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/*

 *  linux/init/main.c

 *

 *  Copyright (C) 1991, 1992  Linus Torvalds

 *

 *  GK 2/5/95  -  Changed to support mounting root fs via NFS

 *  Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96

 *  Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96

 *  Simplified starting of init:  Michael A. Griffith <grif@acm.org>

 */

#define __KERNEL_SYSCALLS__

#include <linux/config.h>

#include <linux/proc_fs.h>

#include <linux/devfs_fs_kernel.h>

#include <linux/unistd.h>

#include <linux/string.h>

#include <linux/ctype.h>

#include <linux/delay.h>

#include <linux/utsname.h>

#include <linux/ioport.h>

#include <linux/init.h>

#include <linux/smp_lock.h>

#include <linux/blk.h>

#include <linux/hdreg.h>

#include <linux/iobuf.h>

#include <linux/bootmem.h>

#include <linux/file.h>

#include <linux/tty.h>

#include <asm/io.h>

#include <asm/bugs.h>

#if defined(CONFIG_ARCH_S390)

#include <asm/s390mach.h>

#include <asm/ccwcache.h>

#endif

#ifdef CONFIG_ACPI

#include <linux/acpi.h>

#endif

#ifdef CONFIG_PCI

#include <linux/pci.h>

#endif

#ifdef CONFIG_DIO

#include <linux/dio.h>

#endif

#ifdef CONFIG_ZORRO

#include <linux/zorro.h>

#endif

#ifdef CONFIG_MTRR

#  include <asm/mtrr.h>

#endif

#ifdef CONFIG_NUBUS

#include <linux/nubus.h>

#endif

#ifdef CONFIG_ISAPNP

#include <linux/isapnp.h>

#endif

#ifdef CONFIG_IRDA

extern int irda_proto_init(void);

extern int irda_device_init(void);

#endif

#ifdef CONFIG_X86_LOCAL_APIC

#include <asm/smp.h>

#endif

/*

 * Versions of gcc older than that listed below may actually compile

 * and link okay, but the end product can have subtle run time bugs.

 * To avoid associated bogus bug reports, we flatly refuse to compile

 * with a gcc that is known to be too old from the very beginning.

 */

#if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 91)

#error Sorry, your GCC is too old. It builds incorrect kernels.

#endif

extern char _stext, _etext;

extern char *linux_banner;

static int init(void *);

extern void init_IRQ(void);

extern void init_modules(void);

extern void sock_init(void);

extern void fork_init(unsigned long);

extern void mca_init(void);

extern void sbus_init(void);

extern void ppc_init(void);

extern void sysctl_init(void);

extern void signals_init(void);

extern int init_pcmcia_ds(void);

extern void free_initmem(void);

#ifdef CONFIG_TC

extern void tc_init(void);

#endif

extern void ecard_init(void);

#if defined(CONFIG_SYSVIPC)

extern void ipc_init(void);

#endif

/*

 * Boot command-line arguments

 */

#define MAX_INIT_ARGS 8

#define MAX_INIT_ENVS 8

extern void time_init(void);

extern void softirq_init(void);

int rows, cols;

char *execute_command;

static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };

char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };

static int __init profile_setup(char *str)

{

    int par;

    if (get_option(&str,&par)) prof_shift = par;

        return 1;

}

__setup("profile=", profile_setup);

static int __init checksetup(char *line)

{

        struct kernel_param *p;

        p = &__setup_start;

        do {

                int n = strlen(p->str);

                if (!strncmp(line,p->str,n)) {

                        if (p->setup_func(line+n))

                                return 1;

                }

                p++;

        } while (p < &__setup_end);

        return 0;

}

/* this should be approx 2 Bo*oMips to start (note initial shift), and will

   still work even if initially too large, it will just take slightly longer */

unsigned long loops_per_jiffy = (1<<12);

/* This is the number of bits of precision for the loops_per_jiffy.  Each

   bit takes on average 1.5/HZ seconds.  This (like the original) is a little

   better than 1% */

#define LPS_PREC 8

void __init calibrate_delay(void)

{

        unsigned long ticks, loopbit;

        int lps_precision = LPS_PREC;

        loops_per_jiffy = (1<<12);

        printk("Calibrating delay loop... ");

        while (loops_per_jiffy <<= 1) {

                /* wait for "start of" clock tick */

                ticks = jiffies;

                while (ticks == jiffies)

                        /* nothing */;

                /* Go .. */

                ticks = jiffies;

                __delay(loops_per_jiffy);

                ticks = jiffies - ticks;

                if (ticks)

                        break;

        }

/* Do a binary approximation to get loops_per_jiffy set to equal one clock

   (up to lps_precision bits) */

        loops_per_jiffy >>= 1;

        loopbit = loops_per_jiffy;

        while ( lps_precision-- && (loopbit >>= 1) ) {

                loops_per_jiffy |= loopbit;

                ticks = jiffies;

                while (ticks == jiffies);

                ticks = jiffies;

                __delay(loops_per_jiffy);

                if (jiffies != ticks)   /* longer than 1 tick */

                        loops_per_jiffy &= ~loopbit;

        }

/* Round the value and print it */

        printk("%lu.%02lu BogoMIPS\n",

                loops_per_jiffy/(500000/HZ),

                (loops_per_jiffy/(5000/HZ)) % 100);

}

static int __init debug_kernel(char *str)

{

        if (*str)

                return 0;

        console_loglevel = 10;

        return 1;

}

static int __init quiet_kernel(char *str)

{

        if (*str)

                return 0;

        console_loglevel = 4;

        return 1;

}

__setup("debug", debug_kernel);

__setup("quiet", quiet_kernel);

/*

 * This is a simple kernel command line parsing function: it parses

 * the command line, and fills in the arguments/environment to init

 * as appropriate. Any cmd-line option is taken to be an environment

 * variable if it contains the character '='.

 *

 * This routine also checks for options meant for the kernel.

 * These options are not given to init - they are for internal kernel use only.

 */

static void __init parse_options(char *line)

{

        char *next,*quote;

        int args, envs;

        if (!*line)

                return;

        args = 0;

        envs = 1;       /* TERM is set to 'linux' by default */

        next = line;

        while ((line = next) != NULL) {

                quote = strchr(line,'"');

                next = strchr(line, ' ');

                while (next != NULL && quote != NULL && quote < next) {

                        /* we found a left quote before the next blank

                         * now we have to find the matching right quote

                         */

                        next = strchr(quote+1, '"');

                        if (next != NULL) {

                                quote = strchr(next+1, '"');

                                next = strchr(next+1, ' ');

                        }

                }

                if (next != NULL)

                        *next++ = 0;

                if (!strncmp(line,"init=",5)) {

                        line += 5;

                        execute_command = line;

                        /* In case LILO is going to boot us with default command line,

                         * it prepends "auto" before the whole cmdline which makes

                         * the shell think it should execute a script with such name.

                         * So we ignore all arguments entered _before_ init=... [MJ]

                         */

                        args = 0;

                        continue;

                }

                if (checksetup(line))

                        continue;

                /*

                 * Then check if it's an environment variable or

                 * an option.

                 */

                if (strchr(line,'=')) {

                        if (envs >= MAX_INIT_ENVS)

                                break;

                        envp_init[++envs] = line;

                } else {

                        if (args >= MAX_INIT_ARGS)

                                break;

                        if (*line)

                                argv_init[++args] = line;

                }

        }

        argv_init[args+1] = NULL;

        envp_init[envs+1] = NULL;

}

extern void setup_arch(char **);

extern void cpu_idle(void);

unsigned long wait_init_idle;

#ifndef CONFIG_SMP

#ifdef CONFIG_X86_LOCAL_APIC

static void __init smp_init(void)

{

        APIC_init_uniprocessor();

}

#else

#define smp_init()      do { } while (0)

#endif

#else

/* Called by boot processor to activate the rest. */

static void __init smp_init(void)

{

        /* Get other processors into their bootup holding patterns. */

        smp_boot_cpus();

        wait_init_idle = cpu_online_map;

        clear_bit(current->processor, &wait_init_idle); /* Don't wait on me! */

        smp_threads_ready=1;

        smp_commence();

        /* Wait for the other cpus to set up their idle processes */

        printk("Waiting on wait_init_idle (map = 0x%lx)\n", wait_init_idle);

        while (wait_init_idle) {

                cpu_relax();

                barrier();

        }

        printk("All processors have done init_idle\n");

}

#endif

/*

 * We need to finalize in a non-__init function or else race conditions

 * between the root thread and the init thread may cause start_kernel to

 * be reaped by free_initmem before the root thread has proceeded to

 * cpu_idle.

 */

static void rest_init(void)

{

        kernel_thread(init, NULL, CLONE_FS | CLONE_FILES | CLONE_SIGNAL);

        unlock_kernel();

        current->need_resched = 1;

        cpu_idle();

}

/*

 *      Activate the first processor.

 */

asmlinkage void __init start_kernel(void)

{

        char * command_line;

        extern char saved_command_line[];

/*

 * Interrupts are still disabled. Do necessary setups, then

 * enable them

 */

        lock_kernel();

        printk(linux_banner);

        setup_arch(&command_line);

        printk("Kernel command line: %s\n", saved_command_line);

        parse_options(command_line);

        trap_init();

        init_IRQ();

        sched_init();

        softirq_init();

        time_init();

        /*

         * HACK ALERT! This is early. We're enabling the console before

         * we've done PCI setups etc, and console_init() must be aware of

         * this. But we do want output early, in case something goes wrong.

         */

        console_init();

#ifdef CONFIG_MODULES

        init_modules();

#endif

        if (prof_shift) {

                unsigned int size;

                /* only text is profiled */

                prof_len = (unsigned long) &_etext - (unsigned long) &_stext;

                prof_len >>= prof_shift;

                size = prof_len * sizeof(unsigned int) + PAGE_SIZE-1;

                prof_buffer = (unsigned int *) alloc_bootmem(size);

        }

        kmem_cache_init();

        sti();

        calibrate_delay();

#ifdef CONFIG_BLK_DEV_INITRD

        if (initrd_start && !initrd_below_start_ok &&

                        initrd_start < min_low_pfn << PAGE_SHIFT) {

                printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "

                    "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);

                initrd_start = 0;

        }

#endif

        mem_init();

        kmem_cache_sizes_init();

        pgtable_cache_init();

        /*

         * For architectures that have highmem, num_mappedpages represents

         * the amount of memory the kernel can use.  For other architectures

         * it's the same as the total pages.  We need both numbers because

         * some subsystems need to initialize based on how much memory the

         * kernel can use.

         */

        if (num_mappedpages == 0)

                num_mappedpages = num_physpages;

        fork_init(num_mappedpages);

        proc_caches_init();

        vfs_caches_init(num_physpages);

        buffer_init(num_physpages);

        page_cache_init(num_physpages);

#if defined(CONFIG_ARCH_S390)

        ccwcache_init();

#endif

        signals_init();

#ifdef CONFIG_PROC_FS

        proc_root_init();

#endif

        check_bugs();

        printk("POSIX conformance testing by UNIFIX\n");

        /*

         *      We count on the initial thread going ok

         *      Like idlers init is an unlocked kernel thread, which will

         *      make syscalls (and thus be locked).

         */

        smp_init();

#if defined(CONFIG_SYSVIPC)

        ipc_init();

#endif

        rest_init();

}

struct task_struct *child_reaper = &init_task;

static void __init do_initcalls(void)

{

        initcall_t *call;

        call = &__initcall_start;

        do {

                (*call)();

                call++;

        } while (call < &__initcall_end);

        /* Make sure there is no pending stuff from the initcall sequence */

        flush_scheduled_tasks();

}

/*

 * Ok, the machine is now initialized. None of the devices

 * have been touched yet, but the CPU subsystem is up and

 * running, and memory and process management works.

 *

 * Now we can finally start doing some real work..

 */

static void __init do_basic_setup(void)

{

        /*

         * Tell the world that we're going to be the grim

         * reaper of innocent orphaned children.

         *

         * We don't want people to have to make incorrect

         * assumptions about where in the task array this

         * can be found.

         */

        child_reaper = current;

#if defined(CONFIG_MTRR)        /* Do this after SMP initialization */

/*

 * We should probably create some architecture-dependent "fixup after

 * everything is up" style function where this would belong better

 * than in init/main.c..

 */

        mtrr_init();

#endif

#ifdef CONFIG_SYSCTL

        sysctl_init();

#endif

        /*

         * Ok, at this point all CPU's should be initialized, so

         * we can start looking into devices..

         */

#if defined(CONFIG_ARCH_S390)

        s390_init_machine_check();

#endif

#ifdef CONFIG_ACPI_INTERPRETER

        acpi_init();

#endif

#ifdef CONFIG_PCI

        pci_init();

#endif

#ifdef CONFIG_SBUS

        sbus_init();

#endif

#if defined(CONFIG_PPC)

        ppc_init();

#endif

#ifdef CONFIG_MCA

        mca_init();

#endif

#ifdef CONFIG_ARCH_ACORN

        ecard_init();

#endif

#ifdef CONFIG_ZORRO

        zorro_init();

#endif

#ifdef CONFIG_DIO

        dio_init();

#endif

#ifdef CONFIG_NUBUS

        nubus_init();

#endif

#ifdef CONFIG_ISAPNP

        isapnp_init();

#endif

#ifdef CONFIG_TC

        tc_init();

#endif

        /* Networking initialization needs a process context */

        sock_init();

        start_context_thread();

        do_initcalls();

#ifdef CONFIG_IRDA

        irda_proto_init();

        irda_device_init(); /* Must be done after protocol initialization */

#endif

#ifdef CONFIG_PCMCIA

        init_pcmcia_ds();               /* Do this last */

#endif

}

static void run_init_process(char *init_filename)

{

        argv_init[0] = init_filename;

        execve(init_filename, argv_init, envp_init);

}

extern void prepare_namespace(void);

static int init(void * unused)

{

        struct files_struct *files;

        lock_kernel();

        do_basic_setup();

        prepare_namespace();

        /*

         * Ok, we have completed the initial bootup, and

         * we're essentially up and running. Get rid of the

         * initmem segments and start the user-mode stuff..

         */

        free_initmem();

        unlock_kernel();

        /*

         * Right now we are a thread sharing with a ton of kernel

         * stuff. We don't want to end up in user space in that state

         */

        files = current->files;

        if(unshare_files())

                panic("unshare");

        put_files_struct(files);

        if (open("/dev/console", O_RDWR, 0) < 0)

                printk("Warning: unable to open an initial console.\n");

        (void) dup(0);

        (void) dup(0);

        /*

         * We try each of these until one succeeds.

         *

         * The Bourne shell can be used instead of init if we are

         * trying to recover a really broken machine.

         */

        if (execute_command)

                run_init_process(execute_command);

        run_init_process("/sbin/init");

        run_init_process("/etc/init");

        run_init_process("/bin/init");

        run_init_process("/bin/sh");

        panic("No init found.  Try passing init= option to kernel.");

}