rvdb disables mouse

[UweBonnes]

Hello,

I can see the GD32FV chips now. Debugger is a LPCLinkV2 with newest firmware.

./cmd/rvdbg/rvdbg --i daplink -t gd32v
2020/12/02 19:32:43 main.go:136 main(): INFO using debug interface: daplink
2020/12/02 19:32:43 rv13.go:68 New(): INFO 0.13 debug module
2020/12/02 19:32:44 rv13.go:133 New(): INFO hartsellen 10
2020/12/02 19:32:44 rv13.go:157 New(): INFO sbasize 0
2020/12/02 19:32:44 rv13.go:193 New(): INFO progbufsize 2 impebreak 1 autoexecprogbuf true
2020/12/02 19:32:44 rv13.go:194 New(): INFO datacount 4 autoexecdata true
2020/12/02 19:32:44 rv13.go:228 New(): INFO 1 hart(s) found
2020/12/02 19:32:44 hart.go:326 examine(): INFO hart0: MXLEN 32
2020/12/02 19:32:44 hart.go:334 examine(): INFO hart0: MISA 0x40901105
2020/12/02 19:32:44 hart.go:383 examine(): INFO hart0: unable to determine FLEN
2020/12/02 19:32:44 hart.go:407 examine(): INFO hart0: MHARTID 0
2020/12/02 19:32:44 hart.go:419 examine(): INFO hart0: nscratch 2 words
2020/12/02 19:32:44 hart.go:420 examine(): INFO hart0: datasize 4 words
2020/12/02 19:32:44 hart.go:421 examine(): INFO hart0: dataaccess memory(1)
2020/12/02 19:32:44 hart.go:422 examine(): INFO hart0: dataaddr 0xc0
2020/12/02 19:32:44 hart.go:432 examine(): INFO hart0: disassembler ISA RV32 ext "acim"
gd32v.0r> exit
However when started, the mouse
Bus 001 Device 015: ID 046d:c050 Logitech, Inc. RX 250 Optical Mouse
gets unresponsive. Nothing in dmesg. Un/replug the mouse makes it usable again, until the next start of rvdb. Is your scan of the USB bus too aggressive?

[deadsy]

So CMSIS-DAP is a HID device , and so is your mouse.
I access them via the hidapi library. https://github.com/libusb/hidapi
If you haven't done so I recommend that you get and install the latest version of this library.
I haven't seen any interference issues between this code and other HID devices so the hidapi library being used may be a source of variance.

[UweBonnes]

I installed 0.9.0 for OpenSuse, but the problem persists. From the git page, hidapi-0.9.0 seems the latest. Otherwise I use hidapi also for the black magic probe debugger https://github.com/blacksphere/blackmagic/ . But I search via libusb for CMSIS-DAP devices and only later handle a cmsid-dap device found with hidapi.

BMP is also the cause for my interest in rvdbg. There is blackmagic-debug/blackmagic#292 and another branch starting riscv support. As BMP now also works with cmsis-dap and jlink, I can have one setup and test with rvdbg and bmp and so hope to get riscv support going. #292 is not for the present riscv debug version.

[deadsy]

0.10.1 is the latest.
That ok, I've actually been running 0.8.rc1. After a 6 year break they've started doing work on the library again.

If you have a segger jlink you might want to try that.

1. It's not HID so I don't think it'll have a problem with mice.
2. It's faster than CMSIS-DAP - that may be a bug in my cmsis-dap interface code, but at the moment the jlink is quite a bit faster.

[UweBonnes]

It is OK with 0.10.1 . Regarding speed: CMSIS-DAP can read and write chunks of memory on ARM with one USB command, so reading chunks on riscv needs to be assembled from lower level commands and probably needs a lot of USB round trips. libjaylink probably is more intelligent here.

[deadsy]

OK with 0.10.1

Good to know.

read and write chunks of memory on ARM with one USB command

For my usage of CMSIS-DAP and Jlink they both use basic JTAG operations - neither supports any macro operations to read/write RISC-V memory. But yes- fast USB is about minimising round trip transactions, and it may be that I can do something else to bundle together multiple state machine operations into a single USB transaction thereby achieve some speedup.

[UweBonnes]

Getting RISCV support into BMP would be another option. BMP can be used as is, with the GDB server running on the dongle and gdb attaching to the dongle usb-serial gdb device or with the gdb server running on the host and the PC exchanging low-and high level (SWD/Jtag) commands with the dongle via USB/serial. Running the server on the PC helps to develop algorithms.

[deadsy]

I'm not a big fan on the "gdb server on dongle" approach the BMP guys are using. I tend to like the idea of dongles just being jtag/swd so you can use put all the smarts in the host software. E.g. platform specific register field decodes.

In any case I tried hidapi 0.10.1 and that works fine for me. This is the CMSIS-DAP device I use:

https://www.artekit.eu/products/debug/ak-cmsis-dap/