Intel spec解析

2024-09-04 01:32

文章标签 解析 intel spec

本文主要是介绍Intel spec解析，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

Intel的XMM6360 modem telephone部分分成两块：

1.The Radio Interface Layer (RIL) component.

2.The Java Middleware layer (Android* Telephony services).

modem chip和主处理器的接口是MIPI HSI，用的通信协议是Multiplexer Protocol

DLCI is a 6 bit field that identifies the virtual channel.上面的那个协议就是多路复用协议，到底用哪一路通信就是依靠DLCI这几个bit来识别。

其实最重要的是mmgr，mmgr的作用:

• Modem reset / boot sequence and IPC components being ready for communication.

moden的重启和下载自身驱动，ipc组件用来准备和用户空间通信
• Enables and configures the Cloverview SoC-to-XMM6360 IPC multiplexed
communications.

使能以及配置多路复用
• Synchronizes modem client(s) start-up with modem communication readiness.

同步modem当modem通信做好准备
• Monitors communication exceptions, informs RIL about modem state and recovers
from error situations (modem self-reset, unresponsive commands, core dumps).

监控modem的状态，比如出错之后怎么重置

默认情况下，modem一开始只支持单路通信，只有等多路复用的协议驱动启动完毕之后才能多路通信。mmgr保证modem正常启动，MMgr is declared as a native service in init.rc.是一个系统一开始就启动的服务。

对telephony sub-system来说一般是以下几个事件：

• Start-up.
• Shutdown and Switch to/from airplane mode.
• Fatal Modem Exceptions and recovery

mmgr做了以下几件事：

• It makes sure the modem has finished its boot sequence, before attempting any
further operation

保证modem的boot过程的完成，在下一步操作之前

• It establishes modem-to-Cloverview SoC communication:

Switches the modem into MUX mode

切换到多路复用模式

Activates the MUX driver by attaching a 3GPP 27.010 compliant line discipline
to ttyIFX, then configuring the line discipline parameters (including retry
timers). This step creates a set of gsmtty interfaces

使能多路复用驱动，配置参数，这个步骤生成了一系列的gsmtty接口

• Once MUX communication is set up, MMgr informs gsmtty clients (such as the RIL)
that the modem and ttys are ready. To send this information, MMgr first establishes
an IPC (socket-based) with those clients.

当多路复用建立后，通知client准备完毕，和这些client建立一个socket的通道

After that, MMgr enters a polling loop (based on the no-overhead, blocking poll

function call) to monitor the status of the modem in case the modem performs a
self-reset and core dump. When this situation occurs:

做完这些事之后进入一个loop中，监视modem的状态
— MMgr sends a message to inform gsmtty clients that ttys are temporarily not
available and shall not be used.

— MMgr monitors the modem boot (as in a fresh boot), then re-configures the
MUX mode

— MMgr sends a message again to gsmtty clients that the modem and ttys are
ready again. It is up to clients to decide their recovery procedure, but this must
include at least closing and opening gsmtty again (as the older gsmtty handles
are invalid). For instance, the RIL closes them and exits completely, and relies
on Android* init to be automatically re-started.

• MMgr also monitors messages sent from a gsmtty client such as the RIL, which can
also detect modem unresponsiveness.

监控client发送信息给modem之后如果modem没有回应

The MMgr provides an API to the Client to perform the following services:
• Modem State.
• Request for Modem Restart or Recovery.
• Modem Resource Management.
• Update Modem Firmware and Configuration (Will be described in a future version)