.\"	$NetBSD: dbsym.8,v 1.7 2022/12/23 17:09:56 christos Exp $
.\"
.Dd August 14, 2014
.Dt DBSYM 8
.Os
.Sh NAME
.Nm dbsym
.Nd copy kernel symbol table into db_symtab space
.Sh SYNOPSIS
.Nm
.Op Fl Ppv
.Op Fl b Ar bfdname
.Ar kernel
.Sh DESCRIPTION
.Nm
is used to copy the symbol table in a newly linked kernel into the
.Va db_symtab
array (in the data section) so that the
.Xr ddb 4
kernel debugger can find the symbols.
This program is only used
on systems for which the boot program does not load the symbol table
into memory with the kernel.
The space for these symbols is
reserved in the data segment using a config option like:
.Dl options		SYMTAB_SPACE=72000
The size of the db_symtab array (the value of SYMTAB_SPACE) must be
at least as large as the kernel symbol table.
If insufficient space
is reserved, dbsym will refuse to copy the symbol table.
.Pp
To recognize kernel executable format, the
.Fl b
flag specifies BFD name of kernel.
.Pp
If the
.Fl P
flag is given,
.Nm
will report the size of the kernel symbol table.
.Pp
If the
.Fl p
flag is given,
.Nm
will report the size of the kernel symbol table and the size of the
db_symtab space.
Two values are printed out in a line separated by a space.
.Pp
If the
.Fl v
flag is given,
.Nm
will print out status information as
it is copying the symbol table.
.Pp
Note that debugging symbols are not useful to the
.Xr ddb 4
kernel debugger, so to minimize the size of the kernel, one should
either compile the kernel without debugging symbols (no
.Fl g
flag) or use the
.Xr strip 1
command to strip debugging symbols from the kernel before
.Nm
is used to copy the symbol table.
The command
.Dl strip -d netbsd
will strip out debugging symbols.
.Sh SEE ALSO
.Xr strip 1 ,
.Xr ddb 4