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/*
 * crt0.S -- startup file for m68k-coff
 *
 * Copyright (c) 1995, 1996, 1998 Cygnus Support
 *
 * The authors hereby grant permission to use, copy, modify, distribute,
 * and license this software and its documentation for any purpose, provided
 * that existing copyright notices are retained in all copies and that this
 * notice is included verbatim in any distributions. No written agreement,
 * license, or royalty fee is required for any of the authorized uses.
 * Modifications to this software may be copyrighted by their authors
 * and need not follow the licensing terms described here, provided that
 * the new terms are clearly indicated on the first page of each file where
 * they apply.
 */
 
#include "asm.h"
 
        .title "crt0.S for m68k-coff"
#define STACKSIZE       0x4000
 
/*
 * Define an empty environment.
 */
        .data
        .align 2
SYM (environ):
        .long 0
 
        .align  2
        .text
 
/*
 * These symbols are defined in C code, so they need to always be
 * named with SYM because of the difference between object file formats.
 */
 
/* These are defined in C code. */
        .extern SYM (main)
        .extern SYM (exit)
        .extern SYM (hardware_init_hook)
        .extern SYM (software_init_hook)
        .extern SYM (atexit)
        .extern SYM(__do_global_dtors)
 
/*
 * These values are set in the linker script, so they must be
 * explicitly named here without SYM.
 */
        .extern __stack
        .extern __bss_start
        .extern _end
 
/*
 * set things up so the application will run. This *must* be called start.
 */
        .global SYM (start)
 
SYM (start):
        /*
         * put any hardware init code here
         */
 
        /* See if user supplied their own stack (__stack != 0).  If not, then
         * default to using the value of %sp as set by the ROM monitor.
         */
        movel   IMM(__stack), a0
        cmpl    IMM(0), a0
        jbeq    1f
        movel   a0, sp
1:
        /* set up initial stack frame */
        link    a6, IMM(-8)
 
/*
 * zero out the bss section.
 */
        movel   IMM(__bss_start), d1
        movel   IMM(_end), d0
        cmpl    d0, d1
        jbeq    3f
        movl    d1, a0
        subl    d1, d0
        subql   IMM(1), d0
2:
        clrb    (a0)+
#ifndef __mcf5200__
        dbra    d0, 2b
        clrw    d0
        subql   IMM(1), d0
        jbcc    2b
#else
        subql   IMM(1), d0
        jbpl    2b
#endif
 
3:
 
/*
 * initialize target specific stuff. Only execute these
 * functions it they exist.
 */
        lea     SYM (hardware_init_hook), a0
        cmpl    IMM(0),a0
        jbeq    4f
        jsr     (a0)
4:
 
        lea     SYM (software_init_hook), a0
        cmpl    IMM(0),a0
        jbeq    5f
        jsr     (a0)
5:
 
/*
 * call the main routine from the application to get it going.
 * main (argc, argv, environ)
 * we pass argv as a pointer to NULL.
 */
 
#ifdef ADD_DTORS
        /* put __do_global_dtors in the atexit list so the destructors get run */
        movel   IMM (SYM(__do_global_dtors)),(sp)
        jsr     SYM (atexit)
#endif
        movel   IMM (__FINI_SECTION__),(sp)
        jsr     SYM (atexit)
 
        jsr     __INIT_SECTION__
 
        pea     0
        pea     SYM (environ)
        pea     sp@(4)
        pea     0
        jsr     SYM (main)
        movel   d0, sp@-
 
/*
 * drop down into exit incase the user doesn't. This should drop
 * control back to the ROM monitor, if there is one. This calls the
 * exit() from the C library so the C++ tables get cleaned up right.
 */
        jsr     SYM (exit)

Line No.	Rev	Author	Line
1	39	lampret	`/*`
2			`* crt0.S -- startup file for m68k-coff`
3			`*`
4			`* Copyright (c) 1995, 1996, 1998 Cygnus Support`
5			`*`
6			`* The authors hereby grant permission to use, copy, modify, distribute,`
7			`* and license this software and its documentation for any purpose, provided`
8			`* that existing copyright notices are retained in all copies and that this`
9			`* notice is included verbatim in any distributions. No written agreement,`
10			`* license, or royalty fee is required for any of the authorized uses.`
11			`* Modifications to this software may be copyrighted by their authors`
12			`* and need not follow the licensing terms described here, provided that`
13			`* the new terms are clearly indicated on the first page of each file where`
14			`* they apply.`
15			`*/`
16
17			`#include "asm.h"`
18
19			`.title "crt0.S for m68k-coff"`
20			`#define STACKSIZE 0x4000`
21
22			`/*`
23			`* Define an empty environment.`
24			`*/`
25			`.data`
26			`.align 2`
27			`SYM (environ):`
28			`.long 0`
29
30			`.align 2`
31			`.text`
32
33			`/*`
34			`* These symbols are defined in C code, so they need to always be`
35			`* named with SYM because of the difference between object file formats.`
36			`*/`
37
38			`/* These are defined in C code. */`
39			`.extern SYM (main)`
40			`.extern SYM (exit)`
41			`.extern SYM (hardware_init_hook)`
42			`.extern SYM (software_init_hook)`
43			`.extern SYM (atexit)`
44			`.extern SYM(__do_global_dtors)`
45
46			`/*`
47			`* These values are set in the linker script, so they must be`
48			`* explicitly named here without SYM.`
49			`*/`
50			`.extern __stack`
51			`.extern __bss_start`
52			`.extern _end`
53
54			`/*`
55			`* set things up so the application will run. This must be called start.`
56			`*/`
57			`.global SYM (start)`
58
59			`SYM (start):`
60			`/*`
61			`* put any hardware init code here`
62			`*/`
63
64			`/* See if user supplied their own stack (__stack != 0). If not, then`
65			`* default to using the value of %sp as set by the ROM monitor.`
66			`*/`
67			`movel IMM(__stack), a0`
68			`cmpl IMM(0), a0`
69			`jbeq 1f`
70			`movel a0, sp`
71			`1:`
72			`/* set up initial stack frame */`
73			`link a6, IMM(-8)`
74
75			`/*`
76			`* zero out the bss section.`
77			`*/`
78			`movel IMM(__bss_start), d1`
79			`movel IMM(_end), d0`
80			`cmpl d0, d1`
81			`jbeq 3f`
82			`movl d1, a0`
83			`subl d1, d0`
84			`subql IMM(1), d0`
85			`2:`
86			`clrb (a0)+`
87			`#ifndef __mcf5200__`
88			`dbra d0, 2b`
89			`clrw d0`
90			`subql IMM(1), d0`
91			`jbcc 2b`
92			`#else`
93			`subql IMM(1), d0`
94	56	joel	`jbpl 2b`
95	39	lampret	`#endif`
96
97			`3:`
98
99			`/*`
100			`* initialize target specific stuff. Only execute these`
101			`* functions it they exist.`
102			`*/`
103			`lea SYM (hardware_init_hook), a0`
104			`cmpl IMM(0),a0`
105			`jbeq 4f`
106			`jsr (a0)`
107			`4:`
108
109			`lea SYM (software_init_hook), a0`
110			`cmpl IMM(0),a0`
111			`jbeq 5f`
112			`jsr (a0)`
113			`5:`
114
115			`/*`
116			`* call the main routine from the application to get it going.`
117			`* main (argc, argv, environ)`
118			`* we pass argv as a pointer to NULL.`
119			`*/`
120
121			`#ifdef ADD_DTORS`
122			`/* put __do_global_dtors in the atexit list so the destructors get run */`
123			`movel IMM (SYM(__do_global_dtors)),(sp)`
124			`jsr SYM (atexit)`
125			`#endif`
126			`movel IMM (__FINI_SECTION__),(sp)`
127			`jsr SYM (atexit)`
128
129			`jsr __INIT_SECTION__`
130
131			`pea 0`
132			`pea SYM (environ)`
133			`pea sp@(4)`
134			`pea 0`
135			`jsr SYM (main)`
136			`movel d0, sp@-`
137
138			`/*`
139			`* drop down into exit incase the user doesn't. This should drop`
140			`* control back to the ROM monitor, if there is one. This calls the`
141			`* exit() from the C library so the C++ tables get cleaned up right.`
142			`*/`
143			`jsr SYM (exit)`

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[/] [or1k/] [trunk/] [newlib/] [libgloss/] [m68k/] [crt0.S] - Blame information for rev 1765