1.\" $NetBSD: isr_add.9,v 1.2 1997/05/22 02:12:18 jeremy Exp $ 2.\" 3.\" Copyright (c) 1997 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Jeremy Cooper. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. All advertising materials mentioning features or use of this software 18.\" must display the following acknowledgement: 19.\" This product includes software developed by the NetBSD 20.\" Foundation, Inc. and its contributors. 21.\" 4. Neither the name of The NetBSD Foundation nor the names of its 22.\" contributors may be used to endorse or promote products derived 23.\" from this software without specific prior written permission. 24.\" 25.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 26.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS BE 29.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35.\" POSSIBILITY OF SUCH DAMAGE. 36.\" 37.Dd May 21, 1997 38.Dt ISR_ADD 9 sun3 39.Os NetBSD 40.Sh NAME 41.Nm isr_add 42.Nd establish interrupt handler 43.Sh SYNOPSIS 44.Fd #include <machine/autoconf.h> 45.Bd -literal 46 47typedef int (*isr_func_t)(void *); 48.Ed 49.Ft void 50.Fn isr_add_autovect "isr_func_t fun" "void *arg" "int level" 51.Ft void 52.Fn isr_add_vectored "isr_func_t fun" "void *arg" "int pri" "int vec" 53.Ft void 54.Fn isr_add_custom "int level" "void *fun" 55.Sh DESCRIPTION 56The 57.Nm 58functions establish interrupt handlers into the system interrupt dispatch table, 59typically called during the autoconfiguration process for a device. 60.Pp 61There are two types of interrupts in the Motorola 68000 architecture, 62which differ in the way that an interrupt request is mapped to a dispatch 63function within the interrupt vector table. 64.Pp 65When the CPU detects an asserted signal on one of its interrupt request lines, 66it stops normal instruction execution and begins an interrupt acknowledge 67sequence on the system bus. 68During this cycle the interrupting device directs how the CPU is to dispatch 69the interrupt request. 70.Pp 71If the interrupting device is sophisticated enough, 72it provides an 8-bit interrupt vector number to the CPU and a 73.Dq vectored 74interrupt occurs. 75This vector number points to a vector entry within the interrupt 76vector table to which instruction execution is immediately transfered. 77.Pp 78If the interrupting device cannot provide a vector number, it asserts a 79specialized bus line and an 80.Dq autovectored 81interrupt occurs. 82The vector number to use is determined by adding the interrupt priority (0-6) 83to an autovector base (typically 0x18). 84.Pp 85.Bl -tag -width isr_add_autovec 86.It Fn isr_add_autovect 87Adds the function 88.Fa fun 89to the list of interrupt handlers to be called during an autovectored interrupt 90of priority 91.Fa level . 92The pointer 93.Fa arg 94is passed to the function as its first argument. 95.It Fn isr_add_vectored 96Adds the function 97.Fa fun 98to the list of interrupt handlers to be called during a vectored interrupts of 99priority 100.Fa pri 101at dispatch vector number 102.Fa vec . 103The pointer 104.Fa arg 105is passed to the function as its first argument. 106.It Fn isr_add_custom 107Establish function 108.Fa fun 109as the interrupt handler for vector 110.Fa level . 111The autovector base number is automatically added to 112.Fa level . 113.Pp 114.Fa fun 115is called directly as the dispatch handler and must handle all of the specifics 116of saving the processor state and returning from a processor exception. 117These requirements generally dictate that 118.Fa fun 119be written in assembler. 120.El 121.Sh "CODE REFERENCES" 122.Fd src/sys/arch/sun3/sun3/isr.c 123.Sh "REFERENCES" 124MC68030 User's Manual, Third edition, MC68030UM/AD Rev 2, Motorola Inc. 125.Sh "BUGS" 126There is no way to remove a handler once it has been added. 127