/*      $OpenBSD: _setjmp.S,v 1.8 2022/05/25 17:32:36 guenther Exp $    */
/*      $NetBSD: _setjmp.S,v 1.5 2003/04/05 23:08:51 bjh21 Exp $        */

/*
 * Copyright (c) 1997 Mark Brinicombe
 * All rights reserved.
 *
 * 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 Mark Brinicombe
 * 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 AUTHOR 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 AUTHOR 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.
 */

#include "DEFS.h"
#include <machine/setjmp.h>

        .section        .openbsd.randomdata,"aw",%progbits
        .balign 4
        .globl  __jmpxor
__jmpxor:
        .zero 4*2               /* (sp, lr) */
        END(__jmpxor)
        .type   __jmpxor,%object


/*
 * 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.
 * The previous signal state is NOT restored.
 *
 * Note: r0 is the return value
 *       r1-r3 are scratch registers in functions
 */

ENTRY(_setjmp)
        ldr     r1, .L_setjmp_magic
        str     r1, [r0], #4
        ldr     r2, .L_jmpxor_setjmp
1:      add     r2, pc, r2                      /* r2 = &__jmpxor */
        ldr     r3, [r2], #4                    /* r3 = __jmpxor[1] */
        ldr     r2, [r2]                        /* r2 = __jmpxor[0] */
        eor     r2, r13, r2                     /* r2 = sp ^ __jmpxor[0] */
        eor     r3, lr, r3                      /* r3 = lr ^ __jmpxor[1] */

#ifdef SOFTFLOAT
        add     r0, r0, #68
#else
        /* Store fpcsr */
        vmrs    r1, fpscr
        str     r1, [r0], #4
        /* Store fp registers */
        vstmia  r0!, {d8-d15}
#endif  /* SOFTFLOAT */
        /* Store integer registers */
        stmia   r0, {r2-r11}

        mov     r0, #0x00000000
        mov     r2, r0                          /* overwrite __jmpxor copies */
        mov     r3, r0
        mov     pc, lr

.L_setjmp_magic:
        .word   _JB_MAGIC__SETJMP

.L_jmpxor_setjmp:
        .word   __jmpxor - 1b
END_STRONG(_setjmp)

ENTRY(_longjmp)
        ldr     r2, .L_setjmp_magic
        ldr     r3, [r0], #4
        teq     r2, r3
        bne     .Lbotch

#ifdef SOFTFLOAT
        add     r0, r0, #68
#else
        /* Restore fpcsr */
        ldr     r4, [r0], #4
        vmsr    fpscr, r4
        /* Restore fp registers */
        vldmia  r0!, {d8-d15}
#endif  /* SOFTFLOAT */
        /* Restore integer registers */
        ldmia   r0, {r2-r11}

        ldr     r0, .L_jmpxor_longjmp
1:      add     r0, pc, r0                      /* r0 = &__jmpxor */
        ldr     lr, [r0], #4                    /* lr = __jmpxor[1] */
        eor     lr, r3, lr                      /* lr ^= jmpbuf[LR] */
        ldr     r0, [r0]                        /* r0 = __jmpxor[0] */
        eor     r13, r0, r2             /* sp = __jmpxor[0] ^ jmpbuf[SP] */
        mov     r2, r1                          /* overwrite __jmpxor copies */
        mov     r3, r1

        /* Validate sp and lr */
        teq     sp, #0
        teqne   lr, #0
        beq     .Lbotch

        /* Set return value */
        mov     r0, r1
        teq     r0, #0x00000000
        moveq   r0, #0x00000001
        mov     pc, lr

.L_jmpxor_longjmp:
        .word   __jmpxor - 1b

        /* validation failed, die die die. */
.Lbotch:
        bl      _HIDDEN(abort)
        b       . - 8           /* Cannot get here */
END_STRONG(_longjmp)