Bell 32V development

[unix-history] / usr / src / slowsys / sys / main.c

#include "../h/param.h"
#include "../h/systm.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/filsys.h"
#include "../h/mount.h"
#include "../h/uba.h"
#include "../h/map.h"
#include "../h/proc.h"
#include "../h/inode.h"
#include "../h/seg.h"
#include "../h/conf.h"
#include "../h/buf.h"
#include "../h/mtpr.h"
#include "../h/page.h"
# include "../h/clock.h"


/*
* Initialization code.
* Called from cold start routine as
* soon as a stack and segmentation
* have been established.
* Functions:
*      clear and free user core
*      turn on clock
*      hand craft 0th process
*      call all initialization routines
*      fork - process 0 to schedule
*           - process 1 execute bootstrap
*
* loop at loc 13 (0xd) in user mode -- /etc/init
*      cannot be executed.
*/
main(firstaddr)
{

       startup(firstaddr);

       /*
        * set up system process
        */

       proc[0].p_addr = firstaddr;
       proc[0].p_size = USIZE;
       proc[0].p_stat = SRUN;
       proc[0].p_flag |= SLOAD|SSYS;
       proc[0].p_nice = NZERO;
       u.u_procp = &proc[0];
       u.u_cmask = CMASK;
       estabur(0, 0, 0, 0, 0);
       clkstart();

       /*
        * Initialize devices and
        * set up 'known' i-nodes
        */

       cinit();
       binit();
       iinit();
       rootdir = iget(rootdev, (ino_t)ROOTINO);
       rootdir->i_flag &= ~ILOCK;
       u.u_cdir = iget(rootdev, (ino_t)ROOTINO);
       u.u_cdir->i_flag &= ~ILOCK;
       u.u_rdir = NULL;

       /*
        * make init process
        * enter scheduling loop
        * with system process
        */

       if(newproc()) {
               expand(USIZE + btoc(szicode));
               u.u_dsize = btoc(szicode);
               estabur(0, btoc(szicode), 0, 0, RO);
               copyout((caddr_t)icode, (caddr_t)0, szicode);
               /*
                * Return goes to loc. 0 of user init
                * code just copied out.
                */
               return;
       }
       sched();
}

/*
* iinit is called once (from main)
* very early in initialization.
* It reads the root's super block
* and initializes the current date
* from the last modified date.
*
* panic: iinit -- cannot read the super
* block. Usually because of an IO error.
*/
iinit()
{
       register struct buf *cp, *bp;
       register struct filsys *fp;
       register unsigned i , j ;

       (*bdevsw[major(rootdev)].d_open)(rootdev, 1);
       bp = bread(rootdev, SUPERB);
       cp = geteblk();
       if(u.u_error)
               panic("iinit");
       bcopy(bp->b_un.b_addr, cp->b_un.b_addr, sizeof(struct filsys));
       brelse(bp);
       mount[0].m_bufp = cp;
       mount[0].m_dev = rootdev;
       fp = cp->b_un.b_filsys;
       fp->s_flock = 0;
       fp->s_ilock = 0;
       fp->s_ronly = 0;
       /* on boot, read VAX TODR register (GMT 10 ms.
       *       clicks into current year) and set software time
       *       in 'int time' (GMT seconds since year YRREF)
       */
       for (i = 0 , j = YRREF ; j < YRCURR ; j++)
               i += (SECYR + (j%4?0:SECDAY)) ;
       time = udiv(mfpr(TODR),100) + i ;
}

/*
* This is the set of buffers proper, whose heads
* were declared in buf.h.  There can exist buffer
* headers not pointing here that are used purely
* as arguments to the I/O routines to describe
* I/O to be done-- e.g. swbuf for
* swapping.
*/
char    buffers[NBUF][BSIZE+BSLOP];

/*
* Initialize the buffer I/O system by freeing
* all buffers and setting all device buffer lists to empty.
*/
binit()
{
       register struct buf *bp;
       register struct buf *dp;
       register int i;
       struct bdevsw *bdp;

       bfreelist.b_forw = bfreelist.b_back =
           bfreelist.av_forw = bfreelist.av_back = &bfreelist;
       for (i=0; i<NBUF; i++) {
               bp = &buf[i];
               bp->b_dev = NODEV;
               bp->b_un.b_addr = buffers[i];
               bp->b_back = &bfreelist;
               bp->b_forw = bfreelist.b_forw;
               bfreelist.b_forw->b_back = bp;
               bfreelist.b_forw = bp;
               bp->b_flags = B_BUSY;
               brelse(bp);
       }
       for (bdp = bdevsw; bdp->d_open; bdp++) {
               dp = bdp->d_tab;
               if(dp) {
                       dp->b_forw = dp;
                       dp->b_back = dp;
               }
               nblkdev++;
       }
}