static inline void hog_cpu(void)
{
#ifdef CONFIG_ARCH_SIM
/* The simulator doesn't have any mechanism to do asynchronous pre-emption
* (basically because it doesn't have any interupts/asynchronous events).
* The simulator does "fake" a timer interrupt in up_idle() -- the idle
* thread that only executes when nothing else is running. In the simulator,
* we cannot suspend the middle priority task, or we wouldn't have the
* test that we want. So, we have no option but to pump the fake clock
* here by calling up_idle(). Sigh!
*/
up_idle();
#else
/* On real platforms with a real timer interrupt, we really can hog the
* CPU. When the sleep() goes off in priority_inheritance(), it will
* wake up and start the high priority thread.
*/
volatile int i;
for (i = 0; i < INT_MAX; i++);
#endif
}
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();
}
}
void os_start(void)
{
int i;
slldbg("Entry\n");
/* Initialize RTOS Data ***************************************************/
/* 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_delayed_kufree);
#if (defined(CONFIG_BUILD_PROTECTED) || defined(CONFIG_BUILD_KERNEL)) && \
defined(CONFIG_MM_KERNEL_HEAP)
sq_init(&g_delayed_kfree);
#endif
/* 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.cmn;
g_pidhash[PIDHASH(0)].pid = 0;
/* Initialize the IDLE task TCB *******************************************/
/* 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(struct task_tcb_s));
g_idletcb.cmn.task_state = TSTATE_TASK_RUNNING;
g_idletcb.cmn.entry.main = (main_t)os_start;
g_idletcb.cmn.flags = TCB_FLAG_TTYPE_KERNEL;
/* Set the IDLE task name */
#if CONFIG_TASK_NAME_SIZE > 0
strncpy(g_idletcb.cmn.name, g_idlename, CONFIG_TASK_NAME_SIZE);
g_idletcb.cmn.name[CONFIG_TASK_NAME_SIZE] = '\0';
#endif /* CONFIG_TASK_NAME_SIZE */
/* Configure the task name in the argument list. The IDLE task does
* not really have an argument list, but this name is still useful
* for things like the NSH PS command.
*
* In the kernel mode build, the arguments are saved on the task's stack
* and there is no support that yet.
*/
#if CONFIG_TASK_NAME_SIZE > 0
g_idleargv[0] = g_idletcb.cmn.name;
#else
g_idleargv[0] = (FAR char *)g_idlename;
#endif /* CONFIG_TASK_NAME_SIZE */
g_idleargv[1] = NULL;
g_idletcb.argv = g_idleargv;
/* 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 */
up_initial_state(&g_idletcb.cmn);
/* Initialize RTOS facilities *********************************************/
/* Initialize the semaphore facility. This has to be done very early
* because many subsystems depend upon fully functional semaphores.
*/
sem_initialize();
#if defined(MM_KERNEL_USRHEAP_INIT) || defined(CONFIG_MM_KERNEL_HEAP) || defined(CONFIG_MM_PGALLOC)
/* Initialize the memory manager */
{
FAR void *heap_start;
size_t heap_size;
#ifdef MM_KERNEL_USRHEAP_INIT
/* Get the user-mode heap from the platform specific code and configure
* the user-mode memory allocator.
*/
up_allocate_heap(&heap_start, &heap_size);
kumm_initialize(heap_start, heap_size);
#endif
#ifdef CONFIG_MM_KERNEL_HEAP
/* Get the kernel-mode heap from the platform specific code and configure
* the kernel-mode memory allocator.
*/
up_allocate_kheap(&heap_start, &heap_size);
kmm_initialize(heap_start, heap_size);
#endif
#ifdef CONFIG_MM_PGALLOC
/* If there is a page allocator in the configuration, then get the page
* heap information from the platform-specific code and configure the
* page allocator.
*/
up_allocate_pgheap(&heap_start, &heap_size);
mm_pginitialize(heap_start, heap_size);
#endif
}
#endif
#if defined(CONFIG_SCHED_HAVE_PARENT) && defined(CONFIG_SCHED_CHILD_STATUS)
/* Initialize tasking data structures */
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (task_initialize != NULL)
#endif
{
task_initialize();
}
#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) */
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (clock_initialize != NULL)
#endif
{
clock_initialize();
}
#ifndef CONFIG_DISABLE_POSIX_TIMERS
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (timer_initialize != NULL)
#endif
{
timer_initialize();
}
#endif
#ifndef CONFIG_DISABLE_SIGNALS
/* Initialize the signal facility (if in link) */
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (sig_initialize != NULL)
#endif
{
sig_initialize();
}
#endif
#ifndef CONFIG_DISABLE_MQUEUE
/* Initialize the named message queue facility (if in link) */
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (mq_initialize != NULL)
#endif
{
mq_initialize();
}
#endif
#ifndef CONFIG_DISABLE_PTHREAD
/* Initialize the thread-specific data facility (if in link) */
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (pthread_initialize != NULL)
#endif
{
pthread_initialize();
}
#endif
#if CONFIG_NFILE_DESCRIPTORS > 0
/* Initialize the file system (needed to support device drivers) */
fs_initialize();
#endif
#ifdef CONFIG_NET
/* Initialize the networking system. Network initialization is
* performed in two steps: (1) net_setup() initializes static
* configuration of the network support. This must be done prior
* to registering network drivers by up_initialize(). This step
* cannot require upon any hardware-depending features such as
* timers or interrupts.
*/
net_setup();
#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();
#ifdef CONFIG_NET
/* Complete initialization the networking system now that interrupts
* and timers have been configured by up_initialize().
*/
net_initialize();
#endif
#ifdef CONFIG_MM_SHM
/* Initialize shared memory support */
shm_initialize();
#endif
/* Initialize the C libraries. This is done last because the libraries
* may depend on the above.
*/
lib_initialize();
/* IDLE Group Initialization **********************************************/
#ifdef HAVE_TASK_GROUP
/* Allocate the IDLE group */
DEBUGVERIFY(group_allocate(&g_idletcb, g_idletcb.cmn.flags));
#endif
#if CONFIG_NFILE_DESCRIPTORS > 0 || CONFIG_NSOCKET_DESCRIPTORS > 0
/* Create stdout, stderr, stdin on the IDLE task. These will be
* inherited by all of the threads created by the IDLE task.
*/
DEBUGVERIFY(group_setupidlefiles(&g_idletcb));
#endif
#ifdef HAVE_TASK_GROUP
/* Complete initialization of the IDLE group. Suppress retention
* of child status in the IDLE group.
*/
DEBUGVERIFY(group_initialize(&g_idletcb));
g_idletcb.cmn.group->tg_flags = GROUP_FLAG_NOCLDWAIT;
#endif
/* Bring Up the System ****************************************************/
/* Create initial tasks and bring-up the system */
DEBUGVERIFY(os_bringup());
/* The IDLE Loop **********************************************************/
/* 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!
*
* WARNING: This logic could have undesirable side-effects if priority
* inheritance is enabled. Imaginee the possible issues if the
* priority of the IDLE thread were to get boosted! Moral: If you
* use priority inheritance, then you should also enable the work
* queue so that is done in a safer context.
*/
if (kmm_trysemaphore() == 0)
{
sched_garbagecollection();
kmm_givesemaphore();
}
#endif
/* Perform any processor-specific idle state operations */
up_idle();
}
}