Kernel configuration

Preparing a new kernel for RTAI could require some work. Here are some general rules you can follow:

• Start with a vanilla kernel
• When you configure your kernel (e.g. using make menuconfig), always set CONFIG_LOCALVERSION (GENERAL SETUP -> LOCAL VERSION) to identify your kernel (e.g -rtai4.0-HWNAME-vNN with NN starting from 00 and increasing). This will help you when you have to refine or revert some changes in the configuration.
• Copy your System.map, initrd, bzImage and .config to your boot dir appending the localversion, and update your bootloader (grub, lilo etc). Note: nowadays you can just do a make install after you have built your kernel
• If you decide to rebuild your kernel, do a make mrproper to be sure to start with a clean state; WARNING: this will remove your .config but you should have a copy on /boot
• Do not change too many things at the same time, especially when you are touching one of the well-known latency killer options (such as ACPI, APM, HPET etc)
• As your RTAI kernel will strongly depend on your hardware, you will not be able to move it from a machine to another. Therefore, it is suggested that you remove all unused features and all unused hardware-related drivers, even if they are configured as modules. This will greatly reduce your compilation time and, in some cases, your latency.