cos2000v1/noyau/mcb.asm

;Affiche le nombre hexa dans %0[dword]
PROC biosprinth FAR
        ARG     @num:dword
        USES    ax,bx,cx,edx,si,di
        mov     edx,[@num]
        mov 	ah,09h
        mov     di,8
@@hexaize:
        rol     edx,4
        mov     si,dx
	and	si,1111b
	mov	al,[cs:si+offset @@tab]
	mov     cx,1
        cmp     al,32
        jb      @@control
        mov     bx,7
        mov     ah,09h
        int     10h
@@control:
        mov     ah,0Eh
        int     10h
        dec     di
        jnz     @@hexaize
        ret
@@tab db '0123456789ABCDEF'
endp biosprinth

;Affiche le texte ASCIIZ point<6E> par %0
PROC biosprint FAR
        ARG    @pointer:word
        USES   ax,bx,cx,si
        mov    si,[@pointer]
        mov    cx,1
        mov    bx,7
@@again:
        lodsb
        or     al,al
        jz     @@fin
        cmp    al,32
        jb     @@control
        mov    ah,09h
        int    10h
@@control:
        mov    ah,0Eh
        int    10h
        jmp    @@again
@@fin:
        ret
endp biosprint

PROC enablea20 FAR
        USES    ax
        mov     al,0d1h
        out     64h,al
        call    a20wait
        mov     al,0dfh
        out     60h,al
        call    a20wait
        ;mov     al,0ffh
        ;out     64h,al
        ;call    a20wait
        ret
endp enablea20

PROC disablea20 FAR
        USES    ax
        mov     al,0d1h
        out     64h,al
        call    a20wait
        mov     al,0DDh
        out     60h,al
        call    a20wait
        ;mov     al,0ffh
        ;out     64h,al
        ;call    a20wait
        ret
endp disablea20

a20wait:
        in      al,64h
        jmp     @@suite
@@suite:
        and     al,2
        jnz     a20wait
        ret
;par le system control port A
;in al,92h
;or al,2
;out 92h,al

;par le system control port A
;in al,92h
;and al,not 2
;out 92h,al

PROC flatmode FAR
        USES    eax,bx,ds
        push    cs
        pop     ds
        ; first, calculate the linear address of GDT
        xor     eax,eax
        mov     ax,ds
        shl     eax,4
        add     [dword ptr offset @@gdt+2],eax   ; store as GDT linear base addr
        ; now load the GDT into the GDTR
        lgdt    [fword ptr offset @@gdt]   ; load GDT base
        mov     bx,1 * size descriptor ; point to first descriptor
        cli                     ; turn off interrupts
        mov     eax,cr0         ; prepare to enter protected mode
        or      al,1            ; flip the PE bit
        mov     cr0,eax         ; we're now in protected mode
        jmp     @@suite
@@suite:
        mov     fs,bx           ; load the FS segment register
        and     al,0FEh         ; clear the PE bit again
        mov     cr0,eax         ; back to real mode
        jmp     @@suite2
@@suite2:
        sti                     ; resume handling interrupts
        ret                     ;
        
@@gdt descriptor <offset @@gdtend - offset @@gdt - 1, offset @@gdt, 0, 0, 0, 0>  ; the GDT itself
      descriptor <0ffffh, 0, 0, 091h, 0cfh, 0>          ; 4G data segment
@@gdtend:
endp flatmode

;Attend l'appuie sur une touche
PROC bioswaitkey FAR
        USES   ax
        xor    ax,ax
        int    16h
        ret
endp bioswaitkey

firstmb dw 0


;Charge les sections du block %0
PROC mbloadsection FAR
        ARG     @blocks:word
       	USES    ax,bx,cx,si,di,ds,es
       	LOCAL   @@toresov:word:60
       	mov     ax,[@blocks]
       	mov     es,ax
       	mov     ds,ax
        cmp     [word ptr 0],"EC"
        jne     @@notace
        lea     si,[@@toresov]
        mov     [word ptr ss:si],0FFFFh
        mov     bx,[ds:exe.sections]
        cmp     bx,0
        je      @@finishloading
@@loading:
        cmp     [dword ptr bx],0
        je      @@finishloading
        mov     ax,bx
        add     ax,4
pushad
call biosprint,ax
popad
        call    mbcreate,ax,[word ptr bx+2]
        jc      @@error
        inc     si
        inc     si
        mov     [ss:si],ax
        push    si
        mov     si,[bx]
        xor     di,di
        mov     es,ax
        mov     cx,[bx+2]
        cld
        rep     movsb
        pop     si
        add     bx,4
@@gonext:
        inc     bx
        cmp     [byte ptr bx],0
        jne     @@gonext
        inc     bx
        jmp     @@loading
@@finishloading:
        cmp     [word ptr ss:si],0FFFFh
        je      @@finishdepands
        call    mbloadfuncs,[word ptr ss:si]
        jc      @@depandserror
        dec     si
        dec     si
        jmp     @@finishloading
@@finishdepands:
        ret
@@notace:
        stc
        ret
@@error:
        stc
        ret
@@depandserror:
        stc
        ret
endp mbloadsection
        

;Initialise les blocs de m<>moire en prenant memorystart pour segment de base
PROC mbinit FAR
	USES    ax,cx,si,di,ds,es	
	cmp     [cs:firstmb],0
	jne     @@alreadyok
	push    cs
	pop     ds
	mov     [cs:firstmb],memorystart
        mov     ax,memorystart-2
        mov     es,ax
        mov     si,offset afree
        xor     di,di
        mov     cx,size mb
        rep     movsb
	clc
	ret
@@alreadyok:
	stc
	ret
endp mbinit

afree mb <"HN",0,0,0,0A000h-memorystart,"Libre">
         db 0

;Cre<72>r un bloc de nom %0 de taille %1 (octets) -> n<>segment dans AX
PROC mbcreate FAR
        ARG     @blocks:word,@size:word
        USES	bx,cx,dx,si,di,ds,es
        push    gs
        mov     ax,[ss:bp+4]
        mov     dx,ax
        dec     dx
        dec     dx
        mov     gs,dx
        cmp     [word ptr gs:0x0],'NH'
        je      @@oktoset
        mov     ax,memorystart
@@oktoset:
        mov     gs,ax
        mov     cx,[@size]	
	shr	cx,4
	inc	cx
	mov	bx,[cs:firstmb]
	dec	bx
	dec	bx
	mov     dl,true
@@searchfree:
	cmp	dl,false
	je	@@notenougtmem
	mov     es,bx
	cmp	[word ptr es:mb.check],"NH"
	jne	@@memoryerror
	cmp	[es:mb.isnotlast],true
	sete    dl
	cmp	[es:mb.reference],free
	jne	@@notsogood
	mov	ax,[es:mb.sizes]
	cmp	cx,ax
	ja	@@notsogood
        mov     [word ptr es:mb.check],"NH"
	mov	[es:mb.isnotlast],true
	mov	[es:mb.reference],gs
	mov	[es:mb.isresident],false
	lea     di,[es:mb.names]
	push    cx
	mov 	cx,24/4
	mov     si,[@blocks]
        cld
	rep     movsd
	pop     cx
	inc     bx
	inc     bx	
        sub	ax,cx
	cmp     ax,0
	je      @@nofree
	dec	ax
	dec	ax
	mov	[es:mb.sizes],cx
	add	cx,bx
	mov	es,cx
        mov     si,offset afree
        xor     di,di
        mov     cx,size mb
        push    cs
        pop     ds
        cld
        rep     movsb	
	mov	[es:mb.isnotlast],dl
	mov	[es:mb.sizes],ax
@@nofree:
	mov	ax,bx
	pop     gs
	clc
	ret
@@notsogood:
        inc     bx
        inc     bx
	add	bx,[es:mb.sizes]
	jmp	@@searchfree
@@memoryerror:
	pop     gs
	stc
	ret
@@notenougtmem:
        pop     gs
        stc
        ret
endp mbcreate

;Lib<69>re le bloc de m<>moire %0 et ses sous blocs
PROC mbfree FAR
        ARG     @blocks:word
	USES	ax,bx,cx,si,di,ds,es
	mov	bx,[@blocks]
	mov     ax,bx
	dec     bx
	dec     bx
	mov	es,bx
	cmp	[word ptr es:mb.check],"NH"
	jne	@@memoryerror
	cmp	[es:mb.reference],free
	je	@@wasfree
	cmp	[es:mb.isresident],true
	je	@@wasresident
	mov	[es:mb.reference],free
	push    cs
	pop     ds
	mov     si,offset @@isfree
	lea     di,[es:mb.names]
        mov     cx,6
        cld
        rep     movsb
        mov	bx,[cs:firstmb]
	dec	bx
	dec	bx
@@searchtofree:
	mov     es,bx
	cmp	[word ptr es:mb.check],"NH"
	jne	@@memoryerror
        inc     bx
        inc     bx
	add	bx,[es:mb.sizes]
	cmp     [es:mb.sizes],0
	je      @@nottofree
	cmp     ax,[es:mb.reference]
	jne     @@nottofree
	mov	[es:mb.isresident],false
	mov	[es:mb.reference],free
	mov     si,offset @@isfree
	lea     di,[es:mb.names]
        mov     cx,6
        cld
        rep     movsb
@@nottofree:
        cmp	[es:mb.isnotlast],true
	je	@@searchtofree
        call    mbclean	
	ret
@@memoryerror:
	stc
	ret
@@wasfree:
	stc
	ret
@@wasresident:
	stc
	ret
        	
@@isfree db "libre",0
endp mbfree

;Mise a nivo de la m<>moire (jonction de blocs libre)
PROC mbclean FAR
        USES    ax,bx,dx,es,gs
        mov	bx,[cs:firstmb]
	dec	bx
	dec	bx
	xor     ax,ax
	xor     dx,dx
@@searchfree:
	mov     gs,bx
	cmp	[word ptr gs:mb.check],"NH"
	jne	@@memoryerror
        inc     bx
        inc     bx
	add	bx,[gs:mb.sizes]
	cmp     [word ptr gs:mb.sizes],0
	je      @@notenougtmem
	cmp	[gs:mb.reference],free
	jne     @@notfree
	cmp     ax,0
	je      @@notmeetfree
	add     dx,[gs:mb.sizes]
	mov     [word ptr gs:mb.check],0
	mov	[dword ptr gs:mb.names],0	
	inc     dx
	inc     dx
	jmp     @@nottrigered
@@notmeetfree:	
        xor     dx,dx
	mov     ax,gs	
	jmp     @@nottrigered
@@notfree:
        cmp     ax,0
        je      @@nottrigered
        mov     es,ax
        add     [es:mb.sizes],dx
        xor     ax,ax
@@nottrigered:
	cmp	[gs:mb.isnotlast],true
	je	@@searchfree
	cmp     ax,0
	je      @@reallyfinish
	mov     es,ax
        add     [es:mb.sizes],dx
        mov     [es:mb.isnotlast],false
@@reallyfinish:
	clc
	ret
@@notenougtmem:
        stc
        ret
@@memoryerror:
	stc
	ret
endp mbclean

;Rend le segment %0 r<>sident
PROC mbresident FAR
        ARG     @blocks:word
	USES	bx,es
	mov	bx,[@blocks]
	dec	bx
	dec     bx
	mov	es,bx
	cmp	[word ptr es:mb.check],"NH"
	jne	@@memoryerror	
	mov	[es:mb.isresident],true
	ret
@@memoryerror:
        stc
        ret
endp mbresident
	
;Rend le segment %0 non r<>sident
PROC mbnonresident FAR
        ARG     @blocks:word
	USES	bx,es
	mov	bx,[@blocks]
	dec	bx
	dec     bx
	mov	es,bx
	cmp	[word ptr es:mb.check],"NH"
	jne	@@memoryerror	
	mov	[es:mb.isresident],false
	ret
@@memoryerror:
        stc
        ret
endp mbnonresident


;Change le proprietaire de %0 a %1
PROC mbchown FAR
        ARG     @blocks:word,@owner:word
	USES	bx,dx,es
	mov	bx,[@blocks]
	dec     bx
	dec     bx
	mov	es,bx
	cmp	[word ptr es:mb.check],"NH"
	jne	@@memoryerror
	cmp	[es:mb.reference],free
	je	@@wasfree
	mov     dx,[@owner]
	mov	[es:mb.reference],dx
	ret
@@memoryerror:
	stc
	ret
@@wasfree:
	stc
	ret
endp mbchown
	
;Alloue un bloc /data de CX caractere pour le process appelant -> ax
PROC mballoc FAR
        ARG     @size:word
        USES    si,ds	
	push    cs
	pop     ds
	call    mbcreate,offset @@data,[@size]
	call    mbchown,ax,[word ptr ss:bp+4]
	ret

@@data db '/data',0
endp mballoc

;Renvoie en AX le MB n<> %0  carry quand termin<69>
PROC mbget FAR
        ARG     @num:word
        USES    bx,dx,es
        mov	bx,[cs:firstmb]
	dec	bx
	dec	bx
	xor     dx,dx
@@searchfree:
	mov     es,bx
	cmp	[word ptr es:mb.check],"NH"
	jne	@@memoryerror
        inc     bx
        inc     bx
	add	bx,[es:mb.sizes]
	cmp     [es:mb.sizes],0
	je      @@memoryerror
	cmp     dx,[@num]
	je      @@foundmcb
	ja      @@notfound
        inc     dx
	cmp	[es:mb.isnotlast],true
	je	@@searchfree
@@memoryerror:
	stc
	ret
@@foundmcb:
        mov     ax,es
        inc     ax
        inc     ax
	clc
	ret
@@notfound:
 	stc
	ret
endp mbget 		
	
;Renvoie en AX le MCB qui correspond a ds:%0
PROC mbfind FAR
        ARG     @blocks:word
        USES    bx,si,di,es
        mov	bx,[cs:firstmb]
	dec	bx
	dec	bx
	mov     si,[@blocks]
@@search:
	mov     es,bx
	lea     di,[es:mb.names]
	cmp	[word ptr es:mb.check],"NH"
	jne	@@memoryerror
        inc     bx
        inc     bx
	add	bx,[es:mb.sizes]
	cmp     [es:mb.sizes],0
	je      @@memoryerror
	push    si di
@@cmpnames:
        mov     al,[es:di]
        cmp     al,[ds:si]
        jne     @@ok
        cmp     al,0
        je      @@ok
        inc     si
        inc     di
        jmp     @@cmpnames
@@ok:
        pop     di si
	je      @@foundmcb
	cmp	[es:mb.isnotlast],true
	je	@@search
@@notfound:
	stc
	ret
@@memoryerror:
        stc
        ret
@@foundmcb:
        mov     ax,es
        inc     ax
        inc     ax
	clc
	ret
endp mbfind

		
;Renvoie en AX le sous mcb qui correspond a %0 et qui appartien a %1
PROC mbfindsb FAR
        ARG     @blocks:word,@owner:word
        USES    bx,dx,si,di,es
        mov	bx,[cs:firstmb]
	dec	bx
	dec	bx
	mov     si,[@blocks]
	lea     di,[es:mb.names]
	mov     dx,[@owner]
@@search:
	mov     es,bx
	cmp	[word ptr es:mb.check],"NH"
	jne	@@memoryerror
        inc     bx
        inc     bx
	add	bx,[es:mb.sizes]
	cmp     [es:mb.sizes],0
	je      @@memoryerror
	push    si di
@@cmpnames:
        mov     al,[es:di]
        cmp     al,[ds:si]
        jne     @@ok
        cmp     al,0
        je      @@ok
        inc     si
        inc     di
        jmp     @@cmpnames
@@ok:
        pop     di si
	jne     @@notfoundmcb
	cmp     [es:mb.reference],dx
	je      @@foundmcb
@@notfoundmcb:
	cmp	[es:mb.isnotlast],true
	je	@@search
@@notfound:
	stc
	ret
@@foundmcb:
        mov     ax,es
        inc     ax
        inc     ax
	clc
	ret
@@memoryerror:
        stc
        ret
endp mbfindsb

;Resouds les d<>pendances du bloc de m<>moire %0
PROC mbloadfuncs FAR
        ARG     @blocks:word
        USES    ax,bx,cx,dx,si,ds
        mov     ds,[@blocks]
        cmp     [word ptr 0],"EC"
        jne     @@notace
        mov     si,[ds:exe.imports]
        cmp     si,0
        je      @@endofloading
@@loadfuncs:
        cmp     [word ptr si],0
        je      @@endofloading
        call    mbsearchfunc,si
        jnc     @@toendoftext
        mov     bx,si
pushad
call biosprint,si
popad
@@findend:
        inc     bx
        cmp     [byte ptr bx], ':'
        jne     @@findend
        mov     [byte ptr bx],0
        call    [cs:projfile],si
        jc      @@erroronload
        mov     [byte ptr bx],':'
pushad
call biosprint,si
popad
        call    mbsearchfunc,si
        jc      @@libnotexist
@@toendoftext:
        mov     cl,[si]
        cmp     cl,0
        je      @@oktonext
        inc     si
        jmp     @@toendoftext
@@oktonext:
        inc     si
        mov     [si],ax
        mov     [si+2],dx
        add     si,4
        jmp     @@loadfuncs
@@endofloading:
        clc
        ret
@@notace:
        stc
        ret
@@libnotexist:
        stc
        ret
@@erroronload:
        stc
        ret
endp mbloadfuncs


;Recherche une fonction point<6E> par DS:%0 en m<>moire et renvoie son adresse en DX:AX
PROC mbsearchfunc FAR
        ARG     @func:word
        USES    bx,si,di,es
        mov     bx,[@func]
        mov     si,bx
@@findend:
        inc     bx
        cmp     [byte ptr bx], ':'
        jne     @@findend
        mov     [byte ptr bx],0
        call    mbfind,si
        mov     [byte ptr bx],':'
        jc      @@notfoundattallthesb
        mov     es,ax
        cmp     [word ptr es:exe.checks],"EC"
        jne     @@notfoundattallthesb
        mov     di,[es:exe.exports]
        inc     bx
        inc     bx
@@functions:
        cmp     [word ptr es:di],0
        je      @@notfoundattallthesb
        mov     si,bx
@@cmpnamesfunc:
        mov     al,[es:di]
        cmp     al,[ds:si]
        jne     @@notfoundthesb
        cmp     al,0
        je      @@seemsok
        inc     si
        inc     di
        jmp     @@cmpnamesfunc
@@notfoundthesb:
        mov     al,[es:di]
        cmp     al,0
        je      @@oktonext
        inc     di
        jmp     @@notfoundthesb
@@oktonext:
        inc     di
        inc     di
        inc     di
        jmp     @@functions
@@seemsok:
        mov     dx,es
        mov     ax,[es:di+1]
        clc
        ret
@@notfoundattallthesb:
        stc
        ret
endp mbsearchfunc