yocto - "virtual/..."条款从何而来？

Question

在 Bitbake 中，我可以构建例如带有 bitbake virtual/kernel 的 Linux 内核或 U-Boot 与 bitbake virtual/bootloader .

那些“虚拟/……”术语是从哪里来的？

我用了find对于 poky 目录中的“virtual/kernel”等模式，但结果几乎是无限的，我不知道在哪里搜索。

我可以吗？直接virtual/bootloader当我可能已经编写了自己的引导加载程序时，我可以使用自定义配方吗？

Answer 1

From bitbake user-manual

As an example of adding an extra provider, suppose a recipe named foo_1.0.bb contained the following:

PROVIDES += "virtual/bar_1.0"

The recipe now provides both "foo_1.0" and "virtual/bar_1.0". The "virtual/" namespace is often used to denote cases where multiple providers are expected with the user choosing between them. Kernels and toolchain components are common cases of this in OpenEmbedded.

Sometimes a target might have multiple providers. A common example is "virtual/kernel", which is provided by each kernel recipe. Each machine often selects the best kernel provider by using a line similar to the following in the machine configuration file:

PREFERRED_PROVIDER_virtual/kernel = "linux-yocto"