kernel/include/app.h

// Copyright 2016 The Fuchsia Authors
// Copyright (c) 2009-2012 Travis Geiselbrecht
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

#pragma once

#include <stddef.h>
#include <zircon/compiler.h>

__BEGIN_CDECLS

/* app support api */
void apps_init(void); /* one time setup */

/* app entry point */
struct app_descriptor;
typedef void (*app_init)(const struct app_descriptor *);
typedef void (*app_entry)(const struct app_descriptor *, void *args);

/* app startup flags */
#define APP_FLAG_DONT_START_ON_BOOT 0x1
#define APP_FLAG_CUSTOM_STACK_SIZE 0x2

/* each app needs to define one of these to define its startup conditions */
struct app_descriptor {
    const char *name;
    app_init  init;
    app_entry entry;
    unsigned int flags;
    size_t stack_size;
};

#define APP_FLAGS(appname, _init, _entry, _flags, _stack_size) \
    __ALIGNED(sizeof(void *)) __USED __SECTION("apps") \
    static const struct app_descriptor _app_##appname = { \
        .name = #appname, \
        .init = _init, \
        .entry = _entry, \
        .flags = _flags, \
        .stack_size = _stack_size \
    };

#define APP(appname, _init, _entry) \
    APP_FLAGS(appname, _init, _entry, 0, 0);

__END_CDECLS