RTLinux currently supports two types of User-Level signals -- interrupts and timers. In functions such as rtlinux_sigaction(3) and rtlinux_sigaddset(3) you can use the following defines for the signum.
RTLINUX_SIGIRQx signals refer to interrupt-driven signals, where x is the IRQ number. Currently any IRQ supported by Linux can be used in RTLinux signals, and x designates the IRQ number, which can be any number from 0 to one less than the maximum number of IRQs (currently defined as NR_IRQS).
RTLINUX_SIGTIMERx signals can be used to setup real-time timers in userspace as described in rtlinux_sigaction(3). x can be any number from 0 to 15.
Nathan Paul Simons (firstname.lastname@example.org
This function is only available in Linux user processes. RTLinux threads can not use this function.