I had a working uclinux kernel that I tried to make run without the nios2terminal. I selected the " Bypass output when no connection " in menuconfig like shown below. After doing this the make fails trying to resolve the readl function in altjuart.c Has anyone else run into this same issue? Thanks, This is what I have my kernel config set as: In kernel menuconfig, you should usually select either jtag uart or serial uart for console device (but not both). You should use exactly only one of them for console. Device Drivers ---> Character devices ---> Serial drivers ---> [ ] 8250/16550 and compatible serial support *** Non-8250 serial port support *** [*] Altera JTAG UART support [*] Altera JTAG UART console support # if you use a USB (Blaster) cable on a nios2-terminal [ ] Bypass output when no connection # go without a nios2-terminal [*] Altera UART support (4) Maximum number of Altera UART ports (115200) Default baudrate for Altera UART ports [ ] Altera UART console support # if you use a 9-pin RS-232C cable on a terminal emulator such as minicom or ckermit or hyperterminal The jtag uart will freeze if there is no nios2-terminal connected. You can keep the system working without a jtag connection, by turn on [*] Bypass output when no connection The jtag uart will connect again when there is a nios2-terminal on jtag connection. The init prog will start a shell on the console device. So if you want to run app which use uart, then you should not enable uart console.