/****************************************************************************
* I.MX6 Surfaceflinger 机制
* 说明：
* 最近需要去分析一下Surfaceflinger工作机制，记录一下相关的文档和主要的
* 处理函数。
*
* 2016-9-14 深圳 南山平山村 曾剑锋
***************************************************************************/
一、参考文档：
1. Android SurfaceFlinger服务启动过程源码分析
http://blog.csdn.net/yangwen123/article/details/11890941
2. Android 开关机动画显示源码分析
http://blog.csdn.net/yangwen123/article/details/11680759
3. 深入学习EGL
http://blog.sina.com.cn/s/blog_602f87700100p1e7.html
4. Android hwcomposer模块接口
http://blog.sina.com.cn/s/blog_7213e0310102wmc0.html
5. Android VSync信号产生过程源码分析
http://blog.csdn.net/yangwen123/article/details/16969907
6. android HAL浅探
http://www.cnblogs.com/mr-nop/archive/2013/02/27/2935131.html
7. Android： 显示系统模块加载以及调用流程
http://blog.csdn.net/hongzg1982/article/details/49681705
二、cat frameworks/native/services/surfaceflinger/SurfaceFlinger.cpp
......
status_t SurfaceFlinger::readyToRun()
{
ALOGI( "SurfaceFlinger's main thread ready to run. "
"Initializing graphics H/W...");
// initialize EGL for the default display
mEGLDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
eglInitialize(mEGLDisplay, NULL, NULL);
// Initialize the H/W composer object. There may or may not be an
// actual hardware composer underneath.
mHwc = new HWComposer(this,
*static_cast<HWComposer::EventHandler *>(this));
// initialize the config and context
EGLint format = mHwc->getVisualID();
mEGLConfig = selectEGLConfig(mEGLDisplay, format);
mEGLContext = createGLContext(mEGLDisplay, mEGLConfig);
LOG_ALWAYS_FATAL_IF(mEGLContext == EGL_NO_CONTEXT,
"couldn't create EGLContext");
// initialize our non-virtual displays
for (size_t i=0 ; i<DisplayDevice::NUM_DISPLAY_TYPES ; i++) {
DisplayDevice::DisplayType type((DisplayDevice::DisplayType)i);
mDefaultDisplays[i] = new BBinder();
wp<IBinder> token = mDefaultDisplays[i];
// set-up the displays that are already connected
if (mHwc->isConnected(i) || type==DisplayDevice::DISPLAY_PRIMARY) {
// All non-virtual displays are currently considered secure.
bool isSecure = true;
bool isSecure = true;
mCurrentState.displays.add(token, DisplayDeviceState(type));
sp<FramebufferSurface> fbs = new FramebufferSurface(*mHwc, i);
sp<SurfaceTextureClient> stc = new SurfaceTextureClient(
static_cast< sp<ISurfaceTexture> >(fbs->getBufferQueue()));
sp<DisplayDevice> hw = new DisplayDevice(this,
type, isSecure, token, stc, fbs, mEGLConfig);
if (i > DisplayDevice::DISPLAY_PRIMARY) {
// FIXME: currently we don't get blank/unblank requests
// for displays other than the main display, so we always
// assume a connected display is unblanked.
ALOGD("marking display %d as acquired/unblanked", i);
hw->acquireScreen();
}
mDisplays.add(token, hw);
}
}
// we need a GL context current in a few places, when initializing
// OpenGL ES (see below), or creating a layer,
// or when a texture is (asynchronously) destroyed, and for that
// we need a valid surface, so it's convenient to use the main display
// for that.
sp<const DisplayDevice> hw(getDefaultDisplayDevice());
// initialize OpenGL ES
DisplayDevice::makeCurrent(mEGLDisplay, hw, mEGLContext);
initializeGL(mEGLDisplay);
// start the EventThread
mEventThread = new EventThread(this);
mEventQueue.setEventThread(mEventThread);
// initialize our drawing state
mDrawingState = mCurrentState;
// We're now ready to accept clients...
mReadyToRunBarrier.open();
// set initial conditions (e.g. unblank default device)
initializeDisplays();
// start boot animation
startBootAnim();
return NO_ERROR;
}
......
三、cat frameworks/native/services/surfaceflinger/DisplayHardware/HWComposer.cpp
......
// Load and prepare the hardware composer module. Sets mHwc.
void HWComposer::loadHwcModule()
{
hw_module_t const* module;
if (hw_get_module(HWC_HARDWARE_MODULE_ID, &module) != 0) {
ALOGE("%s module not found", HWC_HARDWARE_MODULE_ID);
return;
}
int err = hwc_open_1(module, &mHwc);
if (err) {
ALOGE("%s device failed to initialize (%s)",
HWC_HARDWARE_COMPOSER, strerror(-err));
return;
}
if (!hwcHasApiVersion(mHwc, HWC_DEVICE_API_VERSION_1_0) ||
hwcHeaderVersion(mHwc) < MIN_HWC_HEADER_VERSION ||
hwcHeaderVersion(mHwc) > HWC_HEADER_VERSION) {
ALOGE("%s device version %#x unsupported, will not be used",
HWC_HARDWARE_COMPOSER, mHwc->common.version);
hwc_close_1(mHwc);
mHwc = NULL;
return;
}
}
......
四、cat hardware/imx/mx6/hwcomposer/hwcomposer.cpp
static int hwc_device_open(const struct hw_module_t* module, const char* name,
struct hw_device_t** device)
{
printf("fsl hwc_device_open().\n");
int status = -EINVAL;
if (!strcmp(name, HWC_HARDWARE_COMPOSER)) {
struct hwc_context_t *dev;
dev = (hwc_context_t*)malloc(sizeof(*dev));
/* initialize our state here */
// memset(dev, 0, sizeof(*dev));
/* initialize the procs */
dev->device.common.tag = HARDWARE_DEVICE_TAG;
dev->device.common.module = const_cast<hw_module_t*>(module);
dev->device.common.close = hwc_device_close;
dev->device.prepare = hwc_prepare;
dev->device.set = hwc_set;
dev->device.common.version = HWC_DEVICE_API_VERSION_1_1;
dev->device.registerProcs = hwc_registerProcs;
dev->device.eventControl = hwc_eventControl;
dev->device.query = hwc_query;
dev->device.blank = hwc_blank;
dev->device.getDisplayConfigs = hwc_getDisplayConfigs;
dev->device.getDisplayAttributes = hwc_getDisplayAttributes;
/* our private state goes below here */
dev->m_vsync_thread = new VSyncThread(dev);
dev->m_vsync_thread = new VSyncThread(dev);
dev->m_uevent_thread = new UeventThread(dev);
hwc_get_display_info(dev);
hw_get_module(GRALLOC_HARDWARE_MODULE_ID, &dev->m_gralloc_module);
struct private_module_t *priv_m = (struct private_module_t *)dev->m_gralloc_module;
for(int dispid=0; dispid<HWC_NUM_DISPLAY_TYPES; dispid++) {
if(dev->mDispInfo[dispid].connected && dev->m_gralloc_module != NULL) {
int fbid = dev->mDispInfo[dispid].fb_num;
char fbname[HWC_STRING_LENGTH];
memset(fbname, 0, sizeof(fbname));
sprintf(fbname, "fb%d", fbid);
ALOGI("hwcomposer: open framebuffer %s", fbname);
dev->mFbDev[dispid] = (framebuffer_device_t*)fbid;
dev->m_gralloc_module->methods->open(dev->m_gralloc_module, fbname,
(struct hw_device_t**)&dev->mFbDev[dispid]);
}
}
const hw_module_t *hwc_module;
if(hw_get_module(HWC_VIV_HARDWARE_MODULE_ID,
(const hw_module_t**)&hwc_module) < 0) {
ALOGE("Error! hw_get_module viv_hwc failed");
goto nor_exit;
}
if(hwc_open_1(hwc_module, &(dev->m_viv_hwc)) != 0) {
ALOGE("Error! viv_hwc open failed");
goto nor_exit;
}
nor_exit:
*device = &dev->device.common;
ALOGI("%s,%d", __FUNCTION__, __LINE__);
return 0;
err_exit:
if(dev){
free(dev);
}
/****************************************/
}
return status;
}
