I can read from UARTs but I can not write to any. This: echo /boot/vmlinuz-4.14.71-ti-r80 > /dev/ttyS5
returns immediately for any UART, not even an error message. They can read fine, they can not write, any of them. There is a thread https://groups.google.com/forum/#!category-topic/beagleboard/uart/0Yr9ed6PO2o about pinmuxing, cape overlays, device trees, bootloaders etc. which try to make BB UARTs work. Should I follow it to see, why it does not work also on my board? $ dmesg | grep tty [ 0.000000] Kernel command line: console=ttyO0,115200n8 root=/dev/mmcblk0p1 ro rootfstype=ext4 rootwait coherent_pool=1M [ 0.001858] WARNING: Your 'console=ttyO0' has been replaced by 'ttyS0' [ 1.241161] 44e09000.serial: ttyS0 at MMIO 0x44e09000 (irq = 30, base_baud = 3000000) is a 8250 [ 2.089133] console [ttyS0] enabled [ 2.093844] 48022000.serial: ttyS1 at MMIO 0x48022000 (irq = 31, base_baud = 3000000) is a 8250 [ 2.103698] 48024000.serial: ttyS2 at MMIO 0x48024000 (irq = 32, base_baud = 3000000) is a 8250 [ 2.113638] 481a6000.serial: ttyS3 at MMIO 0x481a6000 (irq = 33, base_baud = 3000000) is a 8250 [ 2.123518] 481a8000.serial: ttyS4 at MMIO 0x481a8000 (irq = 34, base_baud = 3000000) is a 8250 [ 2.133333] 481aa000.serial: ttyS5 at MMIO 0x481aa000 (irq = 35, base_baud = 3000000) is a 8250 -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/b92f073b-df26-4261-9d4c-d74201dd44fd%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
