Beagle Bone AI UART enabling

wojciech_Jasiewicz · June 11, 2021, 4:04pm

Hello everyone,

I have a problem with enabling the UART interface in Beaglebone AI.
I modified “/boot/uEnv.txt” file according the file below:

`#Docs: http://elinux.org/Beagleboard:U-boot_partitioning_layout_2.0

uname_r=4.19.94-ti-r42
#uuid=
#dtb=

###U-Boot Overlays###
###Documentation: http://elinux.org/Beagleboard:BeagleBoneBlack_Debian#U-Boot_Overlays
###Master Enable
enable_uboot_overlays=1

UART 1

uboot_overlay_addr0=/lib/firmware/BB-UART1-00A0.dtbo

UART 2

uboot_overlay_addr1=/lib/firmware/BB-UART2-00A0.dtbo

UART 4

uboot_overlay_addr2=/lib/firmware/BB-UART4-00A0.dtbo

UART 5

uboot_overlay_addr3=/lib/firmware/BB-UART5-00A0.dtbo

UART 3 (only TX). Note that in “uboot_overlay_addrX”, the X need not be = UART id

uboot_overlay_addr4=/lib/firmware/BB-UART3-00A0.dtbo

###Overide capes with eeprom
#uboot_overlay_addr0=/lib/firmware/.dtbo
#uboot_overlay_addr1=/lib/firmware/.dtbo
#uboot_overlay_addr2=/lib/firmware/.dtbo
#uboot_overlay_addr3=/lib/firmware/.dtbo

###Additional custom capes
#uboot_overlay_addr4=/lib/firmware/.dtbo
#uboot_overlay_addr5=/lib/firmware/.dtbo
#uboot_overlay_addr6=/lib/firmware/.dtbo
#uboot_overlay_addr7=/lib/firmware/.dtbo

###Custom Cape
#dtb_overlay=/lib/firmware/.dtbo

###Disable auto loading of virtual capes (emmc/video/wireless/adc)
#disable_uboot_overlay_emmc=1
#disable_uboot_overlay_video=1
#disable_uboot_overlay_audio=1
#disable_uboot_overlay_wireless=1
#disable_uboot_overlay_adc=1

###PRUSS OPTIONS
###pru_rproc (4.14.x-ti kernel)
#uboot_overlay_pru=/lib/firmware/AM335X-PRU-RPROC-4-14-TI-00A0.dtbo
###pru_rproc (4.19.x-ti kernel)
uboot_overlay_pru=/lib/firmware/AM335X-PRU-RPROC-4-19-TI-00A0.dtbo
###pru_uio (4.14.x-ti, 4.19.x-ti & mainline/bone kernel)
#uboot_overlay_pru=/lib/firmware/AM335X-PRU-UIO-00A0.dtbo

###Cape Universal Enable
enable_uboot_cape_universal=1

###Debug: disable uboot autoload of Cape
#disable_uboot_overlay_addr0=1
#disable_uboot_overlay_addr1=1
#disable_uboot_overlay_addr2=1
#disable_uboot_overlay_addr3=1

###U-Boot fdt tweaks… (60000 = 384KB)
#uboot_fdt_buffer=0x60000
###U-Boot Overlays###

cmdline=coherent_pool=1M net.ifnames=0 lpj=1990656 rng_core.default_quality=100 quiet

#In the event of edid real failures, uncomment this next line:
#cmdline=coherent_pool=1M net.ifnames=0 lpj=1990656 rng_core.default_quality=100 quiet video=HDMI-A-1:1024x768@60e

##enable Generic eMMC Flasher:
##make sure, these tools are installed: dosfstools rsync
#cmdline=init=/opt/scripts/tools/eMMC/init-eMMC-flasher-v3.sh

#cape_enable=capemgr.enable_partno=BB-UART1,BB-UART2,BB-UART4,BB-UART5`

It is a code from: here

Of course kernel version was changed according to my version of kernel.
I used that debian image

I saw many examples which were related to the Beagle bone black, but they didn’t work for Beagle bone AI. My Beagle bone wasn’t able to boot after I used the code above. I am sure that the lines below
cause that booting problem.

`# UART 1
uboot_overlay_addr0=/lib/firmware/BB-UART1-00A0.dtbo