Update epicardium_api_development.md

en/firmware/epicardium_api_development.md

@@ -2,92 +2,5 @@
 title: Epicardium API Development
 ---
 
-## Overview
-
-The Epicardium API allows user code running on core 1 (running the pycardium)
-to access functionality running on the epicardium (core 0).  In other words: It
-allows you to call C code running on the Epicardium from a Python module.  You
-can also call the API call from inside Epicardium as well and doing so is
-encouraged.  Calling an API call is as easy as just calling the function like
-it is defined in [`epicardium.h`](https://git.card10.badge.events.ccc.de/card10/firmware/tree/master/epicardium/epicardium.h).
-Our build-script take care of abstracting the core-boundary away.
-
-
-## API definition
-
-The API calls are declared in
-[`epicardium/epicardium.h`](https://git.card10.badge.events.ccc.de/card10/firmware/tree/master/epicardium/epicardium.h)
-and documented with sphinx doc-comments.  API calls should have names prefixed
-with `epic_`.  (For building the API documentation, `python-sphinx` and
-optionally `python-sphinx-hawkmoth` are required.)
-
-Adding an example call to the API would look like this:
-```c
-/**
- * Example API call.
- *
- * :param example_param_a:  An exemplary parameter.
- * :param example_param_b:  Another exemplary parameter.
- */
-API(API_EXAMPLE_CALL, int epic_do_example(int example_param_a, uint8_t example_param_b));
-```
-
-Choose the `API_EXAMPLE_CALL` as you see fit, it just needs to be unique.
-
-
-## API implementation
-
-The API calls are implemented in
-[`epicardium/modules/*.c`](https://git.card10.badge.events.ccc.de/card10/firmware/tree/master/epicardium/modules).
-The `*.c`-files need to be added to
-[`epicardium/modules/meson.build`](https://git.card10.badge.events.ccc.de/card10/firmware/tree/master/epicardium/modules/meson.build).
-
-An exemplary implementation to the declaration above could look like the following:
-```c
-#include <stdio.h>
-#include "epicardium.h"
-
-int epic_example_call(int example_param_a, uint8_t example_param_b)
-{
-	printf("I'm just an example: %d %d\n", example_param_a, example_param_b);
-	return 0;
-}
-```
-
-
-## Best Practices
-
- - In [`epicardium/epicardium.h`](https://git.card10.badge.events.ccc.de/card10/firmware/tree/master/epicardium/epicardium.h)
-   only types from stdlib should be included. Any other types you need
-   (especially structs) should be defined (and documented!) in `epicardium.h`
-   directly.  We do not want other `#includes` in there.
- - Passing pointers into the address space of (py)cardium is fine. Do not pass
-   pointers into the address space of epicardium to (py)cardium.
- - The API functions follow the kernel convention of either returning a boolean
-   if the function is a predicate or returning a success integer (with negative
-   values denoting errors) if it is an action or imperative command. (Ref:
-   https://www.kernel.org/doc/html/v4.10/process/coding-style.html#function-return-values-and-names.)
- - Pay attention while implementing an API call that it might be called from
-   within different FreeRTOS tasks. Calls made from (py)cardium are executed by
-   the dispatcher task but calls from epicardium might be called from any task.
-   Don't make assumptions aboutwhich task you're in. Especially if using a task
-   semaphore.
- - Please format your code using the `tools/code-style.sh`.
-
-
-## Internals
-
-Note: This describes the current state of the API. There exist plans for
-improvement ([issue #9](https://git.card10.badge.events.ccc.de/card10/firmware/issues/9))
-but they have no high priority.
-
-When an API call is called, its arguments and the unique ID of the call are
-written into a shared memory region. Then the epicardium is woken up so the
-dispatcher can read and execute the call.  When the call returnes, the result
-is written into the place where the arguments have been previously and core 1
-is woken up.  This data structure is subject to change as it only allows
-synchronous calls. To allow asynchronous calls, some sort of queue/list/... is
-required.  The code for serialisation and de-serialisation is generated from
-[`epicardium/epicardium.h`](https://git.card10.badge.events.ccc.de/card10/firmware/tree/master/epicardium/epicardium.h)
-using
-[`genapi.py`](https://git.card10.badge.events.ccc.de/card10/firmware/tree/master/epicardium/api/genapi.py).
+## Obsolete:
+Please tend to https://firmware.card10.badge.events.ccc.de/epicardium/overview.html
\ No newline at end of file