cos.asm

操作系统完整源代码大机密!

;程序文件：\TC\G\GFAT16.ASM 清单
; base on gfat16.asm
;only support one hard disk
.MODEL HUGE
.386P
include \tc\g\include\g_def.asm   ; 描述符结构、常量、宏定义,清单见程序1-1
include \tc\g\include\cos_def.asm ; 描述符结构、常量、宏定义,清单见程序1-1
include \tc\g\include\tos_seg.asm ; 定义TOS堆栈段TOS_STACKSEG与TOS任务状态段TOS_TSSSEG
                                  ; 清单见程序1-2
include \tc\g\include\ps_seg.asm  ; 
TOS_CODESEG SEGMENT PARA USE16    ; TOS操作系统的代码段
            ASSUME CS:TOS_CODESEG,DS:DATA,SS:TOS_STACKSEG
TOS_BEGIN:   
            COS_INIT    ; TOS任务初始处理，在包含\tc\g\include\g_def.asm文件中
            CALL V_SEL_SETUP       ;setup v_sel
            ;***********move to 2M 
            CALL SEGS_MOV_2M ;all tos_segs(6 segs) --->2M idt_m
            CALL PGT_INIT
            COS_PAGE_INIT   ;in cos_def
            ;*********** HAVE ENTERED PAGE_MODE

            CALL DISP_COS_HEAD   ;IN gfat_p.ASM
;;;;;;;;;;aaaaaaa    ;after call TURN_TO_PROTECT_PAGE MACRO    
;addition part:    
gaaa:  jmp  gaaa
            MOV BH,0
            mov al,43h
            MOV AH,09H
            mov bl,41h
            mov cx,10
            INT 80H     ;???
            DB 0EAH
            DW OFFSET tee1
            DW TOS_CODE_SEL
Tee1:
            MOV EAX,CR0
            AND EAX,07FFFFFFFH
            MOV CR0,EAX
            jmp short toreal
toreal:
            MOV AX,REAL_SEL
            MOV ES,AX
            MOV FS,AX
            MOV GS,AX
            MOV DS,AX
            MOV SS,AX

            MOV EAX,CR0
            AND EAX,07FFFFFFEH
            MOV CR0,EAX
            DB 0EAH
            DW OFFSET rttt
            DW tos_codeseg
rttt:       ;
            MOV AX,DATA
            MOV DS,AX
            call close_a20
            LGDT FWORD PTR SAVE_GDT
            LIDT FWORD PTR SAVE_IDT
            MOV SS,SAVE_SS
            MOV SP,SAVE_SP
            sti
            MOV AX,4C00H
            INT 21H
;;;;;;;;;;aaaaaaaaaa

            ; setup cursor
            MOV BH,0
            MOV DX,0000H
            MOV AH,2
            INT 80H

TOS_BEGIN_CMD:
            ;; begin command line mode
            ;;;;;;            display "C:\>"
            ; read cursor
            MOV AH,03H 
            MOV BH,0
            INT 80H
            ; set cursor
            MOV AH,02H 
            MOV BH,0
            INC DH
            MOV DL,0
            INT 80H

            MOV AX,V_TOS_DATA_SEL 
            MOV DS,AX
            MOV DX,OFFSET COS_FLAG
            CALL STRDISP           ;display "C:\>"

            ;;;;;;;;;;;;;;;;set "C:\" as current directory
            CALL FILE_INIT
            MOV AX,V_TOS_DATA_SEL 
            MOV DS,AX
            CMP AL,1     ;AL=1 is not FAT16
            JE  PAGE_END

            ;input str    --->G_WORK (  ASCIIZ_STRING)
            MOV AX,V_TOS_DATA_SEL  
            MOV DS,AX
            MOV DX,OFFSET G_WORK
            MOV AL,255     ;MAX COUNT
            MOV AH,0AH     ;=DOS 21H0AH
            INT 21H                ;input string in current position
            CALL DO_CMD
            CMP AL,0       ;=0 OK&NEXT =1 EXIT =2 ERROR 
            JE  TOS_BEGIN_CMD
            CMP AL,1
            JE  PAGE_END

            ;=2 ERROR  display command error
            ; read cursor
            MOV AH,03H 
            MOV BH,0
            INT 80H
            ; set cursor
            MOV AH,02H 
            MOV BH,0
            INC DH
            MOV DL,0
            INT 80H
            ; display ASCIIZ string
            MOV AX,V_TOS_DATA_SEL 
            MOV DS,AX
            MOV DX,OFFSET CMD_ERROR
            CALL STRDISP
            JE  PAGE_END

TOS_BEGIN_CMD_R:

            ;;;;;;;;;;;;;;;;;;;;;;;; copy g_work-->str
            ;MOV AX,V_TOS_DATA_SEL  ;INPUT STRING IN CURRENT POSITION
            ;MOV DS,AX
            ;MOV DX,OFFSET STR1
            ;PUSH DX
            ;PUSH DS
            ;MOV BX,OFFSET G_WORK
            ;INC BX
            ;INC BX                ;from 3 copy
            ;PUSH BX
            ;PUSH DS
            ;DEC BX
            ;MOV AL,DS:[BX]
            ;INC AL
            ;MOV AH,0
            ;PUSH AX
            ;CALL STRNCPY           ;G_WORK--->STR1

            ;strcpy    ASCIIZ str1-->str2
            ;MOV AX,V_TOS_DATA_SEL  
            ;MOV DS,AX
            ;MOV DX,OFFSET STR2
            ;PUSH DX
            ;PUSH DS
            ;MOV DX,OFFSET STR1
            ;PUSH DX
            ;PUSH DS
            ;CALL STRCPY
            
;;
            ;MOV AX,V_TOS_DATA_SEL  ;display g_work
            ;MOV DS,AX
            ;MOV DX,OFFSET G_WORK
            ;INC DX
            ;INC DX
            ;MOV AH,09H     ;=DOS 21H09H
            ;INT 21H

            ;MOV AX,G_VRAM_SEL
            ;MOV ES,AX
            ;MOV AL,41H  ;"A"
            ;MOV AH,41H
            ;MOV ES:500,AX

COMEBACK_TO_TOS:             ; 21h---4ch return
            JMP PAGE_END
ERR_EXEFIL:
            MOV AH,9
            MOV CX,1100H 
            MOV DX,OFFSET ERR_EXEFILE
            INT 21H    
PAGE_END:   ;*********************     should have  next 3 lines   
            DB 0EAH
            DW OFFSET TURN_TO_REAL_MODE
            DW TOS_CODE_SEL
TURN_TO_REAL_MODE:
            MOV EAX,CR0 ;  ；关闭分页模式
            AND EAX,7FFFFFFFH
            MOV CR0,EAX
            JMP SHORT FROM_PAGE
FROM_PAGE:
            CALL TURN_TO_REAL      ;返回实模式，在\tc\g\include\tos_used.asm;中
            include \tc\g\include\COS_USED.ASM ;
            include \tc\g\include\V86_USED.ASM ;
            include \tc\g\include\GFAT16_P.ASM ;

TOS_CODELEN = $
TOS_CODESEG ENDS

GDTSEG      SEGMENT PARA USE16              ;全局描述符表
GDT         LABEL BYTE
G_NULL      GDT_DESC <>
REAL_SEG    GDT_DESC <0FFFFH,0,0,92H,0,0>
REAL_SEL    = REAL_SEG - GDT
GDT_INIT_BEGIN LABEL BYTE
IDT         GDT_DESC <IDTLEN,IDTSEG,0,92H,0,0> ;92H=P ,DPL=0,TYPE=2
IDT_SEL     =  IDT - GDT
TOS_CODE    GDT_DESC <0FFFFH,TOS_CODESEG,0,9AH,0,0> ;9AH=exec/read ,DPL=0
            ;limit must be 0ffffh for returnning to real_mode
TOS_CODE_SEL = TOS_CODE - GDT
TOS_DATA    GDT_DESC <DATA_TOSLEN,DATA_TOS,0,92H,0,0> ;92H=P ,DPL=0,TYPE=2
TOS_DATA_SEL = TOS_DATA - GDT
TOS_STACK   GDT_DESC <TOS_STACKLEN,TOS_STACKSEG,0,93H,0,0>   ;96H=R/W ,DOWN
TOS_STACK_SEL = TOS_STACK - GDT
TOS_TSS     GDT_DESC <TOS_TSSLEN,TOS_TSSSEG,0,089H,0,0> ;89H=386TSS DPL=0
TOS_TSS_SEL  = TOS_TSS - GDT
GDT_ASDATA  GDT_DESC <GDTLEN,GDTSEG,0,92H,0,0>
GDT_ASDATA_SEL = GDT_ASDATA - GDT
TOS_TSSASDATA GDT_DESC <TOS_TSSLEN,TOS_TSSSEG,0,92H,0,0>
TOS_TSSASDATA_SEL  = TOS_TSSASDATA - GDT
USER_PsTSS_mov     GDT_DESC <USER_PsTSSLEN,USER_PsTSSSEG,0,92H,0,0> ;9AH=exec/read ,DPL=0
USER_PsTSS_mov_SEL  = USER_PsTSS_mov - GDT
USER_PsLDT_mov  GDT_DESC <USER_PsLDTLEN,USER_PsLDTSEG,0,92H,0,0>
USER_PsLDT_mov_SEL = USER_PsLDT_mov - GDT ;+ 04H
DATASEG     GDT_DESC <DATALEN,DATA,0,92H,0,0> ;92H=P ,DPL=0,TYPE=2
DATA_SEL    = DATASEG - GDT