How to debug ash_main function in the ash.c by gdb?

[ruifeng yang]

Hello everyone:
     I am reading the busybox's sources,the busybox version is 1.13.4.
     I want to debug the int ash_main(int argc UNUSED_PARAM, char **argv)
function,
     How to do it?

     [root at beijing2008 busybox-1.13.4]# gdb busybox_unstripped
     GNU gdb Red Hat Linux (5.3post-0.20021129.18rh)
     Copyright 2003 Free Software Foundation, Inc.
     GDB is free software, covered by the GNU General Public License, and
you are
     welcome to change it and/or distribute copies of it under certain
conditions.
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     This GDB was configured as "i386-redhat-linux-gnu"...
     (gdb) list
     759     #endif /* !defined(SINGLE_APPLET_MAIN) */
     760
     761
     762
     763     #if ENABLE_BUILD_LIBBUSYBOX
     764     int lbb_main(char **argv)
     765     #else
     766     int main(int argc UNUSED_PARAM, char **argv)
     767     #endif
     768     {
     (gdb) b ash_main
      Breakpoint 1 at 0x805497e: file shell/ash.c, line 13735.
     (gdb) run
     Starting program: /home/yrff/cli/busybox-1.13.4/busybox_unstripped
     BusyBox v1.13.4-200906081408 (2009-06-10 14:48:31 CST) multi-call
binary
     Copyright (C) 1998-2008 Erik Andersen, Rob Landley, Denys Vlasenko
     and others. Licensed under GPLv2.
     See source distribution for full notice.

     Usage: busybox [function] [arguments]...
        or: function [arguments]...

             BusyBox is a multi-call binary that combines many common Unix
             utilities into a single executable.  Most people will create a
             link to busybox for each function they wish to use and BusyBox
             will act like whatever it was invoked as!

     Currently defined functions:
             ash, cttyhack, sh


     Program exited normally.
     (gdb)
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