source: rtems/c/src/lib/libbsp/powerpc/score603e/start/start.S @ 31a5ec8

4.9
Last change on this file since 31a5ec8 was 31a5ec8, checked in by Jennifer Averett <Jennifer.Averett@…>, on May 5, 2009 at 4:18:06 PM

2009-05-05 Jennifer Averett <jennifer.averett@…>

  • Makefile.am, README, configure.ac, preinstall.am, PCI_bus/PCI.c, PCI_bus/PCI.h, PCI_bus/flash.c, PCI_bus/universe.c, console/85c30.c, console/85c30.h, console/console.c, console/consolebsp.h, console/tbl85c30.c, include/bsp.h, include/coverhd.h, include/gen2.h, include/irq-config.h, include/tm27.h, irq/FPGA.c, irq/irq.h, irq/irq_init.c, start/start.S, startup/Hwr_init.c, startup/bspstart.c, timer/timer.c, tod/tod.c: Updated and tested with the latest powerpc isr source
  • irq/no_pic.c: New file.
  • irq/irq.c, startup/genpvec.c, startup/setvec.c, startup/vmeintr.c: Removed.
  • Property mode set to 100644
File size: 3.4 KB
Line 
1/*
2 * This is based on the mvme-crt0.S file from libgloss/rs6000.
3 * crt0.S -- startup file for PowerPC systems.
4 *
5 * Copyright (c) 1995 Cygnus Support
6 *
7 * The authors hereby grant permission to use, copy, modify, distribute,
8 * and license this software and its documentation for any purpose, provided
9 * that existing copyright notices are retained in all copies and that this
10 * notice is included verbatim in any distributions. No written agreement,
11 * license, or royalty fee is required for any of the authorized uses.
12 * Modifications to this software may be copyrighted by their authors
13 * and need not follow the licensing terms described here, provided that
14 * the new terms are clearly indicated on the first page of each file where
15 * they apply.
16 *
17 * $Id$
18 */
19
20#include "ppc-asm.h"
21
22        .file   "start.s"
23        .section ".got2","aw"
24        .align  2
25
26.LCTOC1 = .+32768
27
28        .extern FUNC_NAME(atexit)
29        .globl  FUNC_NAME(__atexit)
30        .section ".sdata","aw"
31        .align  2
32FUNC_NAME(__atexit):                    /* tell C's eabi-ctor's we have an atexit function */
33        .long   FUNC_NAME(atexit)@fixup /* and that it is to register __do_global_dtors */
34
35        .section ".fixup","aw"
36        .align  2
37        .long   FUNC_NAME(__atexit)
38
39        .section ".got2","aw"
40.Ltable = .-.LCTOC1
41        .long   .LCTOC1                 /* address we think .LCTOC1 is loaded at */
42
43.Lbss_start = .-.LCTOC1
44        .long   _edata                 /* includes sbss and bss */
45
46.Lend = .-.LCTOC1
47        .long   _end
48
49.Lstack = .-.LCTOC1                     /* stack address if set by user */
50        .long   __stack
51
52        .text
53.Lptr:
54        .long .LCTOC1-.Laddr
55
56        .globl  _start
57        .type   _start,@function
58_start:
59        b       past_constants
60                                        /* Set MSR */
61        .long   _etext                  /* end of code space */
62        .long   _edata                  /* end of code and data space */
63
64past_constants:
65        lis     r5,0
66        mr      r4,r5
67        ori     r4,r4,0x0000            /* 0x2030  */
68        mtmsr   r4
69
70        /* The first generation board needed initialization here but the */
71        /* second does not. */
72
73        bl      .Laddr                  /* get current address */
74.Laddr:
75        mflr    r4                      /* real address of .Laddr */
76        lwz     r5,(.Lptr-.Laddr)(r4)   /* linker generated address of .LCTOC1 */
77        add     r5,r5,r4                /* correct to real pointer */
78        lwz     r4,.Ltable(r5)          /* get linker's idea of where .Laddr is */
79        subf    r4,r4,r5                /* calculate difference between where linked and current */
80
81        /* clear bss */
82        lwz     r6,.Lbss_start(r5)      /* calculate beginning of the BSS */
83        lwz     r7,.Lend(r5)            /* calculate end of the BSS */
84        add     r6,r6,r4                /* adjust pointers */
85        add     r7,r7,r4
86
87        cmplw   1,r6,r7
88        bc      4,4,.Ldone
89
90        subf    r8,r6,r7                /* number of bytes to zero */
91        srwi    r9,r8,2                 /* number of words to zero */
92        mtctr   r9
93        li      r0,0                    /* zero to clear memory */
94        addi    r6,r6,-4                /* adjust so we can use stwu */
95.Lloop:
96        stwu    r0,4(r6)                /* zero bss */
97        bdnz    .Lloop
98
99.Ldone:
100
101        lwz     r0,.Lstack(r5)          /* stack address or 0 */
102        cmplwi  1,r0,0                  /* equal to 0? */
103        bc      12,6,.Lnostack          /* use default stack if == 0 */
104        mr      sp,r0                   /* use user defined stack */
105
106.Lnostack:
107
108        lis     r13,_SDA_BASE_@ha
109        la      r13,_SDA_BASE_@l(r13)           /* Read-write small data */
110
111        /* set up initial stack frame */
112        addi    sp,sp,-4                /* make sure we don't overwrite debug mem */
113        lis     r0,0
114        stw     r0,0(sp)                /* clear back chain */
115        stwu    sp,-56(sp)              /* push another stack frame */
116
117        lis     r5,environ@ha
118        la      r5,environ@l(r5)        /* environp */
119        li      r4, 0                   /* argv */
120        li      r3, 0                   /* argc */
121        /* Let her rip */
122        bl      FUNC_NAME(boot_card)
123
124        /* return value from boot_card is argument to exit */
125        bl      FUNC_NAME(exit)
126        trap
127.Lstart:
128        .size   _start,.Lstart-_start
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