Switch Linux console output from Altera JTAG UART to Altera UART


I have an Arria II GX development kit that I have successfully booted linux v3.10 on a Nios II processor (w MMU) using the Altera JTAG UART as my console output. However, how I want to direct the console output to a “standard” UART using the Altera UART device that is converted to RS-232 levels on a daughter card and then connected a DB-9 connector which is accessed through a terminal emulator (PuTTY).

So far, I have been unsuccessful at seeing anything coming out of the UART device.

Here is what I have done during my testing:
It appears that the u-boot configuration support file found @ /u-boot-socfpga/include/configs needs to be updated so that at a minimum:

  1. #define CONFIG_ALTERA_JTAG_UART is commented out so it is undefined and #define CONFIG_ALTERA_UART is defined to enable the Altera UART.
  2. #define CONFIG_SYS_NIOS_FIXEDBAUD has been commented out and left undefined so I can set the baud rate based on the CONFIG_SYS_UART_BAUD parameter.
  3. #define CONFIG_SYS_CONSOLE_INFO_QUIET is also been commented out and is undefined so that the console output is active.

I’m also not enabling the UART (8250/16550 compatible) serial port in the kernel menuconfig because I will be using the Altera soft UART device found in the Qsys library. I will only be using some RS-232 level translators in a daughter card that is connected to one of the HSMC connectors on the Arria II GX board.

However, I have made these changes and rebuilt the u-boot image but I still do not see any console output from u-boot when the processor is reset.

Anyone have any ideas of what additional configuration changes that still might be needed?

Any feedback would be appreciated.

  • Brad