Sansa FuzeV2 - Rockbox installation disables DRM even when dual booting into OF

[P.Opus]

I understand that Rockbox does not support playback of DRM.  I understand this completely and I get that an open source, freeware project could not possibly pay or obtain the licensing required to enable Audible DRM or Microsoft PFS DRM used by Rhapsody, Napster, and similar subscription services.  I have NO expectation of the Rockbox team to enable DRM playback via Rockbox. 

What I don't understand at ALL is why DRM is broken when I boot into original firmware.  The Fuze  V2 can be booted into Sansa firmware, and for some reason DRM is broken even in this mode.

I had a rockboxed E280R and that played the Rhapsody tracks perfectly when booted into OF.  Does this have to do with the fact that the E280R read .rax formatted tracks and the DRM playback was "hardware based" somehow?

Can someone who is really familiar with internal Fuze/Clip architecture tell me why the mere installation of Rockbox disables all DRM playback even if the unit is booted in original firmware?  Like I said, I don't expect it "fixed"  I would just like to know why.  Call it curiosity.

If I could find a way to boot into OF to use Rhapsody channels, I would be more than happy.  I would simply reboot in OF and play my rhapsody tracks.

Does the installation of the rockbox bootloader somehow screw up the secure clock, does it overwrite the device certificate?  I'd really like someone who is in the know explain it to me?

I will continue to use Rockbox, it is simply that much better.  I have no expectations of any Rockbox devs to "make this work".  I just figured that Rockbox dev's know the most about the internal architecture than even perhaps the original manufacturers (lol). 

As a side note, uninstalling Rockbox and reinstalling the original "unmodified" OF file seems to correct this, so I imagine it has something to do with the modifications made to the OF file when rockbox is installed.

You guys are the best

[bertrik]

First of all, only Sandisk can really answer what kind of checks they built in to stop DRM from working.
Also I don't know if DRM is really disabled or not for all players under all circumstances, I don't have DRM-ed tracks myself. It seemed to happen for some people, so a warning about DRM and rockbox was added for all AMS (c200v2, e200v2, clipv1, fuze) and all AMSv2 (fuzev2, clipv2, clip+) players.

Rockbox does indeed change the real-time clock in the sansa fuze v2, for example resetting it to a sane date if it contains invalid time.
When adjusting the time in the original firmware (OF), the time in the real-time clock isn't really changed, the OF just adjusts an internal clock offset that is stored separately. Perhaps the internal time is indeed something that the OF uses to stop DRM from working.

When installing a rockbox bootloader, we basically replace the original firmware with a new image that contains both the original firmware and the rockbox bootloader (both compressed, to make both of them fit in the same space). Perhaps the OF does a full checksum over the area where the firmware is stored, which will be different after rockbox bootloader installation.

[P.Opus]

Bertrik,

You hit the nail on the head.  It is not Rockbox per se, but setting the date in Rockbox that kills the DRM tracks. 

If you remove the bootloader by reinstalling the original firmware file, then you can communicate with Rhapsody again.

As long as I don't adjust the "date" in Rockbox, any DRM tracks I have on the device remain playable when I boot into OF.

So the bottom line is to remember the following:
1.  The bootloader interferes with the devices ability to communicate with Rhapsody.  To communicate with Rhapsody, the bootloader must be removed by reloading original firmware.  This will allow DRM tracks to be loaded and license renewal.

2.  Rockbox writes directly to the hardware (secure) clock.  Adjusting the date in Rockbox to actual date will kill all your DRM tracks.

If you DID happen to adjust the date in Rockbox and expire your tracks, you will need to reload the original firmware and then connect to Rhapsody and re-license the device.  You may even have to use the "Reset Secure Clock" option in your Rhapsody software to get the player properly re-licensed.

The bottom line is that at the very minimum, you can get the device to talk with Rhapsody again and delete and reload your DRM material if you have to.