| 1 | /* crt0.S for the Visium processor. |
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| 2 | |
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| 3 | Copyright (c) 2015 Rolls-Royce Controls and Data Services Limited. |
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| 4 | All rights reserved. |
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| 5 | |
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| 6 | Redistribution and use in source and binary forms, with or without |
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| 7 | modification, are permitted provided that the following conditions are met: |
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| 8 | |
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| 9 | * Redistributions of source code must retain the above copyright notice, |
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| 10 | this list of conditions and the following disclaimer. |
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| 11 | * Redistributions in binary form must reproduce the above copyright |
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| 12 | notice, this list of conditions and the following disclaimer in the |
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| 13 | documentation and/or other materials provided with the distribution. |
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| 14 | * Neither the name of Rolls-Royce Controls and Data Services Limited nor |
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| 15 | the names of its contributors may be used to endorse or promote products |
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| 16 | derived from this software without specific prior written permission. |
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| 17 | |
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| 18 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
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| 19 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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| 20 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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| 21 | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
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| 22 | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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| 23 | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
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| 24 | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
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| 25 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
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| 26 | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
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| 27 | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
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| 28 | THE POSSIBILITY OF SUCH DAMAGE. */ |
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| 29 | |
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| 30 | .weak _get_cmdline |
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| 31 | .text |
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| 32 | .align 4 |
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| 33 | .global __start |
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| 34 | __start: |
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| 35 | /* Initialize the stack pointer. */ |
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| 36 | moviu r1,%u _estack |
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| 37 | movil r1,%l _estack |
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| 38 | move.l r23,r1 |
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| 39 | |
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| 40 | /* Terminate the frame chain. */ |
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| 41 | moviq r22,0 |
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| 42 | |
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| 43 | /* Zero the .bss segment. */ |
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| 44 | moviu r1,%u __bss_start |
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| 45 | movil r1,%l __bss_start |
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| 46 | moviu r2,%u __bss_end |
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| 47 | movil r2,%l __bss_end |
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| 48 | .L0: |
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| 49 | cmp.l r1,r1 |
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| 50 | brr eq,.L1 |
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| 51 | nop |
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| 52 | write.b (r1),r0 |
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| 53 | brr tr,.L0 |
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| 54 | addi r1,1 |
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| 55 | .L1: |
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| 56 | /* Register __fini (destructors) with atexit. */ |
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| 57 | moviu r1,%u __fini |
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| 58 | moviu r2,%u atexit |
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| 59 | movil r2,%l atexit |
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| 60 | bra tr,r2,r21 |
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| 61 | movil r1,%l __fini |
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| 62 | |
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| 63 | /* Call __init (constructors). */ |
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| 64 | moviu r1,%u __init |
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| 65 | movil r1,%l __init |
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| 66 | bra tr,r1,r21 |
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| 67 | nop |
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| 68 | |
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| 69 | /* Set up argc and argv. */ |
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| 70 | moviu r3,%u _get_cmdline |
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| 71 | movil r3,%l _get_cmdline |
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| 72 | cmp.l r3,r0 |
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| 73 | moviq r1,0 |
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| 74 | bra ne,r3,r21 |
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| 75 | moviq r2,0 |
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| 76 | |
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| 77 | /* Call the main program. */ |
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| 78 | moviu r3,%u main |
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| 79 | movil r3,%l main |
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| 80 | bra tr,r3,r21 |
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| 81 | nop |
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| 82 | |
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| 83 | /* Call exit in case the main program didn't. */ |
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| 84 | moviu r2,%u exit |
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| 85 | movil r2,%l exit |
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| 86 | bra tr,r2,r21 |
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| 87 | nop |
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| 88 | .end |
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