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 config 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 kernel 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)