[yocto] Difference between target, cross, native and nativesdk.

[Raphael Philipe]

Hi,

I'm working on a set of recipes that must be configurable to be baked
in native, nativesdk, cross and target.

I have a bunch of questions concerning this terms. I searched the
documentation and wasn't able to find a definitive explanation for
these terms.

I will write some statements bellow about my understanding on these
terms, and I will ask you to please correct me if I'm wrong or add any
additional information:

- By default, recipes bake binaries for the target architecture that
is described in the MACHINE variable in the local.conf

- One can use BBCLASSEXTEND = "native nativesdk" to bake binaries for
the host architecture (native) and for target sdk architecture. The
target sdk architecture is described in the SDKMACHINE variable and
the host architecture is the architecture of the machine executing
bitbake. BBCLASSEXTEND = "native nativesdk" will alow you to bake
recipes that are "virtual" using the suffix native ( so ${PN}-native)
and the prefix nativesdk (so nativesdk-${PN}).

- Recipes that are cross need to inherit cross.bbclass. They are used for  ????

I'm looking for the reason why there is a u-boot-fw-utils and a
u-boot-fw-utils-cross. One produces a binary for the target and the
other for???

thank you.