source: mainline/kernel/generic/src/main/main.c@ 7329e6a

/*
 * Copyright (c) 2001-2004 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/** @addtogroup main
 * @{
 */

/**
 * @file
 * @brief Main initialization kernel function for all processors.
 *
 * During kernel boot, all processors, after architecture dependent
 * initialization, start executing code found in this file. After
 * bringing up all subsystems, control is passed to scheduler().
 *
 * The bootstrap processor starts executing main_bsp() while
 * the application processors start executing main_ap().
 *
 * @see scheduler()
 * @see main_bsp()
 * @see main_ap()
 */

#include <arch/asm.h>
#include <context.h>
#include <print.h>
#include <panic.h>
#include <debug.h>
#include <config.h>
#include <time/clock.h>
#include <time/timeout.h>
#include <proc/scheduler.h>
#include <proc/thread.h>
#include <proc/task.h>
#include <proc/tasklet.h>
#include <main/kinit.h>
#include <main/version.h>
#include <console/kconsole.h>
#include <console/console.h>
#include <cpu.h>
#include <align.h>
#include <interrupt.h>
#include <mm/frame.h>
#include <mm/page.h>
#include <genarch/mm/page_pt.h>
#include <mm/tlb.h>
#include <mm/as.h>
#include <mm/slab.h>
#include <synch/waitq.h>
#include <synch/futex.h>
#include <arch/arch.h>
#include <arch.h>
#include <arch/faddr.h>
#include <ipc/ipc.h>
#include <macros.h>
#include <adt/btree.h>
#include <smp/smp.h>
#include <ddi/ddi.h>
#include <main/main.h>
#include <ipc/event.h>
#include <sysinfo/sysinfo.h>
#include <sysinfo/stats.h>

/** Global configuration structure. */
config_t config;

/** Initial user-space tasks */
init_t init = {
        .cnt = 0
};

/** Boot allocations. */
ballocs_t ballocs = {
        .base = (uintptr_t) NULL,
        .size = 0
};

context_t ctx;

/** Lowest safe stack virtual address. */
uintptr_t stack_safe = 0;

/*
 * These two functions prevent stack from underflowing during the
 * kernel boot phase when SP is set to the very top of the reserved
 * space. The stack could get corrupted by a fooled compiler-generated
 * pop sequence otherwise.
 */
static void main_bsp_separated_stack(void);

#ifdef CONFIG_SMP
static void main_ap_separated_stack(void);
#endif

#define CONFIG_STACK_SIZE  ((1 << STACK_FRAMES) * STACK_SIZE)

/** Main kernel routine for bootstrap CPU.
 *
 * The code here still runs on the boot stack, which knows nothing about
 * preemption counts.  Because of that, this function cannot directly call
 * functions that disable or enable preemption (e.g. spinlock_lock()). The
 * primary task of this function is to calculate address of a new stack and
 * switch to it.
 *
 * Assuming interrupts_disable().
 *
 */
NO_TRACE void main_bsp(void)
{
        config.cpu_count = 1;
        config.cpu_active = 1;
        
        config.base = hardcoded_load_address;
        config.kernel_size = ALIGN_UP(hardcoded_ktext_size +
            hardcoded_kdata_size, PAGE_SIZE);
        config.stack_size = CONFIG_STACK_SIZE;
        
        /* Initialy the stack is placed just after the kernel */
        config.stack_base = config.base + config.kernel_size;
        
        /* Avoid placing stack on top of init */
        size_t i;
        for (i = 0; i < init.cnt; i++) {
                if (PA_OVERLAPS(config.stack_base, config.stack_size,
                    init.tasks[i].addr, init.tasks[i].size))
                        config.stack_base = ALIGN_UP(init.tasks[i].addr +
                            init.tasks[i].size, config.stack_size);
        }
        
        /* Avoid placing stack on top of boot allocations. */
        if (ballocs.size) {
                if (PA_OVERLAPS(config.stack_base, config.stack_size,
                    ballocs.base, ballocs.size))
                        config.stack_base = ALIGN_UP(ballocs.base +
                            ballocs.size, PAGE_SIZE);
        }
        
        if (config.stack_base < stack_safe)
                config.stack_base = ALIGN_UP(stack_safe, PAGE_SIZE);
        
        context_save(&ctx);
        context_set(&ctx, FADDR(main_bsp_separated_stack), config.stack_base,
            THREAD_STACK_SIZE);
        context_restore(&ctx);
        /* not reached */
}

/** Main kernel routine for bootstrap CPU using new stack.
 *
 * Second part of main_bsp().
 *
 */
void main_bsp_separated_stack(void)
{
        /* Keep this the first thing. */
        the_initialize(THE);
        
        version_print();
        
        LOG("\nconfig.base=%p config.kernel_size=%zu"
            "\nconfig.stack_base=%p config.stack_size=%zu",
            config.base, config.kernel_size, config.stack_base,
            config.stack_size);
        
#ifdef CONFIG_KCONSOLE
        /*
         * kconsole data structures must be initialized very early
         * because other subsystems will register their respective
         * commands.
         */
        kconsole_init();
#endif
        
        /*
         * Exception handler initialization, before architecture
         * starts adding its own handlers
         */
        exc_init();
        
        /*
         * Memory management subsystems initialization.
         */
        arch_pre_mm_init();
        frame_init();
        
        /* Initialize at least 1 memory segment big enough for slab to work. */
        slab_cache_init();
        sysinfo_init();
        btree_init();
        as_init();
        page_init();
        tlb_init();
        ddi_init();
        tasklet_init();
        arch_post_mm_init();
        arch_pre_smp_init();
        smp_init();
        
        /* Slab must be initialized after we know the number of processors. */
        slab_enable_cpucache();
        
        printf("Detected %u CPU(s), %" PRIu64 " MiB free memory\n",
            config.cpu_count, SIZE2MB(zones_total_size()));
        
        cpu_init();
        
        calibrate_delay_loop();
        clock_counter_init();
        timeout_init();
        scheduler_init();
        task_init();
        thread_init();
        futex_init();
        
        if (init.cnt > 0) {
                size_t i;
                for (i = 0; i < init.cnt; i++)
                        LOG("init[%zu].addr=%p, init[%zu].size=%zu",
                            i, init.tasks[i].addr, i, init.tasks[i].size);
        } else
                printf("No init binaries found.\n");
        
        ipc_init();
        event_init();
        klog_init();
        stats_init();
        
        /*
         * Create kernel task.
         */
        task_t *kernel = task_create(AS_KERNEL, "kernel");
        if (!kernel)
                panic("Cannot create kernel task.");
        
        /*
         * Create the first thread.
         */
        thread_t *kinit_thread
                = thread_create(kinit, NULL, kernel, 0, "kinit", true);
        if (!kinit_thread)
                panic("Cannot create kinit thread.");
        thread_ready(kinit_thread);
        
        /*
         * This call to scheduler() will return to kinit,
         * starting the thread of kernel threads.
         */
        scheduler();
        /* not reached */
}

#ifdef CONFIG_SMP

/** Main kernel routine for application CPUs.
 *
 * Executed by application processors, temporary stack
 * is at ctx.sp which was set during BSP boot.
 * This function passes control directly to
 * main_ap_separated_stack().
 *
 * Assuming interrupts_disable()'d.
 *
 */
void main_ap(void)
{
        /*
         * Incrementing the active CPU counter will guarantee that the
         * *_init() functions can find out that they need to
         * do initialization for AP only.
         */
        config.cpu_active++;
        
        /*
         * The THE structure is well defined because ctx.sp is used as stack.
         */
        the_initialize(THE);
        
        arch_pre_mm_init();
        frame_init();
        page_init();
        tlb_init();
        arch_post_mm_init();
        
        cpu_init();
        calibrate_delay_loop();
        arch_post_cpu_init();
        
        the_copy(THE, (the_t *) CPU->stack);
        
        /*
         * If we woke kmp up before we left the kernel stack, we could
         * collide with another CPU coming up. To prevent this, we
         * switch to this cpu's private stack prior to waking kmp up.
         */
        context_save(&CPU->saved_context);
        context_set(&CPU->saved_context, FADDR(main_ap_separated_stack),
            (uintptr_t) CPU->stack, CPU_STACK_SIZE);
        context_restore(&CPU->saved_context);
        /* not reached */
}

/** Main kernel routine for application CPUs using new stack.
 *
 * Second part of main_ap().
 *
 */
void main_ap_separated_stack(void)
{
        /*
         * Configure timeouts for this cpu.
         */
        timeout_init();
        
        waitq_wakeup(&ap_completion_wq, WAKEUP_FIRST);
        scheduler();
        /* not reached */
}

#endif /* CONFIG_SMP */

/** @}
 */