KVM_DUMP(3)						   BSD Library Functions Manual 					       KVM_DUMP(3)

NAME

     kvm_dump_mkheader, kvm_dump_wrtheader, kvm_dump_inval -- crash dump support functions

LIBRARY

     Kernel Data Access Library (libkvm, -lkvm)

SYNOPSIS

     #include <kvm.h>

     int
     kvm_dump_mkheader(kvm_t *kd, off_t dump_off);

     int
     kvm_dump_wrtheader(kvm_t *kd, FILE *fp, int dumpsize);

     int
     kvm_dump_inval(kvm_t *kd);

DESCRIPTION

     First note that the functions described here were designed to be used by savecore(8).

     The function kvm_dump_mkheader() checks if the physical memory file associated with kd contains a valid crash dump header as generated by a
     dumping kernel.  When a valid header is found, kvm_dump_mkheader() initializes the internal kvm data structures as if a crash dump generated
     by the savecore(8) program was opened.  This has the intentional side effect of enabling the address translation machinery.

     A call to kvm_dump_mkheader() will most likely be followed by a call to kvm_dump_wrtheader().  This function takes care of generating the
     generic header, the CORE_CPU section and the section header of the CORE_DATA section.  The data is written to the file pointed at by fp.  The
     dumpsize argument is only used to properly the set the segment size of the CORE_DATA section.  Note that this function assumes that fp is
     positioned at file location 0.  This function will not seek and therefore allows fp to be a file pointer obtained by zopen().

     The kvm_dump_inval() function clears the magic number in the physical memory file associated with kd.  The address translations must be
     enabled for this to work (thus assuming that kvm_dump_mkheader() was called earlier in the sequence).

RETURN VALUES

     All functions except kvm_dump_mkheader() return 0 on success, -1 on failure.  The function kvm_dump_mkheader() returns the size of the head-
     ers present before the actual dumpdata starts.  If no valid headers were found but no fatal errors occurred, 0 is returned.  On fatal errors
     the return value is -1.

     In the case of failure, kvm_geterr(3) can be used to retrieve the cause of the error.

SEE ALSO

     kvm(3), kvm_open(3)

HISTORY

     These functions first appeared in NetBSD 1.2.

BSD
								  March 17, 1996							       BSD