[XAP][GUIDE] Interop Unlock for WP8 + all Capabilities

It took us much longer than WP7 did, but the first Interop Unlock hack for WP8 is now available. It's currently limited to SAMSUNG phones, although we're trying to extend it to other phones, of course.
WARNING: Samsung is trying to break this hack! If you take the retail upgrade to GDR3 including the Samsung firmware update, it will not work!

A brief summary, for those unfamiliar with interop-lock: Windows Phone allows a number of high-privilege app capabilities, which can be used to make changes to the OS which are normally not possible for a third-party app. The limitation on whether we can use these capabilities or not is based on what "level" of developer unlock the phone has; standard "ISV" (Independent Software Vendor) dev unlock (max 10 apps or less) is what pretty much everybody gets; OEMs, however, get a special OEM Developer Unlock (300 apps or more) which gives them the ability to use much higher-privilege app capabilities than the standard ISV unlock permits. The name comes from ID_CAP_INTEROPSERVICES, the capability which was most important in WP7. In WP8, however, there are a great many interesting capabilities. Note that Interop-unlock by itself does not enable all of these. However, at least on Samsung phones, it is now possible to enable *all* the capabilities.

Guide for Samsung's ATIV phones:

If you want to enable sideloading even more high-privileged apps, you'll want the following:


Capabilities which will be enabled, without further modification, by using interop-unlock:


One of the goals of this thread will be to explore what we can do with interop-unlock, and look for ways to achieve full permissions. I think I've found one, but it requires the ability to write registry multi-string values. Basically, if we could add a "superuser" privilege, or enable the use of ID_CAP_BUILTIN_TCB, which already has it, this would allow the creation of "root" apps.

Aside from myself, credit for this hack goes to @cpuguy for the Native Toast Launcher tool which permits accessing otherwise-unreachable code, and @-W_O_L_F- for helping put the pieces together. I'm not actually certain which one of us achieved the interop-unlock first; we were both working on it. @Heathcliff74 continues to be a help on the quest for full-unlock.

The source code for the apps below is posted at http://xdaforums.com/showpost.php?p=45606584&postcount=88

Root unlock achieved (EDIT: Sigh, not quite) on my ATIV S. Details forthcoming. In the meantime, rest assured: it is possible. This still won't let old apps be used, but it will let new "root" apps be written. Basically, an all-new WP8 Root Tools.

EDIT: Agh. Still not working. I'm trying, though!

WP8 Root Tools progress report

WP8 Root Tools progress report

My two cents...

Hi all,

Sorry for this off-topic message. But everybody who concerns this, follows this thread. So I'll drop it here.

Today something amazing happened. I received a package from Italy. It was the long-awaited Samsung Ativ-S developer device. Many people donated money so we could buy a new phone for @sireangelus and he could send his phone to me. Within a few days money was collected, new device bought and sent to @sireangelus. After that, silence... I sent several PM's to him often no response. Or messages of him trying to be funny or whatever. But nothing was sent. I'm not easily pissed off, but last week, almost 2 months after he promised to send the phone, I got really angry and I sent him a couple of whatsapp messages to convince him he should keep his promise and don't be an @$$. Today I received the package.

This night I had some time to check it out. Conclusion: it is really a developer device and very valuable for research! Yay!

I already had an incident with it. I connected the device in mass-storage mode to my laptop, while I already had a WP8 virtual disk mounted. Windows 8 decided that all partitions needed to be unique and it actually changed the entries in the partition table of the Samsung (!!!) It couldn't boot any more. Luckily, I could still use mass-storage, so I could still inspect the device. I found that the partition table was corrupted and I could manually fix it. Pfew! All is working well again and I can further dissect it.

Thanks to @sireangelus for finally sending the phone. I advise you to act more pertinent the next time you sell something, in order to avoid that people are getting really pissed off at you.
Thanks to all guys who donated to make this possible. I hope to bring you new hacks soon!!

Ciao,
Heathcliff74

Questions and Answers

Can I install WP7 interop apps using this?
They will install, but there's no point. They almost certainly won't actually work. Interop-unlock enables access to parts of the OS which third-party developers were not intended to touch; consequently, there's no backward compatibility. Even the methods used for native code on WP7 (which is different from, but nearly essential to make use of, interop-unlock) won't work on WP8. However, it should be possible to port many of those applications to WP8.

Will this work on Lumia phones / How can I get this on my Lumia / Are you working on this for Lumia phones / What about HTC, or some other OEM?
The current hack relies on a Samsung-specific component. Adding support for other phones will require new hacks. We are looking into it, rest assured; at this time, however, there is no way to gain interop-unlock on any WP8 device other than a Samsung one.
EDIT: It looks like there should soon be a Huawei W1 custom ROM with interop-unlock included. I don't deal with custom ROMs, but you may be able to use homebrew apps on that phone too.
EDIT: Lumia phones *can* be interop-unlocked via JTAG. However, this requires some extra hardware and some phone disassembly. Not an online hack, and not for the faint of heart.

But what if we installed the Diagnosis app on a Lumia phone (using Fiddler proxy or similar) and then followed this guide?
I repeat, Samsung-specific component. Nokia doesn't put the required services/drivers for Samsung's Diagnosis app into their Lumia firmware, so the app would not work!

Can I upgrade my phone to GDR3 if I have this?
Yes. However, be aware: if you install Samsung's updates that come with the retail GDR3 update, it will break your ability to re-unlock, or to use some homebrew apps! (Developer preview updates are fine, as those are purely Microsoft code and don't mess with the Samsung components.)
EDIT: There's a way to unlock the Samsung services for full access again on GDR3. You still need to interop-unlock beforehand, though.

Can I re-lock my phone if I want to?
Yes, easily. The simplest method is to use the Windows Phone Developer Registration tool (the one that comes with the SDK) to de-register the phone (you can then re-register it if you want to get your normal dev-unlock back). This doesn't remove any changes that were made using the interop-unlock, though (for example, it won't undo the EnableAllSideloading hack, not will it set back the Full FS Access hack). Apps that require interop-unlock will still be installed, but may no longer run. To manually remove interop-unlock, you can reset all the registry values that were changed by the interop-unlock hack to their original values, and remove all the apps. There still may be a great many other changes that also need reverting, though, if you want to get back to stock settings. See next question.

Can I get my phone completely back to stock settings without knowing every little thing I changed?
Yes, a hard (factory) reset will undo all changes made by interop-unlock, or any apps (including ones that require interop-unlock), and will remove all apps. If you need to send your phone in for warranty servicing and are worried that they won't take it because you interop-unlocked it, this approach will fix that (they would probably tell you to hard-reset anyhow, if it's conceivably a software problem).

Will the interop-unlock survive a hard reset?
Not using this method! Read the question above. This unlock is purely in software, not firmware; it is reset along with everything else.

Can I upgrade my phone to WP8.1 if I have this?
Tentatively, yes! We're still working on figuring out exactly what WP8.1 means for the homebrew scene. The short version is that most apps and some (but not all) of the hacks they contain seem to still work, though. However, see next question...

Can I interop-unlock my phone on WP8.1?
At this time, I don't believe this is possible (unless you can use a custom ROM). One step of the process appears to have been "fixed" and we will need to find a different way. -W_O_L_F- has indicated that he has one, possibly coming soon...