From 75813bcef30adf76c54ab1f7f02203896320b8c5 Mon Sep 17 00:00:00 2001 From: gdisirio Date: Sat, 7 Mar 2009 10:07:12 +0000 Subject: git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@809 35acf78f-673a-0410-8e92-d51de3d6d3f4 --- docs/src/main.dox | 407 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 407 insertions(+) create mode 100644 docs/src/main.dox (limited to 'docs') diff --git a/docs/src/main.dox b/docs/src/main.dox new file mode 100644 index 000000000..58a96870d --- /dev/null +++ b/docs/src/main.dox @@ -0,0 +1,407 @@ +/* + ChibiOS/RT - Copyright (C) 2006-2007 Giovanni Di Sirio. + + This file is part of ChibiOS/RT. + + ChibiOS/RT is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + ChibiOS/RT is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +*/ + +/** + * @mainpage ChibiOS/RT + * @author Giovanni Di Sirio (gdisirio@users.sourceforge.net). + * + *

Chibi ?

+ * I didn't want a serious name for this project. It is the Japanese word for + * small as in small child. So ChibiOS/RT + * @htmlonly (ちびOS/RT) @endhtmlonly + * means small Real Time Operating System. + * Source Wikipedia. + * + *

Features

+ * - Free software, GPL3 licensed. Stable releases include a exception clause + * to the GPL. + * - Designed for realtime applications. + * - Easily portable. + * - Preemptive scheduling. + * - 128 priority levels. Multiple threads at the same priority level allowed. + * - Round robin scheduling for threads at the same priority level. + * - Offers threads, virtual timers, semaphores, mutexes, condvars, + * event flags, messages, I/O queues. + * - No static setup at compile time, there is no need to configure a maximum + * number of all the above objects. + * - PC simulator target included, the development can be done on the PC + * using MinGW.
+ * Timers, I/O channels and other HW resources are simulated in a + * Win32 process and the application code does not need to be aware of it. + * MinGW demo available. + * - No *need* for a memory allocator, all the kernel structures are static + * and declaratively allocated. + * - Optional, thread safe, Heap Allocator subsystem. + * - Optional, thread safe, Memory Pools Allocator subsystem. + * - Blocking and non blocking I/O channels with timeout and events generation + * capability. + * - Minimal system requirements: about 8KiB ROM with all options enabled and + * speed optimizations on. The size can shrink under 2KiB by disabling the + * the unused subsystems and optimizing for size. + * - Almost totally written in C with little ASM code required for ports. + * . + *

Related pages

+ * - @subpage lic_faq + * - @subpage goals + * - @subpage concepts + * - @subpage articles + * . + */ + +/** + * @defgroup Ports Ports + * @{ + * This section describes the technical details for the various supported + * ChibiOS/RT ports. + */ +/** @} */ + +/** + * @defgroup Kernel Kernel + * @{ + */ +/** @} */ + +/** + * @defgroup Config Configuration + * @{ + * In @p chconf.h are defined the required subsystems for your application. + * @ingroup Kernel + */ +/** @} */ + +/** + * @defgroup Core Generic Port Code Templates + * @{ + * Non portable code templates. + * @ingroup Kernel + */ +/** @} */ + +/** + * @defgroup Types Types + * @{ + * System types and macros. + * @ingroup Kernel + */ +/** @} */ + +/** + * @defgroup System System Management + * @{ + * Initialization, Locks, Interrupt Handling, Power Management, Abnormal + * Termination. + * @ingroup Kernel + */ +/** @} */ + +/** + * @defgroup Inline Inline + * @{ + * System inline-able code. + * @ingroup Kernel + */ +/** @} */ + +/** + * @defgroup Debug Debug + * @{ + * Debug APIs and procedures. + * @ingroup Kernel + */ +/** @} */ + +/** + * @defgroup Scheduler Scheduler + * @{ + * ChibiOS/RT scheduler. + * @ingroup Kernel + */ +/** @} */ + +/** + * @defgroup ThreadLists Thread Lists and Queues + * @{ + * ChibiOS/RT thread lists and queues utilities. + * @ingroup Kernel + */ +/** @} */ + +/** + * @defgroup Threads Threads + * @{ + * Threads creation and termination APIs. + */ +/** @} */ + +/** + * @defgroup Time Time and Virtual Timers + * @{ + * Time and Virtual Timers related APIs. + */ +/** @} */ + +/** + * @defgroup Heap Heap + * @{ + * Heap Allocator related APIs. + *

Operation mode

+ * The heap allocator implements a first-fit strategy and its APIs are + * functionally equivalent to the usual @p malloc() and @p free(). The main + * difference is that the heap APIs are thread safe.
+ * By enabling the @p CH_USE_MALLOC_HEAP option the heap manager will use the + * runtime-provided @p malloc() and @p free() as backend for the heap APIs + * instead of the system provided allocator.
+ * In order to use the heap APIs the @p CH_USE_HEAP option must be specified + * in @p chconf.h. + */ +/** @} */ + +/** + * @defgroup MemoryPools Memory Pools + * @{ + * Memory Pools related APIs. + *

Operation mode

+ * The Memory Pools APIs allow to allocate/free fixed size objects in + * constant time and reliably without memory fragmentation problems.
+ * In order to use the Time APIs the @p CH_USE_MEMPOOLS option must be + * specified in @p chconf.h. + */ +/** @} */ + +/** + * @defgroup Semaphores Semaphores + * @{ + * Semaphores and threads synchronization. + *

Operation mode

+ * A semaphore is a threads synchronization object, some operations + * are defined on semaphores: + * - Signal: The semaphore counter is increased and if the result + * is non-positive then a waiting thread is removed from the semaphore + * queue and made ready for execution. + * - Wait: The semaphore counter is decreased and if the result + * becomes negative the thread is queued in the semaphore and suspended. + * - Reset: The semaphore counter is reset to a non-negative value + * and all the threads in the queue are released. + * . + * Semaphores can be used as guards for mutual exclusion code zones (note that + * mutexes are recommended for this kind of use) but also have other uses, + * queues guards and counters as example.
+ * Semaphores usually use FIFO queues but it is possible to make them + * order threads by priority by specifying CH_USE_SEMAPHORES_PRIORITY in + * @p chconf.h.
+ * In order to use the Semaphores APIs the @p CH_USE_SEMAPHORES + * option must be specified in @p chconf.h.

+ */ +/** @} */ + +/** + * @defgroup Mutexes Mutexes + * @{ + * Mutexes and threads synchronization. + *

Operation mode

+ * A mutex is a threads synchronization object, some operations are defined + * on mutexes: + * - Lock: The mutex is checked, if the mutex is not owned by some + * other thread then it is locked else the current thread is queued on the + * mutex in a list ordered by priority. + * - Unlock: The mutex is released by the owner and the highest + * priority thread waiting in the queue, if any, is resumed and made owner + * of the mutex. + * . + * In order to use the Event APIs the @p CH_USE_MUTEXES option must be + * specified in @p chconf.h.
+ * + *

Constraints

+ * In ChibiOS/RT the Unlock operations are always performed in Lock-reverse + * order. The Unlock API does not even have a parameter, the mutex to unlock + * is taken from an internal stack of owned mutexes. + * This both improves the performance and is required by the priority + * inheritance mechanism. + * + *

The priority inversion problem

+ * The mutexes in ChibiOS/RT implements the full priority + * inheritance mechanism in order handle the priority inversion problem.
+ * When a thread is queued on a mutex, any thread, directly or indirectly, + * holding the mutex gains the same priority of the waiting thread (if their + * priority was not already equal or higher). The mechanism works with any + * number of nested mutexes and any number of involved threads. The algorithm + * complexity (worst case) is N with N equal to the number of nested mutexes. + */ +/** @} */ + +/** + * @defgroup CondVars Condition Variables + * @{ + * Condition Variables and threads synchronization. + *

Operation mode

+ * The condition variable is a synchronization object meant to be used inside + * a zone protected by a @p Mutex. Mutexes and CondVars together can implement + * a Monitor construct.
+ * In order to use the Condition Variables APIs the @p CH_USE_CONDVARS + * option must be specified in @p chconf.h.

+ */ +/** @} */ + +/** + * @defgroup Events Events + * @{ + * Event Sources and Event Listeners. + *

Operation mode

+ * An Event Source is a special object that can be signaled by a thread or + * an interrupt service routine. Signaling an Event Source has the effect + * that all the threads registered on the Event Source will receive + * and serve the event.
+ * An unlimited number of Event Sources can exists in a system and each + * thread can listen on an unlimited number of them.
+ * Note that the events can be asynchronously generated but are synchronously + * served, a thread can serve event by calling a @p chEvtWaitXXX() + * API. If an event is generated while a listening thread is not ready to + * serve it then the event becomes "pending" and will be served as soon the + * thread invokes a @p chEvtWaitXXX().
+ * In order to use the Event APIs the @p CH_USE_EVENTS option must be + * specified in @p chconf.h. + */ +/** @} */ + +/** + * @defgroup Messages Synchronous Messages + * @{ + * Synchronous inter-thread messages. + *

Operation Mode

+ * Synchronoud messages are an easy to use and fast IPC mechanism, threads + * can both serve messages and send messages to other threads, the mechanism + * allows data to be carried in both directions. Data is not copied between + * the client and server threads but just a pointer passed so the exchange + * is very time efficient.
+ * Messages are usually processed in FIFO order but it is possible to process + * them in priority order by specifying CH_USE_MESSAGES_PRIORITY + * in @p chconf.h.
+ * Threads do not need to allocate space for message queues, the mechanism + * just requires two extra pointers in the @p Thread structure (the message + * queue header).
+ * In order to use the Messages APIs the @p CH_USE_MESSAGES option must be + * specified in @p chconf.h. + */ +/** @} */ + +/** + * @defgroup Mailboxes Mailboxes + * @{ + * Asynchronous messages. + *

Operation mode

+ * A mailbox is an asynchronous communication mechanism.
+ * The following operations are possible on a mailbox: + * - Post: Posts a message on the mailbox in FIFO order. + * - Post Ahead: Posts a message on the mailbox with high priority. + * - Fetch: A message is fetched from the mailbox and removed from + * the queue. + * - Reset: The mailbox is emptied and all the stored messages lost. + * . + * A message is a variable of type msg_t that is guaranteed to have the + * same size of and be compatible with pointers (an explicit cast is needed). + * If larger messages need to be exchanged then a pointer to a structure can + * be posted in the mailbox but the posting side has no predefined way to + * know when the message has been processed. A possible approach is to + * allocate memory (from a memory pool as example) from the posting side and + * free it on the fetching side. Another approach is to set a "done" flag into + * the structure pointed by the message. + */ +/** @} */ + +/** + * @defgroup IOQueues I/O Queues + * @{ + * ChibiOS/RT supports several kinds of queues. The queues are mostly used + * in serial-like device drivers. The device drivers are usually designed to + * have a lower side (lower driver, it is usually an interrupt service + * routine) and an upper side (upper driver, accessed by the application + * threads).
+ * There are several kind of queues:
+ * - Input queue, unidirectional queue where the writer is the + * lower side and the reader is the upper side. + * - Output queue, unidirectional queue where the writer is the + * upper side and the reader is the lower side. + * - Half duplex queue, bidirectional queue where the buffer is shared + * between a receive and a transmit queues. This means that concurrent + * buffered input and output operations are not possible, this is perfectly + * acceptable for a lot of applications however, as example an RS485 driver. + * - Full duplex queue, bidirectional queue where read and write + * operations can happen at the same time. Full duplex queues + * are implemented by pairing an input queue and an output queue together. + * . + * In order to use the I/O queues the @p CH_USE_QUEUES option must + * be specified in @p chconf.h.
+ * In order to use the half duplex queues the @p CH_USE_QUEUES_HALFDUPLEX + * option must be specified in @p chconf.h. + */ +/** @} */ + +/** + * @defgroup Serial Serial Drivers + * @{ + * This module implements a generic full duplex serial driver and a generic + * half duplex serial driver. It uses the I/O Queues for communication between + * the upper and the lower driver and events to notify the application about + * incoming data, outcoming data and other I/O events. + * The module also contains functions that make the implementation of the + * interrupt service routines much easier.
+ * In order to use the serial full duplex driver the + * @p CH_USE_SERIAL_FULLDUPLEX option must be specified in @p chconf.h.
+ * In order to use the serial half duplex driver the + * @p CH_USE_SERIAL_HALFDUPLEX option must be specified in @p chconf.h. + */ +/** @} */ + +/** + * @defgroup utilities_library Utilities Library + * @{ + * @brief Utilities Library. + * @details This is a collection of useful library code that is not part of + * the base kernel services. + *

Notes

+ * The library code does not follow the same naming convention of the + * system APIs in order to make very clear that it is not "core" code.
+ * The main difference is that library code is not formally tested in the + * test suite but through usage in the various demo applications. + */ +/** @} */ + +/** + * @defgroup CPlusPlusLibrary C++ Wrapper + * @{ + * C++ wrapper module. This module allows to use the ChibiOS/RT functionalities + * from C++ as classes and objects rather the traditional "C" APIs. + * + * @ingroup utilities_library + */ +/** @} */ + +/** + * @defgroup event_timer Events Generator Timer + * @{ + * @brief Event Generator Timer. + * @details This timer generates an event at regular intervals. The + * listening threads can use the event to perform time related activities. + * Multiple threads can listen to the same timer. + * + * @ingroup utilities_library + */ +/** @} */ + -- cgit v1.2.3