U-Boot Not Working on Raspberry Pi 5
Peter Robinson
pbrobinson at gmail.com
Thu Oct 23 11:02:40 CEST 2025
Hi Mikeyy,
> I'm trying to set up U-Boot as a bootloader on my Raspberry Pi 5 for custom
> kernel development. For some reason though, I don't ever get to the U-Boot
> environment at the end where I can type and input commands. It seemingly
> gets stuck after BL31 (which I believe is the Arm Trusted Firmware). Any
> help would be greatly appreciated.
>
> Setup:
>
> - U-Boot version: v2025.10
> - Built with: make CROSS_COMPILE=aarch64-linux-gnu- rpi_arm64_defconfig
> - Connection: Using the dedicated 3-pin debug UART header with
> USB-to-serial adapter
> - SD card has: u-boot.bin, bcm2712-rpi-5-b.dtb, and config.txt
What sort of partition/filesystem do you have?
> This is my specific adapter:
> https://www.amazon.com.au/Debugger-Raspberry-Connector-Debugging-Transmission/dp/B0CZP8DZK8
> which I plug into my laptop, and run the command: *sudo minicom -D
> /dev/ttyACM0 -b 115200*. I am specifically using the dedicated 3-pin UART
> header which is new on the Rpi5.
>
> My config.txt is
>
> > arm_64bit=1
> > kernel=u-boot.bin
The above should be enough, the device should pass the right DT from
the earlier firmware. What is
> > device_tree=bcm2712-rpi-5-b.dtb
> > os_check=0
> > # Enable UART0
> > enable_uart=1
> > core_freq_min=500
>
>
>
> Here is my output after connecting to minicom:
>
> Welcome to minicom 2.9
> > OPTIONS: I18n
> > Port /dev/ttyACM0, 00:28:12
> > Press CTRL-A Z for help on special keys
> > 1.02 RPi: BOOTSYS release VERSION:5855b10b DATE: 2025/06/13 TIME:
> > 10:39:26
> > 1.02 BOOTMODE: 0x06 partition 0 build-ts BUILD_TIMESTAMP=1749807566
> > serial 0d57824f boardrev c049
> > 1.03 AON_RESET: 00000003 PM_RSTS 00001000
> > 1.04 POWER_OFF_ON_HALT: 0 WAIT_FOR_POWER_BUTTON 0 power-on-reset 1
> > 1.05 RP1_BOOT chip ID: 0x20001927
> > 1.05 PCIEx1: PWR 0 DET_WAKE 0
> > 1.05 part 00000000 reset_info 00000000
> > 1.06 PMIC reset-event 00000000 rtc 00000001 alarm 00000000 enabled 0
> > 1.06 uSD voltage 3.3V
> > 1.07 SDRAM_CONFIG: 15
> > 1.07 Initialising SDRAM rank 2 total-size: 32 Gbit 4267 (0x15 0x15)
> > 1.08 DDR 4267 1 0 32 152 BL:1
> > 2.94 OTP boardrev c04171 bootrom a a
> > 2.94 Customer key hash
> > 0000000000000000000000000000000000000000000000000000000000000000
> > 2.95 VC-JTAG unlocked
> > 2.97 RP1_BOOT chip ID: 0x20001927
> > 3.61 RP1_BOOT chip ID: 0x20001927
> > 3.61 RP1_BOOT: fw size 46888
> > 4.25 PCI2 init
> > 4.25 PCI2 reset
> > 4.30 PCIe scan 00001de4:00000001
> > 4.30 RP1_CHIP_INFO 20001927
> > 4.30 RPi: BOOTLOADER release VERSION:5855b10b DATE: 2025/06/13 TIME:
> > 10:39:26
> > 4.31 BOOTMODE: 0x06 partition 0 build-ts BUILD_TIMESTAMP=1749807566
> > serial 0d57824f boardrev c045
> > 4.32 PCIEx1: PWR 0 DET_WAKE 0
> > 4.24 M.2 PCIe HAT not detected.
> > 4.34 usb_pd_init status 3
> > 4.34 USB_PD CONFIG 0 41
> > 4.42 XHCI-STOP
> > 4.42 xHC0 ver: 272 HCS: 03000440 140000f1 07ff000a HCC: 0240fe6d
> > 4.43 USBSTS 1
> > 4.43 xHC0 ver: 272 HCS: 03000440 140000f1 07ff000a HCC: 0240fe6d
> > 4.43 xHC0 ports 3 slots 64 intrs 4
> > 4.45 XHCI-STOP
> > 4.45 xHC1 ver: 272 HCS: 03000440 140000f1 07ff000a HCC: 0240fe6d
> > 4.45 USBSTS 1
> > 4.45 xHC1 ver: 272 HCS: 03000440 140000f1 07ff000a HCC: 0240fe6d
> > 4.46 xHC1 ports 3 slots 64 intrs 4
> > 4.47 USB-PD: src-cap PDO object1 0x0a01912c
> > 4.47 Current 3000 mA
> > 4.47 Voltage 5000 mV
> > 4.47 USB-PD: src-cap PDO object2 0x0002d12c
> > 4.48 Current 3000 mA
> > 4.48 Voltage 9000 mV
> > 4.48 USB-PD: src-cap PDO object3 0x0004b12c
> > 4.48 Current 3000 mA
> > 4.49 Voltage 15000 mV
> > 4.49 USB-PD: src-cap PDO object4 0x00064145
> > 4.49 Current 3250 mA
> > 4.49 Voltage 20000 mV
> > 4.50 USB-PD: src-cap PDO object5 0xc0dc323c
> > 4.50 USB-PD: src-cap PDO object6 0xc1a4323c
> > 4.10 Boot mode: SD (01) order f4
> > 9.17 SD HOST: 200000000 CTL0: 0x00800000 BUS: 400000 Hz actual: 390625
> > HZ div: 512 (256) status:6
> > 9.18 SD HOST: 200000000 CTL0: 0x00800f00 BUS: 400000 Hz actual: 390625
> > HZ div: 512 (256) status:6
> > 9.40 OCR c0ff8000 [340]
> > CID: 00035344534e363447856a498e400198
> > CSD: 400e0032db790001dbd37f800a404000
> > 9.41 SD: bus-width: 4 spec: 2 SCR: 0x02458487 0x00000000
> > 9.42 SD HOST: 200000000 CTL0: 0x00800f04 BUS: 50000000 Hz actual:
> > 50000000 HZ div: 4 (2) status:2
> > 9.43 MBR: 0x00000800,124733440 type: 0x0b
> > 9.43 MBR: 0x00000000, 0 type: 0x00
> > 9.43 MBR: 0x00000000, 0 type: 0x00
> > 9.44 MBR: 0x00000000, 0 type: 0x00
> > 9.46 Trying partition: 0
> > 9.92 type: 32 lba: 2048 'mkfs.fat' ' NO NAME ' clusters 1948483 (64)
> > 9.49 rsc 64 fat-sectors 15232 root dir cluster 2 sectors 0 entries 0
> > 9.50 FAT32 clusters 1948483
> > 9.50 [sdcard] autoboot.txt not found
> > 9.50 Select partition rsts 0 C(boot_partition) 0 EEPROM config 0 result 1
> > 9.15 Trying partition: 1
> > 9.17 type: 32 lba: 2048 'mkfs.fat' ' NO NAME ' clusters 1948483 (64)
> > 9.52 rsc 64 fat-sectors 15232 root dir cluster 2 sectors 0 entries 0
> > 9.53 FAT32 clusters 1948483
> > 9.40 Read config.txt bytes 122 hnd 0x76
> > 9.54 [sdcard] pieeprom.upd not found
> > 9.45 usb_max_current_enable default 0 max-current 3000
> > 9.55 Selecting USB low current limit
> > 9.55 MESS:00:00:09.557951:0: *** Restart logging
> > 9.62 Read /config.txt bytes 122 hnd 0x76
> > 9.66 Read /config.txt bytes 122 hnd 0x76
> > 9.57 MESS:00:00:09.571810:0: Initial voltage 800000 temp 30136
> > 9.77 MESS:00:00:09.772217:0: avs_2712: AVS pred 9012 901200 temp 30136
> > 9.77 MESS:00:00:09.775819:0: vpred 901 mV +0
> > 9.78 MESS:00:00:09.784492:0: FB framebuffer_swap 1
> > 9.78 MESS:00:00:09.786357:0: Select resolution HDMI0/2 hotplug 0
> > max_mode 2
> > 9.79 MESS:00:00:09.793247:0: Select resolution HDMI1/2 hotplug 0
> > max_mode 2
> > 9.80 Loading 'bcm2712-rpi-5-b.dtb' to 0x00000000 offset 0x100
> > 9.15 Read bcm2712-rpi-5-b.dtb bytes 78728 hnd 0x3c
> > 9.37 /overlays/overlay_map.dtb
> > 9.38 /overlays/bcm2712d0.dtbo
> > 9.86 PCIEx1: PWR 0 DET_WAKE 0
> > 9.80 Read /config.txt bytes 122 hnd 0x76
> > 9.94 [sdcard] /cmdline.txt not found
> > 9.44 /cmdline.txt
> > 9.94 MESS:00:00:09.946696:0: Failed to open command line file
> > 'cmdline.txt'
> > 10.13 MESS:00:00:10.131602:0: RPM 0, max RPM 0
> > 10.16 BMD "armstub8-2712.bin" not found
> > 10.63 fs_open: 'armstub8-2712.bin'
> > 10.16 Loading 'u-boot.bin' to 0x00000000 offset 0x200000
> > 10.04 Read u-boot.bin bytes 700232 hnd 0x5b
It seems to find it on disk and load it OK.
> > 10.20 MESS:00:00:10.206013:0: Kernel relocated to 0x80000
> > 10.21 MESS:00:00:10.210874:0: Device tree loaded to 0x2efec600 (size
> > 0x13957)
> > 10.21 PCI1 reset
> > 10.22 PCI2 reset
> > 10.23 set_reboot_order 0
> > 10.23 set_reboot_arg1 0
> > 10.24 USB-OTG disconnect
> > 10.28 MESS:00:00:10.283221:0: BSC_A no ACK
> > 10.28 MESS:00:00:10.284454:0: BSC_A no ACK
> > 10.28 MESS:00:00:10.288380:0: BSC_A no ACK
> > 10.31 MESS:00:00:10.312311:0: BSC_B no ACK
> > 10.31 MESS:00:00:10.313538:0: BSC_B no ACK
> > 10.31 MESS:00:00:10.317473:0: BSC_B no ACK
> > 10.34 MESS:00:00:10.341242:0: Starting OS 10341 ms
> > 10.34 MESS:00:00:10.346852:0: 00000040: -> 00000480
> > 10.34 MESS:00:00:10.348705:0: 00000030: -> 00100080
> > 10.35 MESS:00:00:10.353418:0: 00000034: -> 00100080
> > 10.35 MESS:00:00:10.358131:0: 00000038: -> 00100080
> > 10.36 MESS:00:00:10.362844:0: 0000003c: -> 00100080
> > NOTICE: BL31: v2.6(release):v2.6-240-gfc45bc492
> > NOTICE: BL31: Built : 12:55:13, Dec 4 2024
More information about the U-Boot
mailing list