Unable to get USB bsdname from macOS Monterey 12 Bate4 of Intel processor

Question

Created Aug ’21

Replies 5

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I can’t get USB bsdname from macOS Monterey 12 Bate4 of Intel processor: I have use the "IORegistryEntrySearchCFProperty" function to get the bsdName of the io_service_t, It worked fine on macOS Big Sur's M1 and Intel MBP. Also it worked fine on macOS Monterey App M1. But it always returned nil on macOS Monterey Intel MBP. It involves the following code:

void getBsdName(io_service_t usbDevice)

{

	CFStringRef bsdName = NULL;

        for(int i = 0; i < 500; i++)

        {

            bsdName = (CFStringRef)IORegistryEntrySearchCFProperty(usbDevice,

                                                                   kIOServicePlane,

                                                                   CFSTR( kIOBSDNameKey ),

                                                                   kCFAllocatorDefault,

                                                                   kIORegistryIterateRecursively );

            if(!bsdName) {

                // If don't get a bsd name, keep waiting in 5s.

                usleep(10000);

                continue;

            }

            

            printf("[%s]: Found bsd name for device %d.\n”, __func__, usbDevice);

            break;

        }

}

Why it happened? Or is there another way to get it?

Boost

Answer 1

DTS Engineer OP

Apple

Aug ’21

I’m not sure why this is failing on macOS 12 beta but I’d like to clarify your goals here. Can you explain more about the big picture? Why are you trying to map in this direction?

I’m curious because any algorithm that involves a usleep is suspect in my opinion.

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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
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0

Answer 2

BliqPhilCS OP

Oct ’21

Same problem here. It seems like kIORegistryIterateRecursively is not working as intended. I tried to dig into the IOUSBDevice entry's children using IORegistryEntryGetChildEntry recursively, but it fails to go deeper than one child (i.e. no grandchildren), so it seems like the IOSerialBSDClient child entry is no longer visible at all from that standpoint.

0

Answer 3

DTS Engineer OP

Apple

Oct ’21

It seems like kIORegistryIterateRecursively is not working as intended. I tried to dig into the IOUSBDevice entry's children using IORegistryEntryGetChildEntry recursively

I’m confused by the above. IORegistryEntryGetChildEntry doesn’t work in terms of iterators. Are you saying that you tried to use it as a workaround for kIORegistryIterateRecursively? If so, what does your original code look like?

And it’d also help if you posted a description of your high-level goal. Many I/O Kit problems problems have easier solutions that don’t involve low-level I/O registry calls.

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—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

0

Answer 4

teddy@siliconmotion OP

Oct ’21

I solved this issue by other ways.

Since the device I'm looking for is an IOMedia object. I found its BSD name by enumerating the kIOMediaClass object. And I looked up IOMedia's parent device to determine the USB device I'm interested in.


CFStringRef mediaDevBsdName = NULL;

mediaDevBsdName = (CFStringRef)IORegistryEntryCreateCFProperty(mediaDevice,

                                                                 CFSTR(kIOBSDNameKey),

                                                                 kCFAllocatorDefault,0);

Hope this answer can help someone~

1

Answer 5

DTS Engineer OP

Apple

Nov ’21

Here's what I ended up doing

Unfortunately I need a bit more context here. Specifically, how did you set up the io_iterator_t that’s passed in to the -serialDevicesForIOIterator: method?

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—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

0