https://www.brobwind.com/archives/291
Brillo: 编译运行example-ledflasher程序
我们之前在建立Brillo编译环境的时候(. build/envsetup.sh), 在lunch的时候,就可以看到ledflasher-userdebug的项目,这个项目是给高通dragonboard使用的sample, 今天试着将这个项目移植到RPi 2B上面。相关的代码和配置文件在product/google/example-ledflasher下面,我们需要用到的文件有sepolicy和src下打面的所有文件。因为这个sample是用来控制LED的,所以我们还需要lights HAL层的代码,可以参考hardware/bsp/qcom/lights下面的代码。具体的操用步骤如下:
- 修改hardware/bsp/qcom/lights下代码,以便生成我们所需要的lights HAL层代码:
修改Android.mk, 将LOCAL_MODULE 改成lights.rpi, 如下所示:
LOCAL_PATH:= $(call my-dir) include $(CLEAR_VARS) LOCAL_SRC_FILES := lights.c LOCAL_MODULE_RELATIVE_PATH := hw LOCAL_SHARED_LIBRARIES := liblog LOCAL_CFLAGS := $(common_flags) -DLOG_TAG="lights" LOCAL_MODULE := lights.rpi LOCAL_MODULE_TAGS := optional include $(BUILD_SHARED_LIBRARY)
出于测试的目的,我并没有在RPi 2B上外接LED, 为了看到效里,暂时先作改lights.c文件,如果LED的状态发生变成,会在logcat中打印log,之后会在硬件上真正实现。相关的代码修改如下:
static int write_int(char const* path, int value) { #if 1 ALOGI(" -> write: %s value=0x08%x(%d", path, value, value); return 0; #else FILE *fd; fd = fopen(path, "w+"); if (fd) { int bytes = fprintf(fd, "%d", value); fclose(fd); return (bytes < 0 ? bytes : 0); } else { ALOGE("write_int failed to open %s ", path); return -errno; } #endif }
最后使用mm编译出lights.rpi.so文件。
- 编译ledflasher与ledservice模块
同样,进入product/google/example-ledflasher/src/ledflasher与product/google/example-ledflasher/src/ledservice文件夹,将这个两模块编译出来。
- 更新ramdisk7.img (selinux配置文件)
修改device/hzak/rpi/BoardConfig.mk,将product/google/example-ledflasher/sepolicy加入编译脚本:
BOARD_SEPOLICY_DIRS += product/google/example-ledflasher/sepolicy
最后make编译整个项目,以便生成我们所需的ramdisk文件。
- 更新系统中的其他模块
我们需要将lights.rpi.so, ledflasher和ledservice这几个文件放在特定的目录下。
但是首先将要更新ramdisk7.img:
$ adb push out/target/product/rpi/ramdisk.img /boot/ramdisk7.img
重启系统,这一步很重要,一定要做:
$ adb reboot
最后才去更新lights.rppi.so, ledflasher和ledservice这三个文件:
$ adb remount $ adb sync system
最后重启系统,就可以通过ps命令看到ledflasher服务在运行了。
由于selinux的关系,system文件夹中的文件是有selinux context的,可以通过ls -Z命令查看
ledflasher与ledservice正确的selinux context应该是:
$ adb shell ls -lZ | grep led -rwxr-xr-x 1 root shell u:object_r:ledflasher_exec:s0 67200 2016-01-05 12:14 ledflasher -rwxr-xr-x 1 root shell u:object_r:ledservice_exec:s0 38528 2016-01-05 12:14 ledservice
如果在kernel log出现如下log, 那么说明你没有按照上面的步骤来做,这个service是不会运行的:
01-01 00:00:03.973 0 0 E init : Service ledservice does not have a SELinux domain defined. 01-01 00:00:03.973 0 0 E init : Service ledflasher does not have a SELinux domain defined.
而你看到的selinux context可能是这样的:
$ adb shell ls -lZ | grep led -rwxr-xr-x 1 root shell u:object_r:system_file:s0 67200 2016-01-05 12:14 ledflasher -rwxr-xr-x 1 root shell u:object_r:system_file:s0 38528 2016-01-05 12:14 ledservice
从/privet/v3/commandDefs中可以看到,已经有led相关的字段了。接下来就要了解怎么去查询,更新LED的状态了。
NOTE: 关于authorization token的获取,请参考之前的文章。
$ curl -H "Authorization: Privet 4oqc8UPPmgY8z+N7vjZTs4sSBcp/4CRVtQD38GIW5RozOjE6MTQ1MTE5NzM2OQ==" -k http://10.0.0.18/privet/v3/commandDefs { "commands": { "_ledflasher": { "_animate": { "minimalRole": "user", "parameters": { "_duration": { "maximum": 100.0, "minimum": 0.1, "type": "number" }, "_type": { "enum": [ "none", "marquee_left", "marquee_right", "blink" ], "type": "string" } } }, "_set": { "minimalRole": "user", "parameters": { "_led": { "maximum": 4, "minimum": 1, "type": "integer" }, "_on": { "type": "boolean" } } }, "_toggle": { "minimalRole": "user", "parameters": { "_led": { "maximum": 4, "minimum": 1, "type": "integer" } } } }, "_metrics": { "_disableAnalyticsReporting": { "minimalRole": "manager" }, "_enableAnalyticsReporting": { "minimalRole": "manager" } }, "base": { "updateBaseConfiguration": { "minimalRole": "manager", "parameters": { "localAnonymousAccessMaxRole": { "enum": [ "none", "viewer", "user" ], "type": "string" }, "localDiscoveryEnabled": { "type": "boolean" }, "localPairingEnabled": { "type": "boolean" } } }, "updateDeviceInfo": { "minimalRole": "manager", "parameters": { "description": { "type": "string" }, "location": { "type": "string" }, "name": { "type": "string" } } } } }, "fingerprint": "3" }
再看看/privet/v3/traits和/privet/v3/components:
$ curl -H "Authorization: Privet 4oqc8UPPmgY8z+N7vjZTs4sSBcp/4CRVtQD38GIW5RozOjE6MTQ1MTE5NzM2OQ==" -k https://10.0.0.18/privet/v3/traits { "fingerprint": "3", "traits": { "_ledflasher": { "commands": { "_animate": { "minimalRole": "user", "parameters": { "_duration": { "maximum": 100.0, "minimum": 0.1, "type": "number" }, "_type": { "enum": [ "none", "marquee_left", "marquee_right", "blink" ], "type": "string" } } }, "_set": { "minimalRole": "user", "parameters": { "_led": { "maximum": 4, "minimum": 1, "type": "integer" }, "_on": { "type": "boolean" } } }, "_toggle": { "minimalRole": "user", "parameters": { "_led": { "maximum": 4, "minimum": 1, "type": "integer" } } } }, "states": { "_leds": { "items": { "type": "boolean" }, "type": "array" }, "_status": { "enum": { "enum": [ "idle", "animating" ], "type": "string" } } } }, "_metrics": { "commands": { "_disableAnalyticsReporting": { "minimalRole": "manager" }, "_enableAnalyticsReporting": { "minimalRole": "manager" } }, "state": { "_AnalyticsReportingState": { "enum": [ "enabled", "disabled" ], "type": "string" } } }, "base": { "commands": { "updateBaseConfiguration": { "minimalRole": "manager", "parameters": { "localAnonymousAccessMaxRole": { "enum": [ "none", "viewer", "user" ], "type": "string" }, "localDiscoveryEnabled": { "type": "boolean" }, "localPairingEnabled": { "type": "boolean" } } }, "updateDeviceInfo": { "minimalRole": "manager", "parameters": { "description": { "type": "string" }, "location": { "type": "string" }, "name": { "type": "string" } } } }, "state": { "firmwareVersion": "string", "localAnonymousAccessMaxRole": [ "none", "viewer", "user" ], "localDiscoveryEnabled": "boolean", "localPairingEnabled": "boolean" } } } } $ curl -H "Authorization: Privet 4oqc8UPPmgY8z+N7vjZTs4sSBcp/4CRVtQD38GIW5RozOjE6MTQ1MTE5NzM2OQ==" -k https://10.0.0.18/privet/v3/components { "components": { "ledflasher": { "state": { "_ledflasher": { "_leds": [ false, false, false, false ], "_status": "idle" } }, "traits": [ "_ledflasher" ] }, "metrics": { "state": { "_metrics": { "_AnalyticsReportingState": "disabled" } }, "traits": [ "_metrics" ] }, "weave": { "state": { "base": { "firmwareVersion": "0.0.0.1451996914", "localAnonymousAccessMaxRole": "viewer", "localDiscoveryEnabled": true, "localPairingEnabled": true } }, "traits": [ "base" ] } }, "fingerprint": "5" }