学步园

1. system/core/init/device.c加上一段代碼以創建/dev/snd:
 ......
        } else if(!strncmp(uevent->subsystem, "mtd", 3)) {
            base = "/dev/mtd/";
            mkdir(base, 0755);
        } else if(!strncmp(uevent->subsystem, "sound", 5)) {
            base = "/dev/snd/";
            mkdir(base, 0755);

2. 修改system/core/init/devices.c,增加设备节点及权限:

 static struct perms_ devperms[] = {
 ...
     { "/dev/snd/",          0664,   AID_SYSTEM,     AID_AUDIO,      1 },
 ...
 
3. 修改/build/target/board/generic/BoardConfig.mk
 
 #BOARD_USES_GENERIC_AUDIO := true
 BOARD_USES_ALSA_AUDIO := true
 BUILD_WITH_ALSA_UTILS := true

4. 下载android上的alsa lib 和alsa utils到external目录

Downloading ALSA projects
Create the local_manifest.xml file which tells repo about the eee_701 branch:

$ cd .repo
$ touch local_manifest.xml
Open local_manifest.xml in your favorite text editor. Paste the following text into local_manifest.xml.

<?xml version="1.0" encoding="UTF-8"?>
<manifest>
 <project path="external/alsa-lib" name="platform/external/alsa-lib"/>
 <project path="external/alsa-utils" name="platform/external/alsa-utils"/>
 <project path="hardware/alsa_sound" name="platform/hardware/alsa_sound"/>
</manifest>

Or use git clone:

For git please refer to
http://blog.csdn.net/stevenliyong/archive/2009/10/27/4732103.aspx

#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 android/hardware/
#git clone git://android.git.kernel.org/platform/hardware/alsa_sound.git

For pre-eclair version, you may need

#git -log

#git checkout v???