nuttx

History

Gregory Nutt 0454ae2a10 This commit removes naming associated with and naming for the now non-existent NXFE graphics layer. Squashed commit of the following: graphics/: Rename nxfe_reportposition to nxmu_reportposition. The is no longer an nxfe layer. graphics/: Renmae nxfe_redrawreq to nxmu_redrawreq. The is no longer an nxfe layer. graphics/nxmu/nxmu.h: Renmae nxfe.h to nxmu.h. There is no long an nxfe layer. graphics/: Rename nxfe_state_s to nxmu_state_s. There is no longer an nxfe layer. graphics/: Rename nxfe_conn_s to nxmu_conn_s. There is no longer an nxfe layer.		2019-03-13 09:16:30 -06:00
..
libc	lib_gethostbyaddrr.c edited online with Bitbucket	2019-03-11 03:55:08 +00:00
libdsp	Merged in raiden00/nuttx_pe (pull request #771 )	2018-12-02 11:49:25 +00:00
libnx	This commit removes naming associated with and naming for the now non-existent NXFE graphics layer.	2019-03-13 09:16:30 -06:00
libxx	libs/libxx/Kconfig: utomatically select CONFIG_LIBC_WCHAR and CONFIG_TIME_EXTENDED when CONFIG_LIBCXX is selected since libcxx compile fails if without these two option	2019-01-27 07:00:07 -06:00
README.txt	Remove trailing spaces at the end of lines.	2018-08-13 07:39:38 -06:00

README.txt

README
======

This directory holds NuttX libraries.  Libraries in NuttX are very special
creatures.  The have these properties:

1. They can be shared by both application logic and logic within the OS when
   using the FLAT build.

2. But in PROTECTED and KERNEL modes, they must be built differently:  The
   copies used by applications and the OS cannot be the same.  Rather,
   separate versions of libraries must be built for the kernel and for
   applications.

3. When used by the OS, some special care must be taken to assure that the
   OS logic does not disrupt the user's errno value and that the OS does
   not create inappropriate cancellation points.

   For example, sem_wait() is both a cancellation point and modifies the
   errno value.  So within the FLAT build and without kernel version for
   the PROTECTED and KERNEL builds, the special internal OS interface
   nxsem_wait() must be used.  Within libraries, the macro  _SEM_WAIT()
   (as defined in include/nuttx/semaphore.h) is used instead.  The
   definition of this macro accounts for the different usage environments.

NOTE:  The libraries under libs/ build differently from other NuttX
components:  There are no build-related files in the libs/ directory; it
is simply a container for other well-known, individual library directories.
The upper level Makefile logic is aware of the libraries within the libs/
container.

The only real function of the libs/ directory is to prevent the top-level
directory from becoming cluttered with individual libraries.