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Re: usb-sticks not recognized

At 12:37 PM -0800 11/10/05, Barry Twycross wrote:

What do you mean by a "usb stick"?

If you mean a mass storage device of some kind, then I find it helpful to use the "ioreg" command in the terminal. You should find output for your device something like this:

    | |   +-o pci1033,e0@1B,2  <class IOPCIDevice, registered, matched,
    | |     +-o IOService  <class IOService, !registered, !matched, act
    | |     +-o AppleUSBEHCI  <class AppleUSBEHCI, registered, matched,
    | |       +-o EHCI Root Hub Simulation@1B,2  <class IOUSBRootHubDev
    | |       | +-o AppleUSBHub  <class AppleUSBHub, !registered, !matc
    | |       | +-o IOUSBInterface@0  <class IOUSBInterface, !registere
    | |       | +-o IOUSBUserClientInit  <class IOUSBUserClientInit,
    | |       +-o iPod@5b100000  <class IOUSBDevice, registered, matc
    | |         +-o AppleUSBComposite  <class AppleUSBComposite, !reg
    | |         +-o IOUSBInterface@0  <class IOUSBInterface, registere
    | |         | +-o IOUSBMassStorageClass  <class IOUSBMassStorageCl
    | |         | | +-o IOSCSIPeripheralDeviceNub  <class IOSCSIPeriph
    | |         | |   +-o com_apple_driver_iPodSBC  <class com_apple_
    | |         | |     +-o com_apple_driver_iPodSBCNub  <class com_
    | |         | |       +-o IOBlockStorageDriver  <class IOBlockSto
    | |         | |       | +-o Apple iPod Media  <class IOMedia, reg
    | |         | |       |   +-o IOMediaBSDClient  <class IOMediaBSD
    | |         | |       |   +-o IOApplePartitionScheme  <class IOAp
    | |         | |       |     +-o partition map@1  <class IOMedia,
    | |         | |       |     | +-o IOMediaBSDClient  <class IOMedi
    | |         | |       |     +-o firmware@2  <class IOMedia, regis
    | |         | |       |     | +-o IOMediaBSDClient  <class IOMedi
    | |         | |       |     +-o disk@3  <class IOMedia, registere
    | |         | |       |       +-o IOMediaBSDClient  <class IOMed
    | |         | |       +-o SCSITaskUserClientIniter  <class SCSIT
    | |         | +-o IOUSBUserClientInit  <class IOUSBUserClientIni
    | |         +-o IOUSBUserClientInit  <class IOUSBUserClientInit

That shows all the layers of drivers involved all the way from the USB hardware up through the USB, SCSI and BSD layers all the way to the volumes on the device.

Quite often when a mass storage device gets stuck, the ioreg will show that the driver stack is not completely there, one layer or another has got stuck for some reason. Looking in the registry like this can hint as to where in the system the problem is. If the IOUSBDevice is missing, I'd suspect hardware problems, such as overcurrent. Other device faults can cause other layers to get stuck

Sometimes there will be a problem when a device is unplugged and stale copies of a device can be seen in the registry, these sometimes seem to prevent a new device being properly recognised.
--
Barry Twycross
email@hidden
---
USB, it's not a Dyslexic BUS. (Thanks to TC.)
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