IPKDB(9)						   BSD Kernel Developer's Manual						  IPKDB(9)

NAME

     ipkdb -- machine-dependent interface to ipkdb

SYNOPSIS

     #include <ipkdb/ipkdb.h>

     void
     ipkdb_init(void);

     void
     ipkdb_connect(int when);

     int
     ipkdbcmds(void);

     void
     ipkdbinit(void);

     void
     ipkdb_trap(void);

     int
     ipkdb_poll(void);

     int
     ipkdbif_init(struct ipkdb_if *kip);

     int
     ipkdbfbyte(u_char *c);

     int
     ipkdbsbyte(u_char *c, int i);

DESCRIPTION

     The machine-dependent code must support this interface for operation with ipkdb(4).

     During system bootstrap, machine-dependent code must invoke ipkdb_init().	If the kernel is booted with RB_KDB set in boothowto (see
     boothowto(9)), ipkdb(4) is enabled by invoking ipkdb_connect(), setting the when argument to 0.

     ipkdbcmds() is invoked by machine-dependent code when the trap mechanism determines that the debugger should be entered, i.e., on a single
     step or breakpoint interrupt from kernel code.  The trapping mechanism should already have stored the registers into the global area ipkd-
     bregs.  The layout of this area must be the same as that expected by gdb(1).  Valid return values are:

	   IPKDB_CMD_RUN     user wants to continue
	   IPKDB_CMD_STEP    user wants to do single stepping
	   IPKDB_CMD_EXIT    user has detached from debugging

FUNCTIONS

     The machine-dependent code must provide the following functions for the machine-independent code.
     ipkdbinit()	  This routine gets called when the debugger should be entered for the first time.
     ipkdb_trap()	  This routine is part of the trap handler.  Whenever a trap happens (e.g., when hitting a breakpoint during debugging),
			  ipkdb_trap() decides if the Debugger needs to be called.  If there are other ways to decide that, it's not necessary to
			  provide an ipkdb_trap() implementation.
     ipkdb_poll()	  This routine gets called after a panic to check for a key press by the user.	If implemented it allows the user to press
			  any key on the console to do the automatic reboot after a panic.  Otherwise the debugging interface will wait forever
			  for some remote debugger to attach in case of a panic.
     ipkdbif_init(kip)	  In order to be able to find the debugging interface, the network driver must invoke ipkdbif_init() with kip specifying a
			  struct ipkdb_if plus some additional parameters that allow it to access the devices registers, hopefully using
			  bus_space(9) methods.  In the ipkdb_if structure, the attach routine must initialize the following fields:

				myenetaddr  fill this with the own ethernet address of the device/machine
				flags	    mark at least IPKDB_MYHW here
				name	    name of the device, only used for a message
				start	    routine called every time ipkdb is entered
				leave	    routine called every time ipkdb is left
				receive     routine called to receive a packet
				send	    routine called to send a packet

			  Additional fields that may be set are:

				myinetaddr  fill this with the own internet address, and mark IPKDB_MYIP in flags
				port	    may be used as a pointer to some device
     ipkdbfbyte(c)	  This routine should fetch a byte from address c.  It must not enter any trap handling code, but instead return -1 on
			  inability to access the data.
     ipkdbsbyte(c, i)	  This routine should set the byte pointed to by c to the value given as i.  The routine must not enter any trap handling
			  code.  Furthermore it should reset the modification bit in the relevant page table entry to the value before the store.

SEE ALSO

     ipkdb(4), boothowto(9)

BSD
								 September 4, 2009							       BSD