1The chosen node 2--------------- 3 4The chosen node does not represent a real device, but serves as a place 5for passing data between firmware and the operating system, like boot 6arguments. Data in the chosen node does not represent the hardware. 7 8 9stdout-path property 10-------------------- 11 12Device trees may specify the device to be used for boot console output 13with a stdout-path property under /chosen, as described in ePAPR, e.g. 14 15/ { 16 chosen { 17 stdout-path = "/serial@f00:115200"; 18 }; 19 20 serial@f00 { 21 compatible = "vendor,some-uart"; 22 reg = <0xf00 0x10>; 23 }; 24}; 25 26If the character ":" is present in the value, this terminates the path. 27The meaning of any characters following the ":" is device-specific, and 28must be specified in the relevant binding documentation. 29 30For UART devices, the preferred binding is a string in the form: 31 32 <baud>{<parity>{<bits>{<flow>}}} 33 34where 35 36 baud - baud rate in decimal 37 parity - 'n' (none), 'o', (odd) or 'e' (even) 38 bits - number of data bits 39 flow - 'r' (rts) 40 41For example: 115200n8r 42 43Implementation note: Linux will look for the property "linux,stdout-path" or 44on PowerPC "stdout" if "stdout-path" is not found. However, the 45"linux,stdout-path" and "stdout" properties are deprecated. New platforms 46should only use the "stdout-path" property. 47