; ; PMIO.ASM -- File I/O for the kernel ; ; Copyright (c) 1991-1995 by Eberhard Mattes ; ; This file is part of emx. ; ; emx is free software; you can redistribute it and/or modify it ; under the terms of the GNU General Public License as published by ; the Free Software Foundation; either version 2, or (at your option) ; any later version. ; ; emx is distributed in the hope that it will be useful, ; but WITHOUT ANY WARRANTY; without even the implied warranty of ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ; GNU General Public License for more details. ; ; You should have received a copy of the GNU General Public License ; along with emx; see the file COPYING. If not, write to ; the Free Software Foundation, 59 Temple Place - Suite 330, ; Boston, MA 02111-1307, USA. ; ; See emx.asm for a special exception. ; INCLUDE EMX.INC INCLUDE SIGNAL.INC INCLUDE PROCESS.INC PUBLIC DEBUG_FLAG PUBLIC OPEN, SEEK, READ, WRITE, CREATE_TMP, CLOSE PUBLIC FORCE_STDOUT, FIND_FILE, ACCESS SV_DATA SEGMENT DEBUG_FLAG DB FALSE STDOUT_NAME DB "CON", 0 SV_DATA ENDS PMIO_BEGIN MACRO PUSH PROCESS_PTR MOV PROCESS_PTR, NO_PROCESS ENDM PMIO_END MACRO POP PROCESS_PTR ENDM SV_CODE SEGMENT ASSUME CS:SV_CODE, DS:NOTHING, ES:SV_DATA ; ; Open file ; ; In: AX:EDX Pointer to name ; CL Access code ; ; Out: CY Error ; EAX File handle or error code ; ASSUME DS:SV_DATA OPEN PROC NEAR PMIO_BEGIN PUSH DS MOV DS, AX ASSUME DS:NOTHING MOV AH, 3DH MOV AL, CL INT 21H POP DS ASSUME DS:SV_DATA PMIO_END RET OPEN ENDP ; ; Close file ; ; In: BX File handle ; ASSUME DS:SV_DATA CLOSE PROC NEAR PMIO_BEGIN MOVZX EBX, BX MOV AH, 3EH INT 21H PMIO_END RET CLOSE ENDP ; ; Create temporary file ; ; In: AX:EDX Pointer to name ; ASSUME DS:SV_DATA CREATE_TMP PROC NEAR PMIO_BEGIN PUSH DS PUSH ECX MOV CX, 0000H MOV DS, AX ASSUME DS:NOTHING MOV AH, 5AH INT 21H POP ECX POP DS ASSUME DS:SV_DATA PMIO_END RET CREATE_TMP ENDP ; ; In: BX File handle ; EDX Position ; ASSUME DS:SV_DATA SEEK PROC NEAR PMIO_BEGIN PUSH EAX MOVZX EBX, BX MOV AL, 0 MOV AH, 42H INT 21H POP EAX PMIO_END RET SEEK ENDP ; ; In: BX File handle ; ECX Number of bytes ; AX:EDX Pointer to buffer ; ; Out: CY Error ; NC NZ EOF ; NC ZR OK ; ASSUME DS:SV_DATA READ PROC NEAR PMIO_BEGIN PUSH EAX PUSH DS MOV DS, AX ASSUME DS:NOTHING MOVZX EBX, BX MOV AH, 3FH INT 21H JC SHORT READ_RET CMP ECX, EAX CLC READ_RET: POP DS ASSUME DS:SV_DATA POP EAX PMIO_END RET READ ENDP ; ; In: BX File handle ; ECX Number of bytes ; AX:EDX Pointer to buffer ; ; Out: CY Error ; NC NZ Disk full ; NC ZR OK ; ASSUME DS:SV_DATA WRITE PROC NEAR PMIO_BEGIN PUSH EAX PUSH DS MOV DS, AX ASSUME DS:NOTHING MOVZX EBX, BX MOV AH, 40H INT 21H JC SHORT WRITE_RET CMP ECX, EAX CLC WRITE_RET: POP DS ASSUME DS:SV_DATA POP EAX PMIO_END RET WRITE ENDP ; ; Force stdout to refer to the CON device (put error message on screen) ; ASSUME DS:SV_DATA FORCE_STDOUT PROC NEAR PMIO_BEGIN XOR EDX, EDX LEA DX, STDOUT_NAME MOV AH, 3DH MOV AL, 41H ; Deny none; write INT 21H JC SHORT FS_RET MOV EBX, EAX MOV ECX, 1 ; stdout MOV AH, 46H ; Force duplicate file handle INT 21H FS_RET: PMIO_END RET FORCE_STDOUT ENDP ; ; Find file in directories listed by an environment variable ; ; In: DS:SI File name ; DS:BX Buffer (filled by FIND_FILE), must be large enough ; ES:EDI Search path (separated by ';', 0 terminated) ; ; Out: CY Not found ; ; Note: ES:EDI must point to the value of the environment variable ; The buffer pointed to by DS:BX will contain the path name on success ; Blanks are not removed ; FIND_FILE PROC NEAR PUSH EDI PUSH CX FF_NEXT_DIR: ; ; Now ES:DI points to the next directory ; Build path name at DS:BX ; PUSH BX PUSH SI XOR CX, CX FF_DIR_COPY: MOV AL, ES:[EDI] OR AL, AL JZ SHORT FF_DIR_END CMP AL, ";" JE SHORT FF_DIR_END MOV [BX], AL INC EDI INC BX INC CX JMP SHORT FF_DIR_COPY FF_DIR_END: JCXZ FF_EMPTY MOV AL, [BX-1] CMP AL, "\" JE SHORT FF_FNAME_COPY CMP AL, "/" JE SHORT FF_FNAME_COPY CMP AL, ":" JE SHORT FF_FNAME_COPY MOV BYTE PTR [BX], "\" INC BX FF_FNAME_COPY: MOV AL, [SI] MOV [BX], AL INC SI INC BX OR AL, AL JNZ SHORT FF_FNAME_COPY FF_EMPTY: POP SI POP BX JCXZ FF_SKIP_DIR ; ; Look for file ; PUSH EDX MOVZX EDX, BX CALL ACCESS POP EDX JNC SHORT FF_RET ; ; Try next directory ; FF_SKIP_DIR: CMP BYTE PTR ES:[EDI], 0 JE SHORT FF_FAILURE INC EDI JMP SHORT FF_NEXT_DIR FF_FAILURE: MOV BYTE PTR [BX], 0 STC FF_RET: POP CX POP EDI RET FIND_FILE ENDP ; ; In: DS:EDX Name ; ; Out: CY Not found or not a file ; ACCESS PROC NEAR PUSH AX PUSH CX MOV AH, 43H ; Get/set file attributes MOV AL, 00H ; Get file attributes INT 21H JC SHORT ACCESS_RET TEST CX, 18H ; Volume label, directory? JZ SHORT ACCESS_RET STC ACCESS_RET: POP CX POP AX RET ACCESS ENDP SV_CODE ENDS END