usr/src/lib/libc/mips/gen/setjmp.s

/*-
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Ralph Campbell.
 *
 * %sccs.include.redist.c%
 */

#include <sys/syscall.h>
#include "DEFS.h"

#if defined(LIBC_SCCS) && !defined(lint)
        ASMSTR("@(#)setjmp.s    5.2 (Berkeley) %G%")
#endif /* LIBC_SCCS and not lint */

/*
 * C library -- setjmp, longjmp
 *
 *      longjmp(a,v)
 * will generate a "return(v)" from
 * the last call to
 *      setjmp(a)
 * by restoring registers from the stack,
 * and a struct sigcontext, see <signal.h>
 */

#define SETJMP_FRAME_SIZE       (STAND_FRAME_SIZE + 8)

NON_LEAF(setjmp, SETJMP_FRAME_SIZE, ra)
        subu    sp, sp, SETJMP_FRAME_SIZE       # allocate stack frame
        .mask   0x80000000, (STAND_RA_OFFSET - STAND_FRAME_SIZE)
        sw      ra, STAND_RA_OFFSET(sp)         # save state
        sw      a0, SETJMP_FRAME_SIZE(sp)
        move    a0, zero                        # get current signal mask
        jal     sigblock
        lw      v1, SETJMP_FRAME_SIZE(sp)       # v1 = jmpbuf
        sw      v0, (1 * 4)(v1)                 # save sc_mask = sigblock(0)
        move    a0, zero
        addu    a1, sp, STAND_FRAME_SIZE        # pointer to struct sigstack
        jal     sigstack
        lw      a0, SETJMP_FRAME_SIZE(sp)       # restore jmpbuf
        lw      v1, STAND_FRAME_SIZE+4(sp)      # get old ss_onstack
        sw      v1, 0(a0)                       # save it in sc_onstack
        lw      ra, STAND_RA_OFFSET(sp)
        addu    sp, sp, SETJMP_FRAME_SIZE
        blt     v0, zero, botch                 # check for sigstack() error
        sw      ra, (2 * 4)(a0)                 # sc_pc = return address
        li      v0, 0xACEDBADE                  # sigcontext magic number
        sw      v0, ((ZERO + 3) * 4)(a0)        #   saved in sc_regs[0]
        sw      s0, ((S0 + 3) * 4)(a0)
        sw      s1, ((S1 + 3) * 4)(a0)
        sw      s2, ((S2 + 3) * 4)(a0)
        sw      s3, ((S3 + 3) * 4)(a0)
        sw      s4, ((S4 + 3) * 4)(a0)
        sw      s5, ((S5 + 3) * 4)(a0)
        sw      s6, ((S6 + 3) * 4)(a0)
        sw      s7, ((S7 + 3) * 4)(a0)
        sw      gp, ((GP + 3) * 4)(a0)
        sw      sp, ((SP + 3) * 4)(a0)
        sw      s8, ((S8 + 3) * 4)(a0)
        li      v0, 1                           # be nice if we could tell
        sw      v0, (37 * 4)(a0)                # sc_fpused = 1
        cfc1    v0, $31
        swc1    $f20, ((20 + 38) * 4)(a0)
        swc1    $f21, ((21 + 38) * 4)(a0)
        swc1    $f22, ((22 + 38) * 4)(a0)
        swc1    $f23, ((23 + 38) * 4)(a0)
        swc1    $f24, ((24 + 38) * 4)(a0)
        swc1    $f25, ((25 + 38) * 4)(a0)
        swc1    $f26, ((26 + 38) * 4)(a0)
        swc1    $f27, ((27 + 38) * 4)(a0)
        swc1    $f28, ((28 + 38) * 4)(a0)
        swc1    $f29, ((29 + 38) * 4)(a0)
        swc1    $f30, ((30 + 38) * 4)(a0)
        swc1    $f31, ((31 + 38) * 4)(a0)
        sw      v0, ((32 + 38) * 4)(a0)
        move    v0, zero
        j       ra
END(setjmp)

LEAF(longjmp)
        sw      a1, ((V0 + 3) * 4)(a0)  # save return value in sc_regs[V0]
        li      v0, SYS_sigreturn
        syscall
botch:
        jal     longjmperror
        jal     abort
END(longjmp)