Android 驱动开发系列二

最近琐碎事太多了，都没什么时间来写blog。

现在继续写这个android驱动的开发调试这一章主要是讲如何测试驱动。

1、驱动的简单测试在上一篇文章中，我们已经把添加驱动模块做完了，并把驱动下载到了板子上。

下面将介绍一下如何测试驱动是否正常。

这个ttt驱动，我们实现了一个读、一个写的接口，就此进行简单的测试：启动板子，进入系统，然后进入命令行（可以用串口，也可以用adb shell）进入dev目录：[plain]view plaincopy1.root@android:/ # cd /dev2.root@android:/dev #查看ttt 设备文件是否存在：[plain]view plaincopy1.root@android:/dev # ls -l ttt2.crw------- root root 249, 0 2013-04-02 09:58 ttt进入到/proc目录，验证设备的输入输出：[plain]view plaincopy1.root@android:/dev # cd /proc/2.root@android:/proc #获取ttt 设备的值：[plain]view plaincopy1.root@android:/proc # cat ttt2.03.root@android:/proc #设置ttt 设备的值：1.root@android:/proc # echo '111' > ttt2.root@android:/proc # cat ttt3.1114.root@android:/proc #这里就可以说明：ttt 设备文件已经OK了，输入输出接口都没有问题。

当然，这里还有其他的方式去验证这个输入输出，如：进入到/sys/class 的ttt 设备目录下：[plain]view plaincopy1.root@android:/proc # cd /sys/class/ttt/ttt/2.root@android:/sys/class/ttt/ttt # ls3.dev4.power5.subsystem6.uevent7.val8.root@android:/sys/class/ttt/ttt #通过访问val 属性文件来读写ttt 设备的值：[plain]view plaincopy1.root@android:/sys/class/ttt/ttt # ls2.dev3.power4.subsystem5.uevent6.val7.root@android:/sys/class/ttt/ttt # cat val8.1119.root@android:/sys/class/ttt/ttt # echo '123' > val10.root@android:/sys/class/ttt/ttt # cat val11.12312.root@android:/sys/class/ttt/ttt #2、编写C程序来测试驱动的读写切换到root权限，并进入到android源码目录下的external 目录：[plain]view plaincopy1.root@brantyou-ubuntu:~# cd workspace/android-4.0.4_r1.2/external/2.root@brantyou-ubuntu:~/workspace/android-4.0.4_r1.2/external# ls3.android-mock freetype libpng safe-iop4.antlr fsck_msdos libvpx skia5.apache-harmony genext2fs libxml2 sonivox6.apache-http giflib libxslt speex7.apache-xml google-diff-match-patch libyuv sqlite8.astl grub llvm srec9.bison gtest lohit-fonts srtp10.blktrace guava markdown stlport11.bluetooth harfbuzz mesa3d strace12.bouncycastle hyphenation mksh svox13.bsdiff icu4c mockwebserver tagsoup14.bzip2 iproute2 mtpd tcpdump15.chromium ipsec-tools netcat tinyalsa16.clang iptables netperf tinyxml17.collada javasqlite neven tremolo18.dbus javassist nist-sip v819.dhcpcd jdiff oauth valgrind20.dnsmasq jhead opencv webkit21.doclava jpeg openssl webp22.dropbear jsilver oprofile webrtc23.e2fsprogs jsr305 pcre wpa_supplicant24.easymock junit ping wpa_supplicant_625.elfutils kernel-headers ping6 wpa_supplicant_826.embunit libffi ppp xmlwriter27.emma libgsm proguard yaffs228.esd liblzf protobuf yapp29.expat libnfc-nxp qemu zlib30.eyes-free libnl-headers qemu-pc-bios31.fdlibm libpcap quake32.flac libphonenumber replicaisland33.root@brantyou-ubuntu:~/workspace/android-4.0.4_r1.2/external#由于这个目录下的文件比较多，为了不混淆，我另外新建了一个yapp目录，用于存放相关的程序。

进入到yapp目录，并创建tttapp 目录：[plain]view plaincopy1.root@brantyou-ubuntu:~/workspace/android-4.0.4_r1.2/external/yapp# mkdir tttapp2.root@brantyou-ubuntu:~/workspace/android-4.0.4_r1.2/external/yapp# ls3.helloapp helloworld tttapp进入到tttapp 目录，并创建tttapp.c 文件：[plain]view plaincopy1.root@brantyou-ubuntu:~/workspace/android-4.0.4_r1.2/external/yapp# cd tttapp/2.root@brantyou-ubuntu:~/workspace/android-4.0.4_r1.2/external/yapp/tttapp# gedit tttapp.ctttapp.c 文件内容如下：[cpp]view plaincopy1.#include <stdio.h>2.#include <stdlib.h>3.#include <fcntl.h>4.5.#define DEVICE_NAME "/dev/ttt"6.7.int main(int argc, char** argv)8.{9.int fd = -1;10.int val = 0;11. fd = open(DEVICE_NAME, O_RDWR);12.if(fd == -1){13. printf("Failed to open device %s.\n", DEVICE_NAME);14.return -1;15. }16.17. printf("Read original value:\n");18. read(fd, &val, sizeof(val));19. printf("%d.\n\n", val);20.21. val = 100;22. printf("Write value %d to %s.\n\n", val, DEVICE_NAME);23. write(fd, &val, sizeof(val));24.25. printf("Read the value again:\n");26. read(fd, &val, sizeof(val));27. printf("%d.\n\n", val);28.29. close(fd);30.31.return 0;32.}创建对应的Android.mk配置文件：[plain]view plaincopy1.root@brantyou-ubuntu:~/workspace/android-4.0.4_r1.2/external/yapp/tttapp# gedit Android.mkAndroid.mk 文件内容如下：[cpp]view plaincopy1.LOCAL_PATH := $(call my-dir)2.include $(CLEAR_VARS)3.LOCAL_MODULE_TAGS := optional4.LOCAL_MODULE := tttapp5.LOCAL_SRC_FILES := tttapp.c6.include $(BUILD_EXECUTABLE)C程序编写完了，下面进行编译：回到android的源码目录，并执行envsetup.sh：[plain]view plaincopy1.root@brantyou-ubuntu:~/workspace/android-4.0.4_r1.2# ls2.abi build device hardware out system3.bionic cts docs libcore packages v8.log4.bootable dalvik external Makefile prebuilt vendor5.boot.img development frameworks ndk sdk6.root@brantyou-ubuntu:~/workspace/android-4.0.4_r1.2# . build/envsetup.sh7.including device/moto/stingray/vendorsetup.sh8.including device/moto/wingray/vendorsetup.sh9.including device/samsung/crespo4g/vendorsetup.sh10.including device/samsung/crespo/vendorsetup.sh11.including device/samsung/maguro/vendorsetup.sh12.including device/samsung/smdkc110/vendorsetup.sh13.including device/samsung/smdkv210/vendorsetup.sh14.including device/samsung/torospr/vendorsetup.sh15.including device/samsung/toro/vendorsetup.sh16.including device/samsung/tuna/vendorsetup.sh17.including device/ti/panda/vendorsetup.sh18.including sdk/bash_completion/adb.bash19.root@brantyou-ubuntu:~/workspace/android-4.0.4_r1.2#执行make tttapp 编译tttapp 程序：[plain]view plaincopy1.root@brantyou-ubuntu:~/workspace/android-4.0.4_r1.2# make tttapp2.============================================3.PLATFORM_VERSION_CODENAME=REL4.PLATFORM_VERSION=4.0.45.TARGET_PRODUCT=full6.TARGET_BUILD_VARIANT=eng7.TARGET_BUILD_TYPE=release8.TARGET_BUILD_APPS=9.TARGET_ARCH=arm10.TARGET_ARCH_VARIANT=armv7-a11.HOST_ARCH=x8612.HOST_OS=linux13.HOST_BUILD_TYPE=release14.BUILD_ID=IMM76I15.============================================16.target thumb C: tttapp <= external/yapp/tttapp/tttapp.c17.target Executable: tttapp (out/target/product/generic/obj/EXECUTABLES/tttapp_intermediates/LINKED/tttapp)18.target Symbolic: tttapp (out/target/product/generic/symbols/system/bin/tttapp)19.target Strip: tttapp (out/target/product/generic/obj/EXECUTABLES/tttapp_intermediates/tttapp)20.Install: out/target/product/generic/system/bin/tttapp21.root@brantyou-ubuntu:~/workspace/android-4.0.4_r1.2#这样就表示编译成功了，我们看一下这个对应的执行程序是否已经生成：[plain]view plaincopy1.root@brantyou-ubuntu:~/workspace/android-4.0.4_r1.2# ls -l out/target/product/generic/system/bin/tttapp2.-rwxr-xr-x 1 root root 5524 2013-04-02 11:04 out/target/product/generic/system/bin/tttapp3.root@brantyou-ubuntu:~/workspace/android-4.0.4_r1.2#这样就表示生成了对应的可执行程序。