Serial driver 16550a on Beaglebone Black

Michał Hanusek mhanusek at
Mon Mar 30 17:08:01 CEST 2020

How to enable a driver 16550a (xeno_16550A) and configure the serial port?

I loaded the driver to the kernel (for the /dev/ttyS4 port) but the device in the /dev/rtdm/rtser... location did not appear.

Please help.

Linux kernel 4.9.88 + Xenomai patch

root at beaglebone:/home/debian# lsmod
Module                  Size  Used by
xeno_16550A            17350  0

root at beaglebone:/home/debian# modprobe xeno_16550A io=0x481A8000 irq=159 baud_base=115200 start_index=0

root at beaglebone:/home/debian# cat /proc/tty/driver/serial
serinfo:1.0 driver revision:
0: uart:8250 mmio:0x44E09000 irq:158 tx:11568 rx:98 brk:63 RTS|CTS|DTR|DSR
1: uart:unknown port:00000000 irq:0
2: uart:unknown port:00000000 irq:0
3: uart:unknown port:00000000 irq:0
4: uart:8250 mmio:0x481A8000 irq:159 tx:2 rx:1 brk:1 CTS|DSR
5: uart:unknown port:00000000 irq:0

root at beaglebone:/home/debian# setserial /dev/ttyS4 
/dev/ttyO4, UART: 8250, Port: 0x0000, IRQ: 159

root at beaglebone:/home/debian# ls /dev/rtdm/
autotune        memdev-private  memdev-shared   memdev-sys      switchtest      timerbench 
Szanujemy Twoją prywatność, dbamy o bezpieczeństwo Twoich danych osobowych,  Sprawdź szczegóły ! 

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