path: root/init/main.c

/*
 *  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/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 <asm/io.h>
#include <asm/bugs.h>

#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_APM
#include <linux/apm_bios.h>
#endif

#ifdef CONFIG_MAC
extern void nubus_init(void);
#endif

#ifdef CONFIG_ISAPNP
#include <linux/isapnp.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__ < 6)
#error sorry, your GCC is too old. It builds incorrect kernels.
#endif

extern char _stext, _etext;
extern char *linux_banner;

extern int console_loglevel;

static int init(void *);

extern void init_IRQ(void);
extern void init_modules(void);
extern long console_init(long, long);
extern void init_inventory(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 filescache_init(void);
extern void signals_init(void);
extern int init_pcmcia_ds(void);

extern void free_initmem(void);
extern void filesystem_setup(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
#if defined(CONFIG_QUOTA)
extern void dquot_init_hash(void);
#endif

#ifdef CONFIG_REMOTE_DEBUG
#include <asm/gdb-stub.h>
#endif

/*
 * Boot command-line arguments
 */
#define MAX_INIT_ARGS 8
#define MAX_INIT_ENVS 8

extern void time_init(void);

static unsigned long memory_start = 0;
static unsigned long memory_end = 0;

int rows, cols;

#ifdef CONFIG_BLK_DEV_INITRD
kdev_t real_root_dev;
#endif

int root_mountflags = MS_RDONLY;
char *execute_command = NULL;

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

/*
 * Read an int from an option string; if available accept a subsequent
 * comma as well.
 *
 * Return values:
 * 0 : no int in string
 * 1 : int found, no subsequent comma
 * 2 : int found including a subsequent comma
 */
int get_option(char **str, int *pint)
{
    char *cur = *str;

    if (!cur || !(*cur)) return 0;
    *pint = simple_strtol(cur,str,0);
    if (cur==*str) return 0;
    if (**str==',') {
        (*str)++;
        return 2;
    }

    return 1;
}

char *get_options(char *str, int nints, int *ints)
{
	int res,i=1;

    while (i<nints) {
        res = get_option(&str, ints+i);
        if (res==0) break;
        i++;
        if (res==1) break;
    }
	ints[0] = i-1;
	return(str);
}

static int __init profile_setup(char *str)
{
    int par;
    if (get_option(&str,&par)) prof_shift = par;
	return 1;
}

__setup("profile=", profile_setup);


static struct dev_name_struct {
	const char *name;
	const int num;
} root_dev_names[] __initdata = {
	{ "nfs",     0x00ff },
	{ "hda",     0x0300 },
	{ "hdb",     0x0340 },
	{ "hdc",     0x1600 },
	{ "hdd",     0x1640 },
	{ "hde",     0x2100 },
	{ "hdf",     0x2140 },
	{ "hdg",     0x2200 },
	{ "hdh",     0x2240 },
	{ "hdi",     0x3800 },
	{ "hdj",     0x3840 },
	{ "hdk",     0x3900 },
	{ "hdl",     0x3940 },
	{ "hdm",     0x5800 },
	{ "hdn",     0x5840 },
	{ "hdo",     0x5900 },
	{ "hdp",     0x5940 },
	{ "hdq",     0x5A00 },
	{ "hdr",     0x5A40 },
	{ "hds",     0x5B00 },
	{ "hdt",     0x5B40 },
	{ "sda",     0x0800 },
	{ "sdb",     0x0810 },
	{ "sdc",     0x0820 },
	{ "sdd",     0x0830 },
	{ "sde",     0x0840 },
	{ "sdf",     0x0850 },
	{ "sdg",     0x0860 },
	{ "sdh",     0x0870 },
	{ "sdi",     0x0880 },
	{ "sdj",     0x0890 },
	{ "sdk",     0x08a0 },
	{ "sdl",     0x08b0 },
	{ "sdm",     0x08c0 },
	{ "sdn",     0x08d0 },
	{ "sdo",     0x08e0 },
	{ "sdp",     0x08f0 },
	{ "ada",     0x1c00 },
	{ "adb",     0x1c10 },
	{ "adc",     0x1c20 },
	{ "add",     0x1c30 },
	{ "ade",     0x1c40 },
	{ "fd",      0x0200 },
	{ "md",      0x0900 },	     
	{ "xda",     0x0d00 },
	{ "xdb",     0x0d40 },
	{ "ram",     0x0100 },
	{ "scd",     0x0b00 },
	{ "mcd",     0x1700 },
	{ "cdu535",  0x1800 },
	{ "sonycd",  0x1800 },
	{ "aztcd",   0x1d00 },
	{ "cm206cd", 0x2000 },
	{ "gscd",    0x1000 },
	{ "sbpcd",   0x1900 },
	{ "eda",     0x2400 },
	{ "edb",     0x2440 },
	{ "pda",	0x2d00 },
	{ "pdb",	0x2d10 },
	{ "pdc",	0x2d20 },
	{ "pdd",	0x2d30 },
	{ "pcd",	0x2e00 },
	{ "pf",		0x2f00 },
	{ "apblock", APBLOCK_MAJOR << 8},
	{ "ddv", DDV_MAJOR << 8},
	{ NULL, 0 }
};

kdev_t __init name_to_kdev_t(char *line)
{
	int base = 0;
	if (strncmp(line,"/dev/",5) == 0) {
		struct dev_name_struct *dev = root_dev_names;
		line += 5;
		do {
			int len = strlen(dev->name);
			if (strncmp(line,dev->name,len) == 0) {
				line += len;
				base = dev->num;
				break;
			}
			dev++;
		} while (dev->name);
	}
	return to_kdev_t(base + simple_strtoul(line,NULL,base?10:16));
}

static int __init root_dev_setup(char *line)
{
	ROOT_DEV = name_to_kdev_t(line);
	return 1;
}

__setup("root=", root_dev_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_sec = (1<<12);

/* This is the number of bits of precision for the loops_per_second.  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_sec = (1<<12);

	printk("Calibrating delay loop... ");
	while (loops_per_sec <<= 1) {
		/* wait for "start of" clock tick */
		ticks = jiffies;
		while (ticks == jiffies)
			/* nothing */;
		/* Go .. */
		ticks = jiffies;
		__delay(loops_per_sec);
		ticks = jiffies - ticks;
		if (ticks)
			break;
	}

/* Do a binary approximation to get loops_per_second set to equal one clock
   (up to lps_precision bits) */
	loops_per_sec >>= 1;
	loopbit = loops_per_sec;
	while ( lps_precision-- && (loopbit >>= 1) ) {
		loops_per_sec |= loopbit;
		ticks = jiffies;
		while (ticks == jiffies);
		ticks = jiffies;
		__delay(loops_per_sec);
		if (jiffies != ticks)	/* longer than 1 tick */
			loops_per_sec &= ~loopbit;
	}

/* finally, adjust loops per second in terms of seconds instead of clocks */	
	loops_per_sec *= HZ;
/* Round the value and print it */	
	printk("%lu.%02lu BogoMIPS\n",
		(loops_per_sec+2500)/500000,
		((loops_per_sec+2500)/5000) % 100);
}

static int __init readonly(char *str)
{
	if (*str)
		return 0;
	root_mountflags |= MS_RDONLY;
	return 1;
}

static int __init readwrite(char *str)
{
	if (*str)
		return 0;
	root_mountflags &= ~MS_RDONLY;
	return 1;
}

static int __init debug_kernel(char *str)
{
	if (*str)
		return 0;
	console_loglevel = 10;
	return 1;
}

__setup("ro", readonly);
__setup("rw", readwrite);
__setup("debug", debug_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;
	int args, envs;

	if (!*line)
		return;
	args = 0;
	envs = 1;	/* TERM is set to 'linux' by default */
	next = line;
	while ((line = next) != NULL) {
		if ((next = strchr(line,' ')) != 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;
			argv_init[++args] = line;
		}
	}
	argv_init[args+1] = NULL;
	envp_init[envs+1] = NULL;
}


extern void setup_arch(char **, unsigned long *, unsigned long *);
extern void cpu_idle(void);

#ifndef __SMP__

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

#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();
	smp_threads_ready=1;
	smp_commence();
}		

#endif

extern void initialize_secondary(void);

/*
 *	Activate the first processor.
 */
 
asmlinkage void __init start_kernel(void)
{
	char * command_line;

#ifdef __SMP__
	static int boot_cpu = 1;
	/* "current" has been set up, we need to load it now */
	if (!boot_cpu)
		initialize_secondary();
	boot_cpu = 0;
#endif

/*
 * Interrupts are still disabled. Do necessary setups, then
 * enable them
 */
	lock_kernel();
	printk(linux_banner);
	setup_arch(&command_line, &memory_start, &memory_end);
	memory_start = paging_init(memory_start,memory_end);
	trap_init();
	init_IRQ();
	sched_init();
	time_init();
	parse_options(command_line);

	/*
	 * 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.
	 */
	memory_start = console_init(memory_start,memory_end);
#ifdef CONFIG_MODULES
	init_modules();
#endif
	if (prof_shift) {
		prof_buffer = (unsigned int *) memory_start;
		/* only text is profiled */
		prof_len = (unsigned long) &_etext - (unsigned long) &_stext;
		prof_len >>= prof_shift;
		memory_start += prof_len * sizeof(unsigned int);
		memset(prof_buffer, 0, prof_len * sizeof(unsigned int));
	}

	memory_start = kmem_cache_init(memory_start, memory_end);
	sti();
	calibrate_delay();
#ifdef CONFIG_BLK_DEV_INITRD
	if (initrd_start && !initrd_below_start_ok && initrd_start < memory_start) {
		printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
		    "disabling it.\n",initrd_start,memory_start);
		initrd_start = 0;
	}
#endif
#ifdef CONFIG_BINFMT_IRIX
	init_inventory();
#endif
	mem_init(memory_start,memory_end);
	kmem_cache_sizes_init();
#ifdef CONFIG_PROC_FS
	proc_root_init();
#endif
	fork_init(memory_end-memory_start);
	filescache_init();
	dcache_init();
	vma_init();
	buffer_init(memory_end-memory_start);
	page_cache_init(memory_end-memory_start);
	kiobuf_init();
	signals_init();
	inode_init();
	file_table_init();
#if defined(CONFIG_SYSVIPC)
	ipc_init();
#endif
#if defined(CONFIG_QUOTA)
	dquot_init_hash();
#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();
	kernel_thread(init, NULL, CLONE_FS | CLONE_FILES | CLONE_SIGHAND);
	unlock_kernel();
	current->need_resched = 1;
 	cpu_idle();
}

#ifdef CONFIG_BLK_DEV_INITRD
static int do_linuxrc(void * shell)
{
	static char *argv[] = { "linuxrc", NULL, };

	close(0);close(1);close(2);
	setsid();
	(void) open("/dev/console",O_RDWR,0);
	(void) dup(0);
	(void) dup(0);
	return execve(shell, argv, envp_init);
}

static int __init no_initrd(char *s)
{
	mount_initrd = 0;
	return 1;
}

__setup("noinitrd", no_initrd);

#endif

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);
}

/*
 * 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)
{
#ifdef CONFIG_BLK_DEV_INITRD
	int real_root_mountflags;
#endif

	/*
	 * 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..
	 */
#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_MAC
	nubus_init();
#endif
#ifdef CONFIG_ISAPNP
	isapnp_init();
#endif
#ifdef CONFIG_TC
	tc_init();
#endif

	/* Networking initialization needs a process context */ 
	sock_init();

	do_initcalls();

#ifdef CONFIG_BLK_DEV_INITRD

	real_root_dev = ROOT_DEV;
	real_root_mountflags = root_mountflags;
	if (initrd_start && mount_initrd) root_mountflags &= ~MS_RDONLY;
	else mount_initrd =0;
#endif

	/* .. filesystems .. */
	filesystem_setup();

#ifdef CONFIG_IRDA
	irda_device_init(); /* Must be done after protocol initialization */
#endif
#ifdef CONFIG_PCMCIA
	init_pcmcia_ds();		/* Do this last */
#endif
	/* Mount the root filesystem.. */
	mount_root();

#ifdef CONFIG_BLK_DEV_INITRD
	root_mountflags = real_root_mountflags;
	if (mount_initrd && ROOT_DEV != real_root_dev
	    && MAJOR(ROOT_DEV) == RAMDISK_MAJOR && MINOR(ROOT_DEV) == 0) {
		int error;
		int i, pid;

		pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
		if (pid>0)
			while (pid != wait(&i));
		if (MAJOR(real_root_dev) != RAMDISK_MAJOR
		     || MINOR(real_root_dev) != 0) {
			error = change_root(real_root_dev,"/initrd");
			if (error)
				printk(KERN_ERR "Change root to /initrd: "
				    "error %d\n",error);
		}
	}
#endif
}

static int init(void * unused)
{
	lock_kernel();
	do_basic_setup();

	/*
	 * 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();

	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)
		execve(execute_command,argv_init,envp_init);
	execve("/sbin/init",argv_init,envp_init);
	execve("/etc/init",argv_init,envp_init);
	execve("/bin/init",argv_init,envp_init);
	execve("/bin/sh",argv_init,envp_init);
	panic("No init found.  Try passing init= option to kernel.");
}