I have an application that has been working great on the rev C boards - it boots from the SD card and is based on Buster release, and upgrading to the latest would be a LOT of rework. Here’s my problem; I got a rev D board and it won’t boot. I have removed overlay references to BB-HDMI_TDA998x and BB-NDHMI-TDA998x ; the serial console gets to ‘Starting kernel …’ and then no output.
uboot_overlays: loading /lib/firmware/AM335X-PRU-RPROC-4-19-TI-00A0.dtbo ...
3801 bytes read in 12 ms (308.6 KiB/s)
loading /boot/initrd.img-4.19.94-ti-r34 ...
5019975 bytes read in 324 ms (14.8 MiB/s)
debug: [console=ttyS0,115200n8 bone_capemgr.uboot_capemgr_enabled=1 root=/dev/mmcblk0p1 ro rootfstype=ext4 rootwait coherent_pool=1M net.ifnames=0 lpj=1990656 rng_core.default_quality=100 quiet logo.nologo vt.global_cursor_default=0] ...
debug: [bootz 0x82000000 0x88080000:4c9947 88000000] ...
Kernel image @ 0x82000000 [ 0x000000 - 0x9d9200 ]
## Flattened Device Tree blob at 88000000
Booting using the fdt blob at 0x88000000
Loading Ramdisk to 8fb36000, end 8ffff947 ... OK
Loading Device Tree to 8faaa000, end 8fb35fff ... OK
Starting kernel ...
Any ideas of how to get some debug out of the kernel boot?
Can you please share the full boot log, i’ve been backporting things for rev d, let’s see what u-boot was doing..
Regards,
So I removed the driver to the TDA998x to see if the kernel would just ignore the error and move forward, no such luck. Here’s what I was seeing.
U-Boot SPL 2022.04-gc6f4cf7d (Apr 24 2025 - 03:22:59 +0000)
Trying to boot from MMC2
U-Boot 2022.04-gc6f4cf7d (Apr 24 2025 - 03:22:59 +0000)
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 EXT4... ** File not found /boot/uboot.env **
** Unable to read "/boot/uboot.env" from mmc0:1 **
Board: BeagleBone Black
<ethaddr> not set. Validating first E-fuse MAC
BeagleBone Black:
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: eth2: ethernet@4a100000, eth3: usb_ether
Press SPACE to abort autoboot in 0 seconds
board_name=[A335BNLT] ...
board_rev=[00D0] ...
switch to partitions #0, OK
mmc0 is current device
SD/MMC found on device 0
Couldn't find partition 0:2 0x82000000
Can't set block device
Couldn't find partition 0:2 0x82000000
Can't set block device
switch to partitions #0, OK
mmc0 is current device
Scanning mmc 0:1...
libfdt fdt_check_header(): FDT_ERR_BADMAGIC
Scanning disk mmc@48060000.blk...
Scanning disk mmc@481d8000.blk...
Found 6 disks
No EFI system partition
BootOrder not defined
EFI boot manager: Cannot load any image
gpio: pin 56 (gpio 56) value is 0
gpio: pin 55 (gpio 55) value is 0
gpio: pin 54 (gpio 54) value is 0
gpio: pin 53 (gpio 53) value is 1
switch to partitions #0, OK
mmc0 is current device
gpio: pin 54 (gpio 54) value is 1
Checking for: /uEnv.txt ...
Checking for: /boot/uEnv.txt ...
gpio: pin 55 (gpio 55) value is 1
2176 bytes read in 4 ms (531.3 KiB/s)
Loaded environment from /boot/uEnv.txt
Checking if uname_r is set in /boot/uEnv.txt...
gpio: pin 56 (gpio 56) value is 1
Running uname_boot ...
loading /boot/vmlinuz-4.19.94-ti-r34 ...
10326528 bytes read in 656 ms (15 MiB/s)
debug: [enable_uboot_overlays=1] ...
debug: [enable_uboot_cape_universal=1] ...
debug: [uboot_base_dtb_univ=am335x-boneblack-uboot-univ.dtb] ...
uboot_overlays: [uboot_base_dtb=am335x-boneblack-uboot-univ.dtb] ...
uboot_overlays: Switching too: dtb=am335x-boneblack-uboot-univ.dtb ...
loading /boot/dtbs/4.19.94-ti-r34/am335x-boneblack-uboot-univ.dtb ...
162266 bytes read in 16 ms (9.7 MiB/s)
Found 0 extension board(s).
uboot_overlays: [fdt_buffer=0x60000] ...
uboot_overlays: loading /lib/firmware/BB-ADC-00A0.dtbo ...
867 bytes read in 6 ms (140.6 KiB/s)
uboot_overlays: loading /lib/firmware/MY_BBY_UART124-00A0.dtbo ...
3007 bytes read in 10 ms (293 KiB/s)
uboot_overlays: loading /lib/firmware/BB-I2C2-RTC-DS1307.dtbo ...
785 bytes read in 6 ms (127 KiB/s)
uboot_overlays: loading /lib/firmware/BB-SPIDEV1-00A0.dtbo ...
1709 bytes read in 11 ms (151.4 KiB/s)
uboot_overlays: loading /lib/firmware/BB-BONE-eMMC1-01-00A0.dtbo ...
1584 bytes read in 9 ms (171.9 KiB/s)
uboot_overlays: uboot loading of [BB-HDMI-TDA998x-00A0.dtbo] disabled by /boot/uEnv.txt [disable_uboot_overlay_audio=1]...
uboot_overlays: unable to find [mmc 0:1 BB-NHDMI-TDA998x-00A0.dtbo]...
uboot_overlays: loading /lib/firmware/AM335X-PRU-RPROC-4-19-TI-00A0.dtbo ...
3801 bytes read in 12 ms (308.6 KiB/s)
loading /boot/initrd.img-4.19.94-ti-r34 ...
5019975 bytes read in 324 ms (14.8 MiB/s)
debug: [console=ttyS0,115200n8 bone_capemgr.uboot_capemgr_enabled=1 root=/dev/mmcblk0p1 ro rootfstype=ext4 rootwait coherent_pool=1M net.ifnames=0 lpj=1990656 rng_core.default_quality=100 quiet logo.nologo vt.global_cursor_default=0] ...
debug: [bootz 0x82000000 0x88080000:4c9947 88000000] ...
Kernel image @ 0x82000000 [ 0x000000 - 0x9d9200 ]
## Flattened Device Tree blob at 88000000
Booting using the fdt blob at 0x88000000
Loading Ramdisk to 8fb36000, end 8ffff947 ... OK
Loading Device Tree to 8faaa000, end 8fb35fff ... OK
Starting kernel ...
Please remove quiet from your boot argument… It’s following the old rev c path like we wanted, but something else is breaking kernel boot up..
PS, what OS (Debian xyz) is this, i’m digging up old userspaces as 4.19.x doesn’t really like Debian 13.. 
duh Buster!
Ok so I removed the ‘quiet’ from the cmd line in /boot/uEnv.txt but the output looks eerily similar. Is there something else I need to change?
U-Boot SPL 2022.04-gc6f4cf7d (Apr 24 2025 - 03:22:59 +0000)
Trying to boot from MMC2
U-Boot 2022.04-gc6f4cf7d (Apr 24 2025 - 03:22:59 +0000)
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 EXT4... ** File not found /boot/uboot.env **
** Unable to read "/boot/uboot.env" from mmc0:1 **
Board: BeagleBone Black
<ethaddr> not set. Validating first E-fuse MAC
BeagleBone Black:
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: eth2: ethernet@4a100000, eth3: usb_ether
Press SPACE to abort autoboot in 0 seconds
board_name=[A335BNLT] ...
board_rev=[00D0] ...
switch to partitions #0, OK
mmc0 is current device
SD/MMC found on device 0
Couldn't find partition 0:2 0x82000000
Can't set block device
Couldn't find partition 0:2 0x82000000
Can't set block device
switch to partitions #0, OK
mmc0 is current device
Scanning mmc 0:1...
libfdt fdt_check_header(): FDT_ERR_BADMAGIC
Scanning disk mmc@48060000.blk...
Scanning disk mmc@481d8000.blk...
Found 5 disks
No EFI system partition
BootOrder not defined
EFI boot manager: Cannot load any image
gpio: pin 56 (gpio 56) value is 0
gpio: pin 55 (gpio 55) value is 0
gpio: pin 54 (gpio 54) value is 0
gpio: pin 53 (gpio 53) value is 1
switch to partitions #0, OK
mmc0 is current device
gpio: pin 54 (gpio 54) value is 1
Checking for: /uEnv.txt ...
Checking for: /boot/uEnv.txt ...
gpio: pin 55 (gpio 55) value is 1
2169 bytes read in 4 ms (529.3 KiB/s)
Loaded environment from /boot/uEnv.txt
Checking if uname_r is set in /boot/uEnv.txt...
gpio: pin 56 (gpio 56) value is 1
Running uname_boot ...
loading /boot/vmlinuz-4.19.94-ti-r34 ...
10326528 bytes read in 655 ms (15 MiB/s)
debug: [enable_uboot_overlays=1] ...
debug: [enable_uboot_cape_universal=1] ...
debug: [uboot_base_dtb_univ=am335x-boneblack-uboot-univ.dtb] ...
uboot_overlays: [uboot_base_dtb=am335x-boneblack-uboot-univ.dtb] ...
uboot_overlays: Switching too: dtb=am335x-boneblack-uboot-univ.dtb ...
loading /boot/dtbs/4.19.94-ti-r34/am335x-boneblack-uboot-univ.dtb ...
162266 bytes read in 14 ms (11.1 MiB/s)
Found 0 extension board(s).
uboot_overlays: [fdt_buffer=0x60000] ...
uboot_overlays: loading /lib/firmware/BB-ADC-00A0.dtbo ...
867 bytes read in 6 ms (140.6 KiB/s)
uboot_overlays: loading /lib/firmware/MY_BBY_UART124-00A0.dtbo ...
3007 bytes read in 10 ms (293 KiB/s)
uboot_overlays: loading /lib/firmware/BB-I2C2-RTC-DS1307.dtbo ...
785 bytes read in 5 ms (153.3 KiB/s)
uboot_overlays: loading /lib/firmware/BB-SPIDEV1-00A0.dtbo ...
1709 bytes read in 11 ms (151.4 KiB/s)
uboot_overlays: loading /lib/firmware/BB-BONE-eMMC1-01-00A0.dtbo ...
1584 bytes read in 9 ms (171.9 KiB/s)
uboot_overlays: uboot loading of [BB-HDMI-TDA998x-00A0.dtbo] disabled by /boot/uEnv.txt [disable_uboot_overlay_video=1]...
uboot_overlays: loading /lib/firmware/AM335X-PRU-RPROC-4-19-TI-00A0.dtbo ...
3801 bytes read in 11 ms (336.9 KiB/s)
loading /boot/initrd.img-4.19.94-ti-r34 ...
5026506 bytes read in 324 ms (14.8 MiB/s)
debug: [console=ttyS0,115200n8 bone_capemgr.uboot_capemgr_enabled=1 root=/dev/mmcblk0p1 ro rootfstype=ext4 rootwait coherent_pool=1M net.ifnames=0 lpj=1990656 rng_core.default_quality=100 logo.nologo vt.global_cursor_default=0] ...
debug: [bootz 0x82000000 0x88080000:4cb2ca 88000000] ...
Kernel image @ 0x82000000 [ 0x000000 - 0x9d9200 ]
## Flattened Device Tree blob at 88000000
Booting using the fdt blob at 0x88000000
Loading Ramdisk to 8fb34000, end 8ffff2ca ... OK
Loading Device Tree to 8faa8000, end 8fb33fff ... OK
Starting kernel ...
I was hoping that would show more.. In /boot/uEnv.txt please add: earlycon before coherent_pool
coherent_pool=1M
→
earlycon coherent_pool=1M
i think we need more than that for earlycon to work on am335x, but it might give us more…
Regards,
Thanks for your help!
Unfortunately that didn’t seem to change anything.
Sorry for being offtopic…
But can you help me with something?
Does the Box that the beaglebone came in still list 4GB eMMC? Or does it say 16GB eMMC? I’m trying to figure out if theres an easier way to determine if a board is new or not
Look for RevD… or June 2025 build date… waiting on a revd box so i can confirm too..
It lists On-board 16GB eMMC flash with :inux (Debian Distribution)
