08-24-2015 03:20 PM
Hi,I have a Nios II system that is running Linux 3.10.31 and I would like to update my system configuration so that the kernel debug messages during bootup that are sent to stdout are routed to a standard UART instead of the Altera JTAG UART. From my understanding, what I need to change is the following:
- Add a UART component to my Qsys system and connect to the Nios II processor.
- In my kernel configuration (menuconfig), I need to disable the Altera JTAG UART serial and turn on the enable the standard UART (8250/16550 compatible) serial port.
- In my console boot parameters, I need to change the console output from ttyJ0 to ttyS0
08-25-2015 10:47 AM
Are you using the Nios Eclipse plugin? If so, in the BSP Editor one of the screens allows you to select the default devices to use for each of STDIN/STDOUT/STDERR.
08-25-2015 11:47 AM
Hi TCWORLD,Thank you for your reply. I'm booting from Linux so I'm not using the Altera Software Build Tool (SBT) chain that allows me to select the default output device for stdout. I'm currently heading down the path that involves updating the kernel build as well as the appropriate support files to use the Altera UART instead of the JTAG UART. - Brad
08-26-2015 07:25 PM
UPDATE (08.26.15):I have an update on what I have found to switch from the Altera JTAG UART to a standard Altera UART for the linux console output for U-Boot. It appears that the u-boot configuration support file found @ /u-boot-socfpga/include/configs needs to be updated so that at a minimum:
- #define config_altera_jtag_uart is undefined and #define config_altera_uart is defined.
- #define config_sys_nios_fixedbaud needs to be undefined so I can set the baud rate based on the config_sys_uart_baud parameter.
- #define config_sys_console_info_quiet is also undefined so that the console output is active.