GitHub - liuzhiping/lpc_jtag: Use a LPC2148 module as a JTAG probe and connect it to GDB via remote protocol over USB Serial.

Branches Tags

Name		Name	Last commit message	Last commit date
Latest commit History 3 Commits
lpcusb/target		lpcusb/target
ARM.h		ARM.h
ArmSingleStep.cpp		ArmSingleStep.cpp
ArmSingleStep.h		ArmSingleStep.h
FlashDriver.h		FlashDriver.h
HexConversion.cpp		HexConversion.cpp
HexConversion.h		HexConversion.h
JTAG_arm.cpp		JTAG_arm.cpp
JTAG_arm.h		JTAG_arm.h
JTAG_arm7tdmi.cpp		JTAG_arm7tdmi.cpp
JTAG_arm7tdmi.h		JTAG_arm7tdmi.h
JTAG_arm9tdmi.cpp		JTAG_arm9tdmi.cpp
JTAG_arm9tdmi.h		JTAG_arm9tdmi.h
JTAG_bf533.cpp		JTAG_bf533.cpp
JTAG_bf533.h		JTAG_bf533.h
LPC214x.h		LPC214x.h
LPCFlash.cpp		LPCFlash.cpp
LPCFlash.h		LPCFlash.h
Makefile		Makefile
README		README
Serial.h		Serial.h
Serial1.cpp		Serial1.cpp
Spec.txt		Spec.txt
TargetManager.cpp		TargetManager.cpp
TargetManager.h		TargetManager.h
Timer.cpp		Timer.cpp
Timer.h		Timer.h
USBSerialStream.cpp		USBSerialStream.cpp
USBSerialStream.h		USBSerialStream.h
WatchPointManager.cpp		WatchPointManager.cpp
WatchPointManager.h		WatchPointManager.h
blackfin.h		blackfin.h
config.h		config.h
cppreq.cpp		cppreq.cpp
crt0.s		crt0.s
debug_out.cpp		debug_out.cpp
debug_out.h		debug_out.h
fifo.h		fifo.h
fifotest.cpp		fifotest.cpp
gdbparser.cpp		gdbparser.cpp
gdbparser.h		gdbparser.h
jtag.cpp		jtag.cpp
jtag.h		jtag.h
jtag_asm.h		jtag_asm.h
jtag_asm.s		jtag_asm.s
jtag_backup.cpp		jtag_backup.cpp
jtag_sync.cpp		jtag_sync.cpp
ld.ld		ld.ld
ld1.ld		ld1.ld
ld1_RAM.ld		ld1_RAM.ld
main.cpp		main.cpp
stream.h		stream.h
syscalls.c		syscalls.c
target.h		target.h
uartStream.cpp		uartStream.cpp
uartStream.h		uartStream.h

Repository files navigation

LPCGDB

Introduction

This project was created as a means to enable fast, cheap and robust debugging of
embedded targets such as ARM, BlackFin and others.
By using a LPC214x chip alot of necessary functionality is already there, such as
USB, UART and a bunch of I/O pins.
The idea is that someone should be able to just buy 2 LPC prototype boards and use
one of them to debug the other via USB and gdb. (Also using MXDB)

Features

JTAG
ARM7 (r4 atleast)
ARM920T
BF533

FLASH Programming:
LPC21x using ISP/IAP?

GDB remote protocol.
Extended remote protocol. (A binary protocol for faster data rates, used by MXDB)

LPC2138 board pins:

J3:
19: RTCK
20: TDO
21: TDI
22: TCK
23: TMS
24: TRST
27: GND

10pin 20pin
1 VCC 1 VCC
2 nTRST 3 nTRST
3 TDI 5 TDI
4 TMS 7 TMS
5 TCK 9 TCK
6 TDO 13 TDO
7 nRST 15 nRST
8 GND Even pins GND
9 GND Even pins GND
10 GND Even pins GND

Example how to load and run something on the gp2x:

(gdb) file <myelf.elf>
(gdb) set debug remote 1
(gdb) target remote /dev/ttyACM0
CTRL-C
(gdb) monitor mmuoff
(gdb) monitor ll@0x100
(gdb) load
(gdb) c

Exmplanation of the "monitor" command.
It sends a command to the GDB stub as a string.
Commands implemented are: "ll", "mmuoff", "mmuon", "id", "targets", "flash", "lpcfreq"

"ll" Loads a small binary into the target RAM at the specified address, and then starts the core at that address.
The small program can read/write target memory communicate through a special debug register that can be read/written from JTAG while the processor is running.
Makes reading/writing memory alot faster.
It's important that the mmu is either off, or that you really know what you're doing regarding virtual addresses and cache.
Also that you don't overwrite the "ll" program with your binary.

"mmuoff" makes sure the MMU is turned off.

"mmuon" Does nothing useful atm.

"id" returns the idcode to GDB

"targets" returns the supported targets.

"flash" instantiates a flash driver, only lpc supported atm.

"lpcfreq" is used by the lpc flash driver internally, it's the lpc's crystal frequency in kHz (iirc)