h_execregs.S revision 1.1 1 /* $NetBSD: h_execregs.S,v 1.1 2025/02/27 00:55:32 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 2025 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #define _LOCORE
30
31 #include <sys/syscall.h>
32
33 #include <machine/asm.h>
34
35 #include "execregs.h"
36
37 #define REGSIZE 4
38 #define BUFSIZE (NEXECREGS * REGSIZE)
39 #define SLOT(n) (n)*REGSIZE(%sp)
40
41 ENTRY(execregs_start, 0)
42 /* store registers to a buffer on stack */
43 subl2 $BUFSIZE,%sp /* space for NEXECREGS registers */
44 movl %fp,SLOT(0) /* order matches execregs.h */
45 movl %ap,SLOT(1)
46 /* sp: stack pointer */
47 movl %r0,SLOT(2)
48 movl %r1,SLOT(3)
49 movl %r2,SLOT(4)
50 movl %r3,SLOT(5)
51 movl %r4,SLOT(6)
52 movl %r5,SLOT(7)
53 /* r6: initial stack pointer */
54 movl %r7,SLOT(8)
55 movl %r8,SLOT(9)
56 /* r9: ps_strings */
57 movl %r10,SLOT(10)
58 movl %r11,SLOT(11)
59
60 /* call write(STDOUT_FILENO, regs, sizeof(regs)) */
61 pushl $BUFSIZE /* arg2 := sizeof(regs) */
62 pushal 4(%sp) /* arg1 := regs */
63 pushl $1 /* arg0 := STDOUT_FILENO */
64 pushl $3 /* number of arguments */
65 movl %sp,%ap /* argument pointer */
66 chmk $SYS_write
67
68 bcs 2f /* bail if write failed */
69 cmpl $BUFSIZE,%r0 /* bail if wrote wrong # of bytes */
70 bneq 2f
71
72 /* call exit(0) */
73 pushl $0 /* arg0 := 0 */
74 1: pushl $1 /* number of arguments */
75 movl %sp,%ap /* argument pointer */
76 chmk $SYS_exit
77 .word 0xffff /* paranoia -- illegal opcode */
78
79 2: /* call exit(127) */
80 pushl $127 /* arg0 := 127 */
81 jmp 1b
82 END(execregs_start)
83
84 /* main stub to simplify linking */
85 ENTRY(main, 0)
86 .word 0xffff /* illegal opcode */
87 END(main)
88