(re)create OSAL for OSX

[skliper]

I use OSX as a development environment and, while I can easily use a VM of Linux, it would be nice to be able to compile/run cFS in OSX natively.

There are a couple issues with using the posix OSAL on OSX:

• There is no timer interface.
• pthreads does not include the priority control API's
• There are no "_init" or "_fini" externs for stack introspection.
• No vfs.h
• dlsym takes special RTLD_* handles to define its namespace search behavior (NULL does not work.)

[skliper]

Imported from trac issue 180. Created by cdknight on 2016-12-09T18:36:48, last modified: 2019-07-08T16:47:00

[skliper]

Trac comment by jhageman on 2019-03-01 14:30:54:

Related to [cfs_psp:75] in the PSP repo.

[skliper]

Trac comment by jhageman on 2019-07-08 16:47:00:

OSX OSAL outside the scope of community CCB. Moved [changeset:ab3b3ee] to techdev-osx-osal and closing ticket as "wontfix".