dbsym(8) - NetBSD Manual Pages

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DBSYM(8)                NetBSD System Manager's Manual                DBSYM(8)


NAME

     dbsym -- copy kernel symbol table into db_symtab space


SYNOPSIS

     dbsym [-Ppv] [-b bfdname] kernel


DESCRIPTION

     dbsym is used to copy the symbol table in a newly linked kernel into the
     db_symtab array (in the data section) so that the 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 con-
     fig option like:
           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.

     To recognize kernel executable format, the -b flag specifies BFD name of
     kernel.

     If the -P flag is given, dbsym will report the size of the kernel symbol
     table.

     If the -p flag is given, dbsym 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.

     If the -v flag is given, dbsym will print out status information as it is
     copying the symbol table.

     Note that debugging symbols are not useful to the ddb(4) kernel debugger,
     so to minimize the size of the kernel, one should either compile the ker-
     nel without debugging symbols (no -g flag) or use the strip(1) command to
     strip debugging symbols from the kernel before dbsym is used to copy the
     symbol table.  The command
           strip -d netbsd
     will strip out debugging symbols.


SEE ALSO

     strip(1), ddb(4)

NetBSD 10.1                     August 14, 2014                    NetBSD 10.1