I can confirm this works for me too. I’m using an FTDI 2232-based Flyswatter2. I only tried with Telnet, not GDB yet. I didn’t see performance issues with Telnet. Will follow-up once I try GDB.
Thank you for posting. It saved me a ton of time trying to figure it out. I would definitely be interested in reading a blog post on how you all worked this out.
Update: Here’s the blog post: VisionFive JTAG adventures, Part 1: JH7100 GPIO -- dramforever
I originally planned to add all sorts of random stuff I found, but decided to just do a part 1 with the JTAG info first.
文章很精彩！！！我也需要JTAG适配器，强烈期待您出个视频特辑，请您推荐或者详细介绍您用的那款JTAG适配器！
我理解的是只要 3.3V 电平的，OpenOCD 支持的 JTAG 适配器都可以。目前听说可以正常连接到 VisionFive 的包括楼上提到的 Flyswatter2，我用的树莓派 GPIO，还有一个朋友用的 USB Blaster 都可以使用，没有明显差别。因为我之前没有用过 JTAG 适配器（要不然也不会拿个树莓派来凑合），所以暂时无法推荐。
我用的就是一个树莓派 4B，用上面的 gpio 端口当成 jtag 用，参考的这两个配置文件编写：
我在树莓派上用的发行版的内核限制了 /dev/mem，所以用不了 bcm2835gpio，我就把两个配置文件里的东西组合了一下，用 linuxgpiod 驱动，但是用树莓派的端口号。JTAG 连接如下，编号是 40-pin 针的编号：
gnd 6
tck 23
tms 22
tdi 19
tdo 21
trst 26
和树莓派那个配置文件里说的一样：
# Do not forget the GND connection, pin 6 of the expansion header.
# Each of the JTAG lines need a gpio number set: tck tms tdi tdo
# Header pin numbers: 23 22 19 21
# Header pin numbers: TRST - 26
抱歉，我之前也没有用过 JTAG，没有这方面经验
您的提点！！！就是给了我正确的学习方向！！！感谢！！！
『只要 3.3V 电平的，OpenOCD 支持的 JTAG 适配器』
『一个树莓派 4B，用上面的 gpio 端口当成 jtag 用』
我使用sifive的openocd，为什么会提示找不到适配器呢？
Open On-Chip Debugger 0.11.0-rc1+dev (SiFive OpenOCD 0.10.0-2020.12.1)
Licensed under GNU GPL v2
For bug reports:
https://github.com/sifive/freedom-tools/issues
Error: The specified debug interface was not found (linuxgpiod)
The following debug adapters are available:
1: ftdi
2: usb_blaster
3: jtag_vpi
4: ft232r
5: presto
6: usbprog
7: openjtag
可能 sifive 的 openocd 不支持这个功能，我用的是 GitHub - riscv/riscv-openocd: Fork of OpenOCD that has RISC-V support
另外就是这个上面的几行需要根据具体使用的 adapter 设置，我用的树莓派所以是 linuxgpiod，用别的适配器的话需要具体参考 openocd 文档设置
I’m interesting in how do you change config.tcl file in ftdi2232? I’ve tried it but it can’t recongnize the visionfive
I have noticed that TRSTN isn’t pulled up in location b, so if your adapter does not have a TRSTN output, connect the board TRSTN to 3.3V through a pull-up resistor (~10k should be fine).
请问你们有遇到这样的问题嘛？接线也检查过了
PS E:\> openocd -f .\visionfive.cfg
Open On-Chip Debugger 0.11.0-rc1+dev (SiFive OpenOCD 0.10.0-2020.12.1)
Licensed under GNU GPL v2
For bug reports:
https://github.com/sifive/freedom-tools/issues
Info : auto-selecting first available session transport "jtag". To override use 'transport select <transport>'.
Warn : Transport "jtag" was already selected
Info : Hardware thread awareness created
Info : clock speed 3000 kHz
Info : JTAG tap: e24.cpu tap/device found: 0xffffffff (mfg: 0x7ff (<invalid>), part: 0xffff, ver: 0xf)
Warn : JTAG tap: e24.cpu UNEXPECTED: 0xffffffff (mfg: 0x7ff (<invalid>), part: 0xffff, ver: 0xf)
Error: JTAG tap: e24.cpu expected 1 of 1: 0x200005fd (mfg: 0x2fe (W5 Networks), part: 0x0000, ver: 0x2)
Info : JTAG tap: u74.cpu tap/device found: 0xffffffff (mfg: 0x7ff (<invalid>), part: 0xffff, ver: 0xf)
Warn : JTAG tap: u74.cpu UNEXPECTED: 0xffffffff (mfg: 0x7ff (<invalid>), part: 0xffff, ver: 0xf)
Error: JTAG tap: u74.cpu expected 1 of 1: 0x200003fd (mfg: 0x1fe (TeraChip), part: 0x0000, ver: 0x2)
Warn : Unexpected idcode after end of chain: 192 0xff80feff
Error: double-check your JTAG setup (interface, speed, ...)
Error: Trying to use configured scan chain anyway...
Error: e24.cpu: IR capture error; saw 0x1f not 0x01
Warn : Bypassing JTAG setup events due to errors
Error: Unsupported DTM version: 15
Warn : target e24.cpu0 examination failed
Error: Unsupported DTM version: 15
Warn : target u74.cpu0 examination failed
Error: Unsupported DTM version: 15
Warn : target u74.cpu1 examination failed
Info : starting gdb server for e24.cpu0 on 3333
Info : Listening on port 3333 for gdb connections
Info : starting gdb server for u74.cpu0 on 3334
Info : Listening on port 3334 for gdb connections
Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Btw Segger J-link has just added support for most of Sifive cores in newest driver.
sifive我用的这个配置可以进入openocd，但是巨慢（stepi 6s）https://gist.github.com/a4lg/f5109021dd5bfeb2b8bdf552c00797d2
你的adaptor用的肯定不是树莓派呀
请问一下，如果直接用jlink v11链接vf的话，要咋弄呀？
写一个连接配置脚本，我给vf2是这么写的，不知道vf1能不能用：
int InitTarget(void) {
//
// TDI -> TAP_#1 -> TAP_#0 -> TDO
//
// TAP_#0 info:
// Maybe E24?
// IRLen: 5
//
// TAP_#1 info:
// U74-MC here
// IRLen: 5
//
//
// Code to connect to TAP_#1
//
JLINK_JTAG_DRPre = 1;
JLINK_JTAG_DRPost = 0;
JLINK_JTAG_IRPre = 5;
JLINK_JTAG_IRPost = 0;
JLINK_JTAG_IRLen = 5;
JLINK_SetDevice("U74-MC");
return 0;
}
参考：
I’m facing the same issue but with JH7110 based VF2, with integration kernel tree.
Solved (partially) on those upstream-based kernels by appending:
jtag_pins_uboot: jtag-0 {
rst-pins {
pinmux = <GPIOMUX(36, GPOUT_HIGH, GPOEN_DISABLE, GPI_SYS_JTAG_RST)>;
input-enable;
};
tdi-pins {
pinmux = <GPIOMUX(61, GPOUT_HIGH, GPOEN_DISABLE, GPI_SYS_JTAG_TDI)>;
input-enable;
};
tms-pins {
pinmux = <GPIOMUX(63, GPOUT_HIGH, GPOEN_DISABLE, GPI_SYS_JTAG_TMS)>;
input-enable;
};
tck-pins {
pinmux = <GPIOMUX(60, GPOUT_HIGH, GPOEN_DISABLE, GPI_SYS_JTAG_TCK)>;
input-enable;
};
tdo-pins {
pinmux = <GPIOMUX(44, GPOUT_SYS_JTAG_TDO, GPOEN_SYS_JTAG_TDO, GPI_NONE)>;
input-disable;
input-schmitt-disable;
drive-strength = <2>;
slew-rate = <0>;
};
};
into:
&sysgpio {
...
}
and replacing the conflicting dtm pinmux with above one:
&tdm {
pinctrl-names = "default";
pinctrl-0 = <&jtag_pins_uboot>;
status = "okay";
};
OpenOCD would still be disconnected shortly when configuring related pinmux but it is possible to reconnect.