www.pudn.com > czxtsycx1.zip > COS_GDT.ASM
GDTSEG SEGMENT PARA USE16 ;È«¾ÖÃèÊö·û±í
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 ;setup to start*************
IDT GDT_DESC ;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 ;92H=P ,DPL=0,TYPE=2
TOS_DATA_SEL = TOS_DATA - GDT
TOS_STACK GDT_DESC ;96H=R/W ,DOWN
TOS_STACK_SEL = TOS_STACK - GDT
TOS_TSS GDT_DESC ;89H=386TSS DPL=0
TOS_TSS_SEL = TOS_TSS - GDT
GDT_ASDATA GDT_DESC
GDT_ASDATA_SEL = GDT_ASDATA - GDT
TOS_TSSASDATA GDT_DESC
TOS_TSSASDATA_SEL = TOS_TSSASDATA - GDT
USER_PsTSS_mov GDT_DESC ;9AH=exec/read ,DPL=0
USER_PsTSS_mov_SEL = USER_PsTSS_mov - GDT
USER_PsLDT_mov GDT_DESC ;11
USER_PsLDT_mov_SEL = USER_PsLDT_mov - GDT ;+ 04H
DATASEG GDT_DESC ;92H=P ,DPL=0,TYPE=2
DATA_SEL = DATASEG - GDT
;***************V86
;***************V86
V86_CODE GDT_DESC <0FFFFH,V86CODESEG,0,0fAH,0,0>
V86_CODE_SEL = (V86_CODE - GDT)
V86_DATA_GDT GDT_DESC <0FFFFH,V86_DATASEG,0,92H,0,0>
V86_DATA_GDT_SEL = (V86_DATA_GDT - GDT)
V86TSS GDT_DESC ;89H=386TSS DPL=0
V86TSS_SEL =V86TSS - GDT
V86TSS_ASDATA GDT_DESC ;89H=386TSS DPL=0
V86TSS_ASDATA_SEL =V86TSS_ASDATA - GDT
V86LDTS GDT_DESC ;82H=LDT DPL=0
V86LDT_SEL =V86LDTS - GDT
;***************V86
;***************V86
GDT_INIT_COUNT = ($ - GDT_INIT_BEGIN)/(SIZE GDT_DESC)
; seg_mode -->start
USER_segs_mov GDT_DESC <0ffffh,0,0C0H,92H,0FH,0> ;9AH=exec/read ,DPL=0
USER_segs_mov_SEL = USER_segs_mov - GDT
; seg_mode -->end
;setup to end *******************************************
V86_VRAM GDT_DESC <0FFFFH,8000H,0BH,092H,0,0> ;92H=P ,DPL=0,TYPE=2
V86_VRAM_SEL = V86_VRAM - GDT ;60h
;;;;;;;;file system
V_SFT GDT_DESC <0FFFFH,0,0FFH,92H,0,0FFH> ;92H=P ,DPL=0,TYPE=2 ,base=FFFF0000H
V_SFT_SEL = V_SFT - GDT
V_FILE_BUF GDT_DESC <0FFFFH,0,0FEH,92H,0,0FFH> ;92H=P ,DPL=0,TYPE=2 ,base=FFFE0000H
V_FILE_BUF_SEL = V_FILE_BUF - GDT
;;;;;;;;file system
;;for schedule
V_PCB GDT_DESC <0ffFFH,0,080H,92H,0fH,0FFH> ;92H=P ,DPL=0,TYPE=2 ,base=FFFF0000H ;LIMIT=1m
V_PCB_SEL = V_PCB - GDT ;LIMIT=4m 21
V_TOS_TSSASDATA GDT_DESC ;89H=386TSS DPL=0
V_TOS_TSSASDATA_SEL = V_TOS_TSSASDATA - GDT
V_GDT_ASDATA GDT_DESC <0FFFFH,2000H,40H,92H,0,0C0H>
V_GDT_ASDATA_SEL = V_GDT_ASDATA - GDT
;V_USER_SEGS GDT_DESC <04FFH,0,40H,92H,10H,0FFH> ;92H=P ,DPL=0,TYPE=2 ,base=FFFF4000H ;LIMIT=4m
V_USER_SEGS GDT_DESC <0FFFFH,0,40H,92H,0FH,0FFH> ;92H=P ,DPL=0,TYPE=2 ,base=FFFF4000H ;LIMIT=1m
V_USER_SEGS_SEL = V_USER_SEGS - GDT
V_STACK0 GDT_DESC <4095,0,40H,92H,0,0FFH> ;92H=P ,DPL=0,TYPE=2 ,base=FFFD0000H
V_STACK0_SEL = V_STACK0 - GDT
V_USER_PsTSS GDT_DESC ;9AH=exec/read ,DPL=0
V_USER_PsTSS_SEL = V_USER_PsTSS - GDT
USER_PsTSS_D GDT_DESC ;9AH=exec/read ,DPL=0
USER_PsTSS_D_SEL = USER_PsTSS_D - GDT
V_USER_PsLDTT GDT_DESC <4095,2000h,40h,82H,0,0FFH> ;82H=LDT
V_USER_PsLDT_SEL = V_USER_PsLDTT - GDT
USER_PsLDTT_ASDATA GDT_DESC <4095,2000H,40H,92H,0,0FFH> ;82H=LDT
USER_PsLDTT_ASDATA_SEL = USER_PsLDTT_ASDATA - GDT ;37
;;for schedule
;***********prepare page_memory
G_PDT GDT_DESC <0FFFH,2000H,21H,92H,0,0>;92H=P ,DPL=0,TYPE=2 ,base=2M+68k
G_PDT_SEL = G_PDT - GDT
G_PT0 GDT_DESC <0FFFFH,3000H,21H,92H,0,0>;92H=P ,DPL=0,TYPE=2 ,base=2M+72k ;16 PAGES
G_PT0_SEL = G_PT0 - GDT
G_MOVSEG GDT_DESC <0FFFFH,0,20H,92H,0FH,0> ;92H=P ,DPL=0,TYPE=2 ,base=2M
G_MOV_SEL = G_MOVSEG - GDT ;LIMIT=1M
;***********next for page_memory
V_DOS_CODE GDT_DESC <0FFFFH,0,0,9AH,0FH,0> ;9AH=exec/read ,DPL=0
V_DOS_CODE_SEL = V_DOS_CODE - GDT
G_VRAM GDT_DESC <0FFFFH,0,0,92H,0,0C0H> ;92H=P ,DPL=0,TYPE=2
G_VRAM_SEL = G_VRAM - GDT
;G_BUF GDT_DESC <1024,0,40H,92H,80H,0> ;92H=P ,DPL=0,TYPE=2 ,base=4M
G_BUF GDT_DESC <0FFFFh,0,40H,92H,0FH,0> ;92H=P ,DPL=0,TYPE=2 ,base=4M
G_BUF_SEL = G_BUF - GDT
V_G_PT0 GDT_DESC <0FFFFH,3000H,41H,92H,0,0C0H>
V_G_PT0_SEL = V_G_PT0 - GDT
V_TOS_TSS GDT_DESC ;89H=386TSS DPL=0
V_TOS_TSS_SEL = V_TOS_TSS - GDT
V_TOS_CODE GDT_DESC <0FFFFH,3000H,42H,9AH,0,0C0H> ;9AH=exec/read ,DPL=0
;limit must be 0ffffh for returnning to real_mode
V_TOS_CODE_SEL = V_TOS_CODE - GDT ;31
V_TOS_STACK GDT_DESC <01000H,3000H,43H,92H,0,0C0H> ;96H=R/W ,DOWN 93
V_TOS_STACK_SEL = V_TOS_STACK - GDT
V_TOS_DATA GDT_DESC <0FFFFH,4000H,43H,92H,0,0C0H> ;92H=P ,DPL=0,TYPE=2
V_TOS_DATA_SEL = V_TOS_DATA - GDT
ps_to_tos_sel =$
GDTLEN = $ - GDT
GDTSEGLEN = $
GDTSEG ENDS