am335x dts文件疑惑

user4796556

Expert 1352 points

am335x在arch/arm/boot/dts目录下有2个dts文件

am335x-evm.dts和am33xx.dtsi

am335-evm.dts里面应该是配置各个驱动的dts文件，那么am33xx.dtsi里面的内容都是用来做什么的？我看了下里面好多模块的status都是“disabled.”

9 年多前

0 Steven Liu1 9 年多前

TI__Mastermind 25020 points

am33xx.dtsi文件中都是对于SoC中所有模块最基础架构的定义，比如寄存器地址，中断号之类的，这些共性的东西是不会随着板子设计应用的改变而改变的。

而am335x-evm.dts文件中，是根据自己的实际办卡应用中做的配置，简而言之，用了哪些接口，使用怎样的pinmux配置，这种类型的信息都会体现在这个板级配置文件中，并且最终在这里吧status修改成为okay生效。

一般来说，我们不建议修改am33xx.dtsi这种SoC架构基础文件，你只要修改你自己的板级配置文件DTS就可以了。

0 user4796556 9 年多前回复 Steven Liu1

Expert 1352 points

基本我理解是说两个文件是合并一起的，am33xx.dtsi里面的内容是基础模块的配置，和am335x-evm.dts配合生成最后的dtb文件。但是在dtsi中的下面这个段是用来做什么的？其中没有mmc,mmc也可以工作。

aliases {
i2c0 = &i2c0;
i2c1 = &i2c1;
i2c2 = &i2c2;
serial0 = &uart0;
serial1 = &uart1;
serial2 = &uart2;
serial3 = &uart3;
serial4 = &uart4;
serial5 = &uart5;
d_can0 = &dcan0;
d_can1 = &dcan1;
usb0 = &usb0;
usb1 = &usb1;
phy0 = &usb0_phy;
phy1 = &usb1_phy;
ethernet0 = &cpsw_emac0;
ethernet1 = &cpsw_emac1;
};

0 Steven Liu1 9 年多前回复 user4796556

TI__Mastermind 25020 points

http://stackoverflow.com/questions/17738709/dts-file-explanation-aliases

In the aliases section of a DTS, we see entries of the format

property = &label;

Each of the entries consists of :
a. property -- A new property defined here.
b. &label -- Complete DTS path to the node referenced by the label.

It basically assigns the value of b to a. Henceforth, the long-name to the node identified by the label can be accessed using the shorthand property.

Note that the RHS of this assignment is using labels and NOT the short-names of the individual nodes. Just like a label in C code refers to an instruction on the line where it is defined, a labelin DTS refers to the individual node (using its complete long path) that is defined on that line.

For example, considering the following DTS,
lxr.free-electrons.com/source/arch/powerpc/boot/dts/mpc8313erdb.dts

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am335x dts文件疑惑