1/*        $NetBSD: _setjmp.S,v 1.7 2024/05/04 14:48:28 skrll Exp $    */
2
3/*-
4 * Copyright (c) 2002 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Matthew Fredette.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include "assym.h"
33
34#include <machine/asm.h>
35#include <machine/frame.h>
36
37#if defined(LIBC_SCCS) && !defined(lint)
38          RCSID("$NetBSD: _setjmp.S,v 1.7 2024/05/04 14:48:28 skrll Exp $")
39#endif /* LIBC_SCCS and not lint */
40
41/*
42 * C library -- setjmp, longjmp
43 *
44 *        longjmp(a,v)
45 * will generate a "return(v)" from
46 * the last call to
47 *        setjmp(a)
48 * by restoring registers from the stack,
49 * and a struct sigcontext, see <signal.h>
50 */
51
52ENTRY(_setjmp,0)
53          /* A sigcontext is at the beginning of our jmp_buf. */
54          stw       %r0, _SC_ONSTACK(%arg0)                 ; no onstack
55          stw       %r0, _SC_MASK13(%arg0)                  ; unused word (old style signal mask)
56          stw       %sp, _SC_REGS_SP(%arg0)                 ; sc.sc_sp = %sp
57          stw       %r0, _SC_REGS_AP(%arg0)                 ; sc.sc_ap = NULL
58          mfsp      %sr0, %r1
59          stw       %r1, _SC_REGS_PCSQH(%arg0)    ; sc.sc_pcsqh = %sr0
60          stw       %rp, _SC_REGS_PCOQH(%arg0)    ; sc.sc_pcoqh = %rp
61          stw       %r1, _SC_REGS_PCSQT(%arg0)    ; sc.sc_pcsqh = %sr0
62          ldo       4(%rp), %r1
63          stw       %r1, _SC_REGS_PCOQT(%arg0)    ; sc.sc_pcoqt = %rp + 4
64          stw       %r0, _SC_REGS_PS(%arg0)                 ; set sc.sc_ps
65
66          /* We store all callee-saved registers after the sigcontext. */
67          ldo       SIZEOF_SIGCONTEXT(%arg0), %r1
68          stwm      %r3, 4(%r1)
69          stwm      %r4, 4(%r1)
70          stwm      %r5, 4(%r1)
71          stwm      %r6, 4(%r1)
72          stwm      %r7, 4(%r1)
73          stwm      %r8, 4(%r1)
74          stwm      %r9, 4(%r1)
75          stwm      %r10, 4(%r1)
76          stwm      %r11, 4(%r1)
77          stwm      %r12, 4(%r1)
78          stwm      %r13, 4(%r1)
79          stwm      %r14, 4(%r1)
80          stwm      %r15, 4(%r1)
81          stwm      %r16, 4(%r1)
82          stwm      %r17, 4(%r1)
83          stwm      %r18, 4(%r1)
84
85          /* Return 0. */
86          bv        %r0(%rp)
87           copy     %r0, %ret0
88EXIT(_setjmp)
89
90ENTRY(_longjmp,0)
91          ldw       _SC_REGS_SP(%arg0), %r1       ; ensure non-zero SP
92          combt,=,n %r0, %r1, botch     ; oops!
93          add,<>    %r0, %arg1, %ret0   ; ensure return value non-zero
94          ldi       1, %ret0
95
96          /* restore callee-saved registers */
97          ldo       SIZEOF_SIGCONTEXT(%arg0), %r1
98          ldwm      4(%r1), %r3
99          ldwm      4(%r1), %r4
100          ldwm      4(%r1), %r5
101          ldwm      4(%r1), %r6
102          ldwm      4(%r1), %r7
103          ldwm      4(%r1), %r8
104          ldwm      4(%r1), %r9
105          ldwm      4(%r1), %r10
106          ldwm      4(%r1), %r11
107          ldwm      4(%r1), %r12
108          ldwm      4(%r1), %r13
109          ldwm      4(%r1), %r14
110          ldwm      4(%r1), %r15
111          ldwm      4(%r1), %r16
112          ldwm      4(%r1), %r17
113          ldwm      4(%r1), %r18
114
115          /* restore the rest */
116          ldw       _SC_REGS_SP(%arg0), %sp
117          ldw       _SC_REGS_PCOQH(%arg0), %rp
118          bv        %r0(%rp)
119           nop
120botch:
121          bl        longjmperror, %rp
122           nop
123          bl        abort, %rp
124           nop
125EXIT(_longjmp)
126
127          .end
128