Source to arch/i386/i386/machdep.c


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/*-
 * Copyright (c) 1992 Terrence R. Lambert.
 * Copyright (c) 1982, 1987, 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 *
 *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
 *	machdep.c,v 1.41 1993/07/19 16:38:35 cgd Exp
 */

#include "npx.h"

#include <stddef.h>
#include "param.h"
#include "systm.h"
#include "signalvar.h"
#include "kernel.h"
#include "map.h"
#include "proc.h"
#include "user.h"
#include "exec.h"            /* for PS_STRINGS */
#include "buf.h"
#include "reboot.h"
#include "conf.h"
#include "file.h"
#include "callout.h"
#include "malloc.h"
#include "mbuf.h"
#include "msgbuf.h"
#include "net/netisr.h"

#include "vm/vm.h"
#include "vm/vm_kern.h"
#include "vm/vm_page.h"

#include "sys/exec.h"
#include "sys/vnode.h"

vm_map_t buffer_map;
extern vm_offset_t avail_end;

#include "machine/cpu.h"
#include "machine/reg.h"
#include "machine/psl.h"
#include "machine/specialreg.h"
#include "i386/isa/rtc.h"


#define	EXPECT_BASEMEM	640	/* The expected base memory*/
#define	INFORM_WAIT	1	/* Set to pause berfore crash in weird cases*/

/*
 * Declare these as initialized data so we can patch them.
 */
int	nswbuf = 0;
#ifdef	NBUF
int	nbuf = NBUF;
#else
int	nbuf = 0;
#endif
#ifdef	BUFPAGES
int	bufpages = BUFPAGES;
#else
int	bufpages = 0;
#endif
int	msgbufmapped;		/* set when safe to use msgbuf */

/*
 * Machine-dependent startup code
 */
int boothowto = 0, Maxmem = 0;
long dumplo;
int physmem, maxmem;
extern int bootdev;
#ifdef SMALL
extern int forcemaxmem;
#endif
int biosmem;

extern cyloffset;

int cpu_class;

void dumpsys __P((void));

void
cpu_startup()
{
	register int unixsize;
	register unsigned i;
	register struct pte *pte;
	int mapaddr, j;
	register caddr_t v;
	int maxbufs, base, residual;
	extern long Usrptsize;
	vm_offset_t minaddr, maxaddr;
	vm_size_t size;
	int firstaddr;

	/*
	 * Initialize error message buffer (at end of core).
	 */

	/* avail_end was pre-decremented in pmap_bootstrap to compensate */
	for (i = 0; i < btoc(sizeof (struct msgbuf)); i++)
		pmap_enter(pmap_kernel(), msgbufp, avail_end + i * NBPG,
			   VM_PROT_ALL, TRUE);
	msgbufmapped = 1;

#ifdef KDB
	kdb_init();			/* startup kernel debugger */
#endif
	/*
	 * Good {morning,afternoon,evening,night}.
	 */
	printf(version);
	identifycpu();
	printf("real mem  = %d\n", ctob(physmem));

	/*
	 * Allocate space for system data structures.
	 * The first available kernel virtual address is in "v".
	 * As pages of kernel virtual memory are allocated, "v" is incremented.
	 * As pages of memory are allocated and cleared,
	 * "firstaddr" is incremented.
	 * An index into the kernel page table corresponding to the
	 * virtual memory address maintained in "v" is kept in "mapaddr".
	 */

	/*
	 * Make two passes.  The first pass calculates how much memory is
	 * needed and allocates it.  The second pass assigns virtual
	 * addresses to the various data structures.
	 */
	firstaddr = 0;
again:
	v = (caddr_t)firstaddr;

#define	valloc(name, type, num) \
	    (name) = (type *)v; v = (caddr_t)((name)+(num))
#define	valloclim(name, type, num, lim) \
	    (name) = (type *)v; v = (caddr_t)((lim) = ((name)+(num)))
/*	valloc(cfree, struct cblock, nclist);  no clists any more!!! - cgd */
	valloc(callout, struct callout, ncallout);
	valloc(swapmap, struct map, nswapmap = maxproc * 2);
#ifdef SYSVSHM
	valloc(shmsegs, struct shmid_ds, shminfo.shmmni);
#endif
	/*
	 * Determine how many buffers to allocate.
	 * Use 10% of memory for the first 2 Meg, 5% of the remaining
	 * memory. Insure a minimum of 16 buffers.
	 * We allocate 1/2 as many swap buffer headers as file i/o buffers.
	 */
	if (bufpages == 0)
	    if (physmem < btoc(2 * 1024 * 1024))
		bufpages = physmem / 10 / CLSIZE;
	    else
		bufpages = (btoc(2 * 1024 * 1024) + physmem) / 20 / CLSIZE;

	bufpages = min(NKMEMCLUSTERS*2/5, bufpages);  /* XXX ? - cgd */

	if (nbuf == 0) {
		nbuf = bufpages / 2;
		if (nbuf < 16) {
			nbuf = 16;
			/* XXX (cgd) -- broken vfs_bio currently demands this */
			bufpages = 32;
		}
	}
	if (nswbuf == 0) {
		nswbuf = (nbuf / 2) &~ 1;	/* force even */
		if (nswbuf > 256)
			nswbuf = 256;		/* sanity */
	}
	valloc(swbuf, struct buf, nswbuf);
	valloc(buf, struct buf, nbuf);

	/*
	 * End of first pass, size has been calculated so allocate memory
	 */
	if (firstaddr == 0) {
		size = (vm_size_t)(v - firstaddr);
		firstaddr = (int)kmem_alloc(kernel_map, round_page(size));
		if (firstaddr == 0)
			panic("startup: no room for tables");
		goto again;
	}
	/*
	 * End of second pass, addresses have been assigned
	 */
	if ((vm_size_t)(v - firstaddr) != size)
		panic("startup: table size inconsistency");
#if 0
	/*
	 * Now allocate buffers proper.  They are different than the above
	 * in that they usually occupy more virtual memory than physical.
	 */
	size = MAXBSIZE * nbuf;
	buffer_map = kmem_suballoc(kernel_map, (vm_offset_t)&buffers,
				   &maxaddr, size, FALSE);
	minaddr = (vm_offset_t)buffers;
	if (vm_map_find(buffer_map, vm_object_allocate(size), (vm_offset_t)0,
			&minaddr, size, FALSE) != KERN_SUCCESS)
		panic("startup: cannot allocate buffers");
	base = bufpages / nbuf;
	residual = bufpages % nbuf;
	if (base >= MAXBSIZE) { /* don't want to alloc more physical mem than needed */
		base = MAXBSIZE;
		residual = 0;
	}
	for (i = 0; i < nbuf; i++) {
		vm_size_t curbufsize;
		vm_offset_t curbuf;

		/*
		 * First <residual> buffers get (base+1) physical pages
		 * allocated for them.  The rest get (base) physical pages.
		 *
		 * The rest of each buffer occupies virtual space,
		 * but has no physical memory allocated for it.
		 */
		curbuf = (vm_offset_t)buffers + i * MAXBSIZE;
		curbufsize = CLBYTES * (i < residual ? base+1 : base);
		vm_map_pageable(buffer_map, curbuf, curbuf+curbufsize, FALSE);
		vm_map_simplify(buffer_map, curbuf);
	}
#else
	/*
	 * Allocate a submap for buffer space allocations.
	 */
	buffer_map = kmem_suballoc(kernel_map, &minaddr, &maxaddr,
		bufpages * CLBYTES, TRUE);
#endif

	/*
	 * Allocate a submap for exec arguments.  This map effectively
	 * limits the number of processes exec'ing at any time.
	 */
/*	exec_map = kmem_suballoc(kernel_map, &minaddr, &maxaddr,
 *				16*NCARGS, TRUE);
 *	NOT CURRENTLY USED -- cgd
 */
	/*
	 * Allocate a submap for physio
	 */
	phys_map = kmem_suballoc(kernel_map, &minaddr, &maxaddr,
				 VM_PHYS_SIZE, TRUE);

	/*
	 * Finally, allocate mbuf pool.  Since mclrefcnt is an off-size
	 * we use the more space efficient malloc in place of kmem_alloc.
	 */
	mclrefcnt = (char *)malloc(NMBCLUSTERS+CLBYTES/MCLBYTES,
				   M_MBUF, M_NOWAIT);
	bzero(mclrefcnt, NMBCLUSTERS+CLBYTES/MCLBYTES);
	mb_map = kmem_suballoc(kernel_map, (vm_offset_t)&mbutl, &maxaddr,
			       VM_MBUF_SIZE, FALSE);
	/*
	 * Initialize callouts
	 */
	callfree = callout;
	for (i = 1; i < ncallout; i++)
		callout[i-1].c_next = &callout[i];

	printf("avail mem = %d\n", ptoa(vm_page_free_count));
	printf("using %d buffers containing %d bytes of memory\n",
		nbuf, bufpages * CLBYTES);

	/*
	 * Set up CPU-specific registers, cache, etc.
	 */
	initcpu();

	/*
	 * Set up buffers, so they can be used to read disk labels.
	 */
	bufinit();

	/*
	 * Configure the system.
	 */
	configure();
}


struct cpu_nameclass i386_cpus[] = {
	{ "Intel 80286",	CPUCLASS_286 },		/* CPU_286   */
	{ "i386SX",		CPUCLASS_386 },		/* CPU_386SX */
	{ "i386DX",		CPUCLASS_386 },		/* CPU_386   */
	{ "i486SX",		CPUCLASS_486 },		/* CPU_486SX */
	{ "i486DX",		CPUCLASS_486 },		/* CPU_486   */
	{ "i586",		CPUCLASS_586 },		/* CPU_586   */
};

identifycpu()	/* translated from hp300 -- cgd */
{
	printf("CPU: ");
	if (cpu >= 0 && cpu < (sizeof i386_cpus/sizeof(struct cpu_nameclass))) {
		printf("%s", i386_cpus[cpu].cpu_name);
		cpu_class = i386_cpus[cpu].cpu_class;
	} else {
		printf("unknown cpu type %d\n", cpu);
		panic("startup: bad cpu id");
	}
	printf(" (");
	switch(cpu_class) {
	case CPUCLASS_286:
		printf("286");
		break;
	case CPUCLASS_386:
		printf("386");
		break;
	case CPUCLASS_486:
		printf("486");
		break;
	case CPUCLASS_586:
		printf("586");
		break;
	default:
		printf("unknown");	/* will panic below... */
	}
	printf("-class CPU)");
	printf("\n");	/* cpu speed would be nice, but how? */

	/*
	 * Now that we have told the user what they have,
	 * let them know if that machine type isn't configured.
	 */
	switch (cpu_class) {
	case CPUCLASS_286:	/* a 286 should not make it this far, anyway */
#if !defined(I386_CPU)
	case CPUCLASS_386:
#endif
#if !defined(I486_CPU)
	case CPUCLASS_486:
#endif
#if !defined(I586_CPU)
	case CPUCLASS_586:
#endif
		panic("CPU class not configured");
	default:
		break;
	}
}

#ifdef PGINPROF
/*
 * Return the difference (in microseconds)
 * between the  current time and a previous
 * time as represented  by the arguments.
 * If there is a pending clock interrupt
 * which has not been serviced due to high
 * ipl, return error code.
 */
/*ARGSUSED*/
vmtime(otime, olbolt, oicr)
	register int otime, olbolt, oicr;
{

	return (((time.tv_sec-otime)*60 + lbolt-olbolt)*16667);
}
#endif

struct sigframe {
	int	sf_signum;
	int	sf_code;
	struct	sigcontext *sf_scp;
	sig_t	sf_handler;
	int	sf_eax;	
	int	sf_edx;	
	int	sf_ecx;	
	struct	sigcontext sf_sc;
} ;

extern int kstack[];

/*
 * Send an interrupt to process.
 *
 * Stack is set up to allow sigcode stored
 * in u. to call routine, followed by kcall
 * to sigreturn routine below.  After sigreturn
 * resets the signal mask, the stack, and the
 * frame pointer, it returns to the user
 * specified pc, psl.
 */
void
sendsig(catcher, sig, mask, code)
	sig_t catcher;
	int sig, mask;
	unsigned code;
{
	register struct proc *p = curproc;
	register int *regs;
	register struct sigframe *fp;
	struct sigacts *ps = p->p_sigacts;
	int oonstack, frmtrap;
	extern char sigcode[], esigcode[];

	regs = p->p_regs;
        oonstack = ps->ps_onstack;
	frmtrap = curpcb->pcb_flags & FM_TRAP;
	/*
	 * Allocate and validate space for the signal handler
	 * context. Note that if the stack is in P0 space, the
	 * call to grow() is a nop, and the useracc() check
	 * will fail if the process has not already allocated
	 * the space with a `brk'.
	 */
        if (!ps->ps_onstack && (ps->ps_sigonstack & sigmask(sig))) {
		fp = (struct sigframe *)(ps->ps_sigsp
				- sizeof(struct sigframe));
                ps->ps_onstack = 1;
	} else {
		if (frmtrap)
			fp = (struct sigframe *)(regs[tESP]
				- sizeof(struct sigframe));
		else
			fp = (struct sigframe *)(regs[sESP]
				- sizeof(struct sigframe));
	}

	if ((unsigned)fp <= (unsigned)p->p_vmspace->vm_maxsaddr + MAXSSIZ - ctob(p->p_vmspace->vm_ssize)) 
		(void)grow(p, (unsigned)fp);

	if (useracc((caddr_t)fp, sizeof (struct sigframe), B_WRITE) == 0) {
		/*
		 * Process has trashed its stack; give it an illegal
		 * instruction to halt it in its tracks.
		 */
		SIGACTION(p, SIGILL) = SIG_DFL;
		sig = sigmask(SIGILL);
		p->p_sigignore &= ~sig;
		p->p_sigcatch &= ~sig;
		p->p_sigmask &= ~sig;
		psignal(p, SIGILL);
		return;
	}

	/* 
	 * Build the argument list for the signal handler.
	 */
	fp->sf_signum = sig;
	fp->sf_code = code;
	fp->sf_scp = &fp->sf_sc;
	fp->sf_handler = catcher;

	/* save scratch registers */
	if(frmtrap) {
		fp->sf_eax = regs[tEAX];
		fp->sf_edx = regs[tEDX];
		fp->sf_ecx = regs[tECX];
	} else {
		fp->sf_eax = regs[sEAX];
		fp->sf_edx = regs[sEDX];
		fp->sf_ecx = regs[sECX];
	}
	/*
	 * Build the signal context to be used by sigreturn.
	 */
	fp->sf_sc.sc_onstack = oonstack;
	fp->sf_sc.sc_mask = mask;
	if(frmtrap) {
		fp->sf_sc.sc_sp = regs[tESP];
		fp->sf_sc.sc_fp = regs[tEBP];
		fp->sf_sc.sc_pc = regs[tEIP];
		fp->sf_sc.sc_ps = regs[tEFLAGS];
		regs[tESP] = (int)fp;
		regs[tEIP] = (int)(((char *)PS_STRINGS) - (esigcode - sigcode));
	} else {
		fp->sf_sc.sc_sp = regs[sESP];
		fp->sf_sc.sc_fp = regs[sEBP];
		fp->sf_sc.sc_pc = regs[sEIP];
		fp->sf_sc.sc_ps = regs[sEFLAGS];
		regs[sESP] = (int)fp;
		regs[sEIP] = (int)(((char *)PS_STRINGS) - (esigcode - sigcode));
	}
}

/*
 * System call to cleanup state after a signal
 * has been taken.  Reset signal mask and
 * stack state from context left by sendsig (above).
 * Return to previous pc and psl as specified by
 * context left by sendsig. Check carefully to
 * make sure that the user has not modified the
 * psl to gain improper priviledges or to cause
 * a machine fault.
 */
struct sigreturn_args {
	struct sigcontext *sigcntxp;
};

sigreturn(p, uap, retval)
	struct proc *p;
	struct sigreturn_args *uap;
	int *retval;
{
	register struct sigcontext *scp;
	register struct sigframe *fp;
	register int *regs = p->p_regs;


	/*
	 * (XXX old comment) regs[sESP] points to the return address.
	 * The user scp pointer is above that.
	 * The return address is faked in the signal trampoline code
	 * for consistency.
	 */
	scp = uap->sigcntxp;
	fp = (struct sigframe *)
	     ((caddr_t)scp - offsetof(struct sigframe, sf_sc));

	if (useracc((caddr_t)fp, sizeof (*fp), 0) == 0)
		return(EINVAL);

	/* restore scratch registers */
	regs[sEAX] = fp->sf_eax ;
	regs[sEDX] = fp->sf_edx ;
	regs[sECX] = fp->sf_ecx ;

	if (useracc((caddr_t)scp, sizeof (*scp), 0) == 0)
		return(EINVAL);
#ifdef notyet
	if ((scp->sc_ps & PSL_MBZ) != 0 || (scp->sc_ps & PSL_MBO) != PSL_MBO) {
		return(EINVAL);
	}
#endif
        p->p_sigacts->ps_onstack = scp->sc_onstack & 01;
	p->p_sigmask = scp->sc_mask &~
	    (sigmask(SIGKILL)|sigmask(SIGCONT)|sigmask(SIGSTOP));
	regs[sEBP] = scp->sc_fp;
	regs[sESP] = scp->sc_sp;
	regs[sEIP] = scp->sc_pc;
	regs[sEFLAGS] = scp->sc_ps;
	return(EJUSTRETURN);
}

/*
 * a simple function to make the system panic (and dump a vmcore)
 * in a predictable fashion
 */
void diediedie()
{
	panic("because you said to!");
}

int	waittime = -1;
struct pcb dumppcb;

void
boot(arghowto)
	int arghowto;
{
	register long dummy;		/* r12 is reserved */
	register int howto;		/* r11 == how to boot */
	register int devtype;		/* r10 == major of root dev */
	extern int cold;

	if(cold) {
		printf("hit reset please");
		for(;;);
	}
	howto = arghowto;
	if ((howto&RB_NOSYNC) == 0 && waittime < 0 && bfreelist[0].b_forw) {
		register struct buf *bp;
		int iter, nbusy;

		waittime = 0;
		(void) splnet();
		printf("syncing disks... ");
		/*
		 * Release inodes held by texts before update.
		 */
		if (panicstr == 0)
			vnode_pager_umount(NULL);
		sync((struct sigcontext *)0);

		for (iter = 0; iter < 20; iter++) {
			nbusy = 0;
			for (bp = &buf[nbuf]; --bp >= buf; )
				if ((bp->b_flags & (B_BUSY|B_INVAL)) == B_BUSY)
					nbusy++;
			if (nbusy == 0)
				break;
			printf("%d ", nbusy);
			DELAY(40000 * iter);
		}
		if (nbusy)
			printf("giving up\n");
		else
			printf("done\n");
		DELAY(10000);			/* wait for printf to finish */
	}
	splhigh();
	devtype = major(rootdev);
	if (howto&RB_HALT) {
		printf("\n");
		printf("The operating system has halted.\n");
		printf("Please press any key to reboot.\n\n");
		cngetc();
	} else {
		if (howto & RB_DUMP) {
			savectx(&dumppcb, 0);
			dumppcb.pcb_ptd = rcr3();
			dumpsys();	
			/*NOTREACHED*/
		}
	}
#ifdef lint
	dummy = 0; dummy = dummy;
	printf("howto %d, devtype %d\n", arghowto, devtype);
#endif
	cpu_reset();
	for(;;) ;
	/*NOTREACHED*/
}

unsigned	dumpmag = 0x8fca0101;	/* magic number for savecore */
int		dumpsize = 0;		/* also for savecore */
/*
 * Doadump comes here after turning off memory management and
 * getting on the dump stack, either when called above, or by
 * the auto-restart code.
 */
void
dumpsys()
{

	if (dumpdev == NODEV)
		return;
	if ((minor(dumpdev)&07) != 1)
		return;
	dumpsize = physmem;
	printf("\ndumping to dev %x, offset %d\n", dumpdev, dumplo);
	printf("dump ");
	switch ((*bdevsw[major(dumpdev)].d_dump)(dumpdev)) {

	case ENXIO:
		printf("device bad\n");
		break;

	case EFAULT:
		printf("device not ready\n");
		break;

	case EINVAL:
		printf("area improper\n");
		break;

	case EIO:
		printf("i/o error\n");
		break;

	case EINTR:
		printf("aborted from console\n");
		break;

	default:
		printf("succeeded\n");
		break;
	}
	printf("\n\n");
	DELAY(1000);
}

#ifdef HZ
/*
 * If HZ is defined we use this code, otherwise the code in
 * /sys/i386/i386/microtime.s is used.  The othercode only works
 * for HZ=100.
 */
microtime(tvp)
	register struct timeval *tvp;
{
	int s = splhigh();

	*tvp = time;
	tvp->tv_usec += tick;
	while (tvp->tv_usec > 1000000) {
		tvp->tv_sec++;
		tvp->tv_usec -= 1000000;
	}
	splx(s);
}
#endif /* HZ */

physstrat(bp, strat, prio)
	struct buf *bp;
	int (*strat)(), prio;
{
	register int s;
	caddr_t baddr;

	/*
	 * vmapbuf clobbers b_addr so we must remember it so that it
	 * can be restored after vunmapbuf.  This is truely rude, we
	 * should really be storing this in a field in the buf struct
	 * but none are available and I didn't want to add one at
	 * this time.  Note that b_addr for dirty page pushes is 
	 * restored in vunmapbuf. (ugh!)
	 */
	baddr = bp->b_un.b_addr;
	vmapbuf(bp);
	(*strat)(bp);
	/* pageout daemon doesn't wait for pushed pages */
	if (bp->b_flags & B_DIRTY)
		return;
	s = splbio();
	while ((bp->b_flags & B_DONE) == 0)
		sleep((caddr_t)bp, prio);
	splx(s);
	vunmapbuf(bp);
	bp->b_un.b_addr = baddr;
}

initcpu()
{
}

/*
 * Clear registers on exec
 */
void
setregs(p, entry, stack, retval)
	struct proc *p;
	u_long entry;
	u_long stack;
	int retval[2];
{
	p->p_regs[sEBP] = 0;	/* bottom of the fp chain */
	p->p_regs[sEIP] = entry;
	p->p_regs[sESP] = stack;
	/* XXX -- do something with retval? */

	p->p_addr->u_pcb.pcb_flags &= 0 /* FM_SYSCTRC */; /* no fp at all */
	load_cr0(rcr0() | CR0_TS);	/* start emulating */
#if	NNPX > 0
	npxinit(__INITIAL_NPXCW__);
#endif
}

/*
 * Initialize 386 and configure to run kernel
 */

/*
 * Initialize segments & interrupt table
 */

#define	GNULL_SEL	0	/* Null Descriptor */
#define	GCODE_SEL	1	/* Kernel Code Descriptor */
#define	GDATA_SEL	2	/* Kernel Data Descriptor */
#define	GLDT_SEL	3	/* LDT - eventually one per process */
#define	GTGATE_SEL	4	/* Process task switch gate */
#define	GPANIC_SEL	5	/* Task state to consider panic from */
#define	GPROC0_SEL	6	/* Task state process slot zero and up */
#define NGDT 	GPROC0_SEL+1

union descriptor gdt[GPROC0_SEL+1];

/* interrupt descriptor table */
struct gate_descriptor idt[NIDT];

/* local descriptor table */
union descriptor ldt[5];
#define	LSYS5CALLS_SEL	0	/* forced by intel BCS */
#define	LSYS5SIGR_SEL	1

#define	L43BSDCALLS_SEL	2	/* notyet */
#define	LUCODE_SEL	3
#define	LUDATA_SEL	4
/* seperate stack, es,fs,gs sels ? */
/* #define	LPOSIXCALLS_SEL	5	/* notyet */

struct	i386tss	tss, panic_tss;

extern  struct user *proc0paddr;

/* software prototypes -- in more palatable form */
struct soft_segment_descriptor gdt_segs[] = {
	/* Null Descriptor */
{	0x0,			/* segment base address  */
	0x0,			/* length */
	0,			/* segment type */
	0,			/* segment descriptor priority level */
	0,			/* segment descriptor present */
	0, 0,
	0,			/* default 32 vs 16 bit size */
	0  			/* limit granularity (byte/page units)*/ },
	/* Code Descriptor for kernel */
{	0x0,			/* segment base address  */
	0xfffff,		/* length - all address space */
	SDT_MEMERA,		/* segment type */
	0,			/* segment descriptor priority level */
	1,			/* segment descriptor present */
	0, 0,
	1,			/* default 32 vs 16 bit size */
	1  			/* limit granularity (byte/page units)*/ },
	/* Data Descriptor for kernel */
{	0x0,			/* segment base address  */
	0xfffff,		/* length - all address space */
	SDT_MEMRWA,		/* segment type */
	0,			/* segment descriptor priority level */
	1,			/* segment descriptor present */
	0, 0,
	1,			/* default 32 vs 16 bit size */
	1  			/* limit granularity (byte/page units)*/ },
	/* LDT Descriptor */
{	(int) ldt,			/* segment base address  */
	sizeof(ldt)-1,		/* length - all address space */
	SDT_SYSLDT,		/* segment type */
	0,			/* segment descriptor priority level */
	1,			/* segment descriptor present */
	0, 0,
	0,			/* unused - default 32 vs 16 bit size */
	0  			/* limit granularity (byte/page units)*/ },
	/* Null Descriptor - Placeholder */
{	0x0,			/* segment base address  */
	0x0,			/* length */
	0,			/* segment type */
	0,			/* segment descriptor priority level */
	0,			/* segment descriptor present */
	0, 0,
	0,			/* default 32 vs 16 bit size */
	0  			/* limit granularity (byte/page units)*/ },
	/* Panic Tss Descriptor */
{	(int) &panic_tss,		/* segment base address  */
	sizeof(tss)-1,		/* length - all address space */
	SDT_SYS386TSS,		/* segment type */
	0,			/* segment descriptor priority level */
	1,			/* segment descriptor present */
	0, 0,
	0,			/* unused - default 32 vs 16 bit size */
	0  			/* limit granularity (byte/page units)*/ },
	/* Proc 0 Tss Descriptor */
{	(int) kstack,			/* segment base address  */
	sizeof(tss)-1,		/* length - all address space */
	SDT_SYS386TSS,		/* segment type */
	0,			/* segment descriptor priority level */
	1,			/* segment descriptor present */
	0, 0,
	0,			/* unused - default 32 vs 16 bit size */
	0  			/* limit granularity (byte/page units)*/ }};

struct soft_segment_descriptor ldt_segs[] = {
	/* Null Descriptor - overwritten by call gate */
{	0x0,			/* segment base address  */
	0x0,			/* length */
	0,			/* segment type */
	0,			/* segment descriptor priority level */
	0,			/* segment descriptor present */
	0, 0,
	0,			/* default 32 vs 16 bit size */
	0  			/* limit granularity (byte/page units)*/ },
	/* Null Descriptor - overwritten by call gate */
{	0x0,			/* segment base address  */
	0x0,			/* length */
	0,			/* segment type */
	0,			/* segment descriptor priority level */
	0,			/* segment descriptor present */
	0, 0,
	0,			/* default 32 vs 16 bit size */
	0  			/* limit granularity (byte/page units)*/ },
	/* Null Descriptor - overwritten by call gate */
{	0x0,			/* segment base address  */
	0x0,			/* length */
	0,			/* segment type */
	0,			/* segment descriptor priority level */
	0,			/* segment descriptor present */
	0, 0,
	0,			/* default 32 vs 16 bit size */
	0  			/* limit granularity (byte/page units)*/ },
	/* Code Descriptor for user */
{	0x0,			/* segment base address  */
	0xfffff,		/* length - all address space */
	SDT_MEMERA,		/* segment type */
	SEL_UPL,		/* segment descriptor priority level */
	1,			/* segment descriptor present */
	0, 0,
	1,			/* default 32 vs 16 bit size */
	1  			/* limit granularity (byte/page units)*/ },
	/* Data Descriptor for user */
{	0x0,			/* segment base address  */
	0xfffff,		/* length - all address space */
	SDT_MEMRWA,		/* segment type */
	SEL_UPL,		/* segment descriptor priority level */
	1,			/* segment descriptor present */
	0, 0,
	1,			/* default 32 vs 16 bit size */
	1  			/* limit granularity (byte/page units)*/ } };

setidt(idx, func, typ, dpl) char *func; {
	struct gate_descriptor *ip = idt + idx;

	ip->gd_looffset = (int)func;
	ip->gd_selector = 8;
	ip->gd_stkcpy = 0;
	ip->gd_xx = 0;
	ip->gd_type = typ;
	ip->gd_dpl = dpl;
	ip->gd_p = 1;
	ip->gd_hioffset = ((int)func)>>16 ;
}

#define	IDTVEC(name)	__CONCAT(X, name)
extern	IDTVEC(div), IDTVEC(dbg), IDTVEC(nmi), IDTVEC(bpt), IDTVEC(ofl),
	IDTVEC(bnd), IDTVEC(ill), IDTVEC(dna), IDTVEC(dble), IDTVEC(fpusegm),
	IDTVEC(tss), IDTVEC(missing), IDTVEC(stk), IDTVEC(prot),
	IDTVEC(page), IDTVEC(rsvd), IDTVEC(fpu), IDTVEC(rsvd0),
	IDTVEC(rsvd1), IDTVEC(rsvd2), IDTVEC(rsvd3), IDTVEC(rsvd4),
	IDTVEC(rsvd5), IDTVEC(rsvd6), IDTVEC(rsvd7), IDTVEC(rsvd8),
	IDTVEC(rsvd9), IDTVEC(rsvd10), IDTVEC(rsvd11), IDTVEC(rsvd12),
	IDTVEC(rsvd13), IDTVEC(rsvd14), IDTVEC(rsvd14), IDTVEC(syscall);

int lcr0(), lcr3(), rcr0(), rcr2();
int _udatasel, _ucodesel, _gsel_tss;

init386(first)
{
	extern ssdtosd(), lgdt(), lidt(), lldt(), etext; 
	int x, *pi;
	unsigned biosbasemem, biosextmem;
	struct gate_descriptor *gdp;
	extern char sigcode[], esigcode[];
	/* table descriptors - used to load tables by microp */
	struct region_descriptor r_gdt, r_idt;
	int	pagesinbase, pagesinext;


	proc0.p_addr = proc0paddr;

	/*
	 * Initialize the console before we print anything out.
	 */

	cninit (KERNBASE+0xa0000);

#ifndef LKM		/* don't do this if we're using LKM's */
	/* make gdt memory segments */
	gdt_segs[GCODE_SEL].ssd_limit = btoc((int) &etext + NBPG);
#endif

	for (x=0; x < NGDT; x++) ssdtosd(gdt_segs+x, gdt+x);
	/* make ldt memory segments */
	ldt_segs[LUCODE_SEL].ssd_limit = btoc(VM_MAXUSER_ADDRESS) - 1;
	ldt_segs[LUDATA_SEL].ssd_limit = btoc(VM_MAXUSER_ADDRESS) - 1;
	/* Note. eventually want private ldts per process */
	for (x=0; x < 5; x++) ssdtosd(ldt_segs+x, ldt+x);

	/* exceptions */
	setidt(0, &IDTVEC(div),  SDT_SYS386TGT, SEL_KPL);
	setidt(1, &IDTVEC(dbg),  SDT_SYS386TGT, SEL_KPL);
	setidt(2, &IDTVEC(nmi),  SDT_SYS386TGT, SEL_KPL);
 	setidt(3, &IDTVEC(bpt),  SDT_SYS386TGT, SEL_UPL);
	setidt(4, &IDTVEC(ofl),  SDT_SYS386TGT, SEL_KPL);
	setidt(5, &IDTVEC(bnd),  SDT_SYS386TGT, SEL_KPL);
	setidt(6, &IDTVEC(ill),  SDT_SYS386TGT, SEL_KPL);
	setidt(7, &IDTVEC(dna),  SDT_SYS386TGT, SEL_KPL);
	setidt(8, &IDTVEC(dble),  SDT_SYS386TGT, SEL_KPL);
	setidt(9, &IDTVEC(fpusegm),  SDT_SYS386TGT, SEL_KPL);
	setidt(10, &IDTVEC(tss),  SDT_SYS386TGT, SEL_KPL);
	setidt(11, &IDTVEC(missing),  SDT_SYS386TGT, SEL_KPL);
	setidt(12, &IDTVEC(stk),  SDT_SYS386TGT, SEL_KPL);
	setidt(13, &IDTVEC(prot),  SDT_SYS386TGT, SEL_KPL);
	setidt(14, &IDTVEC(page),  SDT_SYS386TGT, SEL_KPL);
	setidt(15, &IDTVEC(rsvd),  SDT_SYS386TGT, SEL_KPL);
	setidt(16, &IDTVEC(fpu),  SDT_SYS386TGT, SEL_KPL);
	setidt(17, &IDTVEC(rsvd0),  SDT_SYS386TGT, SEL_KPL);
	setidt(18, &IDTVEC(rsvd1),  SDT_SYS386TGT, SEL_KPL);
	setidt(19, &IDTVEC(rsvd2),  SDT_SYS386TGT, SEL_KPL);
	setidt(20, &IDTVEC(rsvd3),  SDT_SYS386TGT, SEL_KPL);
	setidt(21, &IDTVEC(rsvd4),  SDT_SYS386TGT, SEL_KPL);
	setidt(22, &IDTVEC(rsvd5),  SDT_SYS386TGT, SEL_KPL);
	setidt(23, &IDTVEC(rsvd6),  SDT_SYS386TGT, SEL_KPL);
	setidt(24, &IDTVEC(rsvd7),  SDT_SYS386TGT, SEL_KPL);
	setidt(25, &IDTVEC(rsvd8),  SDT_SYS386TGT, SEL_KPL);
	setidt(26, &IDTVEC(rsvd9),  SDT_SYS386TGT, SEL_KPL);
	setidt(27, &IDTVEC(rsvd10),  SDT_SYS386TGT, SEL_KPL);
	setidt(28, &IDTVEC(rsvd11),  SDT_SYS386TGT, SEL_KPL);
	setidt(29, &IDTVEC(rsvd12),  SDT_SYS386TGT, SEL_KPL);
	setidt(30, &IDTVEC(rsvd13),  SDT_SYS386TGT, SEL_KPL);
	setidt(31, &IDTVEC(rsvd14),  SDT_SYS386TGT, SEL_KPL);

#include	"isa.h"
#if	NISA >0
	isa_defaultirq();
#endif

	r_gdt.rd_limit = sizeof(gdt)-1;
	r_gdt.rd_base = (int) gdt;
	lgdt(&r_gdt);
	r_idt.rd_limit = sizeof(idt)-1;
	r_idt.rd_base = (int) idt;
	lidt(&r_idt);
	lldt(GSEL(GLDT_SEL, SEL_KPL));

#ifdef DDB
	kdb_init();
	if (boothowto & RB_KDB)
		Debugger();
#endif

	/* Use BIOS values stored in RTC CMOS RAM, since probing
	 * breaks certain 386 AT relics.
	 */
	biosbasemem = rtcin(RTC_BASELO)+ (rtcin(RTC_BASEHI)<<8);
	biosextmem = rtcin(RTC_EXTLO)+ (rtcin(RTC_EXTHI)<<8);
/*printf("bios base %d ext %d ", biosbasemem, biosextmem);*/

	/*
	 * 15 Aug 92	Terry Lambert		The real fix for the CMOS bug
	 */
	if( biosbasemem != EXPECT_BASEMEM) {
		printf( "Warning: Base memory %dK, assuming %dK\n", biosbasemem, EXPECT_BASEMEM);
		biosbasemem = EXPECT_BASEMEM;		/* assume base*/
	}

	if( biosextmem > 65536) {
		printf( "Warning: Extended memory %dK(>64M), assuming 0K\n", biosextmem);
		biosextmem = 0;				/* assume none*/
	}

	/*
	 * Go into normal calculation; Note that we try to run in 640K, and
	 * that invalid CMOS values of non 0xffff are no longer a cause of
	 * ptdi problems.  I have found a gutted kernel can run in 640K.
	 */
	pagesinbase = 640/4 - first/NBPG;
#ifdef WEIRD_MEMSIZE
	pagesinext = biosextmem/4;
#else
	pagesinext = (biosextmem/1024) * 256;
			/* basically, round ext. mem size to 1M boundary. */
#endif
	/* use greater of either base or extended memory. do this
	 * until I reinstitue discontiguous allocation of vm_page
	 * array.
	 */
	if (pagesinbase > pagesinext)
		Maxmem = 640/4;
	else {
		Maxmem = pagesinext + 0x100000/NBPG;
		if (first < 0x100000)
			first = 0x100000; /* skip hole */
	}

	/* This used to explode, since Maxmem used to be 0 for bas CMOS*/
	maxmem = Maxmem - 1;	/* highest page of usable memory */
	physmem = maxmem;	/* number of pages of physmem addr space */
/*printf("using first 0x%x to 0x%x\n ", first, maxmem*NBPG);*/
	if (maxmem < 2048/4) {
		printf("Too little RAM memory. Warning, running in degraded mode.\n");
#ifdef INFORM_WAIT
		/*
		 * People with less than 2 Meg have to hit return; this way
		 * we see the messages and can tell them why they blow up later.
		 * If they get working well enough to recompile, they can unset
		 * the flag; otherwise, it's a toy and they have to lump it.
		 */
		cngetc();
#endif	/* !INFORM_WAIT*/
	}
	/*
	 * End of CMOS bux fix
	 */

	/* call pmap initialization to make new kernel address space */
	pmap_bootstrap (first, 0);
	/* now running on new page tables, configured,and u/iom is accessible */

	/* make a initial tss so microp can get interrupt stack on syscall! */
	proc0.p_addr->u_pcb.pcb_tss.tss_esp0 = (int) kstack + UPAGES*NBPG;
	proc0.p_addr->u_pcb.pcb_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL) ;
	_gsel_tss = GSEL(GPROC0_SEL, SEL_KPL);

	((struct i386tss *)gdt_segs[GPROC0_SEL].ssd_base)->tss_ioopt = 
		(sizeof(tss))<<16;

	ltr(_gsel_tss);

	/* make a call gate to reenter kernel with */
	gdp = &ldt[LSYS5CALLS_SEL].gd;
	
	x = (int) &IDTVEC(syscall);
	gdp->gd_looffset = x++;
	gdp->gd_selector = GSEL(GCODE_SEL,SEL_KPL);
	gdp->gd_stkcpy = 0;
	gdp->gd_type = SDT_SYS386CGT;
	gdp->gd_dpl = SEL_UPL;
	gdp->gd_p = 1;
	gdp->gd_hioffset = ((int) &IDTVEC(syscall)) >>16;

	/* transfer to user mode */

	_ucodesel = LSEL(LUCODE_SEL, SEL_UPL);
	_udatasel = LSEL(LUDATA_SEL, SEL_UPL);

	/* setup proc 0's pcb */
	proc0.p_addr->u_pcb.pcb_flags = 0;
	proc0.p_addr->u_pcb.pcb_ptd = IdlePTD;
}

extern struct pte	*CMAP1, *CMAP2;
extern caddr_t		CADDR1, CADDR2;
/*
 * zero out physical memory
 * specified in relocation units (NBPG bytes)
 */
clearseg(n) {

	*(int *)CMAP2 = PG_V | PG_KW | ctob(n);
	load_cr3(rcr3());
	bzero(CADDR2,NBPG);
	*(int *) CADDR2 = 0;
}

/*
 * copy a page of physical memory
 * specified in relocation units (NBPG bytes)
 */
void
copyseg(frm, n) {

	*(int *)CMAP2 = PG_V | PG_KW | ctob(n);
	load_cr3(rcr3());
	bcopy((void *)frm, (void *)CADDR2, NBPG);
}

/*
 * copy a page of physical memory
 * specified in relocation units (NBPG bytes)
 */
void
physcopyseg(frm, to) {

	*(int *)CMAP1 = PG_V | PG_KW | ctob(frm);
	*(int *)CMAP2 = PG_V | PG_KW | ctob(to);
	load_cr3(rcr3());
	bcopy(CADDR1, CADDR2, NBPG);
}

/*aston() {
	schednetisr(NETISR_AST);
}*/

void
setsoftclock() {
	schednetisr(NETISR_SCLK);
}

/*
 * insert an element into a queue 
 */
#undef insque
_insque(element, head)
	register struct prochd *element, *head;
{
	element->ph_link = head->ph_link;
	head->ph_link = (struct proc *)element;
	element->ph_rlink = (struct proc *)head;
	((struct prochd *)(element->ph_link))->ph_rlink=(struct proc *)element;
}

/*
 * remove an element from a queue
 */
#undef remque
_remque(element)
	register struct prochd *element;
{
	((struct prochd *)(element->ph_link))->ph_rlink = element->ph_rlink;
	((struct prochd *)(element->ph_rlink))->ph_link = element->ph_link;
	element->ph_rlink = (struct proc *)0;
}

vmunaccess() {}

cpu_exec_makecmds(p, epp)
struct proc *p;
struct exec_package *epp;
{
#ifdef COMPAT_NOMID
  int error;
  u_long midmag, magic;
  u_short mid;

  midmag = ntohl(epp->ep_execp->a_midmag);
  mid = (midmag >> 16 ) & 0xffff;
  magic = midmag & 0xffff;

  if(magic==0) {
    magic = (epp->ep_execp->a_midmag & 0xffff);
    mid = MID_ZERO;
  }

  switch (mid << 16 | magic) {
  case (MID_ZERO << 16) | ZMAGIC:
    error = cpu_exec_prep_oldzmagic(p, epp);
    break;
  case (MID_ZERO << 16) | QMAGIC:
    error = exec_prep_zmagic(p, epp);
    break;
  default:
    error = ENOEXEC;
  }

  return error;
#else /* ! COMPAT_NOMID */
  return ENOEXEC;
#endif
}

#ifdef COMPAT_NOMID
int
cpu_exec_prep_oldzmagic(p, epp)
     struct proc *p;
     struct exec_package *epp;
{
  struct exec *execp = epp->ep_execp;
  struct exec_vmcmd *ccmdp;

#ifdef EXEC_DEBUG
  printf("exec_prep_oldzmagic: setting up size fields in epp\n");
#endif
  epp->ep_taddr = 0;
  epp->ep_tsize = execp->a_text;
  epp->ep_daddr = epp->ep_taddr + execp->a_text;
  epp->ep_dsize = execp->a_data + execp->a_bss;
  epp->ep_maxsaddr = USRSTACK - MAXSSIZ;
  epp->ep_minsaddr = USRSTACK;
  epp->ep_ssize = p->p_rlimit[RLIMIT_STACK].rlim_cur;
  epp->ep_entry = execp->a_entry;

  /* check if vnode is in open for writing, because we want to demand-page
   * out of it.  if it is, don't do it, for various reasons
   */
  if ((execp->a_text != 0 || execp->a_data != 0) &&
      (epp->ep_vp->v_flag & VTEXT) == 0 && epp->ep_vp->v_writecount != 0) {
#ifdef DIAGNOSTIC
    if (epp->ep_vp->v_flag & VTEXT)
      panic("exec: a VTEXT vnode has writecount != 0\n");
#endif
    epp->ep_vcp = NULL;
#ifdef EXEC_DEBUG
    printf("exec_prep_oldzmagic: returning with ETXTBSY\n");
#endif
    return ETXTBSY;
  }
  epp->ep_vp->v_flag |= VTEXT;

  /* set up command for text segment */
#ifdef EXEC_DEBUG
  printf("exec_prep_oldzmagic: setting up text segment commands\n");
#endif
  epp->ep_vcp = new_vmcmd(vmcmd_map_pagedvn,
			  execp->a_text,
			  epp->ep_taddr,
			  epp->ep_vp,
			  NBPG,                  /* should this be CLBYTES? */
			  VM_PROT_READ|VM_PROT_EXECUTE);
  ccmdp = epp->ep_vcp;

  /* set up command for data segment */
#ifdef EXEC_DEBUG
  printf("exec_prep_oldzmagic: setting up data segment commands\n");
#endif
  ccmdp->ev_next = new_vmcmd(vmcmd_map_pagedvn,
			     execp->a_data,
			     epp->ep_daddr,
			     epp->ep_vp,
			     execp->a_text + NBPG, /* should be CLBYTES? */
			     VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
  ccmdp = ccmdp->ev_next;

  /* set up command for bss segment */
#ifdef EXEC_DEBUG
  printf("exec_prep_oldzmagic: setting up bss segment commands\n");
#endif
  ccmdp->ev_next = new_vmcmd(vmcmd_map_zero,
			     execp->a_bss,
			     epp->ep_daddr + execp->a_data,
			     0,
			     0,
			     VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
  ccmdp = ccmdp->ev_next;

  /* set up commands for stack.  note that this takes *two*, one
   * to map the part of the stack which we can access, and one
   * to map the part which we can't.
   *
   * arguably, it could be made into one, but that would require
   * the addition of another mapping proc, which is unnecessary
   *
   * note that in memory, thigns assumed to be:
   *    0 ....... ep_maxsaddr <stack> ep_minsaddr
   */
#ifdef EXEC_DEBUG
  printf("exec_prep_oldzmagic: setting up unmapped stack segment commands\n");
#endif
  ccmdp->ev_next = new_vmcmd(vmcmd_map_zero,
			     ((epp->ep_minsaddr - epp->ep_ssize) -
			      epp->ep_maxsaddr),
			     epp->ep_maxsaddr,
			     0,
			     0,
			     VM_PROT_NONE);
  ccmdp = ccmdp->ev_next;
#ifdef EXEC_DEBUG
  printf("exec_prep_oldzmagic: setting up mapped stack segment commands\n");
#endif
  ccmdp->ev_next = new_vmcmd(vmcmd_map_zero,
			     epp->ep_ssize,
			     (epp->ep_minsaddr - epp->ep_ssize),
			     0,
			     0,
			     VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);

#ifdef EXEC_DEBUG
  printf("exec_prep_oldzmagic: returning with no error\n");
#endif
  return 0;
}
#endif /* COMPAT_NOMID */