Here are some notes on the subject from the Palm PluggedIn Program (see http://developers.palm.com/pe/forums/displaypost.jsp?postID=10105243):
Be careful with SD card unique IDs. I've worked on several commercial products that rely on the uniqueness of the deviceUniqueIDStr member to enforce copy protection. What follows is a list of caveats I've discovered. * Early Tungstens, and all AlphaSmart Dana units, ship with a big/little Endian bug in the Exchange Manager code which causes the ExgCardInfoType.deviceUniqueIDStr[] member to be misreported by ExpCardInfo. This affects SD and MMC cards. For example, observe the "unique" IDs reported for the SAME SD card: Palm m505: S016B_19F05466100907 Tungsten : S016B_19F054661000D1 Dana: S016B_19F05466 * The UNIQUE ID of the SD/MMC card are really just the 8 chars immediately after the LAST underscore (there can be more than one) in deviceUniqueIDStr. The stuff after that has to do with the date the card was manufactured, and is fortunately where the big/little endian bug occurs. For a workaround that works on all known Palm platforms (that I tested, at least), just use the last 8 digits following the LAST '_' for a unique ID. For a 100% UID across different vendors' SD/MMC cards, you must also hash in the manufacturer name string, since the SD spec allows two cards from two different vendors to report the same 8 digits here (unlikely). -Jeff Ishaq Palm OS® Certified Developer Greg Sepesi wrote: > > Hi Adrien, > > Yes, it would be nice to know if the device dependency is limited to a > certain portion of the reported SD card ID. > > Greg > > Adrien Regimbald wrote: > > > > Hello Greg, > > > > I've seen this as well, and have just assumed it was a matter of the > > different devices reporting the IDs slightly differently, and not that > > the devices were adding on a "device portion" to the ID. One > > possibility that comes to mind is that there may be several components > > to an SD Card ID, and the different devices combine them with > > different endianness, or something along those lines. > > > > Adrien. > > > > Tuesday, April 25, 2006, 9:20:08 AM, you wrote: > > > > GS> Recently a customer upgraded from a Treo 600 to a Treo 650. The > > GS> multimedia that had been encoded according to his particular SD card ID > > GS> stopped working with the upgrade to the Treo 650. It turns out that his > > GS> SD card's ID with the Treo 650, as reported by the Palm OS, changed in > > GS> the last three digits. > > > > GS> What models alter the reported SD card ID? > > > > GS> Is it possible to mask off a portion of the SD card ID to get an ID > > GS> associated with just the card and not the Palm OS device? > > > > GS> Best regards, > > GS> Greg -- For information on using the PalmSource Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/
