FreeBSD-5.3/usr.sbin/kernbb/kernbb.8

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.\" $FreeBSD: src/usr.sbin/kernbb/kernbb.8,v 1.19 2004/08/07 04:27:50 imp Exp $
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.Dd May 22, 1995
.Dt KERNBB 8
.Os
.Sh NAME
.Nm kernbb
.Nd generate a dump of the kernels basic-block profile buffers
.Sh SYNOPSIS
.Nm
.Sh DESCRIPTION
The
.Nm
utility is used to extract the basic-block profiling buffers of the running
kernel into the files needed for the
.Xr gcov 1
tool.
.Pp
At least one source file in the running kernel must have been compiled
with the
.Fl Fl test-coverage
and
.Fl Fl profile-arcs
options.
.Pp
The output is stored in the filenames compiled into the kernel by
.Xr gcc 1 .
If the absolute pathname cannot be written to, the directory part
of the filename is discarded and the file stored in the current
directory under its basename.
.Pp
The output files are named
.Pa *.da ,
and the
.Xr gcov 1
program will extract the counts and merge them with the source
file to show actual execution counts.
.Sh FILES
.Bl -tag -width /boot/kernel/kernel -compact
.It Pa /boot/kernel/kernel
the default system
.It Pa /dev/kmem
the default memory
.El
.Sh SEE ALSO
.Xr cc 1 ,
.Xr gcov 1
.Sh AUTHORS
The
.Nm
utility was written by
.An Poul-Henning Kamp ,
along with the kernel-support.
.Sh BUGS
There are far too much magic and internal knowledge from GCC in this.