I need to change/make some IRQ assignments in /proc/interrupts .
> How/where is this done?
Each device driver requests its own interrupts. For drivers loaded as modules, they're usually specified as command-line parameters when you load the modules. For built-in drivers, they're usually specified as options to the kernel when it is booted.
My board has 4 serial ports but only the 1st is assigned an IRQ.
For some drivers (like the serial ones) there is an ioctl() you can call to configure IRQ usage.
The setserial util is not on this distro, so I am guessing
> these assignments can be make in a config file somewhere, but
> I sure can't find it.
You either have to write an application that uses the same ioctl() that setserial uses, or find out if the serial driver can have it's IRQ usage set by a kernel option passed by the bootloader.