
October 13 1995, Draft 1
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Chapter 7 Software Debugging
structure. The procedures currently available are listed in Table 7-4. According to
GDB configuration convention, the file
remote–udi.c
must be used to implement the
remote interface procedures. In the case of interfacing to the IPC mechanism used by
UDI, the procedures in Table 7-4 are mapped into the UDI–p procedures given in
Table 7-2. With the availability of the UDI–p library, it is a simple task to map the
GDB remote interface procedures for socket communication with a remote target
processor.
Table 7-4.
GDB Remote–Target Operations
Function
Operation
to_open()
to_close()
to_attach()
to_detach()
to_start()
to_wait()
to_resume()
to_fetch_register()
to_store_register()
to_xfer_memory()
to_insert_breakpoint()
to_remove_breakpoint()
to_load()
Open communication connection to remote target
Close connection to remote target
Attach to a loaded and running program
Detach for multitarget debugging
Load program into target–system memory
Wait until target–system execution stops
Startup/Continue target–system execution
Read target–system processor register(s)
Write register(s) in target–system processor
Read/Write data to target–system memory
Establish an instruction break address
Remove a breakpoint
Load a program into target–processor memory
7.5.5 The UDI–MiniMON29K Monitor Connection, MonTIP
MiniMON29K monitor code can not function without the support of a software
module located in a support processor; the software module is known as the target
interface process (TIP). The 29K target processor communicates with the processor
running the TIP process via a serial link or other higher performance channel. This
link supports a message system which is private to the MiniMON29K monitor, by
that I mean it is completely independent of the UDI protocol. (See Figure 7-2.)
MiniMON29K must be installed in target system ROM memory or down–
loaded by the TIP host via a shared memory interface. The target application code,
and additional operating system code, can then be down–loaded via the message sys-
tem. If changes to the code are required, then the message system can be used to
quickly down–load new code without changing any ROM devices.
The MiniMON29K TIP process,
montip
, converts UDI service requests into
MiniMON29K messages. The
montip
program which runs on UNIX machines, typ-
ically communicates with the target using an rs232 link. When run on DOS ma-
chines, it may communicate using an rs232 connection or a PC plug–in board shared
memory scheme. Note, UNIX machines can be also used to debug PC plug–in cards;
the
pcserver
program, run on DOS machines, enables the PC serial port to be con-