Beaglebone Black UART1 can't get it to work

Been using BB for the past 8 years. I have always used config-pin and some overlays to manage the hardware.

I have finally decided to try Debian 12 and 13.

If my uEnv.txt has

#Docs: Making sure you're not a bot!

uname_r=5.10.168-ti-r83
#uuid=
#dtb=

###U-Boot Overlays###
###Documentation: Making sure you're not a bot!
###Master Enable
enable_uboot_overlays=1

###Overide capes with eeprom
uboot_overlay_addr7=BB-UART1-00A0.dtbo
#uboot_overlay_addr0=.dtbo
#uboot_overlay_addr1=.dtbo
#uboot_overlay_addr2=.dtbo
#uboot_overlay_addr3=.dtbo

###Additional custom capes
#uboot_overlay_addr4=.dtbo
#uboot_overlay_addr5=.dtbo
#uboot_overlay_addr6=.dtbo
#uboot_overlay_addr7=.dtbo

why isn’t UART1 showing in beagle-version

root@BeagleBone:~# beagle-version
eeprom:[A335BNLTEIA02042SBI00580]
model:[TI_AM335x_BeagleBone_Black]
dogtag:[BeagleBoard.org Debian Bookworm Base Image 2025-09-05]
bootloader:[microSD-(push-button)]:[/dev/mmcblk0]:[U-Boot SPL 2022.04-ge543709d (Jun 27 2025 - 18:09:26 +0000)]:[location: dd MBR]
UBOOT: Booted Device-Tree:[am335x-boneblack-uboot.dts]
kernel:[5.10.168-ti-r83]
/boot/uEnv.txt Settings:
uboot_overlay_options:[enable_uboot_overlays=1]
uboot_overlay_options:[uboot_overlay_addr7=BB-UART1-00A0.dtbo]
uboot_overlay_options:[disable_uboot_overlay_video=1]
uboot_overlay_options:[disable_uboot_overlay_audio=1]
uboot_overlay_options:[disable_uboot_overlay_wireless=1]
uboot_overlay_options:[disable_uboot_overlay_adc=1]
uboot_overlay_options:[uboot_overlay_pru=AM335X-PRU-UIO-00A0.dtbo]
pkg check: to individually upgrade run: [sudo apt install --only-upgrade ]
pkg:[bb-customizations]:[1.20250808.0-0~bookworm+20250808]
pkg:[bb-usb-gadgets]:[1.20250523.1-0~bookworm+20250527]
pkg:[bb-wl18xx-firmware]:[1.20230703.0-0~bookworm+20240703]
pkg:[kmod]:[30+20221128-1]
groups:[debian : debian adm kmem dialout cdrom floppy audio dip video plugdev users systemd-journal input render netdev i2c bluetooth gpio admin tisdk weston-launch]
cmdline:[console=ttyS0,115200n8 root=/dev/mmcblk0p3 ro rootfstype=ext4 rootwait fsck.repair=yes earlycon coherent_pool=1M net.ifnames=0 lpj=1990656 rng_core.default_quality=100]
dmesg | grep remote
[ 6.002228] remoteproc remoteproc0: wkup_m3 is available
[ 17.155101] systemd[1]: Reached target remote-fs.target - Remote File Systems.
[ 39.583385] remoteproc remoteproc0: powering up wkup_m3
[ 39.602841] remoteproc remoteproc0: Booting fw image am335x-pm-firmware.elf, size 217148
[ 39.635102] remoteproc remoteproc0: remote processor wkup_m3 is now up
[ 48.790715] remoteproc remoteproc1: 4a334000.pru is available
[ 48.851329] remoteproc remoteproc2: 4a338000.pru is available
dmesg | grep pru
[ 48.790715] remoteproc remoteproc1: 4a334000.pru is available
[ 48.851329] remoteproc remoteproc2: 4a338000.pru is available
dmesg | grep pinctrl-single
[ 5.383940] pinctrl-single 44e10800.pinmux: 142 pins, size 568
dmesg | grep gpio-of-helper
dmesg | grep wlcore
lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
END

nor under show-pins

root@BeagleBone:~# show-pins
P8.25 / eMMC d0 0 fast rx up 1 mmc 1 d0
P8.24 / eMMC d1 1 fast rx up 1 mmc 1 d1
P8.05 / eMMC d2 2 fast rx up 1 mmc 1 d2
P8.06 / eMMC d3 3 fast rx up 1 mmc 1 d3
P8.23 / eMMC d4 4 fast rx up 1 mmc 1 d4
P8.22 / eMMC d5 5 fast rx up 1 mmc 1 d5
P8.03 / eMMC d6 6 fast rx up 1 mmc 1 d6
P8.04 / eMMC d7 7 fast rx up 1 mmc 1 d7
P8.19 8 fast rx down 7 gpio 0.22
P8.13 9 fast rx down 7 gpio 0.23
P8.14 10 fast rx down 7 gpio 0.26
P8.17 11 fast rx down 7 gpio 0.27
P8.12 12 fast rx down 7 gpio 1.12
P8.11 13 fast rx down 7 gpio 1.13
P8.16 14 fast rx down 7 gpio 1.14
P8.15 15 fast rx down 7 gpio 1.15
P9.15 16 fast rx down 7 gpio 1.16
P9.23 17 fast rx down 7 gpio 1.17
P9.14 18 fast rx down 7 gpio 1.18
P9.16 19 fast rx down 7 gpio 1.19
P9.11 28 fast rx up 7 gpio 0.30
P9.13 29 fast rx up 7 gpio 0.31
P9.12 30 fast rx up 7 gpio 1.28
P8.26 31 fast rx up 7 gpio 1.29
P8.21 / eMMC clk 32 fast rx up 2 mmc 1 clk
P8.20 / eMMC cmd 33 fast rx up 2 mmc 1 cmd
P9.15 34 fast rx up 7 gpio 2.00
P8.18 35 fast rx down 7 gpio 2.01
P8.07 36 fast rx up 7 gpio 2.02
P8.08 37 fast rx up 7 gpio 2.03
P8.10 38 fast rx up 7 gpio 2.04
P8.09 39 fast rx up 7 gpio 2.05
P8.45 / hdmi / sysboot 0 40 fast rx 7 gpio 2.06
P8.46 / hdmi / sysboot 1 41 fast rx 7 gpio 2.07
P8.43 / hdmi / sysboot 2 42 fast rx 7 gpio 2.08
P8.44 / hdmi / sysboot 3 43 fast rx 7 gpio 2.09
P8.41 / hdmi / sysboot 4 44 fast rx 7 gpio 2.10
P8.42 / hdmi / sysboot 5 45 fast rx 7 gpio 2.11
P8.39 / hdmi / sysboot 6 46 fast rx 7 gpio 2.12
P8.40 / hdmi / sysboot 7 47 fast rx 7 gpio 2.13
P8.37 / hdmi / sysboot 8 48 fast rx 7 gpio 2.14
P8.38 / hdmi / sysboot 9 49 fast rx 7 gpio 2.15
P8.36 / hdmi / sysboot 10 50 fast rx 7 gpio 2.16
P8.34 / hdmi / sysboot 11 51 fast rx 7 gpio 2.17
P8.35 / hdmi / sysboot 12 52 fast rx 7 gpio 0.08
P8.33 / hdmi / sysboot 13 53 fast rx 7 gpio 0.09
P8.31 / hdmi / sysboot 14 54 fast rx 7 gpio 0.10
P8.32 / hdmi / sysboot 15 55 fast rx 7 gpio 0.11
P8.27 / hdmi 56 fast rx down 7 gpio 2.22
P8.29 / hdmi 57 fast rx down 7 gpio 2.23
P8.28 / hdmi 58 fast rx down 7 gpio 2.24
P8.30 / hdmi 59 fast rx down 7 gpio 2.25
P9.22 / spi boot clk 84 fast rx up 7 gpio 0.02
P9.21 / spi boot in 85 fast rx up 7 gpio 0.03
P9.18 / spi boot out 86 fast rx up 7 gpio 0.04
P9.17 / spi boot cs 87 fast rx up 7 gpio 0.05
P9.42 89 fast rx down 7 gpio 0.07
P9.20 / cape i²c sda 94 fast rx up 3 i²c 2 sda i2c@4819c000 (pinmux_i2c2_pins)
P9.19 / cape i²c scl 95 fast rx up 3 i²c 2 scl i2c@4819c000 (pinmux_i2c2_pins)
P9.26 96 fast rx up 7 gpio 0.14
P9.24 97 fast rx up 7 gpio 0.15
P9.31 / hdmi audio clk 100 fast rx down 7 gpio 3.14
P9.29 / hdmi audio fs 101 fast rx down 7 gpio 3.15
P9.30 102 fast rx down 7 gpio 3.16
P9.28 / hdmi audio data 103 fast rx down 7 gpio 3.17
P9.42 104 fast rx down 7 gpio 3.18
P9.27 105 fast rx down 7 gpio 3.19
P9.41 106 fast rx down 7 gpio 3.20
P9.25 / audio osc 107 fast rx down 7 gpio 3.21
P9.41 / jtag emu3 109 fast rx down 7 gpio 0.20

Hope someone can point me in the right direction.

Dean

Depending on the kernel and image used, sometimes gpioinfo shows allocated pin muxing that is present.

There are also docs. now online at docs.beagleboard.org .

I noticed some oomph toward the direction of bone-buses which seem to handle a specification.

Again, depending on the kernel and image, sometimes things are now located in /dev/bone/.

Seth