Wanted to see how gnarly it is to do.

Big number handling could be done with better algorithms
since it can get a bit slow with large integers or tiny
fractions with many lead zeros when only a few digits are
needed.

Anyway, it supports %e, %E, %f, %F, %g and %G. No %a or long
double support seems warranted at the moment.

Assumes IEEE 754 double format but it's laid out to be able to
replace a function to handle others if needed.

Tested in a driver program that has a duplicate vuprintf and
the content was pasted in once it looked sound enough to put
up a patch.

Change-Id: I6dae8624d3208e644c88e36e6a17d8fc9144f988

New support as well as some buggy support fixed.

Still no floating point support if ever that would be desired.

Support (*):
* Flags: '-', '+', ' ', '#', '0'

* Width and precision: 'n', '.n', '*' and '.*'

* Length modifiers: 'hh', 'h', 'j', 'l', 'll', 't', 'z'

* Radix: 'c', 'd', 'i', 'n', 'o', 'p/P', 's', 'u', 'x/X'

(*) Provision exists to switch lesser-used stuff on or off or when
certain functionality isn't desired (bootloader?). The compulsory
radixes are everything but 'o', 'n', 'p/P' and 'x/X' with length
modifiers being optional. The default setup is 'l', 'z', 'c', 'd',
'p/P', 's', 'u', 'x/X'.

* Move fdprintf() to its own file. It was in a strange place.

* Make callers compatible and fix a couple snprintf() bugs while
at it.

Could smush it down in size but I'm gonna get over the binsize
neurosis and just the let optimizer do its thing.

Change-Id: Ibdc613a9b6775802c188b29b9dd46c568c94f7c3

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

Many includes of fat.h are pointless. Some includes are just for
SECTOR_SIZE. Add a file 'firmware/include/fs_defines.h' for that
and to define tuneable values that were scattered amongst various
headers.

Remove some local definitions of SECTOR_SIZE since they have to be
in agreement with the rest of the fs code anyway.

(We'll see what's in fact pointless in a moment ;)

Change-Id: I9ba183bf58bd87f5c45eba7bd675c7e2c1c18ed5

* 8 bits is enough to allow 260 character base names when five
bytes is the minimum indirect storage size (0..255->5..260).

* Don't truncate anything that's too long as that can lead to
bad behavior, simply don't include the offending entry in the
parent.

* Set the .tinyname flag to 1 by default to indicate that
the entry's name doesn't need freeing. Clear it only when
allocating indirect storage.

* Rename some things to help catch all instances

Change-Id: Iff747b624acbb8e03ed26c24afdf0fc715fd9d99

These flags aren't stored for an open file because they're simply
actions for open() to take, corresponding to O_CREAT and O_EXCL.
Just pass the oflag argument along to the deeper call, with some
minor filtering.

Change-Id: Ic8bcfba718ebf4228bdc45de3088af1974820557

Do a few other changes to dircache and file code flags to
accomodate its demands.

Change-Id: I4742a54e8cfbe4d8b9cffb75faaf920dd907cf8a

The file system rework introduced incompatibility between dircache
and the tagcache ramcache and playlist dircache path caching. This
update makes changes to filesystem code to reintegrate all that.

It also fixes a couple bugs that were found when vetting all the
code. The filestream cache was being reset without regard to
the stream even if it was shared in write mode (made work of
.playlist_control). Better handling of unmounting gives files a
better go at force-closing them without risk to disk integrity.

Did some miscellaneous pedantic changes. Improved efficiency of
testing a file's existence (a little) since the path parser will
be shared between file code and parsing for the sake of finding
dircache references, not duplicated as before.

This commit doesn't reenable said items just for the sake of
keeping changes separate and related.

Plan for the next is to enable dircache again for the playlists
(easy peasy) and reenable tagcache ramcache but *without* the
dircache path caching because it's rather substantial to change
in itself. The ramcache will still function without dircache.

Change-Id: I7e2a9910b866251fa8333e1275f72fcfc8425d2d

Somehow it got hooked to simulator file functions when it should
be (and was) using raw OS functions.

Credit: Frank Gevaerts

Change-Id: Iac02fed1067830a432183632a047e00dfd03d3c2

- patch suggested by Massa in http://forums.rockbox.org/index.php/topic,51618.msg238760.html#msg238760

Change-Id: Iba93ff53119db00a18d944d52bc8b1c5fe593fc9