| 1 | ! This is the Modula-2 run-time start-off routine. It's job is to take the
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| 2 | ! arguments as put on the stack by EXEC, and to parse them and set them up the
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| 3 | ! way _m_a_i_n expects them.
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| 4 |
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| 5 | .sect .text; .sect .rom; .sect .data; .sect .bss
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| 6 |
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| 7 | .define begtext, begdata, begbss
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| 8 | .sect .text
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| 9 | begtext:
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| 10 | .sect .rom
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| 11 | begrom:
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| 12 | .sect .data
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| 13 | begdata:
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| 14 | .sect .bss
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| 15 | begbss:
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| 16 |
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| 17 | .define m2rtso, hol0, __penviron, __penvp, __fpu_present
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| 18 | .sect .text
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| 19 | m2rtso:
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| 20 | xor ebp, ebp ! clear for backtrace of core files
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| 21 | mov eax, (esp) ! argc
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| 22 | lea edx, 4(esp) ! argv
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| 23 | lea ecx, 8(esp)(eax*4) ! envp
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| 24 |
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| 25 | ! Test if environ is in the initialized data area and is set to our
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| 26 | ! magic number. If so then it is not redefined by the user.
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| 27 | mov ebx, _environ
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| 28 | cmp ebx, __edata ! within initialized data?
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| 29 | jae 0f
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| 30 | testb bl, 3 ! aligned?
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| 31 | jnz 0f
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| 32 | cmp (ebx), 0x53535353 ! is it our environ?
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| 33 | jne 0f
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| 34 | mov (__penviron), ebx ! _penviron = &environ;
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| 35 | 0: mov ebx, (__penviron)
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| 36 | mov (ebx), ecx ! *_penviron = envp;
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| 37 |
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| 38 | push ecx ! push envp
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| 39 | push edx ! push argv
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| 40 | push eax ! push argc
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| 41 |
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| 42 | ! Test the EM bit of the MSW to determine if an FPU is present and
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| 43 | ! set __fpu_present if one is found.
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| 44 | smsw ax
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| 45 | testb al, 0x4 ! EM bit in MSW
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| 46 | setz (__fpu_present) ! True if not set
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| 47 |
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| 48 | call __m_a_i_n ! run Modula-2 program
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| 49 |
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| 50 | push eax ! push exit status
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| 51 | call __exit
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| 52 |
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| 53 | hlt ! force a trap if exit fails
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| 54 |
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| 55 | .sect .rom
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| 56 | .data4 0 ! Separate I&D: *NULL == 0
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| 57 | ! Also keeps the first string in the
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| 58 | ! program from appearing at location 0!
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| 59 | .sect .data
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| 60 | __penviron:
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| 61 | .data4 __penvp ! Pointer to environ, or hidden pointer
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| 62 |
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| 63 | .sect .bss
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| 64 | .comm __penvp, 4 ! Hidden environment vector
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| 65 | .comm __fpu_present, 4 ! FPU present flag
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| 66 |
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| 67 | .extern endtext ! Force loading of end labels.
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