Metadata in Yocto

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Non technically speaking, metadata is a set of data that describes and gives information about other data.

Yocto:
Metadata refers

  • to the build instructions 
  • data used to control what things get built and to affect how they are build
Metadata also includes:
  • Commands and data used to indicate what version of software are used
  • Where they are obtained from
  • Changes or additions to the software itself (Patches) which are used to fix bugs or customize the software to use in a particular solution

Metadata in Yocto is a collection of 
  • Configuration files (.conf) : Specifies machine architecture, file path, distribution selection
  • Recipes(.bb and .bbappend) : Containing set of instructions , where to fetch the code, build etc
  • Classes(.bbclass) : Abstract common functionality and for other recipes to just use the functionality
  • Includes(.inc) : Similar to header files, this to avoid duplication when there is a recipe of multiple versions, common instructions are placed in .inc file and recipe can just include this file and change the version


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