Disabling ttyS0 console serial port


I have a device connected to ttyS0 at startup and as it sends data from that port, the module cannot boot due to uboot using that port. I changed the extlinux.conf and deleted the console=tty0 and console=ttyS0 and also deleted no_console_suspend=1 and debug_uartport and also earlyprintk parameters.

Then, I also changed the dts’s uart node and deleted the console_uart line from that node.

But it still doesn’t boot.

Any opinions?



The u-boot.bin file itself has been set up to use serial console. You would have to rebuild u-boot to remove its ability to respond to serial console. Here’s a URL on building u-boot:

Generally speaking, the extlinux.conf is about passing parameters on to the Linux kernel. Dtb files set up hardware state, and although this can have an effect during the boot loader stage, this is also generally about setting up what the Linux kernel will inherit. Serial console while actually running u-boot is part of u-boot itself. Think of u-boot’s serial console being a separate program than the Linux serial console, but both use the same parameters and settings and as one overwrites the other the end user will not notice which part of the system is actually driving the serial console. Disabling the Linux version is easy and convenient; disabling the u-boot version is not convenient.

Thanks a lot, i will hack the u-boot source for this and write the result here,
The u-boot source with tx1 config file is in http://nv-tegra.nvidia.com/gitweb/?p=3rdparty/u-boot.git
Is it right?


That is probably correct, but I won’t guarantee it. U-boot source for the particular release is also included with that release for download. For R24.2.1, see:

There is a section on that URL under “Source Packages”, just labeled “Sources”. I think that should include the version guaranteed to have shipped with that release.