Hatzl Posted July 23, 2020 Share Posted July 23, 2020 Armbianmonitor: http://ix.io/2sc6 Hi all, i am trying to enable UART4 on my Cubieboard2 via /boot/armbianEnv.txt: overlay_prefix=sun7i-a20 overlays=i2c1 uart4 param_uart4_pins=a but if it seems that my uart4 is not working. If i look at dmesg | grep tty there is no ttyS4-device - only ttyS0: [ 0.000000] Kernel command line: console=tty1 root=/dev/mmcblk0p1 rootwait rootfstype=ext4 sunxi_ve_mem_reserve=0 sunxi_g2d_mem_reserve=0 sunxi_no_mali_mem_reserve sunxi_fb_mem_reserve=16 hdmi.audio=EDID:0 disp.screen0_output_mode=1920x1080p60 panic=10 consoleblank=0 enforcing=0 loglevel=1 [ 0.000860] console [tty1] enabled [ 1.542600] 1c28000.serial: ttyS0 at MMIO 0x1c28000 (irq = 47, base_baud = 1500000) is a U6_16550A am i doing something wrong or did i forget something? Thanks for your help! Michael Link to comment Share on other sites More sharing options...
Gediz Posted July 24, 2020 Share Posted July 24, 2020 I am not sure if it applies with A20 but while using A64, R_UART (which belongs to co-processor, I assume) is enabled when UART4 is selected. Also this problem occurred not on Linux but on U-Boot. Link to comment Share on other sites More sharing options...
Hatzl Posted July 24, 2020 Author Share Posted July 24, 2020 Hi Gediz, thanks for your answer. Regarding R_UART i didnt find anything which did help me with UART4. The problem not only exists with UART4 - but with all possible UARTs. If i activate UART2, UART3 for example there is also no entry found in dmesg for ttyS2 or ttyS3. in dmesg always there is this entry for ttyS0... :-/ Link to comment Share on other sites More sharing options...
Recommended Posts