OpenCores
URL https://opencores.org/ocsvn/openrisc/openrisc/trunk

Subversion Repositories openrisc

[/] [openrisc/] [trunk/] [gnu-old/] [newlib-1.17.0/] [libgloss/] [pa/] [crt0.S] - Blame information for rev 831

Go to most recent revision | Details | Compare with Previous | View Log

Line No. Rev Author Line
1 148 jeremybenn
/* crt0.S -- startup file for hppa.
2
 *
3
 * Copyright (c) 1995 Cygnus Support
4
 *
5
 * The authors hereby grant permission to use, copy, modify, distribute,
6
 * and license this software and its documentation for any purpose, provided
7
 * that existing copyright notices are retained in all copies and that this
8
 * notice is included verbatim in any distributions. No written agreement,
9
 * license, or royalty fee is required for any of the authorized uses.
10
 * Modifications to this software may be copyrighted by their authors
11
 * and need not follow the licensing terms described here, provided that
12
 * the new terms are clearly indicated on the first page of each file where
13
 * they apply.
14
 */
15
        .VERSION "1.0"
16
        .COPYRIGHT "crt0.o for the PA"
17
 
18
        .DATA
19
 
20
/*
21
 * Set up the standard spaces (sections) These definitions come
22
 * from /lib/pcc_prefix.s.
23
 */
24
        .TEXT
25
 
26
/*
27
 * stuff we need that's defined elsewhere.
28
 */
29
        .IMPORT main, CODE
30
        .IMPORT exit, CODE
31
        .IMPORT _bss_start, DATA
32
        .IMPORT _end, DATA
33
        .IMPORT environ, DATA
34
 
35
/*
36
 * start -- set things up so the application will run.
37
 *
38
 */
39
        .PROC
40
        .CALLINFO SAVE_SP, FRAME=48
41
        .EXPORT $START$,ENTRY
42
$START$
43
 
44
        /* FIXME: this writes to page zero */
45
        ;; setup the %30 (stack pointer) with some memory
46
        ldil    L%_stack,%r30
47
        ldo     R%_stack(%r30),%r30
48
 
49
        ;; we need to set %r27 (global data pointer) here too
50
        ldil    L%$global$,%r27
51
        ldo     R%$global$(%r27),%r27           ; same problem as above
52
 
53
/*
54
 * zerobss -- zero out the bss section
55
 */
56
        ; load the start of bss
57
        ldil    L%_bss_start,%r4
58
        ldo     R%_bss_start(%r4),%r4
59
 
60
        ;  load the end of bss
61
        ldil    L%_end,%r5
62
        ldo     R%_end(%r5),%r5
63
 
64
 
65
L$bssloop
66
        addi    -1,%r5,%r5                      ; decrement _bss_end
67
        stb     %r0,0(0,%r5)                    ; we do this by bytes for now even
68
                                                ; though it's slower, it's safer
69
        combf,= %r4,%r5, L$bssloop
70
        nop
71
 
72
        ldi     1,%ret0
73
 
74
/*
75
 * Call the main routine from the application to get it going.
76
 * main (argc, argv, environ)
77
 * We pass argv as a pointer to NULL.
78
 */
79
 
80
        ldil    L%main,%r22
81
        ble     R%main(%sr4,%r22)
82
        copy    %r31,%r2
83
/*
84
 * Call exit() from the C library with the return value from main()
85
 */
86
        copy    %r28,%r26
87
        ldil    L%exit,%r22
88
        ble     R%exit(%sr4,%r22)
89
        copy    %r31,%r2
90
 
91
        .PROCEND
92
/*
93
 * _exit -- Exit from the application. Normally we cause a user trap
94
 *          to return to the ROM monitor for another run.
95
 */
96
        .EXPORT _exit, ENTRY
97
_exit
98
        .PROC
99
        .CALLINFO
100
        .ENTRY
101
 
102
        ;; This just causes a breakpoint exception
103
        break   0x0,0x0
104
        bv,n    (%rp)
105
        nop
106
        .EXIT
107
        .PROCEND
108
 
109
/*
110
 * _sr4export -- support for called functions. (mostly for GDB)
111
 */
112
        .EXPORT _sr4export, ENTRY
113
_sr4export:
114
        .PROC
115
        .CALLINFO
116
        .ENTRY
117
 
118
        ble     0(%sr4,%r22)
119
        copy    %r31,%rp
120
        ldw     -24(%sr0,%sp),%rp
121
        ldsid   (%sr0,%rp),%r1
122
        mtsp    %r1,%sr0
123
        be,n    0(%sr0,%rp)
124
        nop
125
        .EXIT
126
        .PROCEND
127
 
128
 

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.