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[/] [openrisc/] [trunk/] [gnu-src/] [newlib-1.17.0/] [libgloss/] [mn10300/] [crt0_cygmon.S] - Blame information for rev 626

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/*
 * crt0_cygmon.S -- Minimal startup file for MN10300 targets running Cygmon.
 *
 * Copyright (c) 1995, 1996, 1997, 2000 Red Hat, Inc.
 *
 * 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.
 */
 
/*
 * This file contains the minimal startup code necessary.
 * This will not do any hardware initialization.  It is assumed that we are talking to Cygmon
 * and therefore the hardware will be initialized properly.
 */
 
/*
 * Set up some room for a stack. We just grab a chunk of memory.
 */
#define STACK_SIZE  0x4000
#define GLOBAL_SIZE 0x2000
 
#define STARTUP_STACK_SIZE      0x0100
 
        .comm   __memsize, 12
        .comm   __lstack, STARTUP_STACK_SIZE
        .comm   __stackbase,4
 
        .section .text
        .global _start
_start:
        /*
         * Setup a small stack so we can run some C code,
         * and get the usable memory size.
         */
        mov     __lstack,a0
        add     STARTUP_STACK_SIZE-4,a0
        mov     a0,sp
 
        /*
         * zero out the bss section.
         */
        .global __memsize
        .global _get_mem_info
zerobss:
        mov     __bss_start, a0                         # These variables are defined in the linker script
        mov     _end, a1
 
        cmp     a0, a1                                  # If no bss, then do nothing
        beq     7f
 
        clr     d0
3:
        movbu   d0,(a0)                                 # Clear a byte and bump pointer
        inc     a0
        cmp     a0, a1
        bne     3b
 
7:
        /*
         * Setup the stack pointer --
         *    get_mem_info returns the top of memory, so just use that In
         *    addition, we must subtract 24 bytes for the 3 8 byte
         *    arguments to main, in case main wants to write them back to
         *    the stack.  The caller is supposed to allocate stack space
         *    for parameters in registers in the old MIPS ABIs.  We must
         *    do this even though we aren't passing arguments, because
         *    main might be declared to have them.
         *    Some ports need a larger alignment for the stack, so we
         *    subtract 32, which satisifes the stack for the arguments and
         *    keeps the stack pointer better aligned.
         */
        mov     __memsize, d0
        call    _get_mem_info,[],0
 
        sub     32, a0
        mov     a0, sp
 
        mov     __stackbase, a1
        mov     a0, (a1)                                # keep this for future ref
 
        call    ___main,[],0                            # Call __main to run ctors/dtors
        clr     d0
        clr     d1
        mov     d0, (4,sp)
        call    _main,[],0                              # Call main program
        call    _exit,[],0
 
/* EOF crt0_cygmon.S */

Line No.	Rev	Author	Line
1	148	jeremybenn	`/*`
2			`* crt0_cygmon.S -- Minimal startup file for MN10300 targets running Cygmon.`
3			`*`
4			`* Copyright (c) 1995, 1996, 1997, 2000 Red Hat, Inc.`
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			`/*`
18			`* This file contains the minimal startup code necessary.`
19			`* This will not do any hardware initialization. It is assumed that we are talking to Cygmon`
20			`* and therefore the hardware will be initialized properly.`
21			`*/`
22
23			`/*`
24			`* Set up some room for a stack. We just grab a chunk of memory.`
25			`*/`
26			`#define STACK_SIZE 0x4000`
27			`#define GLOBAL_SIZE 0x2000`
28
29			`#define STARTUP_STACK_SIZE 0x0100`
30
31			`.comm __memsize, 12`
32			`.comm __lstack, STARTUP_STACK_SIZE`
33			`.comm __stackbase,4`
34
35			`.section .text`
36			`.global _start`
37			`_start:`
38			`/*`
39			`* Setup a small stack so we can run some C code,`
40			`* and get the usable memory size.`
41			`*/`
42			`mov __lstack,a0`
43			`add STARTUP_STACK_SIZE-4,a0`
44			`mov a0,sp`
45
46			`/*`
47			`* zero out the bss section.`
48			`*/`
49			`.global __memsize`
50			`.global _get_mem_info`
51			`zerobss:`
52			`mov __bss_start, a0 # These variables are defined in the linker script`
53			`mov _end, a1`
54
55			`cmp a0, a1 # If no bss, then do nothing`
56			`beq 7f`
57
58			`clr d0`
59			`3:`
60			`movbu d0,(a0) # Clear a byte and bump pointer`
61			`inc a0`
62			`cmp a0, a1`
63			`bne 3b`
64
65			`7:`
66			`/*`
67			`* Setup the stack pointer --`
68			`* get_mem_info returns the top of memory, so just use that In`
69			`* addition, we must subtract 24 bytes for the 3 8 byte`
70			`* arguments to main, in case main wants to write them back to`
71			`* the stack. The caller is supposed to allocate stack space`
72			`* for parameters in registers in the old MIPS ABIs. We must`
73			`* do this even though we aren't passing arguments, because`
74			`* main might be declared to have them.`
75			`* Some ports need a larger alignment for the stack, so we`
76			`* subtract 32, which satisifes the stack for the arguments and`
77			`* keeps the stack pointer better aligned.`
78			`*/`
79			`mov __memsize, d0`
80			`call _get_mem_info,[],0`
81
82			`sub 32, a0`
83			`mov a0, sp`
84
85			`mov __stackbase, a1`
86			`mov a0, (a1) # keep this for future ref`
87
88			`call ___main,[],0 # Call __main to run ctors/dtors`
89			`clr d0`
90			`clr d1`
91			`mov d0, (4,sp)`
92			`call _main,[],0 # Call main program`
93			`call _exit,[],0`
94
95			`/* EOF crt0_cygmon.S */`

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[/] [openrisc/] [trunk/] [gnu-src/] [newlib-1.17.0/] [libgloss/] [mn10300/] [crt0_cygmon.S] - Blame information for rev 626