freescale i.mx23平台上移植android2.2-froyo - audio 系统.

作者 QQ： 35327864，msn： [email protected]，mail： [email protected]

基本上参照了http://blog.csdn.net/tianfeng105/archive/2010/03/28 /5425547.aspx

kernel部分不需要改动，只需要在android下面做事情。

1： 下载alsa相关代码

cd android/external git clone git://android.git.kernel.org/platform/external/alsa-lib.git git clone git://android.git.kernel.org/platform/external/alsa-utils.git cd ../hardware git clone git://android.git.kernel.org/platform/hardware/alsa_sound.git

2： 修改：build/target/board/generic/BoardConfig.mk 为如下

# config.mk # # Product-specific compile-time definitions. # # The generic product target doesn't have any hardware-specific pieces. TARGET_NO_BOOTLOADER := true TARGET_NO_KERNEL := true TARGET_CPU_ABI := armeabi #HAVE_HTC_AUDIO_DRIVER := true BOARD_USES_ALSA_AUDIO := true BUILD_WITH_ALSA_UTILS := true BOARD_USES_GENERIC_AUDIO := false # Set /system/bin/sh to mksh, not ash, to test the transition. TARGET_SHELL := mksh

3：make clean
4：make -j2
5：修改 init.rc，在此文件中加入如下代码，注意，应该在比较靠前的地方。

# windsome modify audio     chown root audio /dev/snd/controlC0     chown root audio /dev/snd/pcmC0D0c     chown root audio /dev/snd/pcmC0D0p     chown root audio /dev/snd/timer     chmod 0666 /dev/snd/controlC0     chmod 0666 audio /dev/snd/pcmC0D0c     chmod 0666 audio /dev/snd/pcmC0D0p     chmod 0666 audio /dev/snd/timer

6：增加asound.conf 文件，并放入到system/etc/下。我是从网上抄的一个，稍微改改能用了，也没有仔细分析到底该怎么写。

# # # # Mixer devices # # ctl.AndroidOut {     type hw     card 0 } ctl.AndroidIn {     type hw     card 0 } ctl.AndroidPlayback {     type hw     card 0 # Can replace with drivers name from /proc/asound/cards } ctl.AndroidRecord {     type hw     card 0 } # # # # Playback devices # # pcm.AndroidPlayback {     type hw     card 0     device 0 } pcm.AndroidPlayback_Speaker {                 type hw                 card 0                 device 0 } pcm.AndroidPlayback_Speaker_normal {                 type hw                 card 0                 device 0 } pcm.AndroidPlayback_Speaker_ringtone {                 type hw                 card 0                 device 0 } pcm.AndroidPlayback_Speaker_incall {                 type hw                 card 0                 device 0 } pcm.AndroidPlayback_Earpiece {                 type hw                 card 0                 device 0 }                 pcm.AndroidPlayback_Earpiece_normal {                 type hw                 card 0                 device 0 } pcm.AndroidPlayback_Earpiece_ringtone {                 type hw                 card 0                 device 0 } pcm.AndroidPlayback_Earpiece_incall {                 type hw                 card 0                 device 0 } pcm.AndroidPlayback_Bluetooth {                 type hw                 card 0                 device 0 }                pcm.AndroidPlayback_Bluetooth_normal {                 type hw                 card 0                 device 0 } pcm.AndroidPlayback_Bluetooth_ringtone {                 type hw                 card 0                 device 0 } pcm.AndroidPlayback_Bluetooth_incall {                 type hw                 card 0                 device 0 } pcm.AndroidPlayback_Headset {                 type hw                 card 0                 device 0 }                pcm.AndroidPlayback_Headset_normal {                 type hw                 card 0                 device 0 } pcm.AndroidPlayback_Headset_ringtone {     type hw     card 0     device 0 } pcm.AndroidPlayback_Headset_incall {     type hw     card 0     device 0 } pcm.AndroidPlayback_Bluetooth-A2DP {     type hw     card 0     device 0 }                pcm.AndroidPlayback_Bluetooth-A2DP_normal {     type hw     card 0     device 0 } pcm.AndroidPlayback_Bluetooth-A2DP_ringtone {     type hw     card 0     device 0 } pcm.AndroidPlayback_Bluetooth-A2DP_incall {     type hw     card 0     device 0 } pcm.AndroidRecord {     type hw     card 0     device 0 } pcm.AndroidRecord_Microphone {                 type hw                 card 0                 device 0 }