Claim interface on OS X.

[tcr]

This might not be useful to merge in, but this is the fix I had to apply to fix endpoint enumeration failing on OS X. See #9 for the same error message.

[gicking]

hi Tim,

with your change to main.c (see here) and the described unloading of the kernel extensions (see here) I can now program using stm8flash under MacOS X. Thanks a lot for that!

But is unloading the kernel extensions the only possible solution? Afterwards I cannot use USB-sticks or SD-cards. And I am concerned that I forget to re-load them and lose this important functionality - until reboot (just checked) or I find this thread again...

Under Linux and Windows the ST-Link mounts as a drive with 3 files, under OS X not. Is that the reason why the kernel extensions have to be disabled? If yes, would it be an option to identify and solve the issue with mounting the ST-Link? Sorry to be so annoying, but the current solution just seems very complicated.

For your support thanks a lot in advance!

Georg

[tcr]

But is unloading the kernel extensions the only possible solution? Afterwards I cannot use USB-sticks or SD-cards. And I am concerned that I forget to re-load them and lose this important functionality - until reboot (just checked) or I find this thread again...

There are lots of issues with USB CDC drivers too on OS X which require unloading. You may find some luck in looking into if there are solutions there (google kextunload, CDC, Arduino)

Under Linux and Windows the ST-Link mounts as a drive with 3 files, under OS X not. Is that the reason why the kernel extensions have to be disabled? If yes, would it be an option to identify and solve the issue with mounting the ST-Link?

That's the case. Inside USB Prober the device is listed as a Mass Storage Device, but why it doesn't mount is beyond me. I suspect that solving the mounting issues would not resolve this particular problem though—if it is an issue with the kernel claiming the device, the specified endpoints would still not be able to be accessed.

[TorstenRobitzki]

this works for me on OS/X without the need to unload any kernel extensions.

[gicking]

hi Torsten,

I just downloaded the fresh version of stm8flash from GitHub. And with patch #17 merged I can now compile and run "stm8flash" under MacOSX 10.10.3. However, I just still need to unload the Kernel extensions for USB-sticks and flash cards using:

sudo kextunload -b com.apple.driver.AppleUSBCardReader
sudo kextunload -b com.apple.iokit.IOUSBMassStorageClass

Any idea what do you do different? While the above is not the end of the world it makes stm8flash impossible to use for non-admins and it is inconvenient. Any help is highly appreciated!

Georg

[TorstenRobitzki]

Hi Georg,
sorry, no idea. I have a vanilla OS/X 10.9. and a colleague of mine uses 10.10. without problems. The only problem that we face is that stm8flash hangs very often. But that's fixable by unplugging and plugging the usb cable.

What are the symptoms you are facing?

Cheers,
Torsten

[gicking]

Hi Torsten,

below is the console output with and without unloading kernel extensions. This is similar to what is described (and solved) here

Georg

---

stm8flash -c stlink -p stm8s105 -w blinky.ihx
Determine FLASH area
Writing Intel hex file 427 bytes at 0x8000... OK
Bytes written: 427

---

stm8flash -c stlink -p stm8s105 -w blinky.ihx
Determine FLASH area
libusb: error [darwin_claim_interface] USBInterfaceOpen: another process has device opened for exclusive access
Assertion failed: (r == 0), function usb_init, file main.c, line 103.
make: *** [flash] Abort trap: 6

[TorstenRobitzki]

It would be interesting to know which other process claimed the usb device. Does this occur when starting stm8flash the first time on a freshly booted computer?

[tcr]

I think the process is the kernel extension itself, e.g. AppleUSBCardReader is trying to read the STM8 board as a mass storage device (as its USB descriptor states). As long as the kernel thinks it can talk to the device, it will lock it for exclusive access.

https://github.com/libusb/libusb/wiki/FAQ#how-can-i-run-libusb-applications-under-mac-os-x-if-there-is-already-a-kernel-extension-installed-for-the-device

As for why different machines behave differently—a great question, perhaps this is reflected in the USB Prober logs?

[gicking]

hi Torsten,

yes, this occurs also on a freshly booted computer. I guess tcr is correct, since the ST-Link on the discovery board is mounted as a drive under Win and Linux - and it doesn't under OS X. However, that information doesn't really help...

@tcr: where can I find the USB Prober logs?