrix.com/2017/05/07/fast-boot-linux-with-u-boot-falcon-mode/ (except that I am compiling everything on an Ubuntu server and writing the SD card directly from the BeagleBone Black in Debian, so I skip the section with the five “part” commands in Yocto–hopefully that’s not a problem), so it’s possible there is an error in the tutorial or in my environment in some way. Perhaps there is a timeout issue when reading the kernel, or my device tree file is wrong? I created the uImage from a working zImage, and the uImage header is being read appropriately, so I’m not sure what the issue is. Any help would be greatly appreciated. EDIT: At the suggestion below I changed the config to no longer use the EXT4 filesystem. My environment variables now save, which is great! Unfortunately the kernel checksum problem still persists. My current U-Boot log is below:

U-Boot SPL 2022.04 (Nov 03 2022 - 11:40:28 -0400)
Trying to boot from MMC2


U-Boot 2022.04 (Nov 03 2022 - 11:40:28 -0400)

CPU : AM335X-GP rev 2.1
Model: TI AM335x BeagleBone Black
DRAM: 512 MiB
Reset Source: Power-on reset has occurred.
RTC 32KCLK Source: External.
Core: 150 devices, 14 uclasses, devicetree: separate
WDT: Started wdt@44e35000 with servicing (60s timeout)
MMC: OMAP SD/MMC: 0, OMAP SD/MMC: 1
Loading Environment from MMC... *** Warning - bad CRC, using default environment

Board: BeagleBone Black
 not set. Validating first E-fuse MAC
BeagleBone Black:
Model: BeagleBone Black Industrial:
BeagleBone Cape EEPROM: no EEPROM at address: 0x54
BeagleBone Cape EEPROM: no EEPROM at address: 0x55
BeagleBone Cape EEPROM: no EEPROM at address: 0x56
BeagleBone Cape EEPROM: no EEPROM at address: 0x57
Net: Could not get PHY for ethernet@4a100000: addr 0
eth2: ethernet@4a100000, eth3: usb_ether
Press SPACE to abort autoboot in 0 seconds
=> setenv args_mmc 'setenv bootargs console=${console} ${optargs} root=/dev/mmcblk0p1 ro rootfstype=${mmcrootfstype}'
=> setenv loadfdt 'mmc read ${fdtaddr} 80 180'
=> setenv loadimage 'mmc read ${loadaddr} 900 2000'
=> setenv bootcmd 'run args_mmc; run loadfdt; run loadimage; bootm ${loadaddr} - ${fdtaddr}'
=> saveenv
Saving Environment to MMC... Writing to redundant MMC(0)... OK
=> run args_mmc
=> run loadimage

MMC read: dev # 0, block # 2304, count 8192 ... 8192 blocks read: OK
=> run loadfdt

MMC read: dev # 0, block # 128, count 384 ... 384 blocks read: OK
=> spl export fdt ${loadaddr} - ${fdtaddr}
## Booting kernel from Legacy Image at 82000000 ...
Image Name: Linux kernel
Created: 2022-10-26 17:38:41 UTC
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 9880064 Bytes = 9.4 MiB
Load Address: 80008000
Entry Point: 80008000
Verifying Checksum ... Bad Data CRC
ERROR: can't get kernel image!
XIP Invalid Image
data abort
pc : [] lr : []
reloc pc : [] lr : []
sp : 9df30e08 ip : 00000000 fp : 00000020
r10: 00000003 r9 : 9df45eb0 r8 : 9df30f04
r7 : 00000000 r6 : 9ffe3b1c r5 : 00000000 r4 : 00000000
r3 : edfe0dd0 r2 : 00000003 r1 : 00000000 r0 : 00000000
Flags: nzCv IRQs off FIQs on Mode SVC_32 (T)
Code: bfef 0000 b510 4b24 (6801) 4602
Resetting CPU ...

resetting ...