Can we edit the kernel config options while compiling the kernel so that the uart communications happens to be on ttyS0 instead of ttyMFD2??? or even ttys1 or ttys2??
This will help boot standard ext4 rootfs distributions from other OSes without any significant changes!
There are several threads in the community which has discussed similar subjects to this, like:
https://communities.intel.com/message/353995# 353995 https://communities.intel.com/message/353995# 353995
https://communities.intel.com/message/310265# 310265 https://communities.intel.com/message/310265# 310265
The one that caught my eye is the latter. You can see in the user description the steps he took in order to disable the console output from ttyMFD2, precisely he removed 'console=ttyMFD2 earlyprintk=ttyMFD2,keep' from the kernel boot options. I believe that line is the one that defines where the console output is forwarded. Nevertheless, only changing this line will most likely not take any effect as this changes are likely to be required to be made in the image building process.
I hope thin information helps you, let me know if otherwise.
My problem is i dont want to change the physical port connections!
I only want the name that is mapped to the physical connections to be called ttyS0 or ttyS1 instead of ttyMFD2 which is more standard. Where in the kernel config do I edit it?
Or does it need to be edited somewhere in u-boot? None of the above links mention it?
I understand, in that case, according to udev's manual:
"The name to use for a network interface. The name of a device node cannot be changed by udev, only additional symlinks can be created."
So, if you would like to modify, that would probably imply that you have to modify udev, which could prove quite challenging. So, my suggestion is that if you would like to rename the device, using a symlink is the best approach. This would not make an actual difference but for example, if you, for some reason, need to refer to ttyMFD2 as ttyS8, the symlink can make this possible.
I hope this helps.