embedded - What is the difference between BSP and distribution layers in Yocto -

can please explain briefly bsp , distribution layers , difference between them?

actually i'm not looking yocto project manual references glad explanation understand it, in words.

well, despite ask for, manual has definition: machine , policy configuration

the bsp layer providing machine configuration (describing hw machine have) , provide necessary low level support, kernel , bootloader, external drivers, , possibly other applications support , enablement.

the bsp layer must not modify in recipe, unless machine(s) supported layer selected.

the distribution (policy) layer responsible configuration of distribution wide features , selections. examples package format, c library, init system, etc. should decide whether build enable x11, wifi, bluetooth, etc, support in other recipes. done adding distro_features variable, different recipes later on should check in order decide whether or not build different configurations.

as mentioned, check manual more detailed information.