/**************************************************************************** * sched/init/os_start.c * * Copyright (C) 2007-2014 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "sched/sched.h" #include "signal/signal.h" #include "wdog/wdog.h" #include "semaphore/semaphore.h" #ifndef CONFIG_DISABLE_MQUEUE # include "mqueue/mqueue.h" #endif #ifndef CONFIG_DISABLE_PTHREAD # include "pthread/pthread.h" #endif #include "clock/clock.h" #include "timer/timer.h" #include "irq/irq.h" #ifdef HAVE_TASK_GROUP #include "group/group.h" #endif #include "init/init.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; /* These are lists of dayed memory deallocations that need to be handled * within the IDLE loop or worker thread. These deallocations get queued * by sched_kufree and sched_kfree() if the OS needs to deallocate memory * while it is within an interrupt handler. */ volatile sq_queue_t g_delayed_kufree; #if (defined(CONFIG_BUILD_PROTECTED) || defined(CONFIG_BUILD_KERNEL)) && \ defined(CONFIG_MM_KERNEL_HEAP) volatile sq_queue_t g_delayed_kfree; #endif /* 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. */ struct pidhash_s 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 struct tasklist_s 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 and that user * initialization task is responsible for bringing up the rest of the system. */ static FAR struct task_tcb_s g_idletcb; /* This is the name of the idle task */ static FAR const char g_idlename[] = "Idle Task"; /* This the IDLE idle threads argument list. */ static FAR char *g_idleargv[2]; /**************************************************************************** * Private Function Prototypes ****************************************************************************/ /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: os_start * * Description: * This function is called to initialize the operating system and to spawn * the user initialization thread of execution. This is the initial entry * point into NuttX * * Input Parameters: * None * * Returned value: * Does not return. * ****************************************************************************/ 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(); } }