Black cat takes you to learn UFS Protocol Part 8: UFS initialization (boot operation)

1 Preface

1.1 Statement

This paper is based on UFS3.1 JEDEC Agreement and personal work experience , If there is any mistake, please leave a message .
The article is painstakingly sorted out for individuals , Paid content , Unauthorized reprint .
The column where the article is located ：《 Black cat takes you to learn ：UFS protocol 》

1.2 Reference link

because 《 Egg reading UFS Of the six ：UFS Device initialization and startup 》 One article is right UFS The initialization process is explained clearly , Therefore, part of this article comes from this article , Invasion and deletion .
Link to the original text ：http://www.ssdfans.com/?p=92738

2 Boot configuration

Many platforms will place the system boot code in UFS In the device , When UFS During power on initialization , It is necessary to read out the system startup code to start the whole platform .

UFS in BOOT LU A and BOOT LU B It can be used to store the system boot code , But during startup , only one BOOT LU By using . For read operation , Logical units during startup are mapped to BOOT well known logical unit（W-LUN = 30h）. such , When the host updates the boot code , When the logical unit used is from A Exchange to B Or vice versa , A fixed logical unit number will be reserved .

Some configurable domains in the device descriptor and unit descriptor determine the behavior of the device during boot .

If bBootEnable = 01h when ,UFS The guiding feature of is enabled .

In logical unit descriptor dNumAllocUnits Domains are used to configure the size of logical units ,bBootLunID