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Assembly Source File | 1989-09-04 | 25.6 KB | 1,181 lines

page 82,120 title MemTest - Test Main & Extended Memory .MODEL SMALL .386p ; Gene Czarcinski, 4 Sep 89 ; ; This program is designed to test main and extended (not expanded) ; (ram) memory on a 386 or 386SX. It was developed on a Wave Mate ; Bullet-386SX and some of the ports or hardware values may differ on ; different systems. Because it was developed on a 386, some of the ; specific characteristics of a 386 are used (however, it should be ; possible to convert this program to a 286 with some effort). ; ; NOTE that this program operates in REAL mode to test main memory ; and in 386 PROTECTED mode to test extended memory. ; ; This program owes some of its features and code to some other ; programs and some books (with programs): ; - RAMHAM by Clifford A. McCullough ; - 80386 A Programming and Design Handbook, 2nd Ed. ; by Penn Brumm and Don Brumm ; - Dr. Dobb's Toolbook of 80286/80386 Programming ; Edited by Phillip Robinson ; Finding enough CORRECT information to write this program was a bit ; of a problem - much of it was trial and error (plus the usual set ; of coding/typing errors -- interesting results when a segment reg ; is incorrect in protected mode). ; ; Writing this program was motivated by some memory errors on my ; Wave Mate system board. The bad memory caused a Parity Error ; but not until after the system was up (it did not fail the BIOS ; memory test). The error turned out to be a bad 1meg chip which ; had a bad section of memory (1 chip, 1 bit, 256k bits). This program ; found the error and when I replaced the chip, I had no more problems. ; I hope this may be of use to others. ; ; Note that error handling is VERY PRIMATIVE - the objective was to ; find the memory errors in the extended memory, not to create a full ; environment for the 386 (although some interrupt handling, etc. is ; necessary). This is NOT a turn-key program and some "fiddling" will ; be necessary to get it to work on other systems. ; ; The NMI Parity Error Disable/Enable value may differ. The port ; and values (bit) which indicate a Parity Error may (will) differ - ; these were quessed at since they were added AFTER the problem was ; fixed. ; ; Some simple run-time options: ; ; -f .. fast mode, very short display pause if error ; -x .. skip check for parity error ; -a .. 20 cycles of main memory checking ; -b .. 100 cycles of main memory checking ; -c .. 20 cycles of extended memory checking ; -d .. 100 cycles of extended memory checking ; default is 10 cycles each ; ; Note that errors or program completion cause the program to ; hang in a spin-loop which will require a RESET or the Big-Red- ; Switch power cycle to "terminate" (this was simple) so that messages ; are left on the video screen. ; Equates Line00 equ 0 ; Video Ram Displacements Line01 equ 160 Line02 equ 160*2 Line03 equ 160*3 Line04 equ 160*4 Line05 equ 160*5 Line06 equ 160*6 Line07 equ 160*7 Line08 equ 160*8 Line09 equ 160*9 Line10 equ 160*10 Line11 equ 160*11 Line12 equ 160*12 Line13 equ 160*13 Line14 equ 160*14 Line15 equ 160*15 Line16 equ 160*16 Line17 equ 160*17 Line18 equ 160*18 Line19 equ 160*19 Line20 equ 160*20 Line21 equ 160*21 Line22 equ 160*22 Line23 equ 160*23 Line24 equ 160*24 INTa01 equ 021h ; 8259 Controller #1 INTa02 equ 0A1h ; 8259 Controller #2 Port_a equ 060h ; 8042 Port A Port_b equ 061h ; 8042 Port B Port_c equ 062h ; 8042 Port C Port_Status equ 064h ; 8042 Status Port Port_Par equ 061h ; on WaveMate, others use 062h Bits_Par equ 080h ; on WaveMate 062h, other use 0C0h on 62h NMIPort equ 070h ; to disable/enable parity checking Port_cmos equ 070h ; bit20_disable equ 11011101b ; 8042 function code to degate A20 bit20_enable equ 11011111b ; 8042 function code to GATE A20 ; to run protected on AT, need to enable bit20 so 386 controls the ; address line. ;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; Macros and Structures ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;; ; Convert 8086 segment register value to a linear address segadr macro segr sub eax,eax ; clear reg mov AX,&segr ; get the segment reg shl EAX,4 ; convert to a linear addr endm ; Convert an 8086 segment to linear addr in a segment descriptor segcvt macro segr,segm segadr segr mov segm&.base_l,AX ; get base of data shr EAX,8 ; to AH mov segm&.base_m,AH ; and set mid-range byte endm ; Display Message Vtype macro msg,len,line mov si,offset msg ; addr of msg mov cx,len ; length of message mov di,line ; offset into screen call Video_Output endm ; Define Descriptor Structure desc struc limit dw 0 ; offset to last byte base_l dw 0 ; low 16 bits of base addr base_m db 0 ; bits 16-23 of base addr access db 0 ; access privledges gran db 0 ; Granularity and limit base_h db 0 ; bits 24-31 of base addr desc ends ; Similar to a descriptor, describe the GATE control block gate struc addr_l dw 0 ; Destinations's offset 0...15 select dw 0 ; Destinations's Segment Selector db 0 gate_t db 8Eh ; type, DPL addr_h dw 0 ; offset 16...31 gate ends ; Describe the stack of the level 0 interrrupt handler. stkdef struc oldip dw 0 ; 0..15 of EIP dw 0 oldcs dw 0 ; CS dw 0 oldfl dw 0 ; 0..15 of EFLAGS dw 0 oldsp dw 0 ; 0..15 of SP dw 0 oldss dw 0 ; SP dw 0 oldes dw 0 ; ES dw 0 oldds dw 0 ; DS dw 0 oldfs dw 0 ; FS dw 0 oldgs dw 0 ; GS dw 0 stkdef ends .CODE assume cs:_text, ds:_text, es:_text, ss:_text org 80h command label byte ; tail of DOS command line org 100h ; this is a COM file Start: jmp Main ALIGN 4 stack dw 800h dup(0) stacke dw 0,0 dtsize dw 0 dtload dd 0 dsaddr dd 0 Vram dw 0b800h ; real seg of video ram work dw 0,0,0,0 Cycle dw 0 ; Memory Test Cycles CycleMm dw 10 ; Max Cycles for a pass Main CycleEm dw 10 ; Max Cycles for a pass Extended Errors dw 0 ; number of errors which occured LoopCnt dw 0 Pause_Cnt dw 20 ; Error Pause Loop Count Flag_CheckParity db 1 ; ALIGN 4 MemExtnd label DWORD MemOff dw 0 ; Current Offset MemSeg dw 0 ; Current Segment lastPat dw 0 Mem_Val db 0 Mem_Pat db 0 Mem_Par db 0,0 Msize dw 0 ; Main memory size Esize dw 0 ; Extended memory size Main_S dw 0 ; Start for main memory Main_L dw 0 ; Limit for main memory Extnd_Sw label WORD Extnd_S dd 100000h ; Extended Memory Start (normal 1M or 100000h) Extnd_Lw label WORD Extnd_L dd 0 ; Extended Memory Limit savecs dw 0 savess dw 0 savesp dw 0 i8259_1 db 0 ; save int status i8259_2 db 0 ; save int status ; Memory Test Patterns pattern db 10110010b ;par = e, B2 db 11011001b ;par = o, D9 db 01101100b ;par = e, 6C db 10110110b ;par = o, B6 db 01011011b ;par = o, 5B db 00101101b ;par = e, 2D db 10010110b ;par = e, 96 db 11001011b ;par = o, CB db 01100101b ;par = e, 65 pattern_len equ $-pattern-1 msgd1 db 'Main Memory Test Done' msgd1L equ $-msgd1 msgd2 db 'Extended Memory Test Done' msgd2L equ $-msgd2 msgd2o equ 80 msgd3 db 'All Testing Complete' msgd3L equ $-msgd3 Msg1 db 'MemTest (09/04/89) Main=' Msg1a db 'xxxxxK/' Msg1ax db 'xxxx, Extended=' Msg1b db 'xxxxxK/' Msg1bx db 'xxxx -f=' Msg1c db ' -x=' Msg1d db ' ' Msg1Len equ $-Msg1 Msg2 db ' *** To Terminate: Reset or BRS -- Re-Boot the System ***' Msg2Len equ $-Msg2 MsgTst db ' Test' MsgTstL equ $-MsgTst Msg3 db 'Write Main Segment=' Msg3ao equ ($-Msg3)*2 Msg3a db 'xxxx:0000' Msg3Len equ $-Msg3 Msg3Leno equ ($-Msg3+4)*2 Msg4 db 'Write Extended Segment=' Msg4ao equ ($-Msg4)*2 Msg4a db 'xxxx:' Msg4b db 'xxxx' Msg4Len equ $-Msg4 Msg4Leno equ ($-Msg4+4)*2 Msg5 db '** Error: Address=' Msg5a db 'xxxx:' Msg5b db 'xxxx Pattern:' Msg5c db 'xx, Memory:' Msg5d db 'xx, Parity:' Msg5e db 'xx' msg5Len equ $-Msg5 Msg7 db ' Main Memory Test Segment Start=' Msg7a db 'xxxx Limit=' Msg7b db 'xxxx Max Cycles=' Msg7d db 'xxxxx' Msg7Len equ $-Msg7 Msg8 db 'Extended Memory Test Segment Start=' Msg8a db '0010:' Msg8a2 db '0000 Limit=' Msg8b db 'xxxx:' Msg8c db 'xxxx Max Cycles=' Msg8d db 'xxxxx' Msg8Len equ $-Msg8 Msg9 db 'Cycle=' Msg9ao equ ($-Msg9)*2 Msg9a db 'xxxxx, Errors=' Msg9bo equ ($-Msg9)*2 Msg9b db 'xxxxx' Msg9Len equ $-Msg9 Emsg3 db 'Address Line A20 failed to gate open' Emsg3L equ $-Emsg3 ; 386 Protected Mode Tables, etc. ; Define the Global Descriptor Table (GDT) ALIGN 8 gdt_def LABEL word d_gdt desc <> ; first one is a dummy d_cs desc <0ffffh,0,0,10011010b,00001111b,0> ; Code s_cs equ d_cs-gdt_def d_ds desc <0ffffh,0,0,10010010b,00001111b,0> ; Data s_ds equ d_ds-gdt_def d_ss desc <0,0,0,10010110b,00000000b,0> ; Stack s_ss equ d_ss-gdt_def d_crt desc <0fffh,0,0,10010010b,00001111b,0> ; CRT s_crt equ d_crt-gdt_def d_mem desc <0fffh,0,0,10010010b,10000000b,0> ; To ref hi memory s_mem equ d_mem-gdt_def gdt_size equ $-gdt_def ; Define the Interrupt Descriptor Table (IDT) ALIGN 8 idt_def LABEL WORD gate <int00,s_cs,0,8Eh,0> ; Divide .SALL gate <int01,s_cs,0,8Eh,0> ; Debug gate <int02,s_cs,0,8Eh,0> ; NMI gate <int03,s_cs,0,8Eh,0> ; BrkPt gate <int04,s_cs,0,8Eh,0> ; Overflow gate <int05,s_cs,0,8Eh,0> ; Bounds gate <int06,s_cs,0,8Eh,0> ; Invalid Opcode gate <int07,s_cs,0,8Eh,0> ; CoProcessor Error gate <int08,s_cs,0,8Eh,0> ; Double Fault gate <int09,s_cs,0,8Eh,0> ; Coproc Segment Overrun gate <int10,s_cs,0,8Eh,0> ; Invalid TSS gate <int11,s_cs,0,8Eh,0> ; Segment Not Present gate <int12,s_cs,0,8Eh,0> ; Stack Exception gate <int13,s_cs,0,8Eh,0> ; General Protection gate <int14,s_cs,0,8Eh,0> ; Page Fault gate <intxx,s_cs,0,8Eh,0> ; gate <int16,s_cs,0,8Eh,0> ; Coproc Error gate <intxx,s_cs,0,8Eh,0> ; 17 gate <intxx,s_cs,0,8Eh,0> ; 18 gate <intxx,s_cs,0,8Eh,0> ; 19 gate <intxx,s_cs,0,8Eh,0> ; 20 gate <intxx,s_cs,0,8Eh,0> ; 21 gate <intxx,s_cs,0,8Eh,0> ; 22 gate <intxx,s_cs,0,8Eh,0> ; 23 gate <intxx,s_cs,0,8Eh,0> ; 24 gate <intxx,s_cs,0,8Eh,0> ; 25 gate <intxx,s_cs,0,8Eh,0> ; 26 gate <intxx,s_cs,0,8Eh,0> ; 27 gate <intxx,s_cs,0,8Eh,0> ; 28 gate <intxx,s_cs,0,8Eh,0> ; 29 gate <intxx,s_cs,0,8Eh,0> ; 30 gate <intxx,s_cs,0,8Eh,0> ; 31 REPT 224 gate <intxx,s_cs,0,8Eh,0> ; PE Interrupt Gates ENDM idt_size equ $-idt_def .XALL ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; Entry ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; Main proc near mov ax,cs ; init real-mode seg addr mov ss,ax mov ds,ax mov es,ax mov sp,stacke-_text ; set our stack mov ah,00h ; initialize display mov al,3 ; video mode 3 int 10h mov si,offset command+1 ; process any run-time options cld opt1: lodsb cmp al,0dh ; C/R is end je optend cmp al,'-' ; option marker jne opt1 lodsb ; option found, get next char or al,20h ; fold to lower case cmp al,'f' ; fast mode? jne short opt2 mov pause_cnt,1 jmp opt1 opt2: cmp al,'x' ; skip parity check jne short opt3 mov flag_CheckParity,0 jmp opt1 opt3: cmp al,'a' ; CycleMm=20 Main jne short opt4 mov CycleMm,20 jmp opt1 opt4: cmp al,'b' ; CycleMm=100 Main jne short opt5 mov CycleMm,100 jmp opt1 opt5: cmp al,'c' ; CycleEm=10 Extended jne short opt6 mov CycleEm,20 jmp opt1 opt6: cmp al,'d' ; CycleEm=100 Extended jne short opt7 mov CycleEm,100 jmp opt1 opt7: jmp opt1 optend: cmp Pause_cnt,1 jne short optend1 mov Msg1c,'f' optend1:cmp flag_checkparity,0 jne short optend2 mov Msg1d,'x' optend2:mov ax,cycleMm mov bx,offset Msg7d call Convert_Decimal mov ax,cycleEm mov bx,offset Msg8d call Convert_Decimal int 12h ; get size of convensional memory mov Msize,ax mov bx,offset Msg1a call Convert_Decimal mov ax,Msize mov bx,offset Msg1ax call Convert_Hex mov ah,88h ; get size of extended memory int 15h mov Esize,ax mov bx,offset Msg1b call Convert_Decimal mov ax,Esize mov bx,offset Msg1bx call Convert_Hex vtype Msg1,Msg1Len,Line03 mov Main_S,cs ; calc start of testing. mov ax,Progend-_text add ax,4020h shr ax,4 add ax,Main_S and ax,0fc00h mov Main_S,ax mov bx,offset Msg7a call Convert_Hex mov ax,Msize shl ax,6 mov Main_L,ax mov bx,offset Msg7b call Convert_hex Vtype Msg7,Msg7Len,Line04 ; Intro Msg sub eax,eax mov ax,Esize ; setup extended memory or ax,ax jz Main5 ; NO Extended Memory add ax,0400h shl eax,10 ; in K, mpy by 1024 to get megs dec eax ; limit is minus 1 mov Extnd_L,EAX mov ax,Extnd_Lw+2 mov bx,offset Msg8b call Convert_Hex mov ax,Extnd_Lw mov bx,offset Msg8c call Convert_Hex mov ax,Extnd_Sw+2 mov bx,offset Msg8a call Convert_Hex mov ax,Extnd_Sw mov bx,offset Msg8a2 call Convert_Hex Vtype Msg8,Msg8Len,Line05 Vtype Msg2,Msg2Len,Line23 Main5: mov al,80h ; disable the NMI interrupt out NMIport,al call Check_Main mov ax,Esize or ax,ax jz Done ; NO Extended Memory call Exec_Prot ; Yes, enter PE and Check it. Done: int 20h ; for now Main endp ; Output a message directly to the screen - bypass any use of the BIOS ; SI=offset to msg, CX-msglength, DI=offset into screen Video_Output proc near push ES mov ah,7 ; video attribute mov ES,Vram ; video ram segment (addr or selector) cld ; incrementing Vout1: lodsb stosw dec cx jnz Vout1 pop ES ret Video_Output endp ; Convert number in AX to 5 digit decimal/ASCII equivalent into ; the area (offset) pointed to by BX. Convert_Decimal proc near push cx push dx push si mov cx,5 Conv1: mov byte ptr [BX],' ' ; clear buffer inc bx loop Conv1 mov si,10 ; to get digits or ax,ax ; positive numbers only jns Conv5 neg ax Conv5: sub dx,dx div si add dx,'0' dec bx mov [bx],dl or ax,ax ; done if zero jnz Conv5 pop si pop dx pop cx ret Convert_Decimal endp ; Convert number in AL to 2 digit hex/ASCII equivalent into ; the area (offset) pointed to by BX. Hexit proc near push ax and al,0fh or al,30h cmp al,3ah jl Hex_al add al,7 Hex_al: mov 1[bx],al pop ax shr ax,4 and al,0fh or al,30h cmp al,3ah jl Hex_ah add al,7 Hex_ah: mov [bx],al ret Hexit endp ; Convert number in AX to 4 digit hex/ASCII equivalent into ; the area (offset) pointed to by BX. Convert_Hex proc near push bx push ax mov al,ah call Hexit pop ax add bx,2 call Hexit pop bx ret Convert_Hex endp ;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; Memory bad, report error ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;; Bad_Mem proc near push cx push si push di push bx mov ax,Errors mov bx,offset Msg9b call Convert_Decimal Vtype Msg9b,5,Line10+Msg9bo mov ax,MemSeg mov bx,offset Msg5a call Convert_Hex mov ax,MemOff mov bx,offset Msg5b call Convert_Hex mov al,Mem_Pat mov bx,offset Msg5c call Hexit mov al,Mem_Val mov bx,offset Msg5d call Hexit mov al,Mem_Par mov bx,offset Msg5e call Hexit Vtype Msg5,Msg5Len,Line14 mov bx,pause_cnt ; pause to display msg pause1: sub cx,cx pause2: dec cx jnz pause2 dec bx jnz pause1 pop bx pop di pop si pop cx ret Bad_Mem endp ;;;;;;;;;;;;;;;;;;;;; ; Check Main Memory ; ;;;;;;;;;;;;;;;;;;;;; Check_Main proc near mov ax,Main_S ; setup mov MemSeg,ax mov Cycle,1 mov Errors,0 mov ax,Errors mov bx,offset Msg9b call Convert_Decimal Vtype Msg3,Msg3Len,Line07 Vtype Msg9,Msg9Len,Line10 Main_Loop: mov ax,Cycle mov bx,offset Msg9a call Convert_Decimal Vtype Msg9a,5,Line10+Msg9ao mov ax,LastPat dec ax ; start at different place each time jge short ml1 mov ax,pattern_len ml1: mov LastPat,ax Vtype Msg3,MsgTstL,Line07 mov ax,Main_S ; re-init for writing mov MemSeg,ax ; now write data to main memory cld mov ax,LastPat add ax,offset pattern mov si,ax wm1: push si mov ax,MemSeg mov bx,offset Msg3a call Convert_Hex Vtype Msg3a,4,Line07+Msg3ao pop si mov es,MemSeg ; point to segment to be written mov cx,1000h ; 4K block sub di,di ; start at zero offset wm5: lodsb ; put pattern byte into memory mov es:[di],al inc di cmp si,offset pattern+pattern_len jle short wm6 mov si,offset pattern wm6: loop wm5 mov ax,MemSeg ; bump up 4k add ax,0100h mov MemSeg,ax add ax,0ffh cmp ax,Main_L jb wm1 mov bx,pause_cnt ; pause to display msg wm_x1: sub cx,cx wm_x2: dec cx jnz wm_x2 dec bx jnz wm_x1 Vtype MsgTst,MsgTstL,Line07 mov ax,Main_S ; re-init for testing mov MemSeg,ax ; now test the data in main memory cld mov ax,LastPat add ax,offset pattern mov si,ax tm1: push si mov ax,MemSeg mov bx,offset Msg3a call Convert_Hex Vtype Msg3a,4,Line07+Msg3ao pop si mov es,MemSeg ; point to segment to be tested mov cx,1000h ; 4K block sub di,di ; start at zero offset tm3: mov al,es:[di] ; check pattern byte against memory cmp al,[si] jne tm7 ; bad byte mov Mem_Val,al ; save if bad parity in al,Port_Par ; check parity test al,Bits_Par ; shows parity error jnz tm8 tm4: inc si inc di cmp si,offset pattern+pattern_len jle tm6 mov si,offset pattern tm6: loop tm3 jmp tm9 tm7: inc Errors mov MemOff,di mov Mem_Val,al in al,Port_Par mov Mem_Par,al mov al,[si] mov Mem_Pat,al call Bad_Mem ; display jmp tm4 tm8: inc Errors mov MemOff,di mov MemSeg,ES mov Mem_Par,al mov al,[si] mov Mem_Pat,al call Bad_Mem ; display jmp tm4 tm9: mov ax,MemSeg ; bump up 4k add ax,0100h mov MemSeg,ax add ax,0ffh cmp ax,Main_L jb tm1 mov bx,pause_cnt ; pause to display msg tm_x1: sub cx,cx tm_x2: dec cx jnz tm_x2 dec bx jnz tm_x1 mov ax,Main_S ; re-init mov MemSeg,ax mov ax,Cycle inc ax mov Cycle,ax cmp ax,CycleMm jle Main_loop Vtype msgd1,msgd1L,line21 Vtype Msg9,Msg9Len,Line07+Msg3Leno ret Check_Main endp ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; Initialize and Enter Protected Mode ;; ;; ... Then call Check_Extended ;; ;; ... Finally, return to real mode ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; Check_Extended proc near mov ax,s_mem ; init segment mov GS,ax mov Cycle,1 mov errors,0 mov ax,Errors mov bx,offset Msg9b call Convert_Decimal Vtype Msg4,Msg4Len,Line08 Vtype Msg9,Msg9Len,Line10 ce1: mov ax,Cycle mov bx,offset Msg9a call Convert_Decimal Vtype Msg9a,5,Line10+Msg9ao mov ax,LastPat dec ax ; start at different place each time jge short ce2 mov ax,pattern_len ce2: mov LastPat,ax Vtype Msg4,MsgTstL,Line08 mov eax,Extnd_S ; re-init for writing mov MemExtnd,eax mov LoopCnt,0 ; now write the data to memory cld mov ax,LastPat add ax,offset pattern mov si,ax we1: push si mov ax,MemSeg mov bx,offset Msg4a call Convert_Hex mov ax,MemOff mov bx,offset Msg4b call Convert_Hex Vtype MSg4a,9,Line08+Msg4ao pop si mov cx,LoopCnt mov edi,MemExtnd ; start we5: lodsb ; put pattern byte into memory mov gs:[edi],al inc edi cmp si,offset pattern+pattern_len jle short we6 mov si,offset pattern we6: loop we5 mov MemExtnd,EDI cmp edi,Extnd_L ; at end? jnb short we_x add edi,10000h cmp edi,Extnd_L ; at end? jb we1 mov edi,Extnd_L sub edi,MemExtnd mov LoopCnt,DI jmp we1 we_x: mov bx,pause_cnt ; pause to display msg we_x1: sub cx,cx we_x2: dec cx jnz we_x2 dec bx jnz we_x1 Vtype MsgTst,MsgTstL,Line08 mov eax,Extnd_S ; re-init for testing mov MemExtnd,eax mov LoopCnt,0 ; now test the memory cld mov ax,LastPat add ax,offset pattern mov si,ax te1: push si mov ax,MemSeg mov bx,offset Msg4a call Convert_Hex mov ax,MemOff mov bx,offset Msg4b call Convert_Hex Vtype Msg4a,9,Line08+Msg4ao pop si mov cx,LoopCnt mov edi,MemExtnd ; start te3: mov al,GS:[EDI] ; check pattern byte against memory cmp al,[si] jne te7 ; bad byte cmp flag_CheckParity,0 je short te4 mov Mem_Val,al ; save if bad parity in al,Port_Par ; check parity test al,Bits_Par ; shows parity error jnz te8 te4: inc si inc edi cmp si,offset pattern+pattern_len jle short te6 mov si,offset pattern te6: loop te3 jmp te9 te7: inc Errors ; memory did not compare mov Mem_Val,al mov MemExtnd,EDI mov MemExtnd,EDI in al,Port_Par mov Mem_Par,al mov al,[si] mov Mem_Pat,al call Bad_Mem ; display info call Empty_8042 jmp te4 te8: inc Errors ; memory compared but parity error mov MemExtnd,EDI mov MemExtnd,EDI mov Mem_Par,al mov al,[si] mov Mem_Pat,al call Bad_Mem ; display info call Empty_8042 jmp te4 te9: mov MemExtnd,edi ; at end? cmp edi,Extnd_L jnb short te_x add edi,10000h cmp edi,Extnd_L jb te1 mov edi,Extnd_L sub edi,MemExtnd mov LoopCnt,DI jmp te1 te_x: push si mov ax,MemSeg mov bx,offset Msg4a call Convert_Hex mov ax,MemOff mov bx,offset Msg4b call Convert_Hex Vtype Msg4a,9,Line08+Msg4ao pop si mov bx,pause_cnt ; pause to display msg te_x1: sub cx,cx te_x2: dec cx jnz te_x2 dec bx jnz te_x1 mov eax,Extnd_S ; re-init mov MemExtnd,eax mov ax,Cycle inc ax mov Cycle,ax cmp ax,CycleEm jle ce1 Vtype msgd2,msgd2L,line21+msgd2o Vtype Msg9,Msg9Len,Line08+Msg3Leno ret Check_Extended endp ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; Interrupt Handlers ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; intspv equ 1800h ; base value of interrupt handler stack intspv1 equ 17e0h ; if no code on stack intspv2 equ intspv1-4 ; if code IS stored int_rdisp dw 0 ; to check SP intcod1 dw 0 ; interrupt code word 1 intcod2 dw 0 ; interrupt code word 2 xmsg08 db 'Double Fault' xmsg08l equ $-xmsg08 xmsg1 db 'Fault ' xmsg1a db 'xx' xmsg1l equ $-xmsg1 ; Interrupt Fault Handlers int00: mov cx,0 mov si,0 jmp int_comm int01: mov cx,1 mov si,0 jmp int_comm int02: mov cx,2 mov si,0 jmp int_comm int03: mov cx,3 mov si,0 jmp int_comm int04: mov cx,4 mov si,0 jmp int_comm int05: mov cx,5 mov si,0 jmp int_comm int06: mov cx,6 mov si,0 jmp int_comm int07: mov cx,7 mov si,0 jmp int_comm int08: mov cx,8 ; Double Fault mov AX,s_ds ; get some addressability mov DS,AX Vtype xmsg08,xmsg08l,line02 jmp $ ; SPIN - go no further int09: mov cx,9 mov si,0 jmp int_comm int10: mov cx,10 mov si,0 jmp int_comm int11: mov cx,11 mov si,0 jmp int_comm int12: mov cx,12 mov si,0 jmp int_comm int13: mov cx,13 mov si,0 jmp int_comm int14: mov cx,14 mov si,0 jmp int_comm int15: mov cx,15 mov si,0 jmp int_comm int16: mov cx,16 mov si,0 jmp int_comm ; Misc Interrupt Handler intxx: mov cx,255 mov si,0 jmp int_comm ; Common routine for handling interrupts int_comm: push AX ; temp get a reg mov ax,s_ds ; to get addressability mov DS,AX pop AX pusha ; save all regs mov AX,CX mov BX,offset xmsg1a call Hexit Vtype xmsg1,xmsg1l,Line00 jmp $ ; ****DEBUG**** SPIN popa IretD ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; ; This controls a signal which gates address bit 20. ; ; The gate A20 signal is an output of the 8042 slave processor. ; Address bit 20 should be gated ON before entering protect ; mode so that memory is addressed properly (if not, then odd numbered ; megs are mapped to the next lowest even numbered meg!!. When ; exiting protect mode (going back to real mode), the address A20 ; should be gated back off. ; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; Empty_8042 proc near mov ecx,100000h ; for timeout (big number) empty: in al,port_status ; read the 8042 status port and al,00000010b ; test input buffer full flag loopnz empty ; loop until empty or timeout ret Empty_8042 endp Gate_A20 proc near ; ; On entry, AH contains the code (enable or disable) ; call Empty_8042 jnz short exit_8042 ; yes mov al,0D1h ; 8042 command to write output port (I hope) out port_status,al call empty_8042 jnz short exit_8042 mov al,ah out port_a,al ; output gate signal call empty_8042 Exit_8042: ret Gate_A20 endp Exec_Prot proc near ; Setup and switch to PE cld cli mov savecs,CS mov savess,SS mov savesp,SP ; First, Enable the A20 line mov ah,bit20_enable call gate_a20 or al,al ; zero if OK jz A20_ON Vtype Emsg3,Emsg3L,Line24 ret A20_ON: ; Convert segment regs into linear addresses. mov ES,Vram segcvt ES,d_crt mov Vram,s_crt ; Protected Mode Video segcvt CS,d_cs segcvt DS,d_ds segcvt SS,d_ss ; Setup GDT, IDT, etc. to run protected segadr DS mov dsaddr,EAX sub EBX,EBX lea EBX,gdt_def add EBX,EAX mov dtload,EBX ; set addr mov dtsize,gdt_size-1 LGDT FWORD PTR dtsize sub EBX,EBX lea EBX,idt_def add EBX,EAX mov dtload,EBX ; set addr mov dtsize,idt_size-1 LIDT FWORD PTR dtsize mov EAX,CR0 ; get control reg or AL,1 ; turn PE on mov CR0,EAX ; set it jmp short @f ; clear pipeline, etc. @@: nop mov AX,s_ds ; and seg regs mov DS,AX mov ES,AX mov FS,AX mov GS,AX mov AX,s_ss mov SS,AX db 0eah ; do far jump to set CS dw go_prot_2-_text,s_cs go_prot_2: mov al,80h ; disable the NMI interrupt out NMIport,al call Check_Extended ; restore for real mode cld cli mov EAX,CR0 ; get control reg and AL,0FEh ; turn PE off mov CR0,EAX ; set it jmp go_real go_real: mov SS,savess mov SP,savesp mov AX,savecs mov DS,AX mov ES,AX mov FS,AX mov GS,AX mov Vram,0b800h ; Restore Real Mode Video Vtype msgd3,msgd3L,Line22 jmp $ ; SPIN - pending interrupts screwed up, ; leave video display up rather ; than re-booting. sti ret Exec_Prot endp ProgEnd equ $ _text ends end start