Android双屏.docx

小妞的傻大熊博客园 首页 社区 新随笔 联系 订阅 管理 随笔-14 评论-34 文章-0 trackbacks-0 android双屏显示的一些修改与尝试转载时请注明出处和作者文章出处：/xl19862005作者：Xandy用的是android2.3的代码这些天来一直在看android display相关的代码和资料并作了一些尝试，现在将这些天来的工作记录如下，有错误的地方希望广大同行指正，谢谢！经过阅读代码和查到的相关一些资料，对android双屏的支持总体思路如下图所示：由于目前跟踪代码只跟到了surfaceflinger这一层，下面先从surfaceflinger说起：在frameworksbaseservicessurfaceflingersurfaceflinger.cpp这个文件中有如下代码片断：status_t SurfaceFlinger:readyToRun() LOGI(SurfaceFlingers main thread ready to run. Initializing graphics H/W.n); / we only support one display currently int dpy = 0; / initialize the main display GraphicPlane& plane(graphicPlane(dpy); DisplayHardware* const hw = new DisplayHardware(this, dpy); DisplayHardware* const hw1 = new DisplayHardware(this, 1); /这个是我加入测试HAL层用的，下面将介绍到 plane.setDisplayHardware(hw); / create the shared control-block mServerHeap = new MemoryHeapBase(4096,MemoryHeapBase:READ_ONLY, SurfaceFlinger read-only heap); LOGE_IF(mServerHeap=0, cant create shared memory dealer); mServerCblk = static_cast(mServerHeap-getBase(); LOGE_IF(mServerCblk=0, cant get to shared control blocks address); new(mServerCblk) surface_flinger_cblk_t; / initialize primary screen / (other display should be initialized in the same manner, but / asynchronously, as they could come and go. None of this is supported / yet). const GraphicPlane& plane(graphicPlane(dpy); const DisplayHardware& hw = plane.displayHardware(); const uint32_t w = hw.getWidth(); const uint32_t h = hw.getHeight(); const uint32_t f = hw.getFormat(); hw.makeCurrent(); / initialize the shared control block mServerCblk-connected |= 1displays + dpy; memset(dcblk, 0, sizeof(display_cblk_t); dcblk-w = plane.getWidth(); dcblk-h = plane.getHeight(); dcblk-format = f; dcblk-orientation = ISurfaceComposer:eOrientationDefault; dcblk-xdpi = hw.getDpiX(); dcblk-ydpi = hw.getDpiY(); dcblk-fps = hw.getRefreshRate(); dcblk-density = hw.getDensity(); / Initialize OpenGL|ES glPixelStorei(GL_UNPACK_ALIGNMENT, 4); glPixelStorei(GL_PACK_ALIGNMENT, 4); glEnableClientState(GL_VERTEX_ARRAY); glEnable(GL_SCISSOR_TEST); glShadeModel(GL_FLAT); glDisable(GL_DITHER); glDisable(GL_CULL_FACE); const uint16_t g0 = pack565(0x0F,0x1F,0x0F); const uint16_t g1 = pack565(0x17,0x2f,0x17); const uint16_t textureData4 = g0, g1, g1, g0 ; glGenTextures(1, &mWormholeTexName); glBindTexture(GL_TEXTURE_2D, mWormholeTexName); glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 2, 2, 0,GL_RGB, GL_UNSIGNED_SHORT_5_6_5, textureData); glViewport(0, 0, w, h); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrthof(0, w, h, 0, 0, 1); LayerDim:initDimmer(this, w, h); mReadyToRunBarrier.open(); /* * Were now ready to accept clients. */ / start boot animation property_set(ctl.start, bootanim); return NO_ERROR;重点看上面用黄色标出的那两行，其中DisplayHardware* const hw1 = new DisplayHardware(this, 1);是我加入用来测试HAL层的buffer分配用的，DisplayHardware这个是在frameworksbaseservicessurfaceflingerDisplayHardwareDisplayHardware.cpp这个文件中定义的，如以下代码片断：/* * Initialize the display to the specified values. * */DisplayHardware:DisplayHardware(const sp& flinger,uint32_t dpy) : DisplayHardwareBase(flinger, dpy),mFlags(0) init(dpy);而在同文件中有如下代码片断：void DisplayHardware:init(uint32_t dpy) mNativeWindow = new FramebufferNativeWindow(dpy); framebuffer_device_t const * fbDev = mNativeWindow-getDevice(); mDpiX = mNativeWindow-xdpi; mDpiY = mNativeWindow-ydpi; mRefreshRate = fbDev-fps; mOverlayEngine = NULL; hw_module_t const* module; if (hw_get_module(OVERLAY_HARDWARE_MODULE_ID, &module) = 0) overlay_control_open(module, &mOverlayEngine); EGLint w, h, dummy; EGLint numConfigs=0; EGLSurface surface; EGLContext context; / initialize EGL EGLint attribs = EGL_SURFACE_TYPE, EGL_WINDOW_BIT, EGL_NONE, 0, EGL_NONE ; / debug: disable h/w rendering char propertyPROPERTY_VALUE_MAX; if (property_get(debug.sf.hw, property, NULL) 0) if (atoi(property) = 0) LOGW(H/W composition disabled); attribs2 = EGL_CONFIG_CAVEAT; attribs3 = EGL_SLOW_CONFIG; / TODO: all the extensions below should be queried through / eglGetProcAddress(). / set to EGL wrapper to load SW OpenGLES only if (property_get(debug.sf.enable_hgl, property, 1) 0) if (atoi(property) = 0) eglSetImplementationAndroid(EGL_TRUE); /*下面这些都是和egl相关的，目前正在研究中，由于代码量太大，一起不好发上来，这里简单介绍一下，frameworksbaseopengllibagl目录下是agl相关的一些代码，这些代码会生成libGLES_android.so 这个动态库，这点可以从此目录下的Android.mk文件里看出：LOCAL_MODULE_PATH := $(TARGET_OUT_SHARED_LIBRARIES)/eglLOCAL_MODULE:= libGLES_android 在frameworksbaseopengllibs目录下是egl相关的一些代码，这些代码主要把agl这个库作了个封装，并向外提供相关接口*/ EGLDisplay display = eglGetDisplay(NativeDisplayType)dpy);/(EGL_DEFAULT_DISPLAY); LOGI(*DisplayHardware.cpp display:%d*n,(int)display); eglInitialize(display, NULL, NULL); eglGetConfigs(display, NULL, 0, &numConfigs); EGLConfig config; status_t err = EGLUtils:selectConfigForNativeWindow(display, attribs, mNativeWindow.get(), &config); LOGE_IF(err, couldnt find an EGLConfig matching the screen format); EGLint r,g,b,a; eglGetConfigAttrib(display, config, EGL_RED_SIZE, &r); eglGetConfigAttrib(display, config, EGL_GREEN_SIZE, &g); eglGetConfigAttrib(display, config, EGL_BLUE_SIZE, &b); eglGetConfigAttrib(display, config, EGL_ALPHA_SIZE, &a); if (mNativeWindow-isUpdateOnDemand() mFlags |= PARTIAL_UPDATES; if (eglGetConfigAttrib(display, config, EGL_CONFIG_CAVEAT, &dummy) = EGL_TRUE) if (dummy = EGL_SLOW_CONFIG) mFlags |= SLOW_CONFIG; /* * Create our main surface */ surface = eglCreateWindowSurface(display, config, mNativeWindow.get(), NULL); eglQuerySurface(display, surface, EGL_WIDTH, &mWidth); eglQuerySurface(display, surface, EGL_HEIGHT, &mHeight); if (mFlags & PARTIAL_UPDATES) / if we have partial updates, we definitely dont need to / preserve the backbuffer, which may be costly. eglSurfaceAttrib(display, surface,EGL_SWAP_BEHAVIOR, EGL_BUFFER_DESTROYED); if (eglQuerySurface(display, surface, EGL_SWAP_BEHAVIOR, &dummy) = EGL_TRUE) if (dummy = EGL_BUFFER_PRESERVED) mFlags |= BUFFER_PRESERVED; /* Read density from build-specific ro.sf.lcd_density property * except if it is overridden by qemu.sf.lcd_density. */ if (property_get(qemu.sf.lcd_density, property, NULL) = 0) if (property_get(ro.sf.lcd_density, property, NULL) format; mPageFlipCount = 0; /* * Gather OpenGL ES extensions */ eglMakeCurrent(display, surface, surface, context); GLExtensions& extensions(GLExtensions:getInstance(); extensions.initWithGLStrings(glGetString(GL_VENDOR), glGetString(GL_RENDERER), glGetString(GL_VERSION), glGetString(GL_EXTENSIONS), eglQueryString(display, EGL_VENDOR), eglQueryString(display, EGL_VERSION), eglQueryString(display, EGL_EXTENSIONS); glGetIntegerv(GL_MAX_TEXTURE_SIZE, &mMaxTextureSize); glGetIntegerv(GL_MAX_VIEWPORT_DIMS, &mMaxViewportDims);#ifdef EGL_ANDROID_swap_rectangle if (extensions.hasExtension(EGL_ANDROID_swap_rectangle) if (eglSetSwapRectangleANDROID(display, surface,0, 0, mWidth, mHeight) = EGL_TRUE) / This could fail if this extension is not supported by this / specific surface (of config) mFlags |= SWAP_RECTANGLE; / when we have the choice between PARTIAL_UPDATES and SWAP_RECTANGLE / choose PARTIAL_UPDATES, which should be more efficient#ifdef FSL_EPDC_FB#else if (mFlags & PARTIAL_UPDATES) mFlags &= SWAP_RECTANGLE;#endif#endif LOGI(EGL informations:); LOGI(# of configs : %d, numConfigs); LOGI(vendor : %s, extensions.getEglVendor(); LOGI(version : %s, extensions.getEglVersion(); LOGI(extensions: %s, extensions.getEglExtension(); LOGI(Client API: %s, eglQueryString(display, EGL_CLIENT_APIS)?:Not Supported); LOGI(EGLSurface: %d-%d-%d-%d, config=%p, r, g, b, a, config); LOGI(OpenGL informations:); LOGI(vendor : %s, extensions.getVendor(); LOGI(renderer : %s, extensions.getRenderer(); LOGI(version : %s, extensions.getVersion(); LOGI(extensions: %s, extensions.getExtension(); LOGI(GL_MAX_TEXTURE_SIZE = %d, mMaxTextureSize); LOGI(GL_MAX_VIEWPORT_DIMS = %d, mMaxViewportDims); LOGI(flags = %08x, mFlags); / Unbind the context from this thread eglMakeCurrent(display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);上面代码黄色标出的将会new一个framebufferNativeWindow，其实就是通过HAL层的Gralloc这个库映射到kernel层中的framebuffer在frameworksbaselibsuiFramebufferNativeWindow.cpp这个文件中有如下代码片断：FramebufferNativeWindow:FramebufferNativeWindow(uint32_t dpy) : BASE(), fbDev(0), grDev(0), mUpdateOnDemand(false) hw_module_t const* module; char GRALLOC_MODE10; char GRALLOC_FB10; char GRALLOC_GPU10; if(dpy = DISPLAY0) strcpy(GRALLOC_MODE,GRALLOC_HARDWARE_MODULE_ID0); strcpy(GRALLOC_FB,GRALLOC_HARDWARE_FB0); strcpy(GRALLOC_GPU,GRALLOC_HARDWARE_GPU0); else if(dpy = DISPLAY1) strcpy(GRALLOC_MODE,GRALLOC_HARDWARE_MODULE_ID1); strcpy(GRALLOC_FB,GRALLOC_HARDWARE_FB1); strcpy(GRALLOC_GPU,GRALLOC_HARDWARE_GPU1); else strcpy(GRALLOC_MODE,GRALLOC_HARDWARE_MODULE_ID0); strcpy(GRALLOC_FB,GRALLOC_HARDWARE_FB0); strcpy(GRALLOC_GPU,GRALLOC_HARDWARE_GPU0); /*这个函数的原型是没有传入参数的，为了增加对second display的支持自行加入的，上面这些代码也是后来加入的，为的是根据传入的dpy（display 0/1）打开相应的Gralloc和GPU的库文件*/ if (hw_get_module(GRALLOC_MODE, &module) = 0) int stride; int err; int i; err = framebuffer_open(module,GRALLOC_FB, &fbDev); LOGE_IF(err, couldnt open framebuffer HAL (%s), strerror(-err); err = gralloc_open(module,GRALLOC_GPU, &grDev); LOGE_IF(err, couldnt open gralloc HAL (%s), strerror(-err); / bail out if we cant initialize the modules if (!fbDev | !grDev) return; mUpdateOnDemand = (fbDev-setUpdateRect != 0); / initialize the buffer FIFO mNumBuffers = fbDev-reserved0; if (mNumBuffers != 3 & mNumBuffers != 2) LOGE(The framebuffer number got from HAL is not supported(%d), mNumBuffers); return; mNumFreeBuffers = mNumBuffers; mBufferHead = mNumBuffers-1; for (i = 0; i width, fbDev-height, fbDev-format, GRALLOC_USAGE_HW_FB); for (i = 0; i alloc(grDev,fbDev-width, fbDev-height, fbDev-format,GRALLOC_USAGE_HW_FB, &buffersi-handle, &buffersi-stride); LOGE_IF(err, fb buffer %d allocation failed w=%d, h=%d, err=%s,i, fbDev-width, fbDev-height, strerror(-err); const_cast(ANativeWindow:flags) = fbDev-flags; const_cast(ANativeWindow:xdpi) = fbDev-xdpi; const_cast(ANativeWindow:ydpi) = fbDev-ydpi; const_cast(ANativeWindow:minSwapInterval) = fbDev-minSwapInterval; const_cast(ANativeWindow:maxSwapInterval) = fbDev-maxSwapInterval; else LOGE(Couldnt get gralloc module); ANativeWindow:setSwapInterval = setSwapInterval; ANativeWindow:dequeueBuffer = dequeueBuffer; ANativeWindow:lockBuffer = lockBuffer; ANativeWindow:queueBuffer = queueBuffer; ANativeWindow:query = query; ANativeWindow:perform = perform;重点在上面用黄色标出的这几行代码，hw_get_module会根据传入的dpy选择打开gralloc0还是gralloc1，framebuffer_open会根据传入的dpy选择打开fb0还是fb1，gralloc_open会根据传入的dpy选择打开gpu0还是gpu1；接下来的几行代码都是和buffer相关，mNumBuffers在这里等于3，先new NativeBuffer得到相应的buffersi(i=0/1/2)，grDev-alloc将会为这些buffers分配内存。在hardwarelibhardwareincludehardwareGralloc.h文件中有如下定义，为了加入second display我这里作了一些修改/* * The id of this module */#define GRALLOC_HARDWARE_MODULE_ID0 gralloc0#define GRALLOC_HARDWARE_MODULE_ID1 gralloc1/* * Name of the graphics device to open */#define GRALLOC_HARDWARE_FB0 fb0#define GRALLOC_HARDWARE_FB1 fb1#define GRALLOC_HARDWARE_GPU0 gpu0#define GRALLOC_HARDWARE_GPU1 gpu1./* convenience API for opening and closing a supported device 下面这些封装都是在得到了module这个结构体之后得到相应的函数入口*/static inline int gralloc_open(const struct hw_module_t* module, const char * name,struct alloc_device_t* device) return module-methods-open(module, name, (struct hw_device_t*)device);static inline int gralloc_close(struct alloc_device_t* device) return device-common.close(&device-common);static inline int framebuffer_open(const struct hw_module_t* module,const char * name, struct framebuffer_device_t* device) return module-methods-open(module,name, (struct hw_device_t*)device);static inline int framebuffer_close(struct framebuffer_device_t* device) return device-common.close(&device-common);上面这些代码就是通过打开不同的gralloc模块，得到不同的函数入口地址，这里我对gralloc分别新建了两个，一个映射到fb0，一个映射到fb1，如下文件列表：其中libgralloc_sec_display是我后来加入的，先看libgralloc里面的内容：在gralloc.cpp这个文件里有如下代码片断：/*这里的open就是打开gralloc这个模块之后与在gralloc.h中module-methods-open相对应了*/static struct hw_module_methods_t gralloc_module_methods = open: gralloc_device_open;struct private_module_t HAL_MODULE_INFO_SYM = base: common: tag: HARDWARE_MODULE_TAG, version_major: 1, version_minor: 0, id: GRALLOC_HARDWARE_MODULE_ID0, name: Graphics Memory Allocator Module, author: The Android Open Source Project, methods: &gralloc_module_methods , registerBuffer: gralloc_register_buffer, unregisterBuffer: gralloc_unregister_buffer, lock: gralloc_lock, unlock: gralloc_unlock, , framebuffer: 0, flags: 0, numBuffers: 0, bufferMask: 0, lock: PTHREAD_MUTEX_INITIALIZER, currentBuffer: 0, pmem_master: -1, pmem_master_base: 0, master_phys: 0;open的实现代码如下：int gralloc_device_open(const hw_module_t* module, const char* name,hw_device_t* device) int status = -EINVAL; /name = GRALLOC_HARDWARE_FB0 or GRALLOC_HARDWARE_GPU0 GRALLLOGI0(*gralloc_devide_open : name = %s*n,name); if (!strcmp(name, GRALLOC_HARDWARE_GPU0) gralloc_context_t *dev; dev = (gralloc_context_t*)malloc(sizeof(*dev); /* initialize our state here */ memset(dev, 0, sizeof(*dev); /* initialize the procs */ mon.tag = HARDWARE_DEVICE_TAG; mon.version = 0; mon.module