OpenHarmony最新版本的L2標準版圖形子系統相比之前版本有著非常大的改動，使用了全新設計的框架，并使用Render Service替換了原來的Weston。
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前言
本次采用的開發板為揚帆“競”開發板，揚帆“競”采用瑞芯微RK3568（Cortex-A55）四核64位超強CPU，搭載OpenHarmony最新操作系統，主頻最高達2.0GHz。采用 Mali-G52 GPU，支持4K、H.265/H.264視頻解碼。
OpenHarmony最新版本的L2標準版圖形子系統相比之前版本有著非常大的改動，使用了全新設計的框架，并使用Render Service替換了原來的Weston。圖形棧整體上分為三層，從上到下依次為接口層、框架層和引擎層。設計上更加清晰，可以更加的靈活的適配不同的底層圖形庫和不同的顯示硬件，最大限度的發揮硬件性能而不用影響到整體圖形棧。
框架層的整體功能如下表，框架層的核心就是Render Service渲染服務。
模塊 | 能力描述 |
Render Servicel （渲染服務） | 提供UI框架的繪制能力，其核心職責是將ArkUI的控件描述轉換成繪制樹信息，根據對應的渲染策略，進行最佳路徑渲染。同時，負責多窗口流暢和空間態下UI共享的核心底層機制。 |
Drawing （繪制） | 提供圖形子系統內部的標準化接口，主要完成2D渲染、3D渲染和渲染引擎的管理等基本功能。 |
Animation (動畫） | 提供動畫引擎的相關能力。 |
Effect （效果） | 主要完成圖片效果、渲染特效等效果處理的能力，包括：多效果的串聯、并聯處理，在布局時加入渲染特效、控件交互特效等相關能力。 |
顯示與內存管理 | 此模塊是圖形棧與硬件解耦的主要模塊，主要定義了OpenHarmony 顯示與內存管理的能力，其定義的南向HDI 接口需要讓不同的OEM廠商完成對OpenHarmony圖形棧的適配。 |
新的Render Service圖形框架默認提供了對OpenGL的支持，并使用API HOOK技術，實現了OpenGL接口和實現的分離，大幅度降低了OpenGL庫的適配難度。
揚帆“競”開發板默認使用的是閉源的libmali-bifrost-g52-g2p0-ohos庫，也可以使用開源的Mesa 3D庫，實現對OpenGL的支持，在高級圖形應用的開發和調試方面非常方便。
使用Mesa庫
編譯Mesa庫
OpenHarmony已經在三方庫中集成Mesa庫。下載OpenHarmony全量代碼，Mesa庫在third_party/mesa3d。
進入third_party/mesa3d/目錄，OpenHarmony已經提供了編譯腳本。其中ohos/build_ohos.py就是針對新圖形框架的編譯腳本，參考README_zh.md文檔，先進行一次全量編譯，然后執行。
#python ohos/build_ohos.py </path/to/openharmony> yangfan-j </path/to/openharmony>/third_party/mesa3d
命令編譯出mesa庫。
生成Mesa組件
1、在device/soc/rockchip/rk3568/hardware/gpu/目錄下新建lib-mesa目錄，用于存放Mesa 3D庫文件。
#mkdir …/device/soc/rockchip/rk3568/hardware/gpu/lib-mesa
2、將編譯生成的Mesa 3D庫文件拷貝到lib-mesa目錄：
#cp build-ohos/install/lib/libgbm.so.1.0.0 ../device/soc/rockchip/rk3568/hardware/gpu/lib-mesa/
#cp build-ohos/install/lib/libglapi.so.0.0.0 ../device/soc/rockchip/rk3568/hardware/gpu/lib-mesa/
#cp build-ohos/src/egl/libEGL.so.1.0.0 ../device/soc/rockchip/rk3568/hardware/gpu/lib-mesa/
#cp build-ohos/install/lib/libGLESv1_CM.so.1.1.0 ../device/soc/rockchip/rk3568/hardware/gpu/lib-mesa/
#cp build-ohos/install/lib/libGLESv2.so.2.0.0 ../device/soc/rockchip/rk3568/hardware/gpu/lib-mesa/
#cp build-ohos/src/gallium/targets/dri/libgallium_dri.so ../ device/soc/rockchip/rk3568/hardware/gpu/lib-mesa/
#cp build-ohos/install/lib/dri/panfrost_dri.so ../device/soc/rockchip/rk3568/hardware/gpu/lib-mesa/
3、修改device/soc/rockchip/rk3568/hardware/gpu/BUILD.gn
index 7d269ac..690a69d 100644
--- a/rk3568/hardware/gpu/BUILD.gn
+++ b/rk3568/hardware/gpu/BUILD.gn
@@ -47,3 +47,108 @@ ohos_prebuilt_shared_library("mali-bifrost-g52-g2p0-ohos") {
"libmali.so.1",
]
}
+
+ohos_prebuilt_shared_library("mesa_gbm") {
+ source = "lib-mesa/libgbm.so.1.0.0"
+ install_enable = true
+ install_images = [ chipset_base_dir ]
+ relative_install_dir = "chipsetsdk"
+ subsystem_name = "rockchip_products"
+ part_name = "rockchip_products"
+ symlink_target_name = [
+ "libgbm.so.1",
+ "libgbm.so",
+ ]
+}
+
+ohos_prebuilt_shared_library("mesa_egl") {
+ source = "lib-mesa/libEGL.so.1.0.0"
+ install_enable = true
+ install_images = [ chipset_base_dir ]
+ relative_install_dir = "chipsetsdk"
+ subsystem_name = "rockchip_products"
+ part_name = "rockchip_products"
+ symlink_target_name = [
+ "libEGL.so.1",
+ "libEGL.so",
+ "libGLESv1.so",
+ "libEGL_impl.so",
+ ]
+}
+
+ohos_prebuilt_shared_library("mesa_glapi") {
+ source = "lib-mesa/libglapi.so.0.0.0"
+ install_enable = true
+ install_images = [ chipset_base_dir ]
+ relative_install_dir = "chipsetsdk"
+ subsystem_name = "rockchip_products"
+ part_name = "rockchip_products"
+ symlink_target_name = [
+ "libglapi.so.0",
+ "libglapi.so",
+ ]
+}
+
+ohos_prebuilt_shared_library("mesa_glesv1") {
+ source = "lib-mesa/libGLESv1_CM.so.1.1.0"
+ install_enable = true
+ install_images = [ chipset_base_dir ]
+ relative_install_dir = "chipsetsdk"
+ subsystem_name = "rockchip_products"
+ part_name = "rockchip_products"
+ symlink_target_name = [
+ "libGLESv1_CM.so.1",
+ "libGLESv1_CM.so",
+ "libGLESv1_impl.so",
+ ]
+}
+
+ohos_prebuilt_shared_library("mesa_glesv2") {
+ source = "lib-mesa/libGLESv2.so.2.0.0"
+ install_enable = true
+ install_images = [ chipset_base_dir ]
+ relative_install_dir = "chipsetsdk"
+ subsystem_name = "rockchip_products"
+ part_name = "rockchip_products"
+ symlink_target_name = [
+ "libGLESv2.so.2",
+ "libGLESv2.so",
+ "libGLESv2_impl.so",
+ "libGLESv3_impl.so",
+ ]
+}
+
+ohos_prebuilt_shared_library("libgallium_dri") {
+ source = "lib-mesa/libgallium_dri.so"
+ install_enable = true
+ install_images = [ chipset_base_dir ]
+ relative_install_dir = "chipsetsdk"
+ subsystem_name = "rockchip_products"
+ part_name = "rockchip_products"
+ symlink_target_name = [ "libgallium_dri.so" ]
+}
+
+ohos_prebuilt_shared_library("panfrost_dri") {
+ source = "lib-mesa/panfrost_dri.so"
+ install_enable = true
+ install_images = [ "system" ]
+ subsystem_name = "rockchip_products"
+ part_name = "rockchip_products"
+ symlink_target_name = [
+ "rockchip_dri.so",
+ "libmali.so.0",
+ "libmali.so.1",
+ ]
+}
+
+group("mesa-gpu") {
+ public_deps = [
+ ":mesa_egl",
+ ":mesa_gbm",
+ ":mesa_glapi",
+ ":mesa_glesv1",
+ ":mesa_glesv2",
+ ":libgallium_dri",
+ ":panfrost_dri",
+ ]
+}
4、修改device/soc/rockchip/rk3568/hardware/BUILD.gn，使用Mesa 3D庫
index 479847d..e778fb0 100644
--- a/rk3568/hardware/BUILD.gn
+++ b/rk3568/hardware/BUILD.gn
@@ -15,7 +15,8 @@ import("http://build/ohos.gni")
group("hardware_group") {
deps = [
- "http://device/soc/rockchip/rk3568/hardware/gpu:mali-bifrost-g52-g2p0-ohos",
+ #"http://device/soc/rockchip/rk3568/hardware/gpu:mali-bifrost-g52-g2p0-ohos",
+ "http://device/soc/rockchip/rk3568/hardware/gpu:mesa-gpu",
"http://device/soc/rockchip/rk3568/hardware/isp:isp",
"http://device/soc/rockchip/rk3568/hardware/mpp:mpp",
"http://device/soc/rockchip/rk3568/hardware/wifi:ap6xxx",
修改內核的配置文件
修改內核配置文件，啟用panforst驅動
index 9a9501c..52b3232 100644
--- a/linux-5.10/arch/arm64/configs/yangfan-j_standard_defconfig
+++ b/linux-5.10/arch/arm64/configs/yangfan-j_standard_defconfig
@@ -3622,7 +3622,7 @@ CONFIG_DVB_SP2=m
#
# CONFIG_VGA_ARB is not set
CONFIG_DRM=y
-CONFIG_DRM_IGNORE_IOTCL_PERMIT=y
+# CONFIG_DRM_IGNORE_IOTCL_PERMIT is not set
CONFIG_DRM_MIPI_DSI=y
# CONFIG_DRM_DP_AUX_CHARDEV is not set
# CONFIG_DRM_DEBUG_MM is not set
@@ -3636,6 +3636,8 @@ CONFIG_DRM_FBDEV_OVERALLOC=100
CONFIG_DRM_LOAD_EDID_FIRMWARE=y
# CONFIG_DRM_DP_CEC is not set
CONFIG_DRM_GEM_CMA_HELPER=y
+CONFIG_DRM_GEM_SHMEM_HELPER=y
+CONFIG_DRM_SCHED=y
#
# I2C encoder or helper chips
@@ -3793,7 +3795,7 @@ CONFIG_DRM_DW_MIPI_DSI=y
# CONFIG_TINYDRM_ST7735R is not set
# CONFIG_DRM_PL111 is not set
# CONFIG_DRM_LIMA is not set
-# CONFIG_DRM_PANFROST is not set
+CONFIG_DRM_PANFROST=y
# CONFIG_DRM_TIDSS is not set
# CONFIG_DRM_LEGACY is not set
CONFIG_DRM_PANEL_ORIENTATION_QUIRKS=y
修改揚帆“競”內核補丁
內核補丁需要在Linux系統上使用vim編輯器修改，Windows編輯器修改可能導致編譯錯誤。
index 41a7df5..1a5e5a3 100644
--- a/linux-5.10/yangfan-j_patch/kernel.patch
+++ b/linux-5.10/yangfan-j_patch/kernel.patch
@@ -100948,36 +100948,36 @@ index 000000000..372617fee
+ };
+
+ gpu: gpu@fde60000 {
-+ compatible = "arm,mali-bifrost";
-+ reg = <0x0 0xfde60000 0x0 0x4000>;
++ compatible = "rockchip, rk3568-mali","arm,mali-bifrost";
++ reg = <0x0 0xfde60000 0x0 0x20000>;
+
-+ interrupts = <GIC_SPI 39 IRQ_TYPE_LEVEL_HIGH>,
++ interrupts = <GIC_SPI 40 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 41 IRQ_TYPE_LEVEL_HIGH>,
-+ <GIC_SPI 40 IRQ_TYPE_LEVEL_HIGH>;
-+ interrupt-names = "GPU", "MMU", "JOB";
++ <GIC_SPI 39 IRQ_TYPE_LEVEL_HIGH>;
++ interrupt-names = "job", "mmu", "gpu";
+
-+ upthreshold = <40>;
-+ downdifferential = <10>;
++ /* upthreshold = <40>; */
++ /* downdifferential = <10>; */
+
+ clocks = <&scmi_clk 1>, <&cru CLK_GPU>;
-+ clock-names = "clk_mali", "clk_gpu";
++ clock-names = "core", "bus";
+ power-domains = <&power RK3568_PD_GPU>;
+ #cooling-cells = <2>;
+ operating-points-v2 = <&gpu_opp_table>;
+
+ status = "disabled";
-+ gpu_power_model: power-model {
-+ compatible = "simple-power-model";
-+ leakage-range= <5 15>;
-+ ls = <(-24002) 22823 0>;
-+ static-coefficient = <100000>;
-+ dynamic-coefficient = <953>;
-+ ts = <(-108890) 63610 (-1355) 20>;
-+ thermal-zone = "gpu-thermal";
-+ };
-+ };
-+
-+ gpu_opp_table: opp-table2 {
++ /* gpu_power_model: power-model { */
++ /* compatible = "simple-power-model"; */
++ /* leakage-range= <5 15>; */
++ /* ls = <(-24002) 22823 0>; */
++ /* static-coefficient = <100000>; */
++ /* dynamic-coefficient = <953>; */
++ /* ts = <(-108890) 63610 (-1355) 20>; */
++ /* thermal-zone = "gpu-thermal"; */
++ /* }; */
++ };
++
++ gpu_opp_table: gpu-opp-table {
+ compatible = "operating-points-v2";
+
+ mbist-vmin = <825000 900000 950000>;
測試和驗證
1、查看GPU中斷，panforst驅動已經正常工作。桌面顯示和操作正常
2、游戲效果
測試表明，揚帆“競”開發板的圖形界面使用正常且流暢，基礎應用都可以正常運行，體驗與使用libmali-g52庫基本一致。
??想了解更多關于開源的內容，請訪問：??
??51CTO 開源基礎軟件社區??
??https://ost.51cto.com??
