| 1 | /* crt0.S -- startup file for hppa. |
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| 2 | * |
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| 3 | * Copyright (c) 1995 Cygnus Support |
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| 4 | * |
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| 5 | * The authors hereby grant permission to use, copy, modify, distribute, |
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| 6 | * and license this software and its documentation for any purpose, provided |
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| 7 | * that existing copyright notices are retained in all copies and that this |
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| 8 | * notice is included verbatim in any distributions. No written agreement, |
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| 9 | * license, or royalty fee is required for any of the authorized uses. |
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| 10 | * Modifications to this software may be copyrighted by their authors |
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| 11 | * and need not follow the licensing terms described here, provided that |
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| 12 | * the new terms are clearly indicated on the first page of each file where |
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| 13 | * they apply. |
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| 14 | */ |
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| 15 | .VERSION "1.0" |
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| 16 | .COPYRIGHT "crt0.o for the PA" |
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| 17 | |
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| 18 | .DATA |
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| 19 | |
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| 20 | /* |
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| 21 | * Set up the standard spaces (sections) These definitions come |
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| 22 | * from /lib/pcc_prefix.s. |
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| 23 | */ |
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| 24 | .TEXT |
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| 25 | |
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| 26 | /* |
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| 27 | * stuff we need that's defined elsewhere. |
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| 28 | */ |
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| 29 | .IMPORT main, CODE |
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| 30 | .IMPORT exit, CODE |
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| 31 | .IMPORT _bss_start, DATA |
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| 32 | .IMPORT _end, DATA |
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| 33 | .IMPORT environ, DATA |
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| 34 | |
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| 35 | /* |
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| 36 | * start -- set things up so the application will run. |
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| 37 | * |
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| 38 | */ |
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| 39 | .PROC |
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| 40 | .CALLINFO SAVE_SP, FRAME=48 |
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| 41 | .EXPORT $START$,ENTRY |
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| 42 | $START$ |
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| 43 | |
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| 44 | /* FIXME: this writes to page zero */ |
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| 45 | ;; setup the %30 (stack pointer) with some memory |
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| 46 | ldil L%_stack,%r30 |
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| 47 | ldo R%_stack(%r30),%r30 |
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| 48 | |
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| 49 | ;; we need to set %r27 (global data pointer) here too |
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| 50 | ldil L%$global$,%r27 |
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| 51 | ldo R%$global$(%r27),%r27 ; same problem as above |
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| 52 | |
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| 53 | /* |
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| 54 | * zerobss -- zero out the bss section |
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| 55 | */ |
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| 56 | ; load the start of bss |
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| 57 | ldil L%_bss_start,%r4 |
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| 58 | ldo R%_bss_start(%r4),%r4 |
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| 59 | |
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| 60 | ; load the end of bss |
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| 61 | ldil L%_end,%r5 |
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| 62 | ldo R%_end(%r5),%r5 |
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| 63 | |
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| 64 | |
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| 65 | L$bssloop |
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| 66 | addi -1,%r5,%r5 ; decrement _bss_end |
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| 67 | stb %r0,0(0,%r5) ; we do this by bytes for now even |
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| 68 | ; though it's slower, it's safer |
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| 69 | combf,= %r4,%r5, L$bssloop |
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| 70 | nop |
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| 71 | |
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| 72 | ldi 1,%ret0 |
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| 73 | |
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| 74 | /* |
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| 75 | * Call the main routine from the application to get it going. |
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| 76 | * main (argc, argv, environ) |
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| 77 | * We pass argv as a pointer to NULL. |
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| 78 | */ |
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| 79 | |
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| 80 | ldil L%main,%r22 |
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| 81 | ble R%main(%sr4,%r22) |
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| 82 | copy %r31,%r2 |
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| 83 | /* |
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| 84 | * Call exit() from the C library with the return value from main() |
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| 85 | */ |
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| 86 | copy %r28,%r26 |
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| 87 | ldil L%exit,%r22 |
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| 88 | ble R%exit(%sr4,%r22) |
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| 89 | copy %r31,%r2 |
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| 90 | |
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| 91 | .PROCEND |
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| 92 | /* |
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| 93 | * _exit -- Exit from the application. Normally we cause a user trap |
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| 94 | * to return to the ROM monitor for another run. |
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| 95 | */ |
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| 96 | .EXPORT _exit, ENTRY |
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| 97 | _exit |
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| 98 | .PROC |
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| 99 | .CALLINFO |
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| 100 | .ENTRY |
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| 101 | |
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| 102 | ;; This just causes a breakpoint exception |
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| 103 | break 0x0,0x0 |
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| 104 | bv,n (%rp) |
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| 105 | nop |
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| 106 | .EXIT |
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| 107 | .PROCEND |
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| 108 | |
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| 109 | /* |
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| 110 | * _sr4export -- support for called functions. (mostly for GDB) |
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| 111 | */ |
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| 112 | .EXPORT _sr4export, ENTRY |
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| 113 | _sr4export: |
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| 114 | .PROC |
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| 115 | .CALLINFO |
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| 116 | .ENTRY |
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| 117 | |
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| 118 | ble 0(%sr4,%r22) |
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| 119 | copy %r31,%rp |
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| 120 | ldw -24(%sr0,%sp),%rp |
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| 121 | ldsid (%sr0,%rp),%r1 |
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| 122 | mtsp %r1,%sr0 |
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| 123 | be,n 0(%sr0,%rp) |
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| 124 | nop |
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| 125 | .EXIT |
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| 126 | .PROCEND |
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| 127 | |
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| 128 | |
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