tree 18ce99f4ca719e69768853d2c4d14cbd5d0b8d62
parent 1d3731f1e552a0bc2fab14ac4379185f3152bb60
author Andrew Boie <andrew.p.boie@intel.com> 1506193549 -0700
committer Andrew Boie <andrewboie@gmail.com> 1506614180 -0700

syscalls: reorganize headers

- syscall.h now contains those APIs needed to support invoking calls
  from user code. Some stuff moved out of main kernel.h.
- syscall_handler.h now contains directives useful for implementing
  system call handler functions. This header is not pulled in by
  kernel.h and is intended to be used by C files implementing kernel
  system calls and driver subsystem APIs.
- syscall_list.h now contains the #defines for system call IDs. This
  list is expected to grow quite large so it is put in its own header.
  This is now an enumerated type instead of defines to make things
  easier as we introduce system calls over the new few months. In the
  fullness of time when we desire to have a fixed userspace/kernel ABI,
  this can always be converted to defines.

Some new code added:

- _SYSCALL_MEMORY() macro added to check memory regions passed up from
  userspace in handler functions
- _syscall_invoke{7...10}() inline functions declare for invoking system
  calls with more than 6 arguments. 10 was chosen as the limit as that
  corresponds to the largest arg list we currently have
  which is for k_thread_create()

Other changes

- auto-generated K_SYSCALL_DECLARE* macros documented
- _k_syscall_table in userspace.c is not a placeholder. There's no
  strong need to generate it and doing so would require the introduction
  of a third build phase.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>