1.\" $NetBSD: kvm_dump.3,v 1.2 1996/06/23 20:28:12 leo Exp $ 2.\" 3.\" Copyright (c) 1996 Leo Weppelman 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by Leo Weppelman. 17.\" 4. Neither the name of the University nor the names of its contributors 18.\" may be used to endorse or promote products derived from this software 19.\" without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31.\" 32.\" 33.Dd March 17, 1996 34.Dt KVM_DUMP 3 35.Os 36.Sh NAME 37.Nm kvm_dump_mkheader , 38.Nm kvm_dump_wrtheader , 39.Nm kvm_dump_inval 40.Nd crash-dump support functions 41.Sh SYNOPSIS 42.Fd #include <kvm.h> 43.br 44.Ft int 45.Fn kvm_dump_mkheader "kvm_t *kd" "off_t dump_off" 46.Ft int 47.Fn kvm_dump_wrtheader "kvm_t *kd" "FILE *fp" "int dumpsize" 48.Ft int 49.Fn kvm_dump_inval "kvm_t *kd" 50.Sh DESCRIPTION 51First note that the functions described here were designed to be used by 52.Xr savecore 8 . 53.Pp 54The function 55.Fn kvm_dump_mkheader 56checks if the physical memory file associated with 57.Fa kd 58contains a valid crash-dump header as generated by a dumping kernel. When a 59valid header is found, 60.Fn kvm_dump_mkheader 61initializes the internal kvm data structures as if a crash-dump generated by 62the 63.Xr savecore 8 64program was opened. This has the intentional side effect of enabling the 65address translation machinery. 66.Pp 67A call to 68.Fn kvm_dump_mkheader 69will most likely be followed by a call to 70.Fn kvm_dump_wrtheader . 71This function takes care of generating the generic header, the CORE_CPU 72section and the section header of the CORE_DATA section. The data is written 73to the file pointed at by 74.Fa fp . 75The 76.Fa dumpsize 77argument is only used to properly the set the segment size of the CORE_DATA 78section. Note that this function assumes that 79.Fa fp 80is positioned at file location 0. This function will not seek and therefore 81allows 82.Fa fp 83to be a file pointer obtained by 84.Fn zopen . 85.Pp 86The 87.Fn kvm_dump_inval 88function clears the magic number in the physical memory file associated with 89.Fa kd . 90The address translations must be enabled for this to work (thus assuming 91that 92.Fn kvm_dump_mkheader 93was called earlier in the sequence). 94.Sh RETURN VALUES 95All functions except 96.Fn kvm_dump_mkheader 97return 0 on success, -1 on failure. The function 98.Fn kvm_dump_mkheader 99returns the size of the headers present before the actual dumpdata starts. If 100no valid headers were found but no fatal errors occured, 0 is returned. On 101fatal errors the return value is -1. 102.Pp 103In the case of failure, 104.Xr kvm_geterr 3 105can be used to retrieve the cause of the error. 106.Sh HISTORY 107These functions first appeared in NetBSD 1.1A. 108.Sh BUGS 109There probably are... 110.Sh SEE ALSO 111.Xr kvm 3 112