Taken from the xvortex fork (Roman Stolyarov)
Ported, rebased, and cleaned up by myself.

Change-Id: I7b2bca2d29502f2e4544e42f3d122786dd4b7978

This reverts commit 6f0320a9535bc1aa81d83fa879ac14d5ee603658.

Change-Id: I7425d422a4a0af7a49e9194cfe0bb55d431bc401

Cleaned up, rebased, and forward-ported from the xvortex fork.

(original credit to vsoftster@gmail.com)

Change-Id: Ibcc023a0271ea81e901450a88317708c2683236d
Signed-off-by: Solomon Peachy <pizza@shaftnet.org>

Allow user to select cpu undervolt

There have been quite a few issues across the SANSA AMS line related
to CPU undervolting while most players show greatly increased runtime
some crash.
Rather than constanly upping the voltage we now have a
setting with a safe value for all players and the option for lower voltages

I plan to add a few other options here later such as disk
timings and maybe some other clocks/experimental settings

Added: Disk Low speed option for AS3525v2 devices cuts
	frequency to 12 MHz from 24 MHz
Added: Disk Low speed option for AS3525v1 devices cuts
        frequency to 15.5 MHz from 31 MHz

Added: I2c Low Speed AS3525 devices, should be bigger improvement for v1 devices

Fixed: Debug menu for AS3525v2 No SDSLOT frequency,
	Showed IDE freq though it is unused

Added: DBOP and SSP underclocking affects display on v1/v2 respectively

Fixed: debug menu now has SSP frequency, and SSP_CPSR

Update: made settings menu more generic

Update: cleaned up code

Added: Clip v1 & Fuze v1 didn't have HAVE_ADJUSTABLE_CPU_VOLTAGE.
	not sure why but,  waiting on testing to confirm

Added: C200v2 and E200v2 devices and HAVE_ADJUSTABLE_CPU_VOLTAGE.

Fixed: v1 devices don't like display timing set lower (dbop)
       v1 devices don't have a divider set for ssp (causes divide by 0)

Fixed: ClipZip display lags with Max SSP divider changed from 0xFE to 0x32

Fixed: v1 devices didn't work properly with highspeed sd cards
	Added code from http://gerrit.rockbox.org/r/#/c/1704/
	Added powersave and IDE interface enable/disable

Added: V2 devices now have powersave enabled on sd interface

Update: cleaned up code, lang defines, added manual entries

Update ssp clock mechanism added calculated ssp divider to clipzip

Update turn display clock off when clip+ turns off display

Fixed: clipzip wrong register for SSP clock

Change-Id: I04137682243be92f0f8d8bf1cfa54fbb1965559b
TODO: add other players?

Change-Id: I26b51106c7b1c36a603fba6d521e917d79b5a95b

This ports Fabien Sanglard's Chocolate Duke to run on a version of SDL
for Rockbox.

Change-Id: I8f2c4c78af19de10c1633ed7bb7a997b43256dd9

Instead of checking ticks, set a sticky dirty flag that indicates
that the RTC needs to be read. This gives a timely update and more
accurate readout without actually reading the RTC until it changes.
The implementation should atomically read the flag and clear it.
Setting the flag would typically happen in an RTC tick ISR.

Change-Id: I6fd325f22845029a485c502c884812d3676026ea

Adds the ability to load firmware from other drives on MULTIVOLUME targets
Mihail Zenkov <mihail.zenkov@gmail.com> had posted a hard coded patch
to allow this on several Sansa players, I made it more universal

Redirect file rockbox_main.<name> should placed in root of
drive you would like to be main, if this file empty or there a single
slash '/' firmware will be loaded from /.rockbox in root of this drive
If instead a /<*DIRECTORY*> is supplied in rockbox_main.<name> then
firmware will be loaded from /<dir>/.rockbox/

NOTES*

The directory can have multiple levels however..
leading slash MUST be included
trailing slash can be omitted
(eg. /test/.rockbox would be simply '/test' in the redirect file)

Redirect file will not work on internal drive (whatever is default boot drive)

Volume with the highest index containing redirect file will be loaded
first.

Firmware file is checked for boot data region, if missing, firmware
image will not be loaded.

On failure or if no redirect file is found load will fallback to
internal drive

Currently only Sansa Fuze+, Sansa Clip+,
Sansa Clip Zip, Sansa Fuzev2, and Sansa Fuzev1 are implemented.

Players (with HAVE_MULTIVOLUME)
will need #define HAVE_BOOTDATA and #define BOOT_REDIR "rockbox_main.<name>"
added to their config file

boot_data is implemented in crt0.s file (See g#1552)
ARM and IMX233 have aleady been implemented

Once these conditions are met <HAVE_MULTIBOOT> will be defined by config.h

Partitions on the drives are able to have a redirect as
well.

Change-Id: Iada3263919f6bcad7d0d7d8279b4239aafa07ee9

Strangely it has the SAME encryption key as the E450. Either they didn't bother
changing it or more likely they have exactly the same internals and a slightly
different case.

Change-Id: I39ab88845b3e40db34160c2e61dde421f391df44

Change-Id: I9050129949809b3dbe9f4f9e816f8980c4f3a904