Changes between Version 6 and Version 7 of serial


Ignore:
Timestamp:
03/13/2018 10:49:25 PM (19 months ago)
Author:
Tim Harvey
Comment:

added details on setting serial console for newport

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  • serial

    v6 v7  
    646646See [wiki:gpio gpio] for details on using GPIO from Linux userspace or use the U-Boot bootloader {{{gpio}}} command.
    647647
     648The CN80XX / CN81XX has 4 TTL level UARTs with the following mapping:
     649||= UART =||= device-tree alias =||= Linux device =||
     650|| UART0 || serial0 || /dev/ttyAMA0 ||
     651|| UART1 || serial1 || /dev/ttyAMA1 ||
     652|| UART2 || serial2 || /dev/ttyAMA2 ||
     653|| UART3 || serial3 || /dev/ttyAMA3 ||
     654
     655The Linux kernel uses the {{{console}}} parameter from the Kernel cmdline to specify the serial console. You can usually modify the 'console' U-boot env variable if you want to change the default console UART as it typically gets passed on to the kernel:
     656{{{
     657Newport > setenv console '/dev/ttyAMA2,115200n8'; saveenv
     658}}}
     659 * Specify that Linux and userspace use UART2
     660
     661The U-Boot Bootloader (as well as kernel if the {{{console}}} cmdline is not specified) uses the device-tree 'chosen' node 'stdout-path' property to specify serial console. For example the default is specified in the cn81xx-linux.dtsi:
     662{{{
     663        chosen {
     664               stdout-path = "serial0:115200n8";
     665        };
     666}}}
     667
     668If you wish to change the serial console in the BDK or ATF, you will need to modify the source code which will take some digging.
    648669
    649670=== Laguna: GW2382 ===