NVIDIA DRIVE SDK学习（一）——整体架构

整体架构

架构图：

图上描述了NVIDIA车载软件架构的整体架构，NVIDIA提供了：

1. Orin硬件，和安全岛
2. DRIVE Hypervisor
3. Linux及其配套驱动
4. NvStremer/NvMediaVukan等媒体组件
5. CUDA、TersorRT等
6. 安全服务、功耗管理、OTA等

英伟达提供的软件整体架构：

子模块介绍

基础组件

Hypervisor：Trusted Software server that separates the system into partitions。

• Guest OS partitions and the isolation between them.
• Partitions’ virtual views of the CPU and memory resources.
• Hardware interactions
• Run-lists
• Channel recovery

guest OS：Allocates peripherals that Guest OS needs to control.
Services：Services for DRIVE Update.
Bootloader：Firmware that runs during boot to load firmware components
Trusted OS：Trusted OS configuration in the PCT describes the configuration of the virtual Trusted OS device.
Orin SoC：System on a Chip hardware resources.

虚拟化服务组件：

Boot and Power Manager Processor (BPMP) Server： Facilitates communication between Guest Virtual Machines (VM) and BPMP firmware.
VM Server：host1X virtualizes NvHost.
Security Engine (SE) Server：Para-virtualizes and allows multiple Guest Virtual Machines access to the security engine cryptographic hardware accelerator.
Trusted Applications (TA)：Trusted OS exposes a set of core services that use managed security assets in cryptographic operations without exposing them to non-secure guest software.
GPU：
Storage Server：Para-virtualizes storage access to enable sharing physical storage devices among multiple Guest Virtual Machines.
Debug Server：Provides support for kernel-level debugging of Guest Virtual Machines (VM).

媒体组件

NvMedia组件提供了如下功能：

• Robust image processing and sensor control blocks for use by applications.
• Hardware surface to handle all types of image formats such as RGB, YUV and RAW.
• Functional components for image capture, processing, acceleration, encoding, and interoperating with other libraries.

NvMedia组件可以把图像数据路由到其他组件，比如：OpenGL ES 和 NVIDIA CUDA。

媒体组件架构

架构图：

组件介绍：
Video Input (VI)：接收摄像头数据通过CSI
Image Signal Processor(ISP)：图像数据处理器
NVIDIA Encoder (NVENC)：视频编码器
NVIDIA Decoder (NVDEC)：视频解码器
Video Interlace Compositor (VIC)：Converts video data for deinterlacing, composition, and format conversion.
Optical Flow Accelerator (OFA)：加速帧之间的光流和立体视差计算。

媒体软件组件

NvMedia包含下面几个软件组件：
SIPL：用来处理视频流
2D：提供图像数据的操作的能力；例如裁剪、缩放、复制和转换格式。
IEP（Image Encode Processing）：提供数据编码能力，将YCbCr图像转换为H.264/H.265
IJE(Image JPEG Encodin)：将YUV编码为JPEG
IJD(Image JPEG Decoding )：将JPEG格式解码为YUV图像

NvMedia组件进程安全

NvMedia不支持进程安全，通过上层软件来保证进程安全。因此需要注意：

• NvMedia组件可以在所有的进程中例化和使用，但是不能相互调用API
• 同一组件的不同实例可以同时在不同进程中使用
• 编码器被设计成从一个进程拿数据流，从另一个进程拿用于编码的bitstream。