Co-authored-by: fleur <spacecarrot@fleurshax.net>
Signed-off-by: Rahix <rahix@rahix.de>

This commit introduces a lifecycle for core 1.  Based on the new loading
system, a few APIs are made available to control the payload running on
core 1.  These are:

1. From core 1 (Pycardium, L0dable):

    - `epic_exec(name)` API Call:  Request loading of a new payload by
      name.  If the file does not exist, the call will return with an
      error code.  Otherwise, control will go to the new payload.
    - `epic_exit(retcode)` API Call:  Return from payload
      unconditionally.  This call should be called whenever a payload is
      done or when it has hit an unrecoverable error.  On `epic_exit`,
      Epicardium will reset the core back into the menu.

2. From inside Epicardium:

    - `epic_exec(name)`: This is **not** the same as the API call, as it
      needs a different implementation underneath.  It will load a new
      payload and wait until this load actually completed (synchroneous).
    - `return_to_menu()`: Return core 1 to the menu script no matter
      what it is currently doing.  This call is asynchroneous and will
      return immediately after scheduling the lifecycle task.  This task
      will then take care of actually performing the load.

Signed-off-by: Rahix <rahix@rahix.de>

Signed-off-by: Rahix <rahix@rahix.de>

Also add a mutex around API calls in preparation for future changes.

Signed-off-by: Rahix <rahix@rahix.de>

swym authored 5 years ago and rahix committed 5 years ago

- Implement de-initialization
- Wrap filesystem operations in semaphore
- Introduce EpicFileSystem object and move epic_file_FOO(...)
  imlementations into efs_FOO(EpicFileSystem*, ...) functions.
- epic_file_FOO(...) functions are now wrappers around the _fs_
  functions, but lock and unlock the global filesystem object before &
  after calls.  This way, all efs_ functions can assume that the
  necessary lock has been acquired.
- libff: don't use FF_FS_REENTRANT, our own FS lock is enough

Signed-off-by: Rahix <rahix@rahix.de>

Signed-off-by: Rahix <rahix@rahix.de>

Closes #41

Signed-off-by: Rahix <rahix@rahix.de>

Signed-off-by: Rahix <rahix@rahix.de>

Signed-off-by: Rahix <rahix@rahix.de>

Signed-off-by: Rahix <rahix@rahix.de>

Signed-off-by: Rahix <rahix@rahix.de>