Annotation of 41BSD/games/compat/Original/dosig.c, revision 1.1

1.1     ! root        1: #
        !             2: /*     Handle signal trapping from version 6 or version 7 compatability
        !             3:  *     mode programs.
        !             4:  *     Art Wetzel      November 1979
        !             5:  */
        !             6: #ifdef TRACE
        !             7: #include <stdio.h>
        !             8: #endif
        !             9: #include <signal.h>
        !            10: #include "defs.h"
        !            11: unsigned int  sigvals[NSIG+1];
        !            12: /* actual catch point for all signals */
        !            13: sigcatch(signum) int signum; {
        !            14:        unsigned short *pcptr;
        !            15:        extern getregs();
        !            16:        if(incompat) {
        !            17:                /* hurry up and get the registers before they are destroyed */
        !            18:                getregs();
        !            19:        } else {
        !            20:                /* we were in native mode simulating a sys call */
        !            21:                /* set it up with the old values */
        !            22:                dosig(signum, pc);
        !            23:                /* go back where we were doing the sys call */
        !            24:                return(0);
        !            25:        }
        !            26:        /* figure out the pc */
        !            27:        pcptr = (unsigned short *)((char *)&pcptr + 20);
        !            28:        pc = (unsigned short *) *pcptr;
        !            29:        /* get the psl with condition codes */
        !            30:        /* requires UNIX-32V patch to not clear out condition codes */
        !            31:        psl = 0x83c00000 | (*(pcptr - 6) & 017);
        !            32:        /* actually do the thing */
        !            33:        if(sigvals[signum] != (unsigned int)SIG_DFL && (sigvals[signum] & (unsigned int)SIG_IGN) == 0)
        !            34:                dosig(signum, pc);
        !            35:        /* go back to compatability mode and the signal routine there */
        !            36:        incompat++;
        !            37:        compat();
        !            38: }
        !            39: /* routine to set up pdp11 space for return from a signal */
        !            40: dosig(signum, from) {
        !            41:        unsigned short *sp;
        !            42: #ifdef TRACE
        !            43:        fprintf(stderr,"Caught sig %d from 0%o -> 0%o\n",signum,(pc-1),*(pc-1));
        !            44: #endif
        !            45:        /* where is the stack */
        !            46:        sp = (unsigned short *)regs[6];
        !            47:        /* stack up psw condition codes so rti works */
        !            48:        *(--sp) = psl & 017;
        !            49:        /* stack pc */
        !            50:        *(--sp) = (unsigned short)(int)pc;
        !            51:        /* reset stack pointer */
        !            52:        regs[6] = (unsigned short)(int)sp;
        !            53:        /* reset pc to signal catching routine */
        !            54:        pc = (unsigned short *)sigvals[signum];
        !            55: }

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