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Version 1: this patch prolongs startup time by 2 seconds, because the sleep happens early before other threads have started. The patch is tested on CreativeZEN and Fuze+. The datasheet was not very helpfull, so some experimentation was needed. I came to the following conclusions: * setting HP to ground: to prevent popping noises, the headphone output can be set to ground. This however must be done before any part of the audioout module is powered up (setting HP to ground itself will lead to a pop otherwise). This consequently means that HP must NOT be set to ground for powerdown sequence! Further study showed that setting HP out to ground has no audible benefit, controversly not setting/resetting allows for noiseless RoLo-ing. * headphone amp class A/AB mode: initially the HP amp is in class A mode, and should be set to class AB before playing audio, as the datasheet mentions. If the HP output is set to ground, it must be released BEFORE setting class AB! Releasing from ground while in AB mode leads to a very loud pop! * release HP from ground: as said before: never release the HP from ground if the HP amp is set to class AB mode. Therefore the correct order is to power up the headphone amp, wait some time, release HP from ground, and then set the amp to class AB mode. To prevent pop, some time is needed before releasing the HP from gnd. On CreativeZEN 2 sec seems to be ideal; 1 sec have no audible effect, 1.5 sec softenes the pop to some degree. * shutting player off The popping noise when shutting off is much quieter that on power up, so depopping measures are not absolutely necessary. However the power off pop can be silenced by inserting a wait time after the audioout block is closed and before the rest of the chip is powered down. The longer the better, a time of 5 sec practically eliminates the pop. Note that RoLo-ing can still produce noise, because the audio device is not properly shut down. Change-Id: Ib20e1d613b346433d2a711c442e303ededc26e78 |
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| backdrops | ||
| bootloader | ||
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| gdb | ||
| icons | ||
| lib | ||
| manual | ||
| packaging | ||
| tools | ||
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| utils | ||
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__________ __ ___.
Open \______ \ ____ ____ | | _\_ |__ _______ ___
Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
\/ \/ \/ \/ \/
Build Your Own Rockbox
1. Clone 'rockbox' from git (or extract a downloaded archive).
$ git clone git://git.rockbox.org/rockbox
or
$ tar xJf rockbox.tar.xz
2. Create a build directory, preferably in the same directory as the firmware/
and apps/ directories. This is where all generated files will be written.
$ cd rockbox
$ mkdir build
$ cd build
3. Make sure you have mips/m68k/arm-elf-gcc and siblings in the PATH. Make sure
that you have 'perl' in your PATH too. Your gcc cross compiler needs to be
a particular version depending on what player you are compiling for. These
can be generated using the rockboxdev.sh script in the /tools/ folder of the
source.
$ which arm-elf-eabi-gcc
$ which perl
4. In your build directory, run the 'tools/configure' script and enter what
target you want to build for and if you want a debug version or not (and a
few more questions). It'll prompt you. The debug version is for making a
gdb version out of it. It is only useful if you run gdb towards your target
Archos.
$ ../tools/configure
5. *ploink*. Now you have got a Makefile generated for you.
6. Run 'make' and soon the necessary pieces from the firmware and the apps
directories have been compiled, linked and scrambled for you.
$ make
$ make zip
7. unzip the rockbox.zip on your music player, reboot it and
*smile*.
If you want to build for more than one target, just create several build
directories and create a setup for each target:
$ mkdir build-fuzeplus
$ cd build-fuzeplus
$ ../tools/configure
$ mkdir build-xduoox3
$ cd build-xduoox3
$ ../tools/configure
Questions anyone? Ask on the mailing list or on IRC. We'll be happy to help you!