usr/src/sys/kern/init_main.c

/*
 * Copyright (c) 1982, 1986, 1989, 1991, 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * %sccs.include.redist.c%
 *
 *      @(#)init_main.c 8.12 (Berkeley) %G%
 */

#include <sys/param.h>
#include <sys/filedesc.h>
#include <sys/errno.h>
#include <sys/exec.h>
#include <sys/kernel.h>
#include <sys/mount.h>
#include <sys/map.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/systm.h>
#include <sys/vnode.h>
#include <sys/conf.h>
#include <sys/buf.h>
#include <sys/clist.h>
#include <sys/device.h>
#include <sys/protosw.h>
#include <sys/reboot.h>
#include <sys/user.h>
#include <sys/syscallargs.h>


#include <machine/cpu.h>

#include <vm/vm.h>

#ifdef HPFPLIB
char    copyright[] =
"Copyright (c) 1982, 1986, 1989, 1991, 1993\n\tThe Regents of the University of California.\nCopyright (c) 1992 Hewlett-Packard Company\nCopyright (c) 1992 Motorola Inc.\nAll rights reserved.\n\n";
#else
char    copyright[] =
"Copyright (c) 1982, 1986, 1989, 1991, 1993\n\tThe Regents of the University of California.  All rights reserved.\n\n";
#endif

/* Components of the first process -- never freed. */
struct  session session0;
struct  pgrp pgrp0;
struct  proc proc0;
struct  pcred cred0;
struct  filedesc0 filedesc0;
struct  plimit limit0;
struct  vmspace vmspace0;
struct  proc *curproc = &proc0;
struct  proc *initproc, *pageproc;

int     cmask = CMASK;
extern  struct user *proc0paddr;

struct  vnode *rootvp, *swapdev_vp;
int     boothowto;
struct  timeval boottime;
struct  timeval runtime;

static void start_init __P((struct proc *p, void *framep));

/*
 * System startup; initialize the world, create process 0, mount root
 * filesystem, and fork to create init and pagedaemon.  Most of the
 * hard work is done in the lower-level initialization routines including
 * startup(), which does memory initialization and autoconfiguration.
 */
main(framep)
        void *framep;
{
        register struct proc *p;
        register struct filedesc0 *fdp;
        register struct pdevinit *pdev;
        register int i;
        int s;
        register_t rval[2];
        extern int (*mountroot) __P((void));
        extern struct pdevinit pdevinit[];
        extern void roundrobin __P((void *));
        extern void schedcpu __P((void *));

        /*
         * Initialize the current process pointer (curproc) before
         * any possible traps/probes to simplify trap processing.
         */
        p = &proc0;
        curproc = p;
        /*
         * Attempt to find console and initialize
         * in case of early panic or other messages.
         */
        consinit();
        printf(copyright);

        vm_mem_init();
        kmeminit();
        cpu_startup();

        /*
         * Initialize process and pgrp structures.
         */
        procinit();

        /*
         * Create process 0 (the swapper).
         */
        LIST_INSERT_HEAD(&allproc, p, p_list);
        p->p_pgrp = &pgrp0;
        LIST_INSERT_HEAD(PGRPHASH(0), &pgrp0, pg_hash);
        LIST_INIT(&pgrp0.pg_members);
        LIST_INSERT_HEAD(&pgrp0.pg_members, p, p_pglist);

        pgrp0.pg_session = &session0;
        session0.s_count = 1;
        session0.s_leader = p;

        p->p_flag = P_INMEM | P_SYSTEM;
        p->p_stat = SRUN;
        p->p_nice = NZERO;
        bcopy("swapper", p->p_comm, sizeof ("swapper"));

        /* Create credentials. */
        cred0.p_refcnt = 1;
        p->p_cred = &cred0;
        p->p_ucred = crget();
        p->p_ucred->cr_ngroups = 1;     /* group 0 */

        /* Create the file descriptor table. */
        fdp = &filedesc0;
        p->p_fd = &fdp->fd_fd;
        fdp->fd_fd.fd_refcnt = 1;
        fdp->fd_fd.fd_cmask = cmask;
        fdp->fd_fd.fd_ofiles = fdp->fd_dfiles;
        fdp->fd_fd.fd_ofileflags = fdp->fd_dfileflags;
        fdp->fd_fd.fd_nfiles = NDFILE;

        /* Create the limits structures. */
        p->p_limit = &limit0;
        for (i = 0; i < sizeof(p->p_rlimit)/sizeof(p->p_rlimit[0]); i++)
                limit0.pl_rlimit[i].rlim_cur =
                    limit0.pl_rlimit[i].rlim_max = RLIM_INFINITY;
        limit0.pl_rlimit[RLIMIT_NOFILE].rlim_cur = NOFILE;
        limit0.pl_rlimit[RLIMIT_NPROC].rlim_cur = MAXUPRC;
        i = ptoa(cnt.v_free_count);
        limit0.pl_rlimit[RLIMIT_RSS].rlim_max = i;
        limit0.pl_rlimit[RLIMIT_MEMLOCK].rlim_max = i;
        limit0.pl_rlimit[RLIMIT_MEMLOCK].rlim_cur = i / 3;
        limit0.p_refcnt = 1;

        /* Allocate a prototype map so we have something to fork. */
        p->p_vmspace = &vmspace0;
        vmspace0.vm_refcnt = 1;
        pmap_pinit(&vmspace0.vm_pmap);
        vm_map_init(&p->p_vmspace->vm_map, round_page(VM_MIN_ADDRESS),
            trunc_page(VM_MAX_ADDRESS), TRUE);
        vmspace0.vm_map.pmap = &vmspace0.vm_pmap;
        p->p_addr = proc0paddr;                         /* XXX */

        /*
         * We continue to place resource usage info and signal
         * actions in the user struct so they're pageable.
         */
        p->p_stats = &p->p_addr->u_stats;
        p->p_sigacts = &p->p_addr->u_sigacts;

        /*
         * Charge root for one process.
         */
        (void)chgproccnt(0, 1);

        rqinit();

        /* Configure virtual memory system, set vm rlimits. */
        vm_init_limits(p);

        /* Initialize the file systems. */
        vfsinit();

        /* Start real time and statistics clocks. */
        initclocks();

        /* Initialize mbuf's. */
        mbinit();

        /* Initialize clists. */
        clist_init();

#ifdef SYSVSHM
        /* Initialize System V style shared memory. */
        shminit();
#endif

        /* Attach pseudo-devices. */
        for (pdev = pdevinit; pdev->pdev_attach != NULL; pdev++)
                (*pdev->pdev_attach)(pdev->pdev_count);

        /*
         * Initialize protocols.  Block reception of incoming packets
         * until everything is ready.
         */
        s = splimp();
        ifinit();
        domaininit();
        splx(s);

#ifdef GPROF
        /* Initialize kernel profiling. */
        kmstartup();
#endif

        /* Kick off timeout driven events by calling first time. */
        roundrobin(NULL);
        schedcpu(NULL);

        /* Mount the root file system. */
        if ((*mountroot)())
                panic("cannot mount root");

        /* Get the vnode for '/'.  Set fdp->fd_fd.fd_cdir to reference it. */
        if (VFS_ROOT(mountlist.tqh_first, &rootvnode))
                panic("cannot find root vnode");
        fdp->fd_fd.fd_cdir = rootvnode;
        VREF(fdp->fd_fd.fd_cdir);
        VOP_UNLOCK(rootvnode);
        fdp->fd_fd.fd_rdir = NULL;
        swapinit();

        /*
         * Now can look at time, having had a chance to verify the time
         * from the file system.  Reset p->p_rtime as it may have been
         * munched in mi_switch() after the time got set.
         */
        p->p_stats->p_start = runtime = mono_time = boottime = time;
        p->p_rtime.tv_sec = p->p_rtime.tv_usec = 0;

        /* Initialize signal state for process 0. */
        siginit(p);

        /* Create process 1 (init(8)). */
        if (fork(p, NULL, rval))
                panic("fork init");
        if (rval[1]) {
                start_init(curproc, framep);
                return;
        }

        /* Create process 2 (the pageout daemon). */
        if (fork(p, NULL, rval))
                panic("fork pager");
        if (rval[1]) {
                /*
                 * Now in process 2.
                 */
                p = curproc;
                pageproc = p;
                p->p_flag |= P_INMEM | P_SYSTEM;        /* XXX */
                bcopy("pagedaemon", curproc->p_comm, sizeof ("pagedaemon"));
                vm_pageout();
                /* NOTREACHED */
        }

        /* The scheduler is an infinite loop. */
        scheduler();
        /* NOTREACHED */
}

/*
 * List of paths to try when searching for "init".
 */
static char *initpaths[] = {
        "/sbin/init",
        "/sbin/oinit",
        "/sbin/init.bak",
        NULL,
};

/*
 * Start the initial user process; try exec'ing each pathname in "initpaths".
 * The program is invoked with one argument containing the boot flags.
 */
static void
start_init(p, framep)
        struct proc *p;
        void *framep;
{
        vm_offset_t addr;
        struct execve_args /* {
                syscallarg(char *) path;
                syscallarg(char **) argp;
                syscallarg(char **) envp;
        } */ args;
        int options, i, error;
        register_t retval[2];
        char flags[4] = "-", *flagsp;
        char **pathp, *path, *ucp, **uap, *arg0, *arg1;

        initproc = p;

        /*
         * We need to set the system call frame as if we were entered through
         * a syscall() so that when we call execve() below, it will be able
         * to set the entry point (see setregs) when it tries to exec.  The
         * startup code in "locore.s" has allocated space for the frame and
         * passed a pointer to that space as main's argument.
         */
        cpu_set_init_frame(p, framep);

        /*
         * Need just enough stack to hold the faked-up "execve()" arguments.
         */
        addr = trunc_page(VM_MAX_ADDRESS - PAGE_SIZE);
        if (vm_allocate(&p->p_vmspace->vm_map, &addr, PAGE_SIZE, FALSE) != 0)
                panic("init: couldn't allocate argument space");
        p->p_vmspace->vm_maxsaddr = (caddr_t)addr;

        for (pathp = &initpaths[0]; (path = *pathp) != NULL; pathp++) {
                /*
                 * Construct the boot flag argument.
                 */
                options = 0;
                flagsp = flags + 1;
                ucp = (char *)USRSTACK;
                if (boothowto & RB_SINGLE) {
                        *flagsp++ = 's';
                        options = 1;
                }
#ifdef notyet
                if (boothowto & RB_FASTBOOT) {
                        *flagsp++ = 'f';
                        options = 1;
                }
#endif
                /*
                 * Move out the flags (arg 1), if necessary.
                 */
                if (options != 0) {
                        *flagsp++ = '\0';
                        i = flagsp - flags;
                        (void)copyout((caddr_t)flags, (caddr_t)(ucp -= i), i);
                        arg1 = ucp;
                }

                /*
                 * Move out the file name (also arg 0).
                 */
                i = strlen(path) + 1;
                (void)copyout((caddr_t)path, (caddr_t)(ucp -= i), i);
                arg0 = ucp;

                /*
                 * Move out the arg pointers.
                 */
                uap = (char **)((long)ucp & ~ALIGNBYTES);
                (void)suword((caddr_t)--uap, 0);        /* terminator */
                if (options != 0)
                        (void)suword((caddr_t)--uap, (long)arg1);
                (void)suword((caddr_t)--uap, (long)arg0);

                /*
                 * Point at the arguments.
                 */
                SCARG(&args, path) = arg0;
                SCARG(&args, argp) = uap;
                SCARG(&args, envp) = NULL;

                /*
                 * Now try to exec the program.  If can't for any reason
                 * other than it doesn't exist, complain.
                 */
                if ((error = execve(p, &args, retval)) == 0)
                        return;
                if (error != ENOENT)
                        printf("exec %s: error %d\n", path, error);
        }
        printf("init: not found\n");
        panic("no init");
}