Commit 508c3e0c authored by Thomas Petazzoni's avatar Thomas Petazzoni
Browse files

docs/manual: document usage of BR2_TOOLCHAIN_HAS_SYNC_x 



This commit updates the documentation to detail when and how to use
the BR2_TOOLCHAIN_HAS_SYNC_x dependency. Note that we chose to not add
a comment about this dependency, because it is mainly tied to
architecture capabilities (except in very specific cases, which would
be way too complicated to explain in a Config.in comment).

Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
parent 6856e417

docs/manual/adding-packages-directory.txt

+14 −0
Original line number Diff line number Diff line
@@ -279,6 +279,20 @@ use in the comment. 
** Dependency symbol: +BR2_ARCH_HAS_ATOMICS+

** Comment string: no comment to be added



* Gcc +__sync_*+ built-ins used for atomic operations. They are

  available in variants operating on 1 byte, 2 bytes, 4 bytes and 8

  bytes. Since different architectures support atomic operations on

  different sizes, one dependency symbol is available for each size:

** Dependency symbol: +BR2_TOOLCHAIN_HAS_SYNC_1+ for 1 byte,

   +BR2_TOOLCHAIN_HAS_SYNC_2+ for 2 bytes,

   +BR2_TOOLCHAIN_HAS_SYNC_4+ for 4 bytes, +BR2_TOOLCHAIN_HAS_SYNC_8+

   for 8 bytes.

** Comment string: no comment to be added



* Gcc +__atomic_*+ built-ins used for atomic operations.

** Dependency symbol: +BR2_TOOLCHAIN_HAS_ATOMIC+.

** Comment string: no comment to be added



* Kernel headers

** Dependency symbol: +BR2_TOOLCHAIN_HEADERS_AT_LEAST_X_Y+, (replace

   +X_Y+ with the proper version, see +toolchain/toolchain-common.in+)