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Assembly Source File | 1999-01-19 | 83.2 KB | 2,077 lines

; PMODE v2.51 raw, DPMI, VCPI, & XMS compliant protected mode header. ; By Tran (a.k.a. Thomas Pytel). ; NASM (The Netwide Assembler) 0.95 port 0.1 ; By Cyborg/Mistery <cyborg@otitsun.oulu.fi> ; NASM 0.97 port 0.2 ; by Ike (a.k.a. Ivan Tomac) <ike@technologist.com> %include "nasmmac.inc" global v86r_eax ; D global v86r_ebx ; D global v86r_ecx ; D global v86r_edx ; D global v86r_esi ; D global v86r_edi ; D global v86r_ebp ; D global v86r_ah ; B global v86r_al ; B global v86r_bh ; B global v86r_bl ; B global v86r_ch ; B global v86r_cl ; B global v86r_dh ; B global v86r_dl ; B global v86r_ax ; W global v86r_bx ; W global v86r_cx ; W global v86r_dx ; W global v86r_si ; W global v86r_di ; W global v86r_bp ; W global v86r_ds ; W global v86r_es ; W global v86r_fs ; W global v86r_gs ; W global _selcode ; W global _seldata ; W global _selzero ; W global _lomembase ; D global _lomemtop ; D global _himembase ; D global _himemtop ; D global _pspa ; D global _code16a ; D global _code32a ; D global _getirqvect ; D global _setirqvect ; D global _sysbyte0 ; B global _setselector ; D global _exitcode ; B global _getmem ; near global _getlomem ; near global _gethimem ; near global _lomemsize ; near global _himemsize ; near global _ret ; near global _exit ; near global _getirqmask ; near global _setirqmask ; near global _rmpmirqset ; near global _rmpmirqfree ; near global _getselector ; near global _freeselector ; near extern _main LOWMIN equ 0 ; minimum free low memory (in K) EXTMIN equ 0 ; minimum free extended memory (in K) SELECTORS equ 8 ; extra selectors for allocation != 0 STAKMAIN equ 100h ; main execution stream stack size (in para) STAKRMODE equ 10h ; real mode call stack size (in para) STAKPMODE equ 20h ; protected mode call stack size (in para) MODENESTING equ 8 ; max number of nested mode switches RMODENUM equ (MODENESTING+1) >> 1 PMODENUM equ MODENESTING >> 1 STAKSIZE equ STAKMAIN+(PMODENUM*STAKPMODE)+(RMODENUM*STAKRMODE) ;<0fffh! ;▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ ; Real mode and 16bit code ;▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ section code bits 16 ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ; 16 bit common system data ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ errmsg0 db '386 or better not detected!!!',7,'$' errmsg1 db 'Not enough low memory!!!',7,'$' errmsg2 db 'System is already in V86 mode, and no VCPI or DPMI found!!!',7,'$' errmsg3 db 'Not enough extended memory!!!',7,'$' errmsg4 db 'Could not enable A20 gate!!!',7,'$' errmsg5 db 'Extended memory allocation failure. (weird eh???)',7,'$' nullint db 0CFh ; IRET instruction exitrout dw exit ; exit routine, modified if XMS, VCPI savedstakoff dw ? ; current saved stack offset savedstakseg dw ? ; current saved stack segment ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ; 16 bit common system code ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ;═════════════════════════════════════════════════════════════════════════════ intreal: ; real mode int, load FS and GS here pushf ;----------------------------------------------------------------------------- callreal: ; real mode call, load FS and GS here push cs push W icreald mov fs,[cs:v86r_fs] mov gs,[cs:v86r_gs] mov eax,[cs:v86r_eax] mov ecx,[cs:v86r_ecx] mov edx,[cs:v86r_edx] mov ebx,[cs:v86r_ebx] mov esi,[cs:v86r_esi] mov edi,[cs:v86r_edi] mov ebp,[cs:v86r_ebp] ;----------------------------------------------------------------------------- icreal: ; real mode int, call, or IRQ db 66h,68h ; PUSH destination addx icrealm1 dd ? ; icrealm0 db ? ; CLI or STI retf ;----------------------------------------------------------------------------- icreald: ; done with real int or call cli pushf pop W[cs:v86r_flags] mov [cs:v86r_eax],eax mov [cs:v86r_ecx],ecx mov [cs:v86r_edx],edx mov [cs:v86r_ebx],ebx mov [cs:v86r_esi],esi mov [cs:v86r_edi],edi mov [cs:v86r_ebp],ebp mov [cs:v86r_ds],ds mov [cs:v86r_es],es mov [cs:v86r_fs],fs mov [cs:v86r_gs],gs icreald2: mov ax,cs mov ds,ax icrealm2: ; return to pmode modifiable to JMP ;----------------------------------------------------------------------------- mov ebx,[cp_savedstakoff] ; DPMI return to pmode mov dx,[dp_savedstaksel] mov edi,dp_int3_d mov si,[_selcode] mov cx,dx mov ax,[_seldata] jmp far [d_switchaddx] ;----------------------------------------------------------------------------- VICREAL1D equ (($-(icrealm2+2)) << 8) + 0EBh v_icreal1d: ; VCPI return to pmode from safe mov edi,cp_int3_d ;----------------------------------------------------------------------------- ; EDI=offset to jump to in code32 v_switchtopmode: ; VCPI switch to pmode mov [v_ss_dest],edi mov esi,v_ss_cr3 add esi,[_code16a] mov ax,0DE0Ch int 67h ;----------------------------------------------------------------------------- CICREAL1D equ (($-(icrealm2+2)) << 8) + 0EBh c_icreal1d: ; custom return to pmode from safe mov edi,cp_int3_d ;----------------------------------------------------------------------------- ; EDI=offset in pmode to jump to c_retpmode: ; reenter 32bit pmode lgdt [c_gdt32addx] ; set up pmode GDT and IDT lidt [c_idt32addx] mov B[gdt32task+5],89h ; set task as not busy mov eax,cr0 ; switch to pmode or al,1 mov cr0,eax db 0EAh dw $+4,20h mov ax,30h ; load task register ltr ax jmp c_gotopmode ;═════════════════════════════════════════════════════════════════════════════ int32: ; real mode INT32: EDX=off pushad push ds push es push fs push gs cli mov ax,cs mov ds,ax mov [p_cpmodem0],edx mov al,[esp+45] shr al,1 and al,1 add al,0FAh mov [p_cpmodem1],al push W[savedstakoff] push W[savedstakseg] movzx ebx,W[nextmodestack] lea eax,[ebx-STAKPMODE*16] mov [nextmodestack],ax add ebx,[realstackbase] mov [savedstakseg],ss int32m0: ; jump to pmode, modifiable ;----------------------------------------------------------------------------- sub sp,[dp_savelen] mov [savedstakoff],sp mov ax,ss ; DPMI jump to pmode mov es,ax mov di,sp xor al,al call far [d_saveaddx] mov ax,[_seldata] mov cx,ax mov dx,ax mov edi,p_cpmode0 mov si,[_selcode] jmp far [d_switchaddx] ;----------------------------------------------------------------------------- VINT32 equ (($-(int32m0+2)) << 8) + 0EBh ; JMP short v_int32 v_int32: ; VCPI call pmode push W[p_cpmodem2] mov W[p_cpmodem2],VCPMODED mov [savedstakoff],sp mov edi,p_cpmode1 jmp v_switchtopmode ;----------------------------------------------------------------------------- ; if ($-(int32m0+2)) gt 127 => error CINT32 equ (($-(int32m0+2)) << 8)+0EBh ; JMP short c_int32 c_int32: ; raw/XMS call pmode push W[p_cpmodem2] mov W[p_cpmodem2],CCPMODED mov [savedstakoff],sp mov edi,p_cpmode1 jmp c_retpmode ;═════════════════════════════════════════════════════════════════════════════ int32d0: ; DPMI done with pmode call mov di,sp mov al,1 call far [d_saveaddx] add sp,[dp_savelen] ;----------------------------------------------------------------------------- int32d2: ; done from all pop W[savedstakseg] pop W[savedstakoff] add W[nextmodestack],STAKPMODE*16 mov bx,[v86r_flags] mov ax,[esp+44] and ax,~8D5h and bx,8D5h or ax,bx mov [esp+44],ax pop gs pop fs pop es pop ds popad iret ;═════════════════════════════════════════════════════════════════════════════ int32d1: ; VCPI done with pmode call mov ss,[savedstakseg] pop W[p_cpmodem2] jmp int32d2 ;═════════════════════════════════════════════════════════════════════════════ int32d3: ; raw/XMS done with pmode call mov W[c_retreal0m0],c_sicreal mov ax,cs mov ds,ax movzx esp,W[savedstakoff] mov ss,[savedstakseg] pop W[p_cpmodem2] jmp int32d2 ;───────────────────────────────────────────────────────────────────────────── chek_VCPI: ; Chek for VCPI xor ax,ax mov gs,ax mov ax,[gs:67h*4] or ax,[gs:67h*4+2] jz short chekVCPIa mov ax,0DE00h int 67h or ah,ah clc jz short chekVCPId chekVCPIa: stc chekVCPId: ret ;───────────────────────────────────────────────────────────────────────────── chek_processor: ; Detect if current processor 386 pushf xor ah,ah push ax popf pushf pop ax and ah,0F0h cmp ah,0F0h je short detectno386 mov ah,0F0h push ax popf pushf pop ax and ah,0F0h jz short detectno386 popf ret detectno386: mov dx,errmsg0 jmp short exit16err ;───────────────────────────────────────────────────────────────────────────── chek_V86: ; Chek if already in V86 mode smsw ax test al,1 mov dx,errmsg2 jnz short exit16err ret ;───────────────────────────────────────────────────────────────────────────── pregetlomem: ; Get low memory or abort add eax,[_lomembase] mov ebx,[_lomemtop] cmp eax,ebx ja short pregetlomema mov ecx,eax xchg eax,[_lomembase] sub ebx,ecx cmp ebx,LOWMIN*1024 jb short pregetlomema ret pregetlomema: mov dx,errmsg1 ;───────────────────────────────────────────────────────────────────────────── exit16err: ; Exit program with message mov ah,9 int 21h jmp [exitrout] ;----------------------------------------------------------------------------- exit: ; Guess what??? movzx esp,sp mov ah,4Ch mov al,[_exitcode] int 21h ;═════════════════════════════════════════════════════════════════════════════ ..start: ; Program begins here cli mov ax,stack mov ss,ax mov esp,STAKSIZE*16 cld push cs pop ds call chek_processor ; is it at least a 386¿ mov ax,es ; set up a bunch of pointers movzx eax,ax shl eax,4 mov [_pspa],eax mov ax,cs movzx eax,ax shl eax,4 mov [_code16a],eax or [gdt32code16+2],eax or [gdt32data16+2],eax mov bx,cs movzx ebx,bx shl ebx,4 mov [_code32a],ebx or [gdt32code32+2],ebx or [gdt32data32+2],ebx add [c_gdt32addx+2],ebx mov ax,ss movzx eax,ax shl eax,4 sub eax,ebx mov [_lomembase],eax mov [realstackbase],eax movzx eax,W[es:2] shl eax,4 sub eax,ebx mov [_lomemtop],eax mov eax,STAKSIZE*16 ; get stack memory call pregetlomem push es ; save PSP seg (DPMI chek kills ES) pop fs call chek_VCPI ; chek for VCPI jnc near v_start mov ax,1687h ; chek for DPMI int 2Fh or ax,ax jz near d_start call chek_V86 ; chek for V86 mode mov ax,4300h ; chek for XMS int 2Fh cmp al,80h je near x_start jmp c_start ; custom system start ;───────────────────────────────────────────────────────────────────────────── enableA20: ; hardware enable gate A20 xor ax,ax mov fs,ax dec ax mov gs,ax call testA20 je short enableA20done in al,92h ; PS/2 A20 enable or al,2 jmp short $+2 jmp short $+2 jmp short $+2 out 92h,al call testA20 je short enableA20done call enableA20o1 ; AT A20 enable jnz short enableA20wait mov al,0D1h out 64h,al call enableA20o1 jnz short enableA20wait mov al,0dfh out 60h,al push W enableA20wait enableA20o1: mov ecx,20000h enableA20o1l: jmp short $+2 jmp short $+2 jmp short $+2 in al,64h test al,2 loopnz enableA20o1l enableA20done: ret ;----------------------------------------------------------------------------- enableA20wait: ; wait for A20 mov al,36h out 43h,al xor al,al out 40h,al out 40h,al mov cx,800h enableA20waitl0: call testA20 je enableA20done in al,40h in al,40h mov ah,al enableA20waitl1: in al,40h in al,40h cmp al,ah je enableA20waitl1 loop enableA20waitl0 mov dx,errmsg4 jmp exit16err ;----------------------------------------------------------------------------- testA20: ; Test for enabled A20 mov al,[fs:0] mov ah,al not al mov [gs:10h],al cmp ah,[fs:0] mov [fs:0],ah ret ;───────────────────────────────────────────────────────────────────────────── ; BL=low PIC val, BH=high PIC val setintslots: ; set int nums in table to PIC vals mov edi,intslottbl mov cl,8 setintslotsl0: mov [di],bl inc di inc bl dec cl jnz setintslotsl0 mov cl,8 setintslotsl1: mov [di],bh inc di inc bh dec cl jnz setintslotsl1 ret ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ; 16 bit DPMI system data ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ d_errmsg0 db 'DPMI host is not 32bit!!!',7,'$' d_errmsg1 db 'Ran out of DPMI descriptors!!!',7,'$' d_errmsg2 db 'Could not set DPMI descriptors as needed!!!',7,'$' d_errmsg3 db 'Could not enter 32bit protected mode!!!',7,'$' d_enterpmode dw ?,? ; DPMI switch to pmode addx d_pspsel dw ? ; stupid PSP selector d_oldenvsegsel dw ? ; stupid selector we dont want d_switchaddx dd ? ; switch to pmode addx d_saveaddx dd ? ; save/restore state addx d_nintoff dd dp_irq0, dp_irq1, dp_irq2, dp_irq3 dd dp_irq4, dp_irq5, dp_irq6, dp_irq7 dd dp_irq8, dp_irq9, dp_irqa, dp_irqb dd dp_irqc, dp_irqd, dp_irqe, dp_irqf dd dp_int33, dp_int32 ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ; 16 bit DPMI system code ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ;═════════════════════════════════════════════════════════════════════════════ d_retreal: ; Return to real mode mov ax,0205h ; restore all int vectors needed mov edi,17 d_retreall0: mov bl,[intslottbl+edi] lea ebp,[edi*3] mov edx,D[ds:dp_ointbuf+ebp*2] mov cx,W[ds:dp_ointbuf+ebp*2+4] int 31h sub di,1 jnc d_retreall0 jmp short d_exit ;───────────────────────────────────────────────────────────────────────────── d_exit16err: ; DPMI Exit with error message mov W[v86r_ds],code mov B[v86r_ah],9 mov ax,0300h mov bx,21h xor cx,cx mov edi,v86r_edi push ds pop es int 31h ;───────────────────────────────────────────────────────────────────────────── d_exit: ; DPMI exit to real mode mov es,[d_pspsel] ; restore env selector mov ax,[d_oldenvsegsel] mov [es:2Ch],ax jmp exit ;═════════════════════════════════════════════════════════════════════════════ d_start: ; Start in a crappy DPMI system or B[_sysbyte0],3 ; set system type DPMI byte test bl,1 ; must be 32bit DPMI mov dx,d_errmsg0 jz near exit16err mov [d_enterpmode+0],di ; store enter addx mov [d_enterpmode+2],es push W[fs:2Ch] ; preserve old env seg movzx eax,si ; get mem for DPMI blok shl eax,4 call pregetlomem shr eax,4 add ax,code mov es,ax mov ax,1 ; switch to pmode call far [d_enterpmode] cli ; I don't trust DPMI mov dx,d_errmsg3 jc near exit16err mov W[v86r_dx],d_errmsg1 ; prepare for abort maybe pop ax ; swap old env seg with selector xchg ax,[es:2Ch] mov [d_oldenvsegsel],ax mov [d_pspsel],es ; store stupid selectors mov [data16sel],ds mov [code16sel],cs mov W[code16off],d_retreal ; set return to real mode addx mov D[_setirqvect],dp_setirqvect ; modify some crap mov D[_getirqvect],dp_getirqvect mov D[_setselector],dp_setselector push ds ; no more need for PSP pop es mov ax,0003h ; get selector increment value int 31h mov bx,ax xor ax,ax ; get needed selectors mov cx,3+SELECTORS int 31h jc near d_exit16err mov si,ax ; set up descriptors mov [_selcode],ax lea ecx,[eax+ebx] mov [_seldata],cx lea ebp,[ecx+ebx] mov [_selzero],bp lea eax,[ebp+ebx] mov [selectorbase],ax mov [selectorinc],bx mov W[v86r_dx],d_errmsg2 mov ax,0Ch ; set descriptors from GDT mov bx,si mov edi,gdt32code32 or B[edi+5],01100000b ; set DPL to 3 int 31h jc near d_exit16err mov bx,cx mov edi,gdt32data32 or B[edi+5],01100000b int 31h jc near d_exit16err mov bx,bp mov edi,gdt32zero32 or B[edi+5],01100000b int 31h jc near d_exit16err mov bx,[selectorbase] ; set up extra allocatable selectors mov dx,SELECTORS d_startl1: int 31h ; initialize them all as gdt32zero32 jc near d_exit16err add bx,[selectorinc] dec dx jnz d_startl1 mov es,cx ; ES, FS, and GS what they should be mov fs,cx mov gs,bp mov edi,[_lomembase] ; chek and get extended memory mov eax,[_lomemtop] sub eax,edi cmp eax,48 ; 30h-byte buffer mov W[v86r_dx],errmsg1 jb near d_exit16err mov ax,0500h int 31h mov edx,[es:edi] mov W[v86r_dx],errmsg3 jmp short d_startf0 d_startl2: sub edx,4096 jnc short d_startf0 xor edx,edx d_startf0: mov eax,edx shr eax,10 cmp eax,EXTMIN jb near d_exit16err or edx,edx jz short d_startf1 mov cx,dx shld ebx,edx,16 mov ax,0501h int 31h jc d_startl2 shl ebx,16 mov bx,cx sub ebx,[_code32a] mov [_himembase],ebx add ebx,edx mov [_himemtop],ebx d_startf1: mov ax,0305h ; get save/restore state addxs int 31h mov [dp_savelen],ax mov [dp_saveaddx+0],edi mov [dp_saveaddx+4],si mov [d_saveaddx+0],cx mov [d_saveaddx+2],bx mov ax,0306h ; get switch mode addxs int 31h mov [dp_switchaddx+0],edi mov [dp_switchaddx+4],si mov [d_switchaddx+0],cx mov [d_switchaddx+2],bx mov ax,0400h ; set IRQ handlers to PIC values int 31h xchg dl,dh mov bx,dx call setintslots mov ah,2 ; backup and set all int vectors mov si,[_selcode] mov edi,17 d_startl0: mov bl,[intslottbl+edi] mov al,4 int 31h lea ebp,[edi*3] mov [ds:dp_ointbuf+ebp*2],edx mov [ds:dp_ointbuf+ebp*2+4],cx mov al,5 mov edx,[d_nintoff+edi*4] mov cx,si int 31h sub di,1 jnc d_startl0 mov ax,es ; set up needed regs & go on to 32bit mov ss,ax add esp,[realstackbase] mov ds,ax push D[cs:_selcode] push D p_start db 66h,0CBh ; 32bit RETF ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ; 16bit VCPI system data ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ v_errmsg0 db 'Incompatible VCPI PIC mappings!!!',7,'$' v_pagedirseg dw ? ; seg of page directory v_pagebase dw 0 ; first page of himem (*4)+1000h v_pagetop dw 0 ; top page of himem (*4)+1000h v_ss_cr3 dd ? ; new CR3 for pmode (physical) v_ss_gdtaddxptr dw c_gdt32addx,0 ; ptr to GDT data for pmode v_ss_idtaddxptr dw c_idt32addx,0 ; ptr to IDT data for pmode v_ss_ldtsel dw 0 ; don't need no stinkin LDTs v_ss_trsel dw 30h ; task state segment selector v_ss_dest dd ? ; start in pmode EIP dw 20h ; start in pmode CS ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ; 16bit VCPI system code ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ;═════════════════════════════════════════════════════════════════════════════ v_retreal: ; VCPI return to real mode movzx edi,W[exitrout] mov esi,esp sub esi,[realstackbase] mov cx,code ;═════════════════════════════════════════════════════════════════════════════ ; EDI=offset to jump to, ESI=real mode stack ptr, CX=real mode DS v_retreal0: ; VCPI go to real mode sub esp,8 push ecx push D[v86r_es] dw 06866h,stack,0 ; PUSH dword codeend push esi pushfd dw 06866h,code,0 ; PUSH dword code16 push edi mov ax,gs mov ds,ax mov ax,0DE0Ch call D far [cs:vp_vcpipmentry] ;───────────────────────────────────────────────────────────────────────────── v_exit: ; VCPI exit (clean up pages) mov es,[v_pagedirseg] mov si,[v_pagebase] mov cx,[v_pagetop] sub cx,si jbe short v_exitf0 v_exitl0: mov edx,[es:si] and dx,0F000h mov ax,0DE05h int 67h add si,4 sub cx,4 jnz v_exitl0 v_exitf0: jmp exit ;───────────────────────────────────────────────────────────────────────────── v_exiterr1: ; VCPI not enough low mem exit mov dx,errmsg1 jmp exit16err ;═════════════════════════════════════════════════════════════════════════════ v_start: ; start continues from VCPI or B[_sysbyte0],2 ; set system type VCPI byte mov W[code16off],v_retreal ; VCPI return to real mode mov D[c_idt32handler+40h],vp_int33 ; VCPI safe int handlers mov D[c_idt32handler+44h],vp_int32 mov D[cp_v86irqintr],vp_int33f0 ; VCPI IRQ safe int routine mov W[int32m0],VINT32 ; VCPI real INT32 mov ax,0DE0Ah ; get PIC mappings int 67h mov bh,cl mov dx,v_errmsg0 ; chek for compatible PIC mapping cmp bl,bh je near exit16err cmp bl,30h je near exit16err cmp bh,30h je near exit16err mov ax,70h ; compatible, get highest needed num cmp al,bl ja short v_startf1 mov al,bl v_startf1: cmp al,bh ja short v_startf2 mov al,bh v_startf2: add al,7 mov [c_numofintvects],al lea eax,[eax*8+7] ; set limit of IDT mov [c_idt32addx],ax call setintslots ; set int slots needed movzx eax,ax add eax,2068h+1 call pregetlomem ; allocate TSS, IO bitmap, and IDT mov [cp_tssesp0ptr],eax mov eax,[_code16a] ; adjust mode switch structure add [v_ss_gdtaddxptr],eax add [v_ss_idtaddxptr],eax mov W[exitrout],v_exit ; set VCPI cleanup exit mov eax,[_lomembase] ; align lomem base on a page mov ebx,[_code32a] add ebx,eax lea ecx,[ebx+0FFFh] and ecx,0FFFFF000h sub ebx,ecx sub eax,ebx mov [_lomembase],eax mov ebp,[_lomemtop] ; get available low memory sub ebp,eax sub ebp,LOWMIN*1024 ; die if not enough jc near v_exiterr1 cmp ebp,8192 jb near v_exiterr1 shld eax,ecx,28 ; get segment and clear all pages mov [v_pagedirseg],ax mov es,ax xor di,di mov cx,2048 xor eax,eax rep stosd mov di,1000h ; get VCPI pmode interface mov esi,gdt32vcpi mov ax,0DE01h int 67h mov [vp_vcpipmentry],ebx mov [v_pagebase],di ; set up and go through allocation mov [v_pagetop],di movzx eax,di sub eax,1000h shl eax,10 sub eax,[_code32a] mov [_himembase],eax mov ebx,8192 v_startl2: mov ax,0DE04h int 67h or ah,ah jnz short v_startl2d test di,0FFFh jnz short v_startf4 add ebx,4096 cmp ebx,ebp jbe short v_startf4 mov [v_pagetop],di mov ax,0DE05h int 67h jmp v_exiterr1 v_startf4: and dx,0F000h or dl,7 mov [es:di],edx add di,4 jnc v_startl2 v_startl2d: mov [v_pagetop],di lea si,[di-1000h] movzx eax,si shl eax,10 sub eax,[_code32a] mov [_himemtop],eax sub di,[v_pagebase] cmp di,EXTMIN mov dx,errmsg3 jb near exit16err add [_lomembase],ebx movzx ebx,W[v_pagedirseg] ; set up physical addresses shr ebx,8 mov eax,[es:ebx*4+1000h] mov [v_ss_cr3],eax xor di,di v_startl3: inc ebx mov eax,[es:ebx*4+1000h] and ax,0F000h or al,7 stosd sub si,1000h ja v_startl3 mov edi,c_startf1 ; offset to jump to in pmode mov ebx,[cp_tssesp0ptr] jmp v_switchtopmode ; duh? ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ; 16 bit XMS system data ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ x_calladdx dd ? ; XMS driver addx x_handle dw 0FEDCh ; XMS handle of extended memory ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ; 16 bit XMS system code ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ;───────────────────────────────────────────────────────────────────────────── x_exit: ; XMS exit (clean up allocation) mov ax,cs mov ds,ax mov dx,[x_handle] mov ah,0Dh call far [x_calladdx] mov ah,0Ah call far [x_calladdx] jmp exit ;───────────────────────────────────────────────────────────────────────────── x_exiterr5: ; exit with error message 5 mov dx,errmsg5 jmp exit16err ;═════════════════════════════════════════════════════════════════════════════ x_start: ; start in an XMS system or B[_sysbyte0],1 ; set system type XMS byte mov ax,4310h ; get XMS driver addx int 2Fh mov [x_calladdx+0],bx mov [x_calladdx+2],es mov ah,3 ; XMS enable A20 call far [x_calladdx] or ax,ax mov dx,errmsg4 jz near exit16err mov ah,8 ; chek and get extended memory call far [x_calladdx] sub ax,64 jnc short x_startf0 xor ax,ax x_startf0: cmp ax,EXTMIN mov dx,errmsg3 jb near exit16err mov dx,ax movzx ecx,ax shl ecx,10 mov ah,9 call far [x_calladdx] or ax,ax jz x_exiterr5 mov [x_handle],dx mov W[exitrout],x_exit mov ah,0Ch call far [x_calladdx] or ax,ax jz x_exiterr5 shrd eax,edx,16 mov ax,bx sub eax,[_code32a] mov [_himembase],eax add eax,ecx mov [_himemtop],eax jmp c_startf0 ; go on to custom start ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ; 16 bit custom system data ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ c_idt16addx dw 3FFh, 0,0 ; default real mode IDT addx&limit c_idt32addx dw 3BFh, ?,? ; 32bit IDT addx&limit c_gdt32addx dw 04Fh+SELECTORS*8 ; 32bit GDT addx&limit dd gdt32 ; c_numofintvects db 77h ; number of int vects needed -1 c_idt32handler dd cp_irq0, cp_irq1, cp_irq2, cp_irq3 dd cp_irq4, cp_irq5 dd cp_irq6, cp_irq7, cp_irq8, cp_irq9 dd cp_irqa, cp_irqb dd cp_irqc, cp_irqd, cp_irqe, cp_irqf dd cp_int33, cp_int32, cp_int31 dd cp_exc0, cp_exc1, cp_exc2, cp_exc3 dd cp_exc4, cp_exc5 dd cp_exc6, cp_exc7 ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ; 16 bit custom system code ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ;═════════════════════════════════════════════════════════════════════════════ c_irqreal: ; real mode IRQ pushf push cs push W icreald2 jmp icreal ;----------------------------------------------------------------------------- c_retreal1: ; load some real mode stuff & exit mov ax,stack mov ss,ax mov esp,STAKSIZE*10h jmp [exitrout] ;═════════════════════════════════════════════════════════════════════════════ c_retreal0: ; load real mode IDT and set PE=0 mov ax,28h mov ds,ax mov es,ax mov fs,ax mov gs,ax mov ss,ax lidt [c_idt16addx] mov eax,cr0 and al,0FEh mov cr0,eax db 0EAh ; JMP FAR PTR c_retreal0m0 c_retreal0m0 dw c_sicreal,code ;----------------------------------------------------------------------------- c_sicreal: ; safe real mode int or call mov ax,stack mov ss,ax mov ds,[cs:v86r_ds] mov es,[cs:v86r_es] db 0EAh ; JMP FAR PTR c_sicrealm0 c_sicrealm0 dw ?,code ;═════════════════════════════════════════════════════════════════════════════ c_retreal: ; return to real mode mov W[c_retreal0m0],c_retreal1 mov esp,STAKSIZE*10h jmp c_retreal0 ;═════════════════════════════════════════════════════════════════════════════ c_start: ; custom only start call enableA20 ; enable that stupid A20 thingy mov ah,88h ; chek and get extended mem int 15h cmp ax,EXTMIN mov dx,errmsg3 jb near exit16err movzx eax,ax shl eax,10 mov ebx,100000h sub ebx,[_code32a] mov [_himembase],ebx add eax,ebx mov [_himemtop],eax ;═════════════════════════════════════════════════════════════════════════════ c_startf0: ; start continues from custom or XMS mov W[int32m0],CINT32 ; raw/XMS real INT32 mov eax,2428h ; allocate TSS, IO bitmap, and IDT call pregetlomem mov ebx,eax lgdt [c_gdt32addx] ; switch to pmode mov eax,cr0 or al,1 mov cr0,eax db 0EAh dw $+4,20h ;----------------------------------------------------------------------------- ; EBX->TSS c_startf1: ; in 16bit pmode mov ax,28h ; set up segregs mov ds,ax mov al,18h mov gs,ax mov al,10h mov es,ax mov fs,ax mov ss,ax mov esp,STAKSIZE*16 add esp,[realstackbase] mov W[v_ss_dest+4],8 ; VCPI enter 32bit pmode from now on lea eax,[ebx+4] ; addx of ESP0 in TSS mov [cp_tssesp0ptr],eax mov ebp,[_code32a] ; TSS location in mem to GDT lea eax,[ebx+ebp] mov ecx,gdt32task ; set up task or [ecx+2],eax mov B[ecx+5],89h mov cx,30h ltr cx add eax,2068h ; set up IDT mov ecx,c_idt32addx mov [ecx+2],eax lidt [ecx] mov D[es:ebx+8],10h ; set up TSS stuff (EBX->TSS) mov edi,104 mov [es:ebx+102],di mov W[es:ebx+100],0 add edi,ebx ; fill IO bitmap with 0 xor eax,eax mov ecx,800h a32 rep stosd mov [cp_idt32ptr],edi ; set up blank IDT entries movzx esi,B[c_numofintvects] c_startl0: ; set up interrupt gates mov D[es:edi+esi*8],80000h+cp_excf ; offset, selector 8h mov D[es:edi+esi*8+4],(10001110b<<8) ; P=1, DPL=0 sub si,1 jnc c_startl0 mov si,1Ah ; necessary IDT entries c_startl1: movzx ebp,B[intslottbl+esi] mov eax,[c_idt32handler+esi*4] c_startl1c: mov [es:edi+ebp*8],ax sub si,1 jnc c_startl1 mov edi,p_start ; set up regs & go on to 32bit mov ax,10h mov ds,ax ;----------------------------------------------------------------------------- c_gotopmode: ; jump to 32bit pmode pushfd ; set eflags: NT=0, IOPL=3 pop eax and ah,10111111b ; NT=0 or ah,00110000b ; IOPL=3 push eax popfd dw 6866h,8,0 ; PUSH dword 8 push edi db 66h,0CBh ; 32bit RETF ;▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ ; 32bit pmode code ;▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ bits 32 ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ; 32 bit common system data ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ _lomembase dd ? ; low mem base for allocation _lomemtop dd ? ; top of low mem _himembase dd 0 ; high mem base for allocation _himemtop dd 0 ; top of high mem _pspa dd ? ; offset of start of PSP from 0 _code16a dd ? ; offset of start of 16bit code from 0 _code32a dd ? ; offset of start of 32bit code from 0 _selcode dw 8 ; code segment selector _seldata dw 10h ; data segment alias for code _selzero dw 18h ; data segment starting at 0:0 _sysbyte0 db 0 ; system bits: ; 0-1: 0=raw, 1=XMS, 2=VCPI, 3=DPMI _exitcode db 0 ; exit code for int21h ah=4ch ALIGNZ(4) _getirqvect dd cp_getirqvect ; get IRQ handler offset routine addx _setirqvect dd cp_setirqvect ; set IRQ handler offset routine addx _setselector dd cp_setselector ; set a selector addx offset addx ; /limit15-0\ /base23-0\ /G,X,O,AVL,limit19-16\ /base31-24\ gdt32 dd 0,0 ; /P,DPL,1,TYPE,A\ ; 0h gdt32code32 db 0FFh, 0FFh, 0, 0, 0, 10011010b, 11001111b, 0 ; 8h gdt32data32 db 0FFh, 0FFh, 0, 0, 0, 10010010b, 11001111b, 0 ; 10h gdt32zero32 db 0FFh, 0FFh, 0, 0, 0, 10010010b, 11001111b, 0 ; 18h gdt32code16 db 0FFh, 0FFh, 0, 0, 0, 10011010b, 0, 0 ; 20h gdt32data16 db 0FFh, 0FFh, 0, 0, 0, 10010010b, 0, 0 ; 28h gdt32task db 0FFh, 0FFh, 0, 0, 0, 10001001b, 0, 0 ; 30h gdt32vcpi dd ?,? ; 38h dd ?,? ; 40h dd ?,? ; 48h gdt32free times SELECTORS db 0FFh,0FFh, 0,0,0, 10010010b,11001111b, 0 v86r_edi: ; vregs for pmode<>real communication v86r_di dw ?, ? ; needs to stay this way cuz its a v86r_esi: ; stupid DPMI structure thingy v86r_si dw ?, ? v86r_ebp: v86r_bp dw ?, ? dd 0 v86r_ebx: v86r_bx: v86r_bl db ? v86r_bh db ?, ?,? v86r_edx: v86r_dx: v86r_dl db ? v86r_dh db ?, ?,? v86r_ecx: v86r_cx: v86r_cl db ? v86r_ch db ?, ?,? v86r_eax: v86r_ax: v86r_al db ? v86r_ah db ?, ?,? v86r_flags dw ? v86r_es dw ? v86r_ds dw ? v86r_fs dw ? v86r_gs dw ? dd 0,0 oint1bvect dd ? ; old real int 1Bh vector (ctrl+break) oint32vect dd ? ; old real int 32h vector oirqmask dw ? ; old port 21h and 0A1h masks intslottbl db 8,9,0Ah,0Bh,0Ch,0Dh,0Eh,0Fh,70h,71h,72h,73h,74h,75h,76h,77h db 33h,32h,31h,0,1,2,3,4,5,6,7 selectorbase dw 50h selectorinc dw 8 selectorfree times SELECTORS db 0 code16off dw c_retreal ; offset in 16bit of exit function code16sel dw 20h ; 16bit pmode code selector data16sel dw 28h ; 16bit pmode data selector nextmodestack dw (STAKSIZE-STAKMAIN)*16 ; stack for next mode switch realstackbase dd ? ; linear ptr to beginning of codeend ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ; 32 bit common system code ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ;═════════════════════════════════════════════════════════════════════════════ p_cpmode2: ; call pmode from V86 mov gs,cx mov cl,10h mov ds,cx mov es,cx mov fs,cx sub W[nextmodestack],STAKPMODE*16 push W[p_cpmodem2] mov W[p_cpmodem2],V86CPMODED mov eax,[esp+22] mov [p_cpmodem0],eax mov al,[esp+43] shr al,1 and al,1 add al,0FAh mov [p_cpmodem1],al jmp short p_cpmode ;═════════════════════════════════════════════════════════════════════════════ p_cpmode1: ; call pmode, load all mov esp,ebx mov ax,10h mov ds,ax mov es,ax mov ss,ax ;----------------------------------------------------------------------------- p_cpmode0: ; call pmode, load FS and GS mov fs,[_seldata] mov gs,[_selzero] ;----------------------------------------------------------------------------- p_cpmode: ; call pmode routine from real push D p_cpmoded cld mov eax,[v86r_eax] mov ecx,[v86r_ecx] mov edx,[v86r_edx] mov ebx,[v86r_ebx] mov esi,[v86r_esi] mov edi,[v86r_edi] mov ebp,[v86r_ebp] db 68h ; PUSH destination address p_cpmodem0 dd ? ; p_cpmodem1 db ? ; CLI or STI ret ;----------------------------------------------------------------------------- p_cpmoded: ; call to pmode done cli pushf pop W[v86r_flags] mov [v86r_eax],eax mov [v86r_ecx],ecx mov [v86r_edx],edx mov [v86r_ebx],ebx mov [v86r_esi],esi mov [v86r_edi],edi mov [v86r_ebp],ebp mov ecx,[_code16a] p_cpmodem2: ; return to real, modifiable to JMP ;----------------------------------------------------------------------------- movzx ebx,W[gs:savedstakoff+ecx] ; DPMI return to real mode mov dx,[gs:savedstakseg+ecx] mov ax,code mov cx,dx mov si,ax mov edi,int32d0 jmp D far [dp_switchaddx] ;----------------------------------------------------------------------------- VCPMODED equ (($-(p_cpmodem2+2)) << 8) + 0EBh p_cpmoded2: ; VCPI done with pmode movzx esi,W[gs:savedstakoff+ecx] mov cx,code mov edi,int32d1 db 0EAh ; 16bit JMP FAR 20h:v_retreal0 dw v_retreal0,0,20h ; ;----------------------------------------------------------------------------- CCPMODED equ (($-(p_cpmodem2+2)) << 8) + 0EBh p_cpmoded3: ; raw/XMS done with pmode mov W[gs:c_retreal0m0+ecx],int32d3 db 0EAh ; 16bit JMP FAR 20h:c_retreal0 dw c_retreal0,0,20h ; ;----------------------------------------------------------------------------- ; if ($-(p_cpmodem2+2)) gt 127 => error V86CPMODED equ (($-(p_cpmodem2+2)) << 8) + 0EBh p_cpmoded4: ; V86 done with pmode pop W[p_cpmodem2] jmp cp_int3_d3 ;═════════════════════════════════════════════════════════════════════════════ p_start: ; common 32bit start mov eax,[gs:1Bh*4] ; neutralize crtl+break mov [oint1bvect],eax db 65h,67h,0C7h,6 ; MOV DWORD PTR GS:[1bh*4],code16:nullint dw 1Bh*4,nullint,code ; mov eax,[gs:32h*4] ; set up for new real mode INT32 mov [oint32vect],eax db 65h,67h,0C7h,6 ; MOV DWORD PTR GS:[32h*4],code16:int32 dw 32h*4,int32,code ; in al,21h ; save old PIC masks mov ah,al in al,0A1h mov [oirqmask],ax jmp _main ; go to main code ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; Allocate any mem, (first cheks low, then high) ; In: ; EAX - size requested ; Out: ; CF=0 - memory allocated ; CF=1 - not enough mem ; EAX - linear pointer to mem or ? ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ _getmem: push eax call _getlomem jnc short getmemd pop eax jmp short _gethimem getmemd: add esp,4 _ret: ; generic RET instruction ret ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; Allocate some low mem ; In: ; EAX - size requested ; Out: ; CF=0 - memory allocated ; CF=1 - not enough mem ; EAX - linear pointer to mem or ? ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ _getlomem: add eax,[_lomembase] cmp eax,[_lomemtop] ja short getmemerr xchg eax,[_lomembase] clc ret getmemerr: stc ret ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; Allocate some high mem ; In: ; EAX - size requested ; Out: ; CF=0 - memory allocated ; CF=1 - not enough mem ; EAX - linear pointer to mem or ? ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ _gethimem: add eax,[_himembase] cmp eax,[_himemtop] ja short getmemerr xchg eax,[_himembase] clc ret ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; Get amount of free low mem ; Out: ; EAX - number of bytes free ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ _lomemsize: mov eax,[_lomemtop] sub eax,[_lomembase] ret ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; Get amount of free high mem ; Out: ; EAX - number of bytes free ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ _himemsize: mov eax,[_himemtop] sub eax,[_himembase] ret ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; Get status of IRQ mask bit ; In: ; BL - IRQ num (0-15) ; Out: ; AL - status: 0=enabled, 1=disabled ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ _getirqmask: push ax in al,0A1h mov ah,al in al,21h xchg cl,bl shr ax,cl xchg cl,bl and al,1 mov [esp],al pop ax ret ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; Set status of IRQ mask bit ; In: ; BL - IRQ num (0-15) ; AL - status: 0=enabled, 1=disabled ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ _setirqmask: push ax push bx push cx push dx mov cl,bl mov bx,0FFFEh movzx dx,al rol bx,cl shl dx,cl in al,0A1h mov ah,al in al,21h and ax,bx or ax,dx out 21h,al mov al,ah out 0A1h,al pop dx pop cx pop bx pop ax ret ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; Set a real mode IRQ vect to redirect to pmode ; In: ; BL - IRQ number ; EDX - offset of IRQ handler ; EDI -> 21 byte buffer for code stub created ; Out: ; EAX - old seg:off of real mode IRQ handler ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ rmpmirqsetd0: db 66h,52h ; PUSH EDX db 66h,0BAh,?,?,?,? ; MOV EDX,? db 0CDh,32h ; INT 32h db 66h,5Ah ; POP EDX db 0CFh ; IRET db 9Ch ; PUSHFD db 0Eh ; PUSH CS db 0E8h,?,?,?,? ; CALL ? db 0C3h ; RET ;----------------------------------------------------------------------------- _rmpmirqset: push esi push edi mov esi,rmpmirqsetd0 lea eax,[edi+13] mov [esi+4],eax add eax,7 sub eax,edx neg eax mov [esi+16],eax mov eax,edi movsd movsd movsd movsd movsd movsb add eax,[_code32a] shl eax,12 shr ax,12 movzx edi,bl cmp edi,8 jb short rmpmirqsetf0 add edi,60h rmpmirqsetf0: xchg eax,[gs:edi*4+20h] pop edi pop esi ret ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; Reset a real more IRQ vect back to normal (just sets real mode IRQ vect) ; In: ; BL - IRQ number ; EAX - seg:off of real mode IRQ handler ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ _rmpmirqfree: push ebx movzx ebx,bl cmp bl,8 jb short rmpmirqfreef0 add bl,60h rmpmirqfreef0: mov [gs:ebx*4+20h],eax pop ebx ret ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; Allocate a selector ; Out: ; CF=1 - selector not allocated ; CF=0 - selector allocated ; AX - 4G data selector or ? ; Notes: ; The selector returned is for a 4G r/w data segment with an undefined base ; address. ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ _getselector: push ecx push edi mov edi,selectorfree mov ecx,SELECTORS mov al,0 repne scasb jne short getselectorf0 mov B[edi-1],1 sub ecx,SELECTORS-1 neg ecx imul cx,[selectorinc] mov ax,[selectorbase] add ax,cx clc jmp short getselectorf1 getselectorf0: stc getselectorf1: pop edi pop ecx ret ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; Free an allocated selector ; In: ; AX - selector ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ _freeselector: push eax push dx sub ax,[selectorbase] xor dx,dx div W[selectorinc] movzx eax,ax mov B[selectorfree+eax],0 pop dx pop eax ret ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; Exit to real mode ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ _exit: cli mov eax,[oint1bvect] ; restore ctrl+break mov [gs:1Bh*4],eax mov eax,[oint32vect] ; restore real mode int 32h vector mov [gs:32h*4],eax mov ax,[oirqmask] ; restore PIC masks out 0A1h,al mov al,ah out 21h,al push W[code16sel] ; go to 16bit pmode exit code push W[code16off] mov ds,[data16sel] db 66h,0CBh ; 16bit RETF ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ; 32 bit DPMI system data ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ dp_switchaddx dw ?,?,? ; switch to real mode addx dp_saveaddx dw ?,?,? ; save/restore state addx dp_savelen dw 0,0 ; length of state buffer dp_savedstaksel dw ? ; current saved stack selector dp_ointbuf times 18 dw ?,?,? ; saved interrupt addx buffer ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ; 32 bit DPMI system code ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ;═════════════════════════════════════════════════════════════════════════════ dp_int32: ; DPMI INT32/34: CX:DX=seg:off pushad shl ecx,16 mov cx,dx mov bp,callreal mov dl,1 jmp short dp_int3_ ;═════════════════════════════════════════════════════════════════════════════ dp_int33: ; DPMI INT33/35: AL=int num pushad movzx eax,al mov ecx,[gs:eax*4] mov bp,intreal xor dl,dl ;----------------------------------------------------------------------------- dp_int3_: ; DPMI int or call to real mode mov ax,0900h int 31h push ax and al,dl add al,0FAh mov ebx,[_code16a] mov [gs:icrealm0+ebx],al mov [gs:icrealm1+ebx],ecx push D[cp_savedstakoff] push W[dp_savedstaksel] movzx ebx,W[nextmodestack] lea eax,[ebx-STAKRMODE*16] mov [nextmodestack],ax mov ax,ss mov es,ax sub esp,[dp_savelen] mov edi,esp xor al,al call D far [dp_saveaddx] mov [cp_savedstakoff],esp mov [dp_savedstaksel],ss mov dx,stack mov ax,[v86r_ds] mov cx,[v86r_es] movzx edi,bp mov si,code jmp D far [dp_switchaddx] ;----------------------------------------------------------------------------- dp_int3_d: ; done with real mode int or call mov edi,esp mov al,1 call D far [dp_saveaddx] add esp,[dp_savelen] pop W[dp_savedstaksel] pop D[cp_savedstakoff] add W[nextmodestack],STAKRMODE*16 mov bx,[v86r_flags] pop ax int 31h mov ax,ds mov es,ax mov fs,ax mov gs,[_selzero] jmp cp_int3_d2 ;═════════════════════════════════════════════════════════════════════════════ ; DPMI IRQ redirectors (needed to make all IRQ vector selectors = CS) dp_irq0: jmp D far [cs:dp_ointbuf+0] dp_irq1: jmp D far [cs:dp_ointbuf+6] dp_irq2: jmp D far [cs:dp_ointbuf+12] dp_irq3: jmp D far [cs:dp_ointbuf+18] dp_irq4: jmp D far [cs:dp_ointbuf+24] dp_irq5: jmp D far [cs:dp_ointbuf+30] dp_irq6: jmp D far [cs:dp_ointbuf+36] dp_irq7: jmp D far [cs:dp_ointbuf+42] dp_irq8: jmp D far [cs:dp_ointbuf+48] dp_irq9: jmp D far [cs:dp_ointbuf+54] dp_irqa: jmp D far [cs:dp_ointbuf+60] dp_irqb: jmp D far [cs:dp_ointbuf+66] dp_irqc: jmp D far [cs:dp_ointbuf+72] dp_irqd: jmp D far [cs:dp_ointbuf+78] dp_irqe: jmp D far [cs:dp_ointbuf+84] dp_irqf: jmp D far [cs:dp_ointbuf+90] ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; DPMI get IRQ handler offset ; In: ; BL - IRQ num (0-0fh) ; Out: ; EDX - offset of IRQ handler ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ dp_getirqvect: push ax push ebx push cx movzx ebx,bl mov bl,[intslottbl+ebx] mov ax,0204h int 31h pop cx pop ebx pop ax ret ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; DPMI set IRQ handler offset ; In: ; BL - IRQ num (0-0fh) ; EDX - offset of IRQ handler ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ dp_setirqvect: push ax push ebx push cx movzx ebx,bl mov bl,[intslottbl+ebx] mov cx,cs mov ax,0205h int 31h pop cx pop ebx pop ax ret ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; Set the base addx for a selector ; In: ; AX - selector ; EDX - linear base addx for selector ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ dp_setselector: push ax push bx push ecx shld ecx,edx,16 mov bx,ax mov ax,7 int 31h pop ecx pop bx pop ax ret ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ; 32 bit custom/XMS/VCPI system data ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ vp_vcpipmentry dw 0,0,38h ; VCPI entry point in pmode cp_tssesp0ptr dd 0 ; ptr to ESP0 in TSS, or null in VCPI cp_idt32ptr dd ? ; ptr to 32bit IDT cp_validexcdesp dd 0 ; valid ESP value for exc 13 cp_v86irqintr dd cp_int33f0 cp_v86irqnum db ? ; IRQ num for V86 mode cp_savedstakoff dd ? ; current saved stack offset ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ; 32 bit custom/XMS/VCPI system code ;▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ;═════════════════════════════════════════════════════════════════════════════ cp_int31: ; INT 31h: AX=900h,901h,902h cmp al,1 mov al,[esp+9] jb short cp_int31f0 ja short cp_int31f1 or B[esp+9],2 jmp short cp_int31f1 cp_int31f0: and B[esp+9],0FDh cp_int31f1: shr al,1 and al,1 iretd ;═════════════════════════════════════════════════════════════════════════════ vp_int32: ; VCPI INT 32h: safe CX:DX=seg:off pushad mov ebp,callreal mov si,VICREAL1D mov bl,2 jmp short cp_int34f0 ;═════════════════════════════════════════════════════════════════════════════ vp_int33: ; VCPI INT 33h: safe AL=int num pushad mov ebp,intreal ;----------------------------------------------------------------------------- vp_int33f0: mov si,VICREAL1D mov bl,2 jmp short cp_int35f0 ;═════════════════════════════════════════════════════════════════════════════ cp_int32: ; INT 32h: safe CX:DX=seg:off pushad mov ebp,callreal mov si,CICREAL1D mov bl,1 jmp short cp_int34f0 ;═════════════════════════════════════════════════════════════════════════════ cp_int33: ; INT 33h: safe AL=int num pushad mov ebp,intreal ;----------------------------------------------------------------------------- cp_int33f0: mov si,CICREAL1D mov bl,1 jmp short cp_int35f0 ;----------------------------------------------------------------------------- cp_int34f0: ; relic from times past shl ecx,16 mov cx,dx mov bh,1 jmp short cp_int3_ ;----------------------------------------------------------------------------- cp_int35f0: ; another one, but functional movzx eax,al mov ecx,[gs:eax*4] xor bh,bh ;----------------------------------------------------------------------------- cp_int3_: ; int or call to real mode mov edi,[esp+40] shld eax,edi,23 and al,bh add al,0FAh mov edx,[_code16a] mov [gs:icrealm0+edx],al mov [gs:icrealm1+edx],ecx xchg [gs:icrealm2+edx],si push si movzx esi,W[nextmodestack] lea eax,[esi-STAKRMODE*16] mov [nextmodestack],ax add eax,[realstackbase] mov edx,[cp_tssesp0ptr] push D[edx] mov [edx],eax sub eax,40 push D[cp_validexcdesp] mov [cp_validexcdesp],eax push D[cp_savedstakoff] mov [cp_savedstakoff],esp cmp bl,1 ja short vp_int3_s ;----------------------------------------------------------------------------- cp_int3_s: ; safe real mode int or call mov edx,[_code16a] mov [gs:c_sicrealm0+edx],bp mov esp,esi db 0EAh ; 16bit JMP FAR 20h:c_retreal0 dw c_retreal0,0,20h ; ;----------------------------------------------------------------------------- vp_int3_s: ; safe VCPI real mode int or call mov edi,ebp mov cx,[v86r_ds] mov ax,28h mov ds,ax db 0EAh ; 16bit JMP FAR 20h:v_retreal0 dw v_retreal0,0,20h ; ;----------------------------------------------------------------------------- cp_int3_d: ; done with real mode int or call mov ax,18h mov gs,ax mov ax,10h mov ds,ax mov es,ax mov fs,ax mov ss,ax mov esp,[cp_savedstakoff] pop D[cp_savedstakoff] pop D[cp_validexcdesp] mov ebx,[cp_tssesp0ptr] pop D[ebx] mov ebx,[_code16a] pop W[gs:icrealm2+ebx] ;----------------------------------------------------------------------------- cp_int3_d3: ; done from real mode pmode call add W[nextmodestack],STAKRMODE*16 mov bx,[v86r_flags] ;----------------------------------------------------------------------------- cp_int3_d2: ; done from DPMI also mov ax,[esp+40] and ax,~8D5h and bx,8D5h or ax,bx mov [esp+40],ax popad iretd ;═════════════════════════════════════════════════════════════════════════════ ; low 8 exceptions and undefined interrupt. cp_exc0: push eax xor al,al jmp cp_irq cp_exc1: push eax mov al,1 jmp cp_irq cp_exc2: push eax mov al,2 jmp cp_irq cp_exc3: push eax mov al,3 jmp cp_irq cp_exc4: push eax mov al,4 jmp cp_irq cp_exc5: push eax mov al,5 jmp cp_irq cp_exc6: pushad mov al,6 jmp short cp_exc cp_exc7: push eax mov al,7 jmp cp_irq cp_excf: pushad mov al,0FFh ;----------------------------------------------------------------------------- cp_exc: ; main exception handler mov bx,10h mov ds,bx mov es,bx mov fs,bx mov gs,[_selzero] cld jmp _exit ;═════════════════════════════════════════════════════════════════════════════ ; IRQ redirector between modes cp_irq0: push eax mov al,08h jmp short cp_irq cp_irq1: push eax mov al,09h jmp short cp_irq cp_irq2: push eax mov al,0Ah jmp short cp_irq cp_irq3: push eax mov al,0Bh jmp short cp_irq cp_irq4: push eax mov al,0Ch jmp short cp_irq cp_irq5: push eax mov al,0Dh jmp short cp_irq cp_irq6: push eax mov al,0Eh jmp short cp_irq cp_irq7: push eax mov al,0Fh jmp short cp_irq cp_irq8: push eax mov al,70h jmp short cp_irq cp_irq9: push eax mov al,71h jmp short cp_irq cp_irqa: push eax mov al,72h jmp short cp_irq cp_irqb: push eax mov al,73h jmp short cp_irq cp_irqc: push eax mov al,74h jmp short cp_irq cp_irqd: push eax mov al,75h jmp short cp_irq cp_irqe: push eax mov al,76h jmp short cp_irq cp_irqf: push eax mov al,77h ;───────────────────────────────────────────────────────────────────────────── cp_irq: ; main IRQ handler thingy mov [ss:cp_v86irqnum],al pop eax push ds push es push fs push gs pushfd push cs push D cp_irqpd pushad mov ax,10h mov ds,ax mov al,18h mov gs,ax mov al,[cp_v86irqnum] mov ebp,c_irqreal jmp [cp_v86irqintr] cp_irqpd: pop gs pop fs pop es pop ds iretd ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; Custom get IRQ handler offset ; In: ; BL - IRQ num (0-0fh) ; Out: ; EDX - offset of IRQ handler ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ cp_getirqvect: push ebx pushfd cli movzx ebx,bl mov bl,[intslottbl+ebx] lea ebx,[ebx*8] add ebx,[cp_idt32ptr] mov dx,[ebx+6] shl edx,16 mov dx,[ebx] popfd pop ebx ret ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; Custom set IRQ handler offset ; In: ; BL - IRQ num (0-0fh) ; EDX - offset of IRQ handler ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ cp_setirqvect: push ebx push edx pushfd cli movzx ebx,bl mov bl,[intslottbl+ebx] lea ebx,[ebx*8] add ebx,[cp_idt32ptr] mov [ebx],dx shr edx,16 mov [ebx+6],dx popfd pop edx pop ebx ret ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ; Custom set the base addx for a selector ; In: ; AX - selector ; EDX - linear base addx for selector ;░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ cp_setselector: push eax push edx movzx eax,ax and edx,0FFFFFFh or edx,92000000h mov [gdt32+eax+2],edx mov dl,[esp+3] mov [gdt32+eax+7],dl pop edx pop eax ret section stack stack align=16 resb STAKSIZE*16