source: trunk/libs/newlib/src/libgloss/sparc/cygmon-crt0.S @ 495

Last change on this file since 495 was 444, checked in by satin@…, 7 years ago

add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc

File size: 2.9 KB
RevLine 
[444]1/*
2 * C startup code for the Fujitsu SPARClite demo board
3 *
4 * Copyright (c) 1995, 1996 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#include "asm.h"
17
18#ifdef TARGET_CPU_SPARC64
19#define STACK_BIAS 2047
20#define SAVE_SIZE -128
21#else
22#define SAVE_SIZE -64
23#endif
24
25.register %g2, #scratch
26.register %g3, #scratch
27       
28.data
29        .align  8
30SYM(environ):                   ! this is the first address in the data section
31        .long   0
32
33SYM(argc):
34        .long   0
35
36        .text
37        .align 8
38
39        .globl SYM(start)
40        .globl start
41SYM(start):
42start:
43        /* see if the stack is already setup. if not, then default
44         *  to using the value of %sp as set by the ROM monitor
45         */
46        sethi   %hi(__stack), %g1
47        or      %g1,%lo(__stack),%g1
48        cmp     %g0,%g1
49        be      1f
50        nop
51#ifdef STACK_BIAS
52        sub     %g1, STACK_BIAS, %g1
53#endif
54        mov     %g1, %sp                                ! set the stack pointer
55        mov     0, %fp
561:     
57
58        /* zero the bss section */
59        sethi %hi(__bss_start),%g2
60        or    %g2,%lo(__bss_start),%g2          ! start of bss
61        sethi %hi(_end),%g3
62        or    %g3,%lo(_end),%g3                 ! end of bss
63        mov   %g0,%g1                           ! so std has two zeros
64zerobss:
65        std    %g0,[%g2]
66        add    %g2,8,%g2
67        cmp    %g2,%g3
68        bleu,a zerobss
69        nop
70       
71/*
72 * initialize target specific stuff. Only execute these
73 * functions it they exist.
74 */
75init:
76        sethi   %hi(SYM(hardware_init_hook)), %g1
77        or      %g1,%lo(SYM(hardware_init_hook)),%g1
78        cmp     %g0,%g1
79        be      1f
80        nop
81        call    SYM(hardware_init_hook)
82        nop
83
841:     
85        sethi   %hi(SYM(software_init_hook)), %g1
86        or      %g1,%lo(SYM(software_init_hook)),%g1
87        cmp     %g0,%g1
88        be      2f
89        nop
90        call    SYM(software_init_hook)
91        nop
922:
93        set     SYM(__sigtramp), %o0
94        call    SYM(__install_signal_handler)
95        nop
96
97        set     do_dtors,%o0
98        call    SYM(atexit)
99        nop
100
101        call    do_ctors
102        nop
103
104        set     SYM(argc), %o0
105        call    SYM(__getProgramArgs)
106        nop
107
108        mov     %o0, %o1
109        set     SYM(argc), %o0
110        ld      [%o0], %o0
111        call SYM(main)
112        nop
113
114        /* call exit from the C library so atexit gets called, and the
115         * C++ destructors get run. This calls our exit routine below   
116         * when it's done.
117         */
118        call    SYM(exit)
119        nop
120
121do_ctors:
122        save    %sp,SAVE_SIZE,%sp
123        set     __CTOR_LIST__,%l0
124our_entry:
125        ld      [%l0],%l1
126        add     %l0,4,%l0
127        tst     %l1
1281:
129        beq     2f
130        nop
131        ld      [%l0],%l2
132        add     %l0,4,%l0
133
134        call    %l2
135        nop
136        deccc   %l1
137        b       1b
138        nop
1392:
140        ret
141        restore
142
143do_dtors:
144        save    %sp,SAVE_SIZE,%sp
145        set     __DTOR_LIST__,%l0
146        b       our_entry
147        nop
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