Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror
×
Media Microsoft Cellphones Data Storage Handhelds Hardware

Windows Phone Permanently Modifies MicroSD Cards, Warns Samsung 426

dotancohen writes "Don't put your MicroSD cards into Windows Phones. According to Samsung, doing so is a 'permanent modification' to the card, and it can no longer be used in other devices."
This discussion has been archived. No new comments can be posted.

Windows Phone Permanently Modifies MicroSD Cards, Warns Samsung

Comments Filter:
  • by omglolbah ( 731566 ) on Sunday November 14, 2010 @01:34PM (#34223814)

    Say what now?.... If this is even possible there is something really wrong with the SD card in question...

    • Furthermore is there any warning on the phone that it alters SD cards as such?
      This sounds like a major defect in both the phones and the SD cards.

      • by BradleyUffner ( 103496 ) on Sunday November 14, 2010 @03:00PM (#34224570) Homepage

        Furthermore is there any warning on the phone that it alters SD cards as such?
        This sounds like a major defect in both the phones and the SD cards.

        There is a yellow sticker completely covering the SD slot that says it will void your warranty if it is removed. I think that's' warning enough that it isn't a general purpose SD card slot. It also required an SD card that is certified as Windows Phone 7 complaint. Currently no such cards exist.

      • Re: (Score:3, Funny)

        by jav1231 ( 539129 )
        That would require finding someone with a Windows phone. Happy hunting.
        • Re: (Score:3, Interesting)

          odd, as i have one in my hot sweaty palm as we speak. seems to work pretty good too.

          regarding the SD thing, i've seen reports that the Samsung Focus (currently the only phone with SD storage, and the one i own) is very picky about the cards being used, it doesnt seem to matter which class of card you use or what size, though it can allocate up to 32GB. from what i understand, WP7 will append it on to the existing partition, and the fault occurs when the card is removed and reinserted, the device will only r

    • Re: (Score:2, Insightful)

      best guess is this socalled permant modification is changes to the filesystem nothing more, which for normal users would amount to the same, if their windows platform cant see the card anymore, inserting such a card would not be shown by windows except for people entering the computer management/ disk management and repartiton/format it again.
      • If you insert a card with a munged and/or not-recognized-by-windows FS/partition structure in any reasonably recent windows box, it will just ask you if you would like to format it. Excellent way to lose a giant chunk of data stored on an HFS+ or extN volume; but otherwise pretty noob friendly...
    • by yup2000 ( 182755 ) on Sunday November 14, 2010 @01:40PM (#34223848) Homepage

      The S in SD means "Secure" which is an acronym for DRM ... and how that DRM exactly works is not public... Microsoft is probably using the DRM feature of the cards... where as most other companies to this point have not been that brave...

      • by Anonymous Coward on Sunday November 14, 2010 @01:50PM (#34223948)

        The S in SD means "Secure" which is an acronym for DRM ...

        May I respectfully suggest that you acquire a dictionary and use it to find out what everyone else in the world means when they say "acronym"?

        • Unfortunately, what most other people mean when they say 'acronym' seems to be incorrect as well, confusing it for 'abbreviation' in many cases. An acronym is a type of abbreviation, but not all abbreviations are acronyms.

          Of course, what yup2000 did was even further from accuracy than that.

          • Re: (Score:2, Offtopic)

            by hedwards ( 940851 )
            Technically speaking, they're usually confusing an acronym with an initialism. Sort of like snafu versus FBI. Then there's the confusing cases which have gone from initialism to acronym in ways most inexplicable such as SCSI.
          • Agreed. And I think we can do even better. An abbreviation isn't necessarily an initialism and an initalism isn't necessarily an acronym. I think the word he wanted was euphemism. I think it would be fantastic if someone a million times more charismatic than me started a campaign to save the word acronym from confusion with initialisms. FDA is not an acronym, but NASA is. Quick, someone make a website.
        • by duguk ( 589689 )

          The S in SD means "Secure" which is an acronym for DRM ...

          May I respectfully suggest that you acquire a dictionary and use it to find out what everyone else in the world means when they say "acronym"?

          Common mistake. This depends if you're American or not.
          The Oxford English Dictionary permits both Acronym or Initalism for this term.

          I suggest reading this article for your full compliment of knowledge on this [randomcat.co.uk].

          We can clearly agree that:

          • If it’s made by initial letters and is pronounceable, it’s an acronym.
          • Whether pronounceable or not, it is an abbreviation.
          • If it’s made from initial letters and isn't pronounceable as a whole world, it is an initialism, but it also may be an acronym dep
        • nailed it
        • May I respectfully suggest that you acquire a dictionary and use it to find out what everyone else in the world means when they say "acronym"?

          I guess you're referring to the nicknames the Greeks used instead of their real names whenever they went to talk democracy on Acropolis.

        • by bluestar ( 17362 ) on Sunday November 14, 2010 @02:46PM (#34224430) Homepage

          The S in SD means "Secure" which is an acronym for DRM ...

          May I respectfully suggest that you acquire a dictionary and use it to find out what everyone else in the world means when they say "acronym"?

          Acronym is just a homonym for euphemism.

        • Re: (Score:2, Insightful)

          by noidentity ( 188756 )

          The S in SD means "Secure" which is an acronym for DRM ...

          May I respectfully suggest that you acquire a dictionary and use it to find out what everyone else in the world means when they say "acronym"?

          I think Shitty Euphemism Causing Unjustified Retarded Expenditures describes DRM pretty well.

      • Re: (Score:2, Interesting)

        by Shyfer ( 1875644 )

        The S in SD means "Secure" which is an acronym for DRM ... and how that DRM exactly works is not public....

        That is why SD cards are scary... Once I tried to do a low-level formatting on my SD card, but the program I used to do do it went crazy and I guess it sent random comands to my card and killed it. Using another SD-specific low-level formatter on my pda it was back, nothing else could fix it.

        Scary.

      • by Que_Ball ( 44131 ) on Sunday November 14, 2010 @03:58PM (#34225012)

        The SD Card can be locked to a specific device using a password.

        example:
        http://www.embeddedarm.com/software/arm-linux-sdcard-security.php [embeddedarm.com]

        An SD card can be locked using a password, or it can be set to permanent write protected mode.

        Also the manufacturer of an SD card may not include the secure features in their cards (which would probably mean it wouldn't work on these phones)

        From the linked article:
        Technologic Systems has developed a Linux application named "sdlock" which can be used to manipulate SD card hardware-enforced password locks and set the card's permanent write-protect feature. Using a password protected SD card is a great way to ensure software security and/or to make sure your TS-7000 SBC based product cannot be used in an unintended matter once deployed. This utility is only available for the TS-7300 and TS-7400 products, which are configured with the TS-SDBOOT firmware.
        Some of the possibilities include:
                        Password protecting SD Cards
                        Set the SBC to boot only locked SD Cards
                        Set the SD Card readable only on a specific SBC
                        Checksum verification of bootable SD Cards
                        Make an SD Card permanently write-protected
        How To Use It
        Usage and command line help for this command:
        $ sdlock –help
        Usage: sdlock [OPTION] ...
        Controls SD card lock and permanent write-protect features.
        General options:
        -p, --password=PASS Use PASS as password
        -c, --clear Remove password lock
        -s, --set Set password lock
        -u, --unlock Unlock temporarily
        -e, --erase Erase entire device (clears password)
        -w, --wprot Enable permanent write protect
        -h, --help This help

      • by SuricouRaven ( 1897204 ) on Sunday November 14, 2010 @05:31PM (#34225788)
        Specifically it means the cards support the old CPRM scheme. When first invented it was planned to form part of a consistant, interlinked set of DRM technologies. Others in the suite included CPPM, CSS, DTCP, HDCP, Macrovision*, CGMS-D* and -A*, and a whole lot of others - all under the management of a consortium called the 4C entity. It was very elaborate, with a system of device revocation thrown in. The whole thing collapsed - a series of disasterous breaks of the constituent DRM technologies (Most significently CSS) caused a loss of faith in the idea to the extent that the supporting companies pulled out.

        A few of the technologies went on to be used on their own, without the unified framework - HDCP now forms the DRM component of HDMI, CSS remained in use on DVDs - while others fell into total disuse. CPRM is one of the latter. It's a dead technology, which continues to be present in SD cards like a vestigal organ because it's part of the SD specification. It's possible Windows Phone 7 is using a remnant of the old CPRM to encrypt SD cards - they arn't intended as removeable storage, but perminant upgrades to the phone.

        If this is the case, then it is possible to reset the cards (Doing so would render their existing contents unreadable, of course), but it would require software that I doubt anyone has ever had reason to write. No-one ever bothered cracking CPRM or even making tools to reset it, because no device ever used it. *Predated the unified framework initiative, but intigrated into it.
    • by Graff ( 532189 ) on Sunday November 14, 2010 @01:56PM (#34224018)

      If this is even possible there is something really wrong with the SD card in question

      You have to dig further into the links in the article to find out what is really happening [engadget.com]. Apparently the Windows Phone 7 devices are stressing the SD cards in a manner which is not in-spec for a normal SD card. This means that a SD card which is perfectly fine by the normal spec might be ruined by the way the Windows Phone 7 OS uses the card [microsoft.com].

      This means that you will need a SD card which is certified under more stringent requirements in order to not be destroyed by the Windows Phone 7 OS.

      On top of that the OS also completely reformats the card so that it is a "permanent" part of the device. It probably sets up special space for swap space and other OS-specific data structures so that they can be accessed quickly and easily by the OS but this results in the card not having a normal disk layout that other devices can read using default software.

      • by hitmark ( 640295 )

        it would not surprise me if exfat is part of this process...

      • by K. S. Kyosuke ( 729550 ) on Sunday November 14, 2010 @02:31PM (#34224322)

        Windows Phone 7 requires a certified high-speed microSD card for optimal performance.

        If "optimal performance" means for MS engineers "doesn't break things down", then it explains a lot of my experience. (Talk about lowering one's expectations!)

        • by Graff ( 532189 )

          If "optimal performance" means for MS engineers "doesn't break things down", then it explains a lot of my experience. (Talk about lowering one's expectations!)

          I'm all for breaking compatibility if you are going to get huge reliability and performance gains and there are no decent open alternatives to be had but this is certainly something that needs to be avoided, if possible. However, it seems to me that Microsoft does a lot of needless "throwing the baby out with the bathwater" in these circumstances when they really should do their best to try to re-use a more open format.

          Of course, I'm a bit cynical and I figure that this is just a ploy on their part to lock

      • Re: (Score:3, Informative)

        by phantomfive ( 622387 )

        It probably sets up special space for swap space and other OS-specific data structures so that they can be accessed quickly and easily by the OS but this results in the card not having a normal disk layout that other devices can read using default software.

        Specifically, it sets up a kind of RAID0, with the data being striped across the SD card and the internal flash. In theory this speeds up access to data in permanent storage, but I haven't really noticed a difference compared to Android phones. The downside is that if you remove it, both the internal and external SD card cannot be recovered, and all your data is lost (since the data is spread between both).

      • Re: (Score:3, Interesting)

        by Jesus_666 ( 702802 )
        So let me get this... Not only does WP7 lock the card through standard SD mechanisms, it uses it in a RAID0 configuration with the internal memory (as pointed out by another poster) and accesses it so frequenly that virtually all cards on the market will be physically damaged. If the card is damaged or removed, not only will the card be unusable but so will be any data you had on the phone.

        Microsoft has really managed to create a device less compatible with microSD cards than the iPhone, which doesn't eve
    • Re: (Score:3, Informative)

      by cookd ( 72933 )

      1. The "modification" mentioned is that Windows Phone uses the "LOCK" command of the SD card, which sets a password on the card. This is not commonly used, but it is part of the SD card standard. The S in "SD" stands for "Secure", and the "LOCK" command is one of the security features. It is possible to unlock the card via an UNLOCK command (requires the password) or via the ERASE command (does not require the password). Unfortunately, tools that support the LOCK, UNLOCK, and ERASE commands are essentially

  • Borg phone (Score:5, Funny)

    by Bai jie ( 653604 ) on Sunday November 14, 2010 @01:36PM (#34223820)
    Your memory will be made to service us. You will be assimilated, resistance is futile.
  • by maxwell demon ( 590494 ) on Sunday November 14, 2010 @01:39PM (#34223842) Journal

    This information alone means that I'll avoid ever getting a Windows phone, even if it should have tremendous advantages otherwise.

    • by Haeleth ( 414428 ) on Sunday November 14, 2010 @01:53PM (#34223980) Journal

      Extra! Extra! Slashdotter vows to avoid Microsoft product! Read all about it!

      • Was this really a surprise? Sure, no one probably saw this particular problem coming, but we all knew something really screwed up would be discovered soon after MS released its "Win7" mobile OS. The only question here is whether "MS certified" is a lame attempt to make excuses for the problem or if represents a new revenue stream creation strategy. Watch out, now MicoSD cards have to be "certified" to work in a MS product. Something tells me that the certification comes cheap. Thank God that we all still h
        • by bloodhawk ( 813939 ) on Sunday November 14, 2010 @03:44PM (#34224870)
          The SD card in question is not supposed to be a removable peice of the device. some phones even have it soldered in. Others have labels on it saying removing it voids your warranty. It may be an SD card but in this case it is the equivalent to prying a chip off the board and replacing it with your own and being pissed that it didn't work.
    • by vux984 ( 928602 ) on Sunday November 14, 2010 @02:30PM (#34224316)

      This information alone means that I'll avoid ever getting a Windows phone, even if it should have tremendous advantages otherwise.

      Why? Because of a hyperbole laden /. thread? That's a terrible reason to decide anything.

      There is a warning on the phone. There is clear documentation that this will happen. The slot is not designed for convenient insertion/removal. It is not intended to be used as a portable storage.

      It is intended to be a permanent expansion module for the phone, not removal SD storage.

      Let me ask you this: Suppose they didn't use an SD card slot. Suppose they had instead developed a proprietary connector instead and sold the expansion as proprietary modules that had to be installed at a service center. Would that trigger the same sort of averse reaction from you?

      I'm curious, because if you wanted to upgrade your 16GB iPhone to 32GB that's essentially the process assuming you could even get it done... do you avoid iPhones because of that?

      MS is using the SD form factor for this because it meets their needs, and using an existing form factor reduces engineering and manufacturing costs. Don't think of it as 'SD removal storage' and think of it as an upgrade kit that just happens use the SD form factor. Honestly, most consumers will likely never even use the functionality at all. And for those few that do decide to expand their phone this way, it requires very specific SD cards, and its well documented that its a permanent upgrade using SD form factor and not plug/play removal storage.

    • They are selling fairly poorly, so far anyways. ~40k on launch, less than either the iPhone or Android based phones on a regular day.
    • by Wooky_linuxer ( 685371 ) on Sunday November 14, 2010 @02:54PM (#34224514)
      The SD card in WP7 devices is NOT user serviceable. MS uses SD cards as a cheap alternative to other kinds of storage solutions. To exchange the SD card, you have to tore open the phone. People have been trying to replace the provided card to get more space, that's it. So I see it as no big deal that the OS thrashes it, since it was never intended to leave the phone anyway. That said, I wouldn't buy a WP7 phone for other reasons: it copied the iOS model by Apple by the book - specially the silly restrictions (no multitasking to 3rd party apps, tie-in to a proprietary app, no fscking copy-and-paste, etc.).
  • by Zocalo ( 252965 ) on Sunday November 14, 2010 @01:40PM (#34223854) Homepage
    Gotta love the very first line from the article:

    "There has been discussion for a few weeks now about how Microsoft’s new smartphone OS handles expendable storage, with many people reporting that inserting the wrong card can reduce the OS to a crawl"

    I guess putting a MicroSD card into one of these phones probably would have to qualify it as "expendable"...

  • by Anonymous Coward on Sunday November 14, 2010 @01:42PM (#34223882)

    Meantime, AT&T has warned customers via Engadget that only ”Certified for Windows Phone 7” microSD cards should be used in Microsoft’s mobile devices. The reason, according to the mobile carrier, is that the Windows Phone platform ”requires a certified high-speed microSD card for optimal performance.”

    At present, no such ”certified” cards exist and no indication has been given as to when they will hit store shelves. According to Microsoft support documents, certification comes down to more than just ”a simple matter of judging its speed class.”

    So as far as the consumer is concerned, you can't expand the storage on a Windows 7 phone either.

  • The ghacks story that is linked to just cites engadget as a source... who don't mention *anything* about it "permanently modifying" the MicroSD cards, just that the manufacturers and microsoft are requiring that the cards are certified.
    • by QuietLagoon ( 813062 ) on Sunday November 14, 2010 @01:53PM (#34223972)
      From the engdget article:

      But what appears to have fried our card is the fact that any card inserted into a Windows Phone 7 device "will no longer be readable or writable on any other devices such as computers, cameras, printers, and so on" according to documentation on Samsung's site -- including, amazingly, the ability to format the card.

      Sounds like the card is being "permanently modified" (and not for the better) to me.

    • Samsung have documented the feature for the Focus, saying that inserting a MicroSD card into a Windows Phone can be considered a “pernament modification” adding ”it will no longer be readable or writable on any other devices such as computers, cameras, printers, and so on”.

      The two sources quoted (Samsung and MS) aren't contradictory. Given these two (incomplete) statements, I would guess that Windows Phone is formatting the card using some sort of disk pooling scheme, similar to LVM, and thus the data on the card is only meaningful as part of the entire pool. This may not be truly permanent from the point of view that you might be able to reformat the card, but it is permanent in the sense that any data that was on there before has been lost for good.

      • The two sources quoted (Samsung and MS) aren't contradictory. Given these two (incomplete) statements, I would guess that Windows Phone is formatting the card using some sort of disk pooling scheme, similar to LVM, and thus the data on the card is only meaningful as part of the entire pool. This may not be truly permanent from the point of view that you might be able to reformat the card, but it is permanent in the sense that any data that was on there before has been lost for good.

        The article specifically mentions that you can't even reformat the card. So yeah - it's permanent in the usual sense of the word.

  • by gmuslera ( 3436 ) on Sunday November 14, 2010 @01:50PM (#34223940) Homepage Journal
    They turn into Blue MicroSDs Of Death, something very valuable for cyber ninjas.
  • by Nukenin ( 646365 ) on Sunday November 14, 2010 @01:53PM (#34223978)

    From Microsoft's KB2450831 [microsoft.com] support article:

    Windows Phone 7 Secure Digital Card Limitations

    [...]

    Some Windows Phone 7 devices include a Secure Digital (SD) card slot underneath the battery cover. If you buy a Windows Phone 7 device that includes an SD card slot, you should be aware of several important differences from other devices that use SD cards:

    • The SD card slot in your phone is intended to be used only by the Original Equipment Manufacturer (OEM) that built your phone and your Mobile Operator (MO). These partners can add an SD card to this slot to expand the amount of storage on your phone.
    • To help ensure a great user experience, Microsoft has performed exhaustive testing to determine which SD cards perform well with Windows Phone 7 devices. Microsoft has worked closely with OEMs and MOs to ensure that they only add these cards to Windows Phone 7 devices.
    • You should not remove the SD card in your phone or add a new one because your Windows Phone 7 device might not work properly. Existing data on the phone will be lost, and the SD card in your phone can't be used in other Windows Phones, PCs, or other devices.

    [...]

    • Re: (Score:3, Interesting)

      by Spad ( 470073 )

      Question:

      If the MicroSD card in your Windows Phone 7 device cannot be removed or replaced, what is the point of making it a MicroSD card rather than simply more onboard memory?

      • Re: (Score:3, Insightful)

        by am 2k ( 217885 )

        It's probably done so the manufacturer can decide on the memory capacity of the phone after it has been produced outside of the factory and react quicker to market demands.

        Plus, rebranders can put different amounts of memory into previously brandless phones.

      • Re: (Score:3, Interesting)

        by adolf ( 21054 )

        If the MicroSD card in your Windows Phone 7 device cannot be removed or replaced, what is the point of making it a MicroSD card rather than simply more onboard memory?

        Good question!

        I want to say that cost is the reason, but I can't: As highly-integrated as a modern smartphone is, it'd almost certainly be cheaper to put the extra flash memory on the same board as everything else than it would be to build a socket to house an SD card.

        Perhaps marketing flexibility: They may want to be like Apple and advertis

        • Given how much of a pain in the ass it is to access the slot in most of the WP7 phones, "your favorite option" doesn't hold much water.
      • by Overzeetop ( 214511 ) on Sunday November 14, 2010 @02:55PM (#34224522) Journal

        Easy - you build phones with the "sweet spot" memory today, but in 6 months they look far behind in capacity. Instead of scrapping a containerload of $300 phones, you upgrade them with $10 of memory and sell them.

        Sure you might save a little with onboard memory, but this leaves the market segmentation decision until later.

  • ..The Microsoft Phones are going to use the SD card for some sort or Swapfile / Cache (Or something like that)
    Since the "approved" card must have fast, random Read/Write access.

    Expect to require a new SD card every few months if that's the case...

  • you don't have a windows 7 phone anyway! (Neither do I.. due to stupid shortages in Canadialand) but that's besides the point.

  • by sensationull ( 889870 ) on Sunday November 14, 2010 @02:08PM (#34224124)

    Its probably just the media class that is being changed. Within the first sectors of SD cards and flash drives there is a section which defines what kind of removable storage device it is. You can change this with certain tools to make things like flash drives that usually show up as removable storage show up like fixed drives so that you can boot from them. This simple change in the first chunk of the memory makes the system treat it entirely differently, allowing multiple partitions etc. So if the device is re-labeled as a different class in this memory segment it is quite possible that it would behave like this. The hp bootable USB utility can make this kind of change to a drive and so would probably be able to recover one of these 'modified' cards to a format usable by other devices.

    • by zlogic ( 892404 )

      I had an Olympus Camedia C830L camera and it required a special "panorama" SM card (obviously more expensive than regular cards) to be able to take panorama images. Turns out that after using a modified format utility an ordinary SM card could be turned into "panorama" card.
      The process was complicated, the first phase involved damaging contents of the first sectors. The card was no longer recognized by Windows or the camera. After that the modified restore utility restored the proper sectors, along with the

  • by caywen ( 942955 ) on Sunday November 14, 2010 @02:38PM (#34224362)

    The SD slot is intended to be used by the carrier to upgrade device internal memory. That's why there's a big old sticker over it saying it will void your warranty of you install it. There's really nothing wrong with this, IMO. It's more flexible than baking in the flash memory and having to go back to Foxconn for new orders of 64GB models.

    • by Lehk228 ( 705449 )
      what shitty phone is that true on? my blackberry certainly didn't have any idiotic stickers like that on it.
      • Are you suggesting it shouldn't have such a warning for something that could easily damage the card and/or possibly the phone?

      • What phone (or any digital electronic item) isn't it on? Practically every electronic device that can be tampered with has a "warranty void if removed" sticker on it. Those that don't usually have it implied, or in the warranty terms. If you alter or disassemble an electronic item, it's pretty unlikely that the warranty will be honored.

        This SD card isn't a consumer-usable slot, it's the internal phone memory. They've just chosen (presumably for economic reasons) not to solder the chips to the board.

  • Microsoft says that you're not even supposed to be using the card slot yourself with your own cards; that it's intended for the manufacturer of your phone, so I'm not really seeing the issue here.

  • by Dr. JJJ ( 325391 ) on Sunday November 14, 2010 @02:46PM (#34224432)

    I've been studying SD cards for the last few months and I've managed to dig up some heretofore "secret" leaked documents about SD Digital Rights Management mechanism and I think I know how such a permanent modification could be performed.

    One of the things that all SD cards support is the ability to designate a certain portion (which can include ALL) of the card's block storage as "secure". Once designated as secure, the blocks in question cannot be read, written to, or the area resized without performing an authentication step with the card. This authentication step is known as "AKE".

    I'm willing to bet that the phone is using this "secure" facility and marking the entire card, or some significant portion thereof, as a secure storage area.

  • Why? (Score:5, Insightful)

    by HalAtWork ( 926717 ) on Sunday November 14, 2010 @02:57PM (#34224540)
    Why does Microsoft eschew conventional methods of interfacing with MicroSD cards for this piece of hardware? Do they have too many problems with customers using their MicroSD cards for multiple things and then messing up files that are important for the WP7 device? Is there a better solution?
  • by davidwr ( 791652 ) on Sunday November 14, 2010 @05:04PM (#34225572) Homepage Journal

    If the SD standard allows for this then the standard is broken.

    All devices - particularly media devices - should be able to be reset to a "clean" state, where the only changes are those put in by the firmware to track remapping, "odometers," and the like and this "firmware"-controlled data is unwritable by ANY consumer device.

    You can make a DRM-enabled chip that meets these requirements and meet what I think are Microsoft's requirements fairly easily. You need to have an instruction to the firmware to "lock" the SD device to the host device so only "authorized" devices - or only this device - can read it, an "unlock/modify lock" instruction that can only be executed by devices authorized to change the lock settings, and a "reset card" instruction accessible to any device that will scrub the card of all usable information and THEN after the scrub finishes, remove all the locks and finally do a standard format operation.

    It sounds like the latter or perhaps the last two operations are missing from the SD standard or missing from most implementations.

What we anticipate seldom occurs; what we least expect generally happens. -- Bengamin Disraeli

Working...