本文介绍openocd开源软件的安装以及搭配JTAG对Xilinx u500VC707devkit的调试
PC OS: Ubuntu20.04 LTS
Target ARCH: riscv64
JTAG: Olimex-ARM-USB-TINY-H
OpenOCD version: OpenOCD v0.10.0
1、OpenOCD简介
OpenOCD(Open On-Chip Debugger)是一款开源的开放式片上调试软件，需要在调试适配器(如: JTAG、SWD等)的配合下可以对片上系统进行相应调试，以及在嵌入式设备上测试系统内程序或边界接扫描测试。
2、下载OpenOCD
可以通过OpenOCD官网下载源码，已经有很多平台提供配套目标平台的OpenOCD源码，也可以通过这些来下载带有相应目标平台配置文件的OpenOCD，本文主要介绍支持riscv64的OpenOCD下载和使用。
riscv-openocd下载链接: https://github.com/sifive/riscv-openocd
通过git下载：
git clone https://github.com/sifive/riscv-openocd.git
3、编译与安装
<1> 进入riscv-openocd源码目录
imaginemiracle@:openocd$ cd riscv-openocd
imaginemiracle@:riscv-openocd$ ls
AUTHORS ChangeLog COPYING HACKING NEWS-0.10.0 NEWS-0.5.0 NEWS-0.9.0 README.Windows TODO
AUTHORS.ChangeLog config_subdir.m4 doc jimtcl NEWS-0.2.0 NEWS-0.6.0 NEWTAPS src tools
bootstrap configure.ac Doxyfile.in Makefile.am NEWS-0.3.0 NEWS-0.7.0 README tcl uncrustify.cfg
BUGS contrib guess-rev.sh NEWS NEWS-0.4.0 NEWS-0.8.0 README.OSX testing
<2> 执行bootstrap生成configure文件，通过configure配置OpenOCD，主要需要配置OpenOCD支持的调试器的类型，笔者使用的JTAG为FTDI类型，因此需要OpenOCD支持FTDI。
[注] 通过查看JTAG手册了解所使用的JTAG是什么类型，通过./configure --help 命令查看所需要开启的类型以及其它配置参数
#创建安装目录
imaginemiracle@:riscv-openocd$ mkdir install_IM
#执行bootstrap
imaginemiracle@:riscv-openocd$ ./bootstrap
bootstrap执行的正常输出：
+ aclocal
+ libtoolize --automake --copy
+ autoconf
+ autoheader
+ automake --gnu --add-missing --copy
configure.ac:26: installing './compile'
configure.ac:37: installing './config.guess'
configure.ac:37: installing './config.sub'
configure.ac:16: installing './install-sh'
configure.ac:16: installing './missing'
Makefile.am:46: warning: wildcard $(srcdir: non-POSIX variable name
Makefile.am:46: (probably a GNU make extension)
Makefile.am: installing './INSTALL'
Makefile.am: installing './depcomp'
Makefile.am:23: installing './mdate-sh'
Makefile.am:23: installing './texinfo.tex'
Setting up submodules
Submodule 'jimtcl' (https://github.com/msteveb/jimtcl) registered for path 'jimtcl'
Cloning into '/media/imaginemiracle/Disk_D/Linux_Workspace/riscv-project/File_System_test/openocd/riscv-openocd/jimtcl'...
Submodule path 'jimtcl': checked out '51f65c6d38fbf86e1f0b036ad336761fd2ab7fa0'
Submodule path 'jimtcl': checked out '51f65c6d38fbf86e1f0b036ad336761fd2ab7fa0'
Generating build system...
libtoolize: putting auxiliary files in AC_CONFIG_AUX_DIR, 'build-aux'.
libtoolize: copying file 'build-aux/config.guess'
libtoolize: copying file 'build-aux/config.sub'
libtoolize: copying file 'build-aux/install-sh'
libtoolize: copying file 'build-aux/ltmain.sh'
libtoolize: putting macros in AC_CONFIG_MACRO_DIRS, 'm4'.
libtoolize: copying file 'm4/libtool.m4'
libtoolize: copying file 'm4/ltoptions.m4'
libtoolize: copying file 'm4/ltsugar.m4'
libtoolize: copying file 'm4/ltversion.m4'
libtoolize: copying file 'm4/lt~obsolete.m4'
configure.ac:42: installing 'build-aux/ar-lib'
configure.ac:37: installing 'build-aux/compile'
configure.ac:30: installing 'build-aux/missing'
Makefile.am: installing './INSTALL'
libjaylink/Makefile.am: installing 'build-aux/depcomp'
Bootstrap complete. Quick build instructions:
./configure ....
成功生成configure文件
#配置安装目录路径必须为绝对路径
imaginemiracle@:riscv-openocd$ ./configure --prefix=/home/imaginemiracle/Disk_D/Linux_Workspace/riscv-project/File_System_test/openocd/openocd-0.10.0/install_IM/ --enable-ftdi
###################只显示关键输出####################
checking that generated files are newer than configure... done
configure: creating ./config.status
config.status: creating Makefile
config.status: creating libjaylink/Makefile
config.status: creating libjaylink/version.h
config.status: creating libjaylink.pc
config.status: creating Doxyfile
config.status: creating config.h
config.status: executing depfiles commands
config.status: executing libtool commands
看到成功成生Makefile文件且没有报错，则说明配置成功。
<3> 配置成功后直接编译并安装即可
直接使用make; make install编译并安装
#编译后并且安装
imaginemiracle@:riscv-openocd$ make; make install
若make; make install直接通过，则跳过<4>这一节直接看下一节的openocd使用介绍。
<4> 编译openocd可能会遇到如下几种错误
<4.1> 报错 1: src/svf/svf.c:663:7: error: this statement may fall through [-Werror=implicit-fallthrough=]
#错误1
src/svf/svf.c: In function ‘svf_read_command_from_file’:
src/svf/svf.c:663:7: error: this statement may fall through [-Werror=implicit-fallthrough=]
663 | i = -1;
| ~~^~~~
src/svf/svf.c:664:4: note: here
664 | case '
':
| ^~~~
src/svf/svf.c:667:8: error: this statement may fall through [-Werror=implicit-fallthrough=]
667 | if (!cmd_pos)
| ^
src/svf/svf.c:669:4: note: here
669 | default:
| ^~~~~~~
cc1: all warnings being treated as errors
解决方案 1: 通过源码分析可以看出，这块的报错只是因为在switch case语句中一个case没有写break，编译器识别到可能会跳到下一个case语句中，因此在这里直接忽略该错误继续编译即可。
imaginemiracle@:openocd$ make -j8 CFLAGS='-Wno-implicit-fallthrough'
<4.2> 报错 2: src/target/arm_disassembler.c:1499:30: error: bitwise comparison always evaluates to false [-Werror=tautological-compare]
#错误2
src/target/arm_disassembler.c: In function ‘evaluate_misc_instr’:
src/target/arm_disassembler.c:1499:30: error: bitwise comparison always evaluates to false [-Werror=tautological-compare]
1499 | if (((opcode & 0x00600000) == 0x00100000) && (x == 0)) {
| ^~
src/target/arm_disassembler.c:1521:29: error: bitwise comparison always evaluates to false [-Werror=tautological-compare]
1521 | if ((opcode & 0x00600000) == 0x00300000) {
| ^~
src/target/arm_disassembler.c:1542:30: error: bitwise comparison always evaluates to false [-Werror=tautological-compare]
1542 | if (((opcode & 0x00600000) == 0x00100000) && (x == 1)) {
| ^~
解决方案 2: 按照道理说这种写法是没什么问题的，但还是会报错，因此将报错的三个位置进行修改，修改后的代码如下。
imaginemiracle@:openocd$ vim src/target/arm_disassembler.c +1499
//File src/target/arm_disassembler.c +1499:In function 'evaluate_misc_instr'
/* SMLAW < y> */
//============================Alter by me==============================
if (!(((opcode & 0x00600000) - 0x00100000)) && (x == 0)) {
//============================ End Alter ==============================
uint8_t Rd, Rm, Rs, Rn;
instruction->type = ARM_SMLAWy;
Rd = (opcode & 0xf0000) >> 16;
Rm = (opcode & 0xf);
Rs = (opcode & 0xf00) >> 8;
Rn = (opcode & 0xf000) >> 12;
snprintf(instruction->text,
128,
"0x%8.8" PRIx32 " 0x%8.8" PRIx32 " SMLAW%s%s r%i, r%i, r%i, r%i",
address,
opcode,
(y) ? "T" : "B",
COND(opcode),
Rd,
Rm,
Rs,
Rn);
}
/* SMUL < x><y> */
//============================Alter by me==============================
if (!((opcode & 0x00600000) - 0x00300000)) {
//============================ End Alter ==============================
uint8_t Rd, Rm, Rs;
instruction->type = ARM_SMULxy;
Rd = (opcode & 0xf0000) >> 16;
Rm = (opcode & 0xf);
Rs = (opcode & 0xf00) >> 8;
snprintf(instruction->text,
128,
"0x%8.8" PRIx32 " 0x%8.8" PRIx32 " SMULW%s%s%s r%i, r%i, r%i",
address,
opcode,
(x) ? "T" : "B",
(y) ? "T" : "B",
COND(opcode),
Rd,
Rm,
Rs);
}
/* SMULW < y> */
//============================Alter by me==============================
if (!(((opcode & 0x00600000) - 0x00100000)) && (x == 1)) {
//============================ End Alter ==============================
uint8_t Rd, Rm, Rs;
instruction->type = ARM_SMULWy;
Rd = (opcode & 0xf0000) >> 16;
Rm = (opcode & 0xf);
Rs = (opcode & 0xf00) >> 8;
snprintf(instruction->text,
128,
"0x%8.8" PRIx32 " 0x%8.8" PRIx32 " SMULW%s%s r%i, r%i, r%i",
address,
opcode,
(y) ? "T" : "B",
COND(opcode),
Rd,
Rm,
Rs);
}
<4.3> 报错 3: src/target/nds32_cmd.c:824:21: error: ‘sprintf’ writing a terminating nul past the end of the destination [-Werror=format-overflow=]
#错误3
src/target/nds32_cmd.c: In function ‘jim_nds32_bulk_read’:
src/target/nds32_cmd.c:824:21: error: ‘sprintf’ writing a terminating nul past the end of the destination [-Werror=format-overflow=]
824 | sprintf(data_str, "0x%08" PRIx32 " ", data[i]);
| ^~~~~~~
src/target/nds32_cmd.c:824:38: note: format string is defined here
824 | sprintf(data_str, "0x%08" PRIx32 " ", data[i]);
| ^
src/target/nds32_cmd.c:824:3: note: ‘sprintf’ output 12 bytes into a destination of size 11
824 | sprintf(data_str, "0x%08" PRIx32 " ", data[i]);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
解决方案 3: 从错误类型format-overflow，格式溢出，一看就是不重要的错误，直接忽略就好继续编译。
imaginemiracle@:openocd$ make -j8 CFLAGS='-Wno-implicit-fallthrough -Wno-format-overflow'
<4.4> 报错 4: /usr/include/x86_64-linux-gnu/sys/sysctl.h:21:2: error: #warning "The <sys/sysctl.h> header is deprecated and will be removed." [-Werror=cpp]
#错误4
In file included from src/helper/options.c:38:
/usr/include/x86_64-linux-gnu/sys/sysctl.h:21:2: error: #warning "The <sys/sysctl.h> header is deprecated and will be removed." [-Werror=cpp]
21 | #warning "The <sys/sysctl.h> header is deprecated and will be removed."
| ^~~~~~~
cc1: all warnings being treated as errors
解决方案 4: 可以看出这里是使用了Linux已经移除的头文件<sys/sysctl.h>报错的，因此进入报错文件，做以下修改。
imaginemiracle@:openocd$ vim src/helper/options.c +38
//File src/helper/options.c +38
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "configuration.h"
#include "log.h"
#include "command.h"
#include <getopt.h>
#include <limits.h>
#include <stdlib.h>
#if IS_DARWIN
#include <libproc.h>
#endif
//===================Alter by me===================
#ifdef HAVE_SYS_SYSCTL_H
//#include <sys/sysctl.h>
#endif
#if IS_WIN32 && !IS_CYGWIN
#include <windows.h>
#endif
//=================== End Alter ===================
static int help_flag, version_flag;
4、OpenOCD的使用
4.1、OpenOCD的配置
安装成功后则会在配置的安装目录里生成如下文件，这里的openocd就是需要用到的可执行程序将它拷贝到需要执行的目录，或者直接在当前目录使用也可以。([注]: 若未配置安装路径，默认安装到“./src目录”中)
imaginemiracle@:openocd$ cd install_IM/
imaginemiracle@:install_IM$ ls
bin share
imaginemiracle@:install_IM$ ls bin/
openocd
imaginemiracle@:openocd$ cp install_IM/bin/openocd ./
使用openocd+JTAG需要用到两个配置文件，分别是JTAG的配置文件和目标平台的配置文件。一般JTAG厂商都会提供购买到的JTAG的openocd配置文件，这里就可以直接使用。
<1> JTAG设备配置文件
前文提到笔者所使用的JTAG型号为Olimex-ARM-USB-TINY-H，其配置文件如下:
# File olimex-arm-usb-tiny-h.cfg
#
# Olimex ARM-USB-TINY-H
#
# http://www.olimex.com/dev/arm-usb-tiny-h.html
#
interface ftdi
#interface jlink
ftdi_device_desc "Olimex OpenOCD JTAG ARM-USB-TINY-H"
ftdi_vid_pid 0x15ba 0x002a
ftdi_layout_init 0x0808 0x0a1b
ftdi_layout_signal nSRST -oe 0x0200
ftdi_layout_signal nTRST -data 0x0100 -oe 0x0100
ftdi_layout_signal LED -data 0x0800
当电脑链接上JTAG后，还需要安装JTAG的驱动，若“lsusb”可以查看到JTAG设备，则说明驱动安装成功。
imaginemiracle@:openocd$ lsusb
Bus 002 Device 002: ID 0424:5744 Microchip Technology, Inc. (formerly SMSC) Hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 004: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)
Bus 001 Device 003: ID 0424:2744 Microchip Technology, Inc. (formerly SMSC) Hub
Bus 001 Device 007: ID 413c:2113 Dell Computer Corp. Dell KB216 Wired Keyboard
Bus 001 Device 006: ID 413c:301a Dell Computer Corp. Dell MS116 USB Optical Mouse
Bus 001 Device 008: ID 15ba:002a Olimex Ltd. ARM-USB-TINY-H JTAG interface
Bus 001 Device 002: ID 10c4:ea60 Silicon Labs CP210x UART Bridge
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
这里的ID后面的值分别为USB设备的VID和PID，这里的值应该与JTAG配置文件中的vid_pid相同才可。
<2> 目标平台配置文件
OpenOCD的配置文件使用的是tcl语言，这里的目标平台配置文件是笔者仿照其它配置文件修改的。
# File riscv64_IM.cfg
proc init_targets {} {
adapter_khz 1000
reset_config trst_and_srst
set _CHIPNAME riscv
jtag newtap $_CHIPNAME cpu -irlen 5
set _TARGETNAME $_CHIPNAME.cpu
target create $_TARGETNAME riscv -endian little -chain-position $_TARGETNAME -coreid 0
# $_TARGETNAME configure -rtos riscv
# $_TARGETNAME configure -work-area-phys 0x3ff0000 -work-area-size 0x10000 -work-area-backup 1
# $_TARGETNAME riscv expose_csrs 3008-3015,4033-4034
}
proc sw_reset_halt {} {
reset halt
}
4.2、OpenOCD链接JTAG
有了JTAG和目标平台的两个配置文件后，就可以启动OpenOCD连接本地JTAG设备了，启动命令如下：
imaginemiracle@:riscv-openocd$ sudo ./src/openocd -s ./tcl -f ./tcl/interface/ftdi/olimex-arm-usb-tiny-h.cfg -f ./tcl/target/riscv64_IM.cfg
[sudo] password for imaginemiracle:
Open On-Chip Debugger 0.10.0+dev-01145-gb7bd3f8d4 (2021-01-12-17:54)
Licensed under GNU GPL v2
For bug reports, read
http://openocd.org/doc/doxygen/bugs.html
sw_reset_halt
Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Info : auto-selecting first available session transport "jtag". To override use 'transport select <transport>'.
0
Info : clock speed 1000 kHz
Info : TAP riscv.cpu has invalid IDCODE (0xfffffffe)
Info : datacount=2 progbufsize=16
Info : Disabling abstract command reads from CSRs.
Info : Examined RISC-V core; found 4 harts
Info : hart 0: XLEN=64, misa=0x800000000014112d
Info : hart 1: currently disabled
Info : hart 2: currently disabled
Info : hart 3: currently disabled
Info : Listening on port 3333 for gdb connections
连接到本地：
imaginemiracle@:riscv-openocd$ telnet localhost 4444
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Open On-Chip Debugger
>
如上进入openocd的命令行则说明OpenOCD+JTAG的整个软件环境搭建完成。
4.3、OpenOCD的一些简单命令
OpenOCD常用命令
halt -暂停CPU
reset -复位目标板
resume -恢复运行
resume 0x123456 -从0x123456地址恢复运行
reg <register> -打印register寄存器的值
load_image <File Name> <Addr> -烧写二进制文件到指定地址
例: load_image image.bin 0x4000000 -烧写image.bin到0x4000000
dump_image <File Name> <Addr> <Size> -将内存从地址Addr开始的Size字节数据读出，保存到文件File Name中
verify_image <File Name> <Addr> [bin|ihex|elf] -将文件File Name与内存Addr开始的数据进行比较，格式可选，bin、ihex、elf
step [Addr] -不加地址：从当前位置单步执行; 加地址：从Addr处单步执行
poll -查询目标板当前状态
bp <Addr> <Length> [hw] -在Addr地址设置断点，指令长度为Length，hw代表硬件断点
rbp <Addr> -删除Addr处的断点
mdw <Addr> [Count] -显示从物理地址Addr开始的Count(缺省则默认为1)个字（4Bytes）
mdh <Addr> [Count] -显示从物理地址Addr开始的Count(缺省则默认为1)个半字（2Bytes）
mdb <Addr> [Count] -显示从物理地址Addr开始的Count(缺省则默认为1)个字节（1Byte）
mww <Addr> <Value> -向物理地址Addr写入Value，大小：一个字（4Bytes）
mwh <Addr> <Value> -向物理地址Addr写入Value，大小：一个半字（2Bytes）
mwb <Addr> <Value> -向物理地址Addr写入Value，大小：一个字节（1Bytes）