Where does the Kernel command line come from?

I would like to modify the behaviour of the XiLinux 3.8.0 kernel on the MicroZed board slightly.

While The board boots from the SD card I see the following command line:

Kernel command line: console=ttyPS0,115200 root=/dev/ram rw ip=192.168.1.10 earlyprintk

I assume the line is generated by U-BOOT when it activates/starts the kernel.

The actual parameters being passed come from "bootargs". The only plave where I can find anything like that is in the file "devicetree-microzed-sdio 125mhz-4gbram-PHY-LED.dts" on the SD card.
I have tried modifying it there (adding mem=800M to the bootargs in it) but that does not make a difference.

So: how do I get it done? rebuild U-BOOT? If so where do you define what gets passed ?

0 Former Member over 10 years ago

Changing it in the dts file is the right thing to do but then you have to run the DTC to generate the dtb file. That should be possible on the virtual CENTOs machine.
We'll get there in the end.
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0 Former Member over 10 years ago

Hello,

Yes, the kernel command line is indeed in the dts file on Xillinux. Note that the dtc compiler is installed in the kernel's headers on Xillinux' file system (look in /usr/src/kernels/, so if you're able to boot Xillinux, you may compile the new dts on the board itself.

Regards,
Eli
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