NVIDIA Bluefield DPU上的启动流程4个阶段分别是什么？作用是什么？

Bluefield上的硬件介绍

本文以Bluefield2为例，可以看到RSHIM实际上是Boot相关的集合。也能看到eMMC上的2个分区。
Bluefield硬件单元图：（尤其可以看到RSHIM在硬件形态上是一个单独的硬件）

Bluefield接口图：

启动流程

The default BlueField bootstream (BFB) shown above is a standard boot BFB that is stored on the embedded Multi-Media Card (eMMC) as can be seen by the boot path that points to a GUID partition (GPT) on the eMMC device

启动流程：

reset（echo "SW_RESET 1" > /dev/rshim0/misc ）之后先进入BL1的BootROM

参考：https://docs.nvidia.com/networking/display/bluefielddpuosv385/upgrading+boot+software

eMMC中的两个存储分区：

When booting from eMMC, these stages make use of two different types of storage within
the eMMC part:
• ATF and UEFI are loaded from a special area known as an eMMC boot partition. Data
from a boot partition is automatically streamed from the eMMC device to the eMMC
controller under hardware control during the initial boot-up. Each eMMC device has two
boot partitions, and the partition w