CODEWITHSUNDEEP
yoctobitbake
Jaehyun Lee
Jaehyun Lee

Reputation: 289

What is the difference between BPN and PN?

In bitbake.conf, I found the definition of BPN and PN.

But I wonder the difference between BPN and PN.

Please explain to me with example. thanks

Upvotes: 3

Views: 1195

Answers (2)

Mo_
Mo_

Reputation: 863

There are docs for BPN, PN and P. However, it's easier to understand by printing the environment for an example recipe. Take asio_1.20.0.bb:

bitbake -e asio-native | grep -e "^P=" -e "^PN=" -e "BPN="

BPN = "asio"
PN  = "asio-native"
P   = "asio-native-1.20.0"

Using the native recipe illustrates the differences well. Both asio and 1.20.0 are inferred from the filename (but can also be explicitly set in the recipe). native is added as a SPECIAL_PKGSUFFIX, because I build asio-native. In contrast, building asio for the target, PN and BPN are the same, because there's no suffix:

bitbake -e asio | grep -e "^P=" -e "^PN=" -e "BPN="

BPN = "asio"
PN  = "asio"
P   = "asio-1.20.0"

Upvotes: 1

Matthew
Matthew

Reputation: 1622

From the yoctoproject docs

BPN This variable is a version of the PN variable with common prefixes and suffixes removed, such as nativesdk-, -cross, -native, and multilib’s lib64- and lib32-. The exact lists of prefixes and suffixes removed are specified by the MLPREFIX and SPECIAL_PKGSUFFIX variables, respectively.

So, PN is the full recipe name including the above mentioned prefixes and suffixes, assuming the recipe has prefixes or suffixes.

I ran into this when bitbake gave me a QA warning that I shouldn't use ${PN} in SRC_URI, and suggested ${BPN} instead.

I was confused, because most recipes scratch don't have suffixes or prefixes the recipe name, so PN is usually the same as BPN.

Also, note that PN can mean recipe-name in some contexts (in a recipe), and package-name in other contexts.

The P = ${PN}-${PV} confusion in the AI answer is actually correct. See the docs. The original value for PV is extracted from the recipe name, but in practice I have often seen it set explicitly in the recipe, especially with Git and SRCREV = ${AUTOREV} and SRCPV.

Update: See the answer from @Mo_. Empirical evidence is best! I confused myself between reading the docs and other answers. I edited my answer to remove incorrect details about PN having version information.

And example that shows a difference between P, PN, and BPN:

$ bitbake -e binutils-cross-aarch64 |grep -e "^PN=" -e "^P=" -e "^BPN="
BPN="binutils"
PN="binutils-cross-aarch64"
P="binutils-cross-aarch64-2.40"

Upvotes: 1

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