[0074691a] | 1 | /* |
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| 2 | * $Id$ |
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| 3 | * |
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| 4 | * Re-written the gen68302 start-up code. |
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| 5 | * |
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| 6 | * Uses gas syntax only, removed the OAR asm.h. |
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| 7 | * |
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| 8 | * Supplies a complete vector table in ROM. |
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| 9 | * |
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| 10 | * Manages all vectors with seperate handlers to trap unhandled |
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| 11 | * execptions. |
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| 12 | * |
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| 13 | * Uses the target specific header file to get the runtime |
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| 14 | * configuration |
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| 15 | * |
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| 16 | * COPYRIGHT (c) 1996 |
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| 17 | * Objective Design Systems Pty Ltd (ODS) |
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| 18 | * |
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| 19 | * COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994. |
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| 20 | * On-Line Applications Research Corporation (OAR). |
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| 21 | * All rights assigned to U.S. Government, 1994. |
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| 22 | * |
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| 23 | * This material may be reproduced by or for the U.S. Government pursuant |
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| 24 | * to the copyright license under the clause at DFARS 252.227-7013. This |
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| 25 | * notice must appear in all copies of this file and its derivatives. |
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| 26 | * |
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| 27 | */ |
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| 28 | |
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| 29 | | |
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| 30 | | Entry from debugger |
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| 31 | | |
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| 32 | .sect .text |
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| 33 | |
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| 34 | | |
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| 35 | | Start |
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| 36 | | |
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| 37 | | Entered from a hardware reset. |
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| 38 | | |
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| 39 | |
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| 40 | .global start | Default entry point for GNU |
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| 41 | start: |
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| 42 | |
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| 43 | move.w #0x2700,%sr | Disable all interrupts |
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| 44 | |
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| 45 | | |
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| 46 | | zero out uninitialized data area |
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| 47 | | |
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| 48 | |
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| 49 | zerobss: |
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| 50 | moveal #end,%a0 | find end of .bss |
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| 51 | moveal #bss_start,%a1 | find beginning of .bss |
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| 52 | moveq #0,%d0 |
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| 53 | |
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| 54 | zerobss_loop: |
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| 55 | |
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| 56 | movel %d0,%a1@+ | to zero out uninitialized |
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| 57 | cmpal %a0,%a1 |
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| 58 | jlt zerobss_loop | loop until _end reached |
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| 59 | |
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| 60 | movel #end,%d0 | d0 = end of bss/start of heap |
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| 61 | addl #heap_size,%d0 | d0 = end of heap |
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| 62 | |
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| 63 | movel %d0,stack_start | Save for brk() routine |
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| 64 | addl #stack_size,%d0 | make room for stack |
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| 65 | andl #0xffffffc0,%d0 | align it on 16 byte boundary |
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| 66 | |
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| 67 | movw #0x3700,%sr | SUPV MODE,INTERRUPTS OFF!!! |
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| 68 | movel %d0,%a7 | set master stack pointer |
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| 69 | movel %d0,%a6 | set base pointer |
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| 70 | |
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| 71 | jsr boot_phase_3 |
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| 72 | |
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| 73 | | |
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| 74 | | Initialised data |
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| 75 | | |
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| 76 | |
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| 77 | .sect .data |
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| 78 | |
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| 79 | .global start_frame |
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| 80 | |
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| 81 | start_frame: |
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| 82 | .space 4,0 |
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| 83 | |
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| 84 | .global stack_start |
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| 85 | |
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| 86 | stack_start: |
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| 87 | .space 4,0 |
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| 88 | |
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| 89 | | |
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| 90 | | Uninitialised data |
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| 91 | | |
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| 92 | |
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| 93 | .sect .bss |
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| 94 | |
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| 95 | .global environ |
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| 96 | .align 2 |
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| 97 | |
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| 98 | environ: |
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| 99 | .long 0 |
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| 100 | |
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| 101 | .global heap_size |
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| 102 | .set heap_size,0x2000 |
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| 103 | |
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| 104 | .global stack_size |
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| 105 | .set stack_size,0x1000 |
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| 106 | |
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| 107 | |
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