[444] | 1 | ! C run time start off |
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| 2 | |
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| 3 | ! This file supports: |
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| 4 | ! |
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| 5 | ! - both 32bit pointer and 64bit pointer environments (at compile time) |
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| 6 | ! - an imposed stack bias (of 2047) (at run time) |
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| 7 | ! - medium/low and medium/anywhere code models (at run time) |
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| 8 | |
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| 9 | ! Initial stack setup: |
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| 10 | ! |
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| 11 | ! bottom of stack (higher memory address) |
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| 12 | ! ... |
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| 13 | ! text of environment strings |
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| 14 | ! text of argument strings |
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| 15 | ! envp[envc] = 0 (4/8 bytes) |
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| 16 | ! ... |
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| 17 | ! env[0] (4/8 bytes) |
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| 18 | ! argv[argc] = 0 (4/8 bytes) |
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| 19 | ! ... |
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| 20 | ! argv[0] (4/8 bytes) |
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| 21 | ! argc (4/8 bytes) |
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| 22 | ! register save area (64 bits by 16 registers = 128 bytes) |
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| 23 | ! top of stack (%sp) |
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| 24 | |
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| 25 | ! Stack Bias: |
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| 26 | ! |
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| 27 | ! It is the responsibility of the o/s to set this up. |
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| 28 | ! We handle both a 0 and 2047 value for the stack bias. |
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| 29 | |
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| 30 | ! Medium/Anywhere code model support: |
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| 31 | ! |
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| 32 | ! In this model %g4 points to the start of the data segment. |
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| 33 | ! The text segment can go anywhere, but %g4 points to the *data* segment. |
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| 34 | ! It is up to the compiler/linker to get this right. |
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| 35 | ! |
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| 36 | ! Since this model is statically linked the start of the data segment |
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| 37 | ! is known at link time. Eg: |
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| 38 | ! |
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| 39 | ! sethi %hh(data_start), %g1 |
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| 40 | ! sethi %lm(data_start), %g4 |
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| 41 | ! or %g1, %hm(data_start), %g1 |
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| 42 | ! or %g4, %lo(data_start), %g4 |
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| 43 | ! sllx %g1, 32, %g1 |
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| 44 | ! or %g4, %g1, %g4 |
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| 45 | ! |
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| 46 | ! FIXME: For now we just assume 0. |
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| 47 | |
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| 48 | ! FIXME: if %g1 contains a non-zero value, atexit() should be invoked |
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| 49 | ! with this value. |
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| 50 | |
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| 51 | #include "syscallasm.h" |
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| 52 | |
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| 53 | #ifndef TARGET_PTR_SIZE |
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| 54 | #define TARGET_PTR_SIZE 32 |
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| 55 | #endif |
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| 56 | |
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| 57 | TEXT_SECTION |
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| 58 | ALIGN (4) |
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| 59 | GLOBAL (ASM_PRIVATE_SYMBOL (start)) |
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| 60 | ASM_PRIVATE_SYMBOL (start): |
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| 61 | clr %fp |
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| 62 | |
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| 63 | ! We use %g4 even if the code model is Medium/Low (simplifies the code). |
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| 64 | |
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| 65 | clr %g4 ! Medium/Anywhere base reg |
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| 66 | |
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| 67 | ! If there is a stack bias in effect, account for it in %g5. Then always |
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| 68 | ! add %g5 to stack references below. This way the code can be used with |
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| 69 | ! or without an imposed bias. |
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| 70 | |
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| 71 | andcc %sp, 1, %g5 |
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| 72 | bnz,a .LHaveBias |
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| 73 | mov 2047, %g5 |
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| 74 | .LHaveBias: |
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| 75 | add %sp, %g5, %sp |
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| 76 | |
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| 77 | #if TARGET_PTR_SIZE == 32 |
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| 78 | ! FIXME: We apparently assume here that there is no reserved word. |
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| 79 | ! This is probably correct, but try to verify it. |
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| 80 | ld [%sp + 0x80], %o0 ! argc |
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| 81 | add %sp, 0x84, %o1 ! argv |
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| 82 | add %o0, 1, %o2 |
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| 83 | sll %o2, 2, %o2 |
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| 84 | #else /* TARGET_PTR_SIZE == 64 */ |
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| 85 | ld [%sp + 0x8c], %o0 ! argc.lo |
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| 86 | add %sp, 0x90, %o1 ! argv |
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| 87 | add %o0, 1, %o2 |
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| 88 | sll %o2, 3, %o2 |
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| 89 | #endif |
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| 90 | add %o1, %o2, %o2 ! envp |
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| 91 | sethi %hi (ASM_SYMBOL (environ)), %o3 |
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| 92 | or %o3, %lo (ASM_SYMBOL (environ)), %o3 |
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| 93 | #if TARGET_PTR_SIZE == 32 |
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| 94 | st %o2, [%o3 + %g4] |
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| 95 | #else /* TARGET_PTR_SIZE == 64 */ |
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| 96 | stx %o2, [%o3 + %g4] |
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| 97 | #endif |
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| 98 | |
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| 99 | ! Restore any stack bias before we call main() ... |
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| 100 | |
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| 101 | sub %sp, %g5, %sp |
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| 102 | |
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| 103 | GLOBAL (ASM_SYMBOL (main)) |
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| 104 | call ASM_SYMBOL (main) |
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| 105 | |
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| 106 | ! FIXME: Not sure if this is needed anymore. |
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| 107 | #if TARGET_PTR_SIZE == 32 |
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| 108 | sub %sp, 0x20, %sp ! room to push args |
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| 109 | #else /* TARGET_PTR_SIZE == 64 */ |
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| 110 | sub %sp, 0x30, %sp ! room to push args |
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| 111 | #endif |
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| 112 | |
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| 113 | GLOBAL (ASM_SYMBOL (exit)) |
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| 114 | call ASM_SYMBOL (exit) |
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| 115 | nop |
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| 116 | |
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| 117 | GLOBAL (ASM_SYMBOL (_exit)) |
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| 118 | call ASM_SYMBOL (_exit) |
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| 119 | nop |
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| 120 | |
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| 121 | set SYS_exit, %g1 |
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| 122 | ta SYSCALL_TRAP ! in case user redefines __exit |
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| 123 | |
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| 124 | ! If all the above methods fail to terminate the program, try an illegal insn. |
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| 125 | ! If that does not work, the o/s is hosed more than we are. |
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| 126 | |
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| 127 | WORD (0) |
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