/****************************************************************************
* sched/os_start.c
*
* Copyright (C) 2007-2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <sys/types.h>
#include <stdbool.h>
#include <debug.h>
#include <string.h>
#include <nuttx/arch.h>
#include <nuttx/compiler.h>
#include <nuttx/fs/fs.h>
#include <nuttx/net/net.h>
#include <nuttx/lib.h>
#include <nuttx/kmalloc.h>
#include <nuttx/init.h>
#include "os_internal.h"
#include "sig_internal.h"
#include "wd_internal.h"
#include "sem_internal.h"
#ifndef CONFIG_DISABLE_MQUEUE
# include "mq_internal.h"
#endif
#ifndef CONFIG_DISABLE_PTHREAD
# include "pthread_internal.h"
#endif
#include "clock_internal.h"
#include "timer_internal.h"
#include "irq_internal.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Type Declarations
****************************************************************************/
/****************************************************************************
* Global Variables
****************************************************************************/
/* Task Lists ***************************************************************/
/* The state of a task is indicated both by the task_state field of the TCB
* and by a series of task lists. All of these tasks lists are declared
* below. Although it is not always necessary, most of these lists are
* prioritized so that common list handling logic can be used (only the
* g_readytorun, the g_pendingtasks, and the g_waitingforsemaphore lists need
* to be prioritized).
*/
/* This is the list of all tasks that are ready to run. The head of this
* list is the currently active task; the tail of this list is always the
* IDLE task.
*/
volatile dq_queue_t g_readytorun;
/* This is the list of all tasks that are ready-to-run, but cannot be placed
* in the g_readytorun list because: (1) They are higher priority than the
* currently active task at the head of the g_readytorun list, and (2) the
* currently active task has disabled pre-emption.
*/
volatile dq_queue_t g_pendingtasks;
/* This is the list of all tasks that are blocked waiting for a semaphore */
volatile dq_queue_t g_waitingforsemaphore;
/* This is the list of all tasks that are blocked waiting for a signal */
#ifndef CONFIG_DISABLE_SIGNALS
volatile dq_queue_t g_waitingforsignal;
#endif
/* This is the list of all tasks that are blocked waiting for a message
* queue to become non-empty.
*/
#ifndef CONFIG_DISABLE_MQUEUE
volatile dq_queue_t g_waitingformqnotempty;
#endif
/* This is the list of all tasks that are blocked waiting for a message
* queue to become non-full.
*/
#ifndef CONFIG_DISABLE_MQUEUE
volatile dq_queue_t g_waitingformqnotfull;
#endif
/* This is the list of all tasks that are blocking waiting for a page fill */
#ifdef CONFIG_PAGING
volatile dq_queue_t g_waitingforfill;
#endif
/* This the list of all tasks that have been initialized, but not yet
* activated. NOTE: This is the only list that is not prioritized.
*/
volatile dq_queue_t g_inactivetasks;
/* This is the list of dayed memory deallocations that need to be handled
* within the IDLE loop. These deallocations get queued by sched_free()
* if the OS attempts to deallocate memory while it is within an interrupt
* handler.
*/
volatile sq_queue_t g_delayeddeallocations;
/* This is the value of the last process ID assigned to a task */
volatile pid_t g_lastpid;
/* The following hash table is used for two things:
*
* 1. This hash table greatly speeds the determination of
* a new unique process ID for a task, and
* 2. Is used to quickly map a process ID into a TCB.
* It has the side effects of using more memory and limiting
*
* the number of tasks to CONFIG_MAX_TASKS.
*/
pidhash_t g_pidhash[CONFIG_MAX_TASKS];
/* This is a table of task lists. This table is indexed by
* the task state enumeration type (tstate_t) and provides
* a pointer to the associated static task list (if there
* is one) as well as a boolean indication as to if the list
* is an ordered list or not.
*/
const tasklist_t g_tasklisttable[NUM_TASK_STATES] =
{
{ NULL, false }, /* TSTATE_TASK_INVALID */
{ &g_pendingtasks, true }, /* TSTATE_TASK_PENDING */
{ &g_readytorun, true }, /* TSTATE_TASK_READYTORUN */
{ &g_readytorun, true }, /* TSTATE_TASK_RUNNING */
{ &g_inactivetasks, false }, /* TSTATE_TASK_INACTIVE */
{ &g_waitingforsemaphore, true } /* TSTATE_WAIT_SEM */
#ifndef CONFIG_DISABLE_SIGNALS
,
{ &g_waitingforsignal, false } /* TSTATE_WAIT_SIG */
#endif
#ifndef CONFIG_DISABLE_MQUEUE
,
{ &g_waitingformqnotempty, true }, /* TSTATE_WAIT_MQNOTEMPTY */
{ &g_waitingformqnotfull, true } /* TSTATE_WAIT_MQNOTFULL */
#endif
#ifdef CONFIG_PAGING
,
{ &g_waitingforfill, true } /* TSTATE_WAIT_PAGEFILL */
#endif
};
/****************************************************************************
* Private Variables
****************************************************************************/
/* This is the task control block for this thread of execution. This thread
* of execution is the IDLE task. NOTE: the system boots into the IDLE
* task. The IDLE task spawns the user initialization task (user_start) and
* that user init task is responsible for bringing up the rest of the system
*/
static FAR _TCB g_idletcb;
/* This is the name of the idle task */
static FAR const char g_idlename[] = "Idle Task";
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: os_start
*
* Description:
* This function is called to initialize the operating system and to spawn
* the user initization thread of execution
*
****************************************************************************/
void os_start(void)
{
int i;
slldbg("Entry\n");
/* Initialize all task lists */
dq_init(&g_readytorun);
dq_init(&g_pendingtasks);
dq_init(&g_waitingforsemaphore);
#ifndef CONFIG_DISABLE_SIGNALS
dq_init(&g_waitingforsignal);
#endif
#ifndef CONFIG_DISABLE_MQUEUE
dq_init(&g_waitingformqnotfull);
dq_init(&g_waitingformqnotempty);
#endif
#ifdef CONFIG_PAGING
dq_init(&g_waitingforfill);
#endif
dq_init(&g_inactivetasks);
sq_init(&g_delayeddeallocations);
/* Initialize the logic that determine unique process IDs. */
g_lastpid = 0;
for (i = 0; i < CONFIG_MAX_TASKS; i++)
{
g_pidhash[i].tcb = NULL;
g_pidhash[i].pid = INVALID_PROCESS_ID;
}
/* Assign the process ID of ZERO to the idle task */
g_pidhash[ PIDHASH(0)].tcb = &g_idletcb;
g_pidhash[ PIDHASH(0)].pid = 0;
/* Initialize a TCB for this thread of execution. NOTE: The default
* value for most components of the g_idletcb are zero. The entire
* structure is set to zero. Then only the (potentially) non-zero
* elements are initialized. NOTE: The idle task is the only task in
* that has pid == 0 and sched_priority == 0.
*/
bzero((void*)&g_idletcb, sizeof(_TCB));
g_idletcb.task_state = TSTATE_TASK_RUNNING;
g_idletcb.entry.main = (main_t)os_start;
#if CONFIG_TASK_NAME_SIZE > 0
strncpy(g_idletcb.name, g_idlename, CONFIG_TASK_NAME_SIZE-1);
g_idletcb.argv[0] = g_idletcb.name;
#else
g_idletcb.argv[0] = (char*)g_idlename;
#endif /* CONFIG_TASK_NAME_SIZE */
/* Then add the idle task's TCB to the head of the ready to run list */
dq_addfirst((FAR dq_entry_t*)&g_idletcb, (FAR dq_queue_t*)&g_readytorun);
/* Initialize the processor-specific portion of the TCB */
g_idletcb.flags = TCB_FLAG_TTYPE_KERNEL;
up_initial_state(&g_idletcb);
/* Initialize the semaphore facility(if in link). This has to be done
* very early because many subsystems depend upon fully functional
* semaphores.
*/
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (sem_initialize != NULL)
#endif
{
sem_initialize();
}
/* Initialize the memory manager */
#ifndef CONFIG_HEAP_BASE
{
FAR void *heap_start;
size_t heap_size;
up_allocate_heap(&heap_start, &heap_size);
kmm_initialize(heap_start, heap_size);
}
#else
kmm_initialize((void*)CONFIG_HEAP_BASE, CONFIG_HEAP_SIZE);
#endif
/* Initialize the interrupt handling subsystem (if included) */
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (irq_initialize != NULL)
#endif
{
irq_initialize();
}
/* Initialize the watchdog facility (if included in the link) */
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (wd_initialize != NULL)
#endif
{
wd_initialize();
}
/* Initialize the POSIX timer facility (if included in the link) */
#ifndef CONFIG_DISABLE_CLOCK
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (clock_initialize != NULL)
#endif
{
clock_initialize();
}
#endif
#ifndef CONFIG_DISABLE_POSIX_TIMERS
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (timer_initialize != NULL)
#endif
{
timer_initialize();
}
#endif
/* Initialize the signal facility (if in link) */
#ifndef CONFIG_DISABLE_SIGNALS
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (sig_initialize != NULL)
#endif
{
sig_initialize();
}
#endif
/* Initialize the named message queue facility (if in link) */
#ifndef CONFIG_DISABLE_MQUEUE
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (mq_initialize != NULL)
#endif
{
mq_initialize();
}
#endif
/* Initialize the thread-specific data facility (if in link) */
#ifndef CONFIG_DISABLE_PTHREAD
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (pthread_initialize != NULL)
#endif
{
pthread_initialize();
}
#endif
/* Initialize the file system (needed to support device drivers) */
#if CONFIG_NFILE_DESCRIPTORS > 0
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (fs_initialize != NULL)
#endif
{
fs_initialize();
}
#endif
/* Initialize the network system */
#ifdef CONFIG_NET
#if 0
if (net_initialize != NULL)
#endif
{
net_initialize();
}
#endif
/* The processor specific details of running the operating system
* will be handled here. Such things as setting up interrupt
* service routines and starting the clock are some of the things
* that are different for each processor and hardware platform.
*/
up_initialize();
/* Initialize the C libraries (if included in the link). This
* is done last because the libraries may depend on the above.
*/
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (lib_initialize != NULL)
#endif
{
lib_initialize();
}
/* Create stdout, stderr, stdin on the IDLE task. These will be
* inherited by all of the threads created by the IDLE task.
*/
(void)sched_setupidlefiles(&g_idletcb);
/* Create initial tasks and bring-up the system */
(void)os_bringup();
/* When control is return to this point, the system is idle. */
sdbg("Beginning Idle Loop\n");
for (;;)
{
/* Perform garbage collection (if it is not being done by the worker
* thread). This cleans-up memory de-allocations that were queued
* because they could not be freed in that execution context (for
* example, if the memory was freed from an interrupt handler).
*/
#ifndef CONFIG_SCHED_WORKQUEUE
/* We must have exclusive access to the memory manager to do this
* BUT the idle task cannot wait on a semaphore. So we only do
* the cleanup now if we can get the semaphore -- this should be
* possible because if the IDLE thread is running, no other task is!
*/
if (kmm_trysemaphore() == 0)
{
sched_garbagecollection();
kmm_givesemaphore();
}
#endif
/* Perform any processor-specific idle state operations */
up_idle();
}
}
