| 1 | ##============================================================================== |
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| 2 | ## |
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| 3 | ## crt0.S |
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| 4 | ## |
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| 5 | ## IQ2000 startup code |
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| 6 | ## |
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| 7 | ##============================================================================== |
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| 8 | ## |
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| 9 | ## Copyright (c) 2000, Cygnus Solutions, A Red Hat Company |
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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 | lui %29,%hi(__stack) |
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| 32 | ori %29,%29,%lo(__stack) |
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| 33 | |
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| 34 | lui %24,%hi(_edata) # get start of bss |
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| 35 | ori %24,%24,%lo(_edata) |
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| 36 | |
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| 37 | lui %25,%hi(_end) # get end of bss |
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| 38 | ori %25,%25,%lo(_end) |
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| 39 | |
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| 40 | beq %24,%25,.L0 # check if end and start are the same |
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| 41 | # do nothing if no bss |
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| 42 | |
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| 43 | .L1: |
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| 44 | sb %0,0(%24) # clear a byte and bump pointer |
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| 45 | addi %24,%24,1 |
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| 46 | bne %24,%25,.L1 |
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| 47 | nop |
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| 48 | |
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| 49 | .L0: |
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| 50 | jal _main # call _main to run ctors/dtors |
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| 51 | nop |
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| 52 | xor %4,%4,%4 |
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| 53 | jal main # call main program |
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| 54 | xor %5,%5,%5 |
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| 55 | jal exit # all done, no need to return or |
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| 56 | or %4,%0,%2 # exit with main's return value |
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| 57 | |
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| 58 | .section .data |
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| 59 | .global __dso_handle |
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| 60 | .weak __dso_handle |
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| 61 | __dso_handle: |
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| 62 | .long 0 |
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