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."
Probably fixable. (Score:1, Informative)
I'd try SDFormatter to fix them.
http://www.sdcard.org/consumers/formatter/
http://www.sdcard.org/consumers/formatter_3/
Do the editors even actually read the stories? (Score:2, Informative)
Re:Maybe it is a problem with the Windows formatti (Score:2, Informative)
I skimmed the articles, and they were short on information regarding exactly what was done.
I don't know anyone with a Win7 phone, nor do I expect that any of my friends will get one, so I won't have a chance to test it. My suspicion is that they use yet another filesystem, which is unusable by other platforms. To the best of my knowledge, there's no way to permanently write to a card so it can only be used on a device. The only way to make a card unusable is to write to it too much, making it worthless to any device. I've only done that to a few. :) If there is a way, I'd love to know how. It would be nice to set up a card that can only be read on *MY* machine, so if someone snags it, they can't read the contents.
Re:Permanently modified? (Score:1, Informative)
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.
Not quite - other reviewers have tried this, and even the partitioning tools get a "media not foud"-ish error. Nice one MS - bone everybody for your FAT32 "patents" for years, then ditch it entirely for a double-secret proprietary format. Remind anybody else of "Plays-for-(not)-Sure"?
Re:Pointless (Score:5, Informative)
Re:Do the editors even actually read the stories? (Score:5, Informative)
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.
SD limitations according to Microsoft KB2450831 (Score:5, Informative)
From Microsoft's KB2450831 [microsoft.com] support article:
Re:Permanently modified? (Score:5, Informative)
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.
Re:Maybe it is a problem with the Windows formatti (Score:4, Informative)
It would be nice to set up a card that can only be read on *MY* machine, so if someone snags it, they can't read the contents.</p><p>
</p></quote>
You could always try encryption - there are many programs which will encrypt any read/writes made to a particular drive
Oh, thank God for Microsoft (Score:2, Informative)
Re:Permanently modified? (Score:1, Informative)
DRM is not Security.
DRM is Slavery.
Re:Probably ExFAT (Score:5, Informative)
Nope.
Anandtech (http://www.anandtech.com/show/4015/htc-surround-review-pocket-boombox/8) say:
The other interesting thing is that cards initialized on WP7 are locked to a specific device, and moreover, stop being recognized on the desktop - perhaps permanently. I took the card out of the Surround and spent considerable time trying to make it format, first on Windows, then OSX, and finally linux by trying to write zeros and random data to the disk using dd. This failed, as I only managed to get 'medium not present' errors every step of the way - in fdisk, gparted, every trick I know for really nuking storage.
So, it actually does trash the card. There may be a way around that, but if there is so far some fairly smart people have failed to find it.
Re:Pointless (Score:3, Informative)
They are on Win7 phones - I think all the ones I've seen reviewed so far have placed the MicroSD card slot behind a "Warranty void if removed" sticker in one way or another.
Probably using SD's DRM Mechanism (Score:5, Informative)
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.
Re:Maybe it is a problem with the Windows formatti (Score:2, Informative)
What I do know is that you could always encrypt the whole card with TrueCrypt, making it readable only to YOU, provided you don't share the key.
Re:Permanently modified? (Score:5, Informative)
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:Permanently modified? (Score:5, Informative)
So if we follow your link and find out what is "really happening," we find out that some blokes plugged a card into a phone and that it seemed to kill the card.
Of course if you read the second link [microsoft.com] I posted you'd see that Microsoft itself spells it out a bit more clearly:
When the operating system integrates the SD card with your phone:
From this point on, the phone's operating system uses all of the available memory as a single storage space for storing applications and data. The phone will stop working properly if you remove the SD card, and the SD card cannot be read by another phone, device, or PC.
It's not just one data point from some casual observer. The manufacturer of the operating system states quite clearly that this is the expected behavior.
Re:Permanently modified? (Score:3, Informative)
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:Zap the card (Score:3, Informative)
Secure Digital includes DRM. See this article [wikipedia.org] for more information.
Re:Oh, thank God for Microsoft (Score:5, Informative)
Re:And they expect to sell those phones? (Score:5, Informative)
Re:Permanently modified? (Score:1, Informative)
there are few errors in the observations made by non-experts.
as an expert in sd card, here is what is going on.
1. card is locked as supported by the 2.0 specification.
2. a locked card can be unlocked in two ways -
2.1. temporarily unlocked the card with old password, and send clear password command with the old password to the card.
2.2. force-erase the card.
3. a locked card can't be unlocked via current desktop OS just because desktop OS can't send low-level command.
Re:Permanently modified? (Score:5, Informative)
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
Re:Permanently modified? (Score:5, Informative)
Well that's the issue, it's NOT supposed to be removable storage. Even if it didn't "break" teh card it still wouldn't be general purpose removable storage. The phone reformats the card along with the internal storage to create a single Volume, kind of like a RAID mirror. Taking out the card would make you lose all your data, on both the card and the internal storage. The only reason it uses an SD card is because it's convenient to build, and it allows the different providers to use whatever size storage they want. In this phone, the SD card it not a user serviceable part.
Re:Permanently modified? (Score:5, Informative)
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.
Re:Permanently modified? (Score:2, Informative)
Sony didn't promote SD cards - in fact they have their own competing format called Memory Stick. (It too has DRM called "MagicGate" which AFAIK has never been used)
Re:Permanently modified? (Score:5, Informative)
Bah, that should be RAID stripe, not Raid Mirror
Meh, considering how much data I've lost and restored from an external source on Windows 7 miroring is a good idea. And lets not even get into the time Windows 7 arbitrarily uninstalled my network connection. Bastards.
Re:Probably using SD's DRM Mechanism (Score:1, Informative)
some heretofore "secret"
It is called "Secure Digital" and one if it's main selling points when the cards were first released was DRM. But good work :-)
Re:And they expect to sell those phones? (Score:3, Informative)
Nice examples, but there's no reason that audio won't work over DVI equally well as over HDMI.
I don't claim to be an expert, but to my knowledge the DVI spec doesn't include audio.
However, yes, its becoming common for PC video cards to provide it anyway. I'm not aware of anything else that can do it "natively".
Normally you need something like this...
http://www.gefen.com/kvm/include/prod_html/closeup/dviaudhdmiclose.shtml [gefen.com]
Which takes separate dvi+spdif and outputs hdmi.
Re:Permanently modified? (Score:3, Informative)
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 non-existent on Windows and (as far as I know) Linux.
2. The "special" card required is really just "fast" (can sustain a reasonable number of reads/writes per second) and "reliable" (properly implements the SD card spec and doesn't glitch out too often). The SD card's "class" doesn't matter here, as the class essentially measures how quickly an SD card can carry out a single large read/write operation, while phone performance depends more on how quickly the card can carry out a large number of small read/write operations. Microsoft tested a bunch of SD cards from a bunch of different vendors and found exactly one that met the minimum reliability and performance requirements. This is now the "approved" SD card. It is a class 2 card, which means it isn't particularly great at saving big JPGs, but it had much better random I/O scores than anything else that was tested. Microsoft doesn't sell this card and as far as I know has no financial interest in the sale of the card. Any card that meets the reliability and speed requirements will work just fine in the phone -- the phone isn't programmed to look for anything special in the SD card.
3. The confusion here comes from the fact that the SD slot is supported in a Windows Phone as a way for the retailer of the phone to easily upgrade the storage without involving a soldering iron, not as a way to share files between the phone and other systems. Selling a Windows Phone with an SD slot is like selling a computer with an unused SATA RAID port -- the user can add storage without going back to the manufacturer, but most users aren't expected to add or remove their computer's hard drive on a daily basis.
Re:Permanently modified? (Score:2, Informative)
http://www.bunniestudios.com/blog/?p=918 [bunniestudios.com]
Also, they've done a KB explaining what happens when you change cards:
http://support.microsoft.com/kb/2450831 [microsoft.com]
Here is the real info about how it works... (Score:2, Informative)
See: http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf [sdcard.org] for the full details.
Now a good question is if the WM7 uses the same password for all roms; or if it uses a hash based on the model/serial number or if it generates a password that it stores somewhere...