BCSP 剖析（二）- BCSP link establish过程

本篇结合着HCI TX,RX log解析蓝牙初始化的过程 over BCSP protocol

BCSP packet format如连接

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记录一下BCSP的分析详细流程：

BCSP先有一个link establish的过程(建立过程芯片会通过uart和平台交互，分四种封包格式，如图）

建立过程分三个阶段：

1.State 1 - Shy

•Don’t allow any otherprotocols

•Send SYNC’s every sooften

–Controlled by PSKEY_BCSP_LM_TSHY

•If you receive a SYNC

–Send a SYNC RESPONSE

•If you receive a SYNCRESPONSE

–Change to Curious State

2.State 2 - Curious

•Send CONF’s every sooften

•If you receive a SYNC

–Reply with a SYNC RESPONSE

•If you receive a CONF

–Reply with a CONF RESPONSE

•If you receive a CONFRESPONSE

–Change to Garrulous State

3.State 3 - Garrulous

•If you receive a CONF

–Reply with a CONF RESPONSE

•If you receive a CONFRESPONSE

–Ignore it

•If you receive a SYNC

–Other end has reset

–Reset stack if possible

–Then change to shy state

过程大概如图表示为：