controlC0 -->用于声卡的控制，例如通道选择，混音，麦克风的控制等
midiC0D0 -->用于播放midi音频
pcmC0D0c-->用于录音的pcm设备
pcmCoDop -->用于播放的pcm设备
seq -->音序器
timer-->定时器
其中，COD0代表的是声卡0中的设备0，pcmC0D0c最后一个c代表capture，pcmC0D0p最后一个p代表playback，
ALSA 是 Linux 下处理音频硬件的核心子系统之一，提供了丰富的编程接口和工具，使得开发者能够高效地管理和控制声音硬件。交叉编译alsa-lib-1.2.3.2.tar.bz2生成相关的命令；
下载(www.alsa-project.org)：alsa-lib-1.2.3.2.tar.bz2
1.解压到home/arm/alsa/
@ubuntu:~/arm/alsd$ tar -xvf alsa-lib-1.2.3.2.tar.bz22.查看./configure 帮助文档
@ubuntu:~/arm/alsd/alsa-lib-1.2.3.2$ ./configure -help
`configure' configures alsa-lib 1.2.3.2 to adapt to many kinds of systems.
Usage: ./configure [OPTION]... [VAR=VALUE]...
To assign environment variables (e.g., CC, CFLAGS...), specify them as
VAR=VALUE. See below for descriptions of some of the useful variables.
Defaults for the options are specified in brackets.
Configuration:
-h, --help display this help and exit
--help=short display options specific to this package
--help=recursive display the short help of all the included packages
-V, --version display version information and exit
-q, --quiet, --silent do not print `checking ...' messages
--cache-file=FILE cache test results in FILE [disabled]
-C, --config-cache alias for `--cache-file=config.cache'
-n, --no-create do not create output files
--srcdir=DIR find the sources in DIR [configure dir or `..']
Installation directories:
--prefix=PREFIX install architecture-independent files in PREFIX
[/usr]
--exec-prefix=EPREFIX install architecture-dependent files in EPREFIX
[PREFIX]
By default, `make install' will install all the files in
`/usr/bin', `/usr/lib' etc. You can specify
an installation prefix other than `/usr' using `--prefix',
for instance `--prefix=$HOME'.
For better control, use the options below.
Fine tuning of the installation directories:
--bindir=DIR user executables [EPREFIX/bin]
--sbindir=DIR system admin executables [EPREFIX/sbin]
--libexecdir=DIR program executables [EPREFIX/libexec]
--sysconfdir=DIR read-only single-machine data [PREFIX/etc]
--sharedstatedir=DIR modifiable architecture-independent data [PREFIX/com]
--localstatedir=DIR modifiable single-machine data [PREFIX/var]
--libdir=DIR object code libraries [EPREFIX/lib]
--includedir=DIR C header files [PREFIX/include]
--oldincludedir=DIR C header files for non-gcc [/usr/include]
--datarootdir=DIR read-only arch.-independent data root [PREFIX/share]
--datadir=DIR read-only architecture-independent data [DATAROOTDIR]
--infodir=DIR info documentation [DATAROOTDIR/info]
--localedir=DIR locale-dependent data [DATAROOTDIR/locale]
--mandir=DIR man documentation [DATAROOTDIR/man]
--docdir=DIR documentation root [DATAROOTDIR/doc/alsa-lib]
--htmldir=DIR html documentation [DOCDIR]
--dvidir=DIR dvi documentation [DOCDIR]
--pdfdir=DIR pdf documentation [DOCDIR]
--psdir=DIR ps documentation [DOCDIR]
Program names:
--program-prefix=PREFIX prepend PREFIX to installed program names
--program-suffix=SUFFIX append SUFFIX to installed program names
--program-transform-name=PROGRAM run sed PROGRAM on installed program names
System types:
--build=BUILD configure for building on BUILD [guessed]
--host=HOST cross-compile to build programs to run on HOST [BUILD]
Optional Features:
--disable-option-checking ignore unrecognized --enable/--with options
--disable-FEATURE do not include FEATURE (same as --enable-FEATURE=no)
--enable-FEATURE[=ARG] include FEATURE [ARG=yes]
--enable-silent-rules less verbose build output (undo: "make V=1")
--disable-silent-rules verbose build output (undo: "make V=0")
--disable-maintainer-mode
disable make rules and dependencies not useful (and
sometimes confusing) to the casual installer
--enable-dependency-tracking
do not reject slow dependency extractors
--disable-dependency-tracking
speeds up one-time build
--enable-static[=PKGS] build static libraries [default=no]
--enable-shared[=PKGS] build shared libraries [default=yes]
--enable-fast-install[=PKGS]
optimize for fast installation [default=yes]
--disable-libtool-lock avoid locking (might break parallel builds)
--enable-symbolic-functions
use -Bsymbolic-functions option if available
(optmization for size and speed)
--enable-debug enable assert call at the default error message
handler
--enable-resmgr support resmgr (optional)
--disable-aload disable reading /dev/aload*
--disable-mixer disable the mixer component
--disable-pcm disable the PCM component
--disable-rawmidi disable the raw MIDI component
--disable-hwdep disable the hwdep component
--disable-seq disable the sequencer component
--disable-ucm disable the use-case-manager component
--disable-topology disable the DSP topology component
--enable-alisp enable the alisp component
--disable-old-symbols disable old obsoleted symbols
--enable-mixer-modules enable the additional mixer modules (experimental)
--enable-mixer-pymods enable the mixer python modules (experimental)
--disable-python disable the python components
--enable-python2 prefer python2
--disable-thread-safety disable thread-safe API functions
Optional Packages:
--with-PACKAGE[=ARG] use PACKAGE [ARG=yes]
--without-PACKAGE do not use PACKAGE (same as --with-PACKAGE=no)
--with-pic[=PKGS] try to use only PIC/non-PIC objects [default=use
both]
--with-aix-soname=aix|svr4|both
shared library versioning (aka "SONAME") variant to
provide on AIX, [default=aix].
--with-gnu-ld assume the C compiler uses GNU ld [default=no]
--with-sysroot[=DIR] Search for dependent libraries within DIR (or the
compiler's sysroot if not specified).
--with-configdir=dir path where ALSA config files are stored
--with-plugindir=dir path where ALSA plugin files are stored
--with-pkgconfdir=dir path where pkgconfig files are stored
--with-versioned shared library will be compiled with versioned
symbols (default = yes)
--with-debug library will be compiled with asserts (default =
yes)
--with-tmpdir=directory directory to put tmp socket files (/tmp)
--with-softfloat do you have floating point unit on this machine?
(optional)
--with-libdl Use libdl for plugins (default = yes)
--with-pthread Use pthread (default = yes)
--with-librt Use librt for monotonic clock (default = yes)
--with-wordexp Use wordexp when expanding configs (default = no)
--with-alsa-devdir=dir directory with ALSA device files (default /dev/snd)
--with-aload-devdir=dir directory with aload* device files (default /dev)
--with-pythonlibs=ldflags
specify python libraries (-lpthread -lm -ldl
-lpython2.4)
--with-pythonincludes=Cflags
specify python C header files
(-I/usr/include/python)
--with-pcm-plugins=<list>
build PCM plugins (default = all)
--with-ctl-plugins=<list>
build control plugins (default = all)
--with-max-cards Specify the max number of cards (default = 32)
Some influential environment variables:
CC C compiler command
CFLAGS C compiler flags
LDFLAGS linker flags, e.g. -L<lib dir> if you have libraries in a
nonstandard directory <lib dir>
LIBS libraries to pass to the linker, e.g. -l<library>
CPPFLAGS (Objective) C/C++ preprocessor flags, e.g. -I<include dir> if
you have headers in a nonstandard directory <include dir>
CPP C preprocessor
LT_SYS_LIBRARY_PATH
User-defined run-time library search path.
Use these variables to override the choices made by `configure' or to help
it to find libraries and programs with nonstandard names/locations.
Report bugs to the package provider.3.配置环境变量
@ubuntu:~/arm/alsd/alsa-lib-1.2.3.2$ export PATH=$PATH:/home/arm/arm-linux-gnueabihf-7.5.0/bin4.生成Makefile
./configure --host=arm --prefix=/home/arm/alsd/armAlsd CC=arm-linux-gnueabihf-gcc --disable-static5.make
6.make install
sound内核配置选项步骤：
