cba54b205b
- refactor code for transfer buffer reads/writes, real mode int 0x21 calls, and assembler segment declarations - define transfer buffer size in one place - beef up error checking for transfer buffer operations (prevent buffer overflows) - also optimize such operations to transfer dword by dword where feasible
40 lines
1.1 KiB
ArmAsm
40 lines
1.1 KiB
ArmAsm
#
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! $Source$
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! $State$
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! $Revision$
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! Copyright (c) 2021--2022 TK Chia
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!
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! The authors hereby grant permission to use, copy, modify, distribute,
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! and license this software and its documentation for any purpose, provided
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! that existing copyright notices are retained in all copies and that this
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! notice is included verbatim in any distributions. No written agreement,
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! license, or royalty fee is required for any of the authorized uses.
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! Modifications to this software may be copyrighted by their authors
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! and need not follow the licensing terms described here, provided that
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! the new terms are clearly indicated on the first page of each file where
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! they apply.
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#include "libsysasm.h"
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! Get the current process identifier. For MS-DOS, use the Program Segment
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! Prefix (PSP) segment as the PID, unless the system supports an actual
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! `getpid' syscall, e.g. European MS-DOS 4.0.
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!
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! (Note that pid_t is a 32-bit type. This is to allow for PSP segments and
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! MS-DOS PIDs above 0x7FFF.)
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.define _getpid
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_getpid:
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movb ah, 0x87
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stc
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int 0x21
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jnc .eur_dos
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movb ah, 0x51
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mov ebx, 0x210000
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callf (interrupt_ptr)
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xchg ebx, eax
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.eur_dos:
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movzx eax, ax
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ret
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