.\" $NetBSD: isr_add.9,v 1.2 1997/05/22 02:12:18 jeremy Exp $ .\" .\" Copyright (c) 1997 The NetBSD Foundation, Inc. .\" All rights reserved. .\" .\" This code is derived from software contributed to The NetBSD Foundation .\" by Jeremy Cooper. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the NetBSD .\" Foundation, Inc. and its contributors. .\" 4. Neither the name of The NetBSD Foundation nor the names of its .\" contributors may be used to endorse or promote products derived .\" from this software without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS .\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED .\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR .\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS BE .\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR .\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF .\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS .\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN .\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE .\" POSSIBILITY OF SUCH DAMAGE. .\" .Dd May 21, 1997 .Dt ISR_ADD 9 sun3 .Os NetBSD .Sh NAME .Nm isr_add .Nd establish interrupt handler .Sh SYNOPSIS .Fd #include .Bd -literal typedef int (*isr_func_t)(void *); .Ed .Ft void .Fn isr_add_autovect "isr_func_t fun" "void *arg" "int level" .Ft void .Fn isr_add_vectored "isr_func_t fun" "void *arg" "int pri" "int vec" .Ft void .Fn isr_add_custom "int level" "void *fun" .Sh DESCRIPTION The .Nm functions establish interrupt handlers into the system interrupt dispatch table, typically called during the autoconfiguration process for a device. .Pp There are two types of interrupts in the Motorola 68000 architecture, which differ in the way that an interrupt request is mapped to a dispatch function within the interrupt vector table. .Pp When the CPU detects an asserted signal on one of its interrupt request lines, it stops normal instruction execution and begins an interrupt acknowledge sequence on the system bus. During this cycle the interrupting device directs how the CPU is to dispatch the interrupt request. .Pp If the interrupting device is sophisticated enough, it provides an 8-bit interrupt vector number to the CPU and a .Dq vectored interrupt occurs. This vector number points to a vector entry within the interrupt vector table to which instruction execution is immediately transfered. .Pp If the interrupting device cannot provide a vector number, it asserts a specialized bus line and an .Dq autovectored interrupt occurs. The vector number to use is determined by adding the interrupt priority (0-6) to an autovector base (typically 0x18). .Pp .Bl -tag -width isr_add_autovec .It Fn isr_add_autovect Adds the function .Fa fun to the list of interrupt handlers to be called during an autovectored interrupt of priority .Fa level . The pointer .Fa arg is passed to the function as its first argument. .It Fn isr_add_vectored Adds the function .Fa fun to the list of interrupt handlers to be called during a vectored interrupts of priority .Fa pri at dispatch vector number .Fa vec . The pointer .Fa arg is passed to the function as its first argument. .It Fn isr_add_custom Establish function .Fa fun as the interrupt handler for vector .Fa level . The autovector base number is automatically added to .Fa level . .Pp .Fa fun is called directly as the dispatch handler and must handle all of the specifics of saving the processor state and returning from a processor exception. These requirements generally dictate that .Fa fun be written in assembler. .El .Sh "CODE REFERENCES" .Fd src/sys/arch/sun3/sun3/isr.c .Sh "REFERENCES" MC68030 User's Manual, Third edition, MC68030UM/AD Rev 2, Motorola Inc. .Sh "BUGS" There is no way to remove a handler once it has been added.