| 1 | ##============================================================================== |
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| 2 | ## |
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| 3 | ## crt0.S |
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| 4 | ## |
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| 5 | ## MN10200 startup code |
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| 6 | ## |
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| 7 | ##============================================================================== |
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| 8 | ## |
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| 9 | ## Copyright (c) 1995, 1996, 1997, 1998 Cygnus Solutions |
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| 10 | ## |
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| 11 | ## The authors hereby grant permission to use, copy, modify, distribute, |
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| 12 | ## and license this software and its documentation for any purpose, provided |
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| 13 | ## that existing copyright notices are retained in all copies and that this |
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| 14 | ## notice is included verbatim in any distributions. No written agreement, |
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| 15 | ## license, or royalty fee is required for any of the authorized uses. |
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| 16 | ## Modifications to this software may be copyrighted by their authors |
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| 17 | ## and need not follow the licensing terms described here, provided that |
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| 18 | ## the new terms are clearly indicated on the first page of each file where |
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| 19 | ## they apply. |
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| 20 | ## |
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| 21 | |
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| 22 | ##------------------------------------------------------------------------------ |
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| 23 | |
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| 24 | .file "crt0.S" |
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| 25 | |
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| 26 | ##------------------------------------------------------------------------------ |
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| 27 | ## Startup code |
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| 28 | .section .text |
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| 29 | .global _start |
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| 30 | _start: |
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| 31 | mov _stack,a3 # Load up the stack pointer and allocate |
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| 32 | # our current frame. |
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| 33 | |
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| 34 | mov _edata,a0 # Get the start/end of bss |
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| 35 | mov _end,a1 |
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| 36 | |
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| 37 | cmp a0,a1 # If no bss, then do nothing |
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| 38 | beqx .L0 |
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| 39 | |
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| 40 | sub d0,d0 # clear d0 |
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| 41 | |
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| 42 | .L1: |
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| 43 | movb d0,(a0) # Clear a byte and bump pointer |
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| 44 | add 1,a0 |
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| 45 | cmp a0,a1 |
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| 46 | bnex .L1 |
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| 47 | |
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| 48 | .L0: |
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| 49 | jsr ___main |
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| 50 | sub d0,d0 |
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| 51 | mov d0,d1 |
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| 52 | mov d0,(a3) |
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| 53 | jsr _main # Call main program |
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| 54 | jmp _exit # All done, no need to return or |
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| 55 | # deallocate our stack. |
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| 56 | |
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| 57 | .section .stack |
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| 58 | _stack: .long 1 |
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