[Yocto RM]11 - Features

11 characteristic

This chapter provides references to shipped machines and release functions that can be included in the image 、 Selectable image function reference and function backfill reference .

Feature provides a mechanism to determine which packages should be included in the generated image . The distribution can be DISTRO_FEATURES Variables choose the functions they want to support , This variable is set or appended in the configuration file of the distribution , for example poky.conf、poky-tiny.conf、poky-lsb.conf etc. . Machine characteristics are in MACHINE_FEATURES Variable , This variable is set in the machine configuration file and specifies the hardware characteristics of a given machine .

These two variables are combined to calculate the kernel module to be included 、 Utilities and other packages . A given distribution can support a selected subset of features , Therefore, if the release does not support some machine functions , They may not be included .

One way you can determine which recipes are being checked to see if they contain a specific function is through the metadata of that function grep. This is an example , It finds that its build may change recipes based on a given function ：

$ cd poky
$ git grep 'contains.*MACHINE_FEATURES.*feature'

11.1 Machine characteristics

The following items are what you can do with MACHINE_FEATURES Functions used together . There is no one-to-one correspondence between functions and packages , They can go beyond simply controlling the installation of one or more packages . Sometimes , A function will affect the way some recipes are built . for example , A function may determine whether it is do_configure Specific configuration options are specified for specific recipes in the task .

This function list only represents Y