This reverts commit 6f0320a9535bc1aa81d83fa879ac14d5ee603658.

Change-Id: I7425d422a4a0af7a49e9194cfe0bb55d431bc401

This reverts commit 568b81202ebd24a3f7e9efe0558b5f6beed05b44.

Change-Id: I2af42cd53d0ce490bf96c68288e9fbde034c0069

Change-Id: Ic5d9de230efceabc2c428e5c78fa6596a5a34840

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?

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

Adds boot data to as3525 devices Sansa C200v2 E200v2 Clip Clipv2 Clip+ ClipZip
fuze, fuzev2 m200v4

Adds boot_data to features.txt

default arm crt0.s now had boot data if HAVE_BOOTDATA is defined

Change-Id: I614a556696540511a69fc12a4520b01c268bf8a9

Targets: sansaclipplus, samsaclipv2, sansaclipzip, sansafuzev2.

Change-Id: I7773528a4e26707dd33fe9cb8948750d49570701

Values taken from Mihail's Clip Zip, should be similar
on all AMSv2 devices.

Change-Id: I9432ecffea94afae224391a86f1d3fa46cd87bc0

With this changes rockbox can be loaded from SD card when internal storage
can't be mount (due to hardware or software problem).

Change-Id: I32b20d3f341566364def747a708a54ba6b4a7f8b

Change-Id: I8d64b8578d28884e326f8b43100b3b4691f95acf