;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ;;
;; Copyright (C) KolibriOS team 2007-2024. All rights reserved. ;;
;; Distributed under terms of the GNU General Public License ;;
;; ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Virtual-8086 mode manager
; diamond, 2007, 2008
DEBUG_SHOW_IO = 0
struct V86_machine
; page directory
process dd ?
; mutex to protect all data from writing by multiple threads at one time
mutex dd ?
; i/o permission map
iopm dd ?
ends
; Create V86 machine
; in: nothing
; out: eax = handle (pointer to struc V86_machine)
; eax = NULL => failure
; destroys: ebx, ecx, edx (due to malloc)
v86_create:
; allocate V86_machine structure
mov eax, sizeof.V86_machine
call malloc
test eax, eax
jz .fail
; initialize mutex
and dword [eax + V86_machine.mutex], 0
; allocate tables
mov ebx, eax
stdcall create_process, 4096
test eax, eax
jz .fail2
mov [eax + PROC.mem_used], 4096
mov [ebx + V86_machine.process], eax
push 2000h
call kernel_alloc
test eax, eax
jz .fail2
mov [ebx + V86_machine.iopm], eax
; initialize tables
push edi
mov edi, eax
mov eax, -1
mov ecx, 2000h/4
rep stosd
mov eax, [ebx + V86_machine.process]
mov eax, [eax + PROC.pdt_0_phys]
pushfd
cli
mov cr3, eax
; now V86 specific: initialize known addresses in first Mb
; first page - BIOS data (shared between all machines!)
; physical address = 0
; linear address = OS_BASE
; page before 0xA0000 - Extended BIOS Data Area (shared between all machines!)
; physical address = 0x9C000
; linear address = 0x8009C000
; (I have seen one computer with EBDA segment = 0x9D80,
; all other computers use less memory)
mov eax, PG_UWR
mov [page_tabs], eax
invlpg [eax]
mov byte [0x500], 0xCD
mov byte [0x501], 0x13
mov byte [0x502], 0xF4
mov byte [0x503], 0xCD
mov byte [0x504], 0x10
mov byte [0x505], 0xF4
mov eax, 0x98000+PG_UWR
mov edi, page_tabs+0x98*4
mov edx, 0x1000
mov ecx, 8
@@:
stosd
add eax, edx
loop @b
; addresses 0xC0000 - 0xFFFFF - BIOS code (shared between all machines!)
; physical address = 0xC0000
mov eax, 0xC0000+PG_UWR
mov edi, page_tabs+0xC0*4
mov ecx, 64
@@:
stosd
add eax, edx
loop @b
mov eax, [sys_proc + PROC.pdt_0_phys]
mov cr3, eax
popfd
pop edi
mov eax, ebx
ret
.fail2:
mov eax, ebx
call free
.fail:
xor eax, eax
ret
;not used
; Destroy V86 machine
; in: eax = handle
; out: nothing
; destroys: eax, ebx, ecx, edx (due to free)
;v86_destroy:
; push eax
; stdcall kernel_free, [eax+V86_machine.pagedir]
; pop eax
; jmp free
; Translate V86-address to linear address
; in: eax=V86 address
; esi=handle
; out: eax=linear address
; destroys: nothing
v86_get_lin_addr:
push ecx edx
mov ecx, eax
shr ecx, 12
mov edx, [page_tabs + ecx*4]
and eax, 0xFFF
and edx, 0xFFFFF000
or eax, edx
pop edx ecx
ret
;not used
; Sets linear address for V86-page
; in: eax=linear address (must be page-aligned)
; ecx=V86 page (NOT address!)
; esi=handle
; out: nothing
; destroys: nothing
;v86_set_page:
; push eax ebx
; mov ebx, [esi+V86_machine.pagedir]
; mov [ebx+ecx*4+0x1800], eax
; call get_pg_addr
; or al, 111b
; mov [ebx+ecx*4+0x1000], eax
; pop ebx eax
; ret
; Allocate memory in V86 machine
; in: eax=size (in bytes)
; esi=handle
; out: eax=V86 address, para-aligned (0x10 multiple)
; destroys: nothing
; недописана!!!
;v86_alloc:
; push ebx ecx edx edi
; lea ebx, [esi+V86_machine.mutex]
; call wait_mutex
; add eax, 0x1F
; shr eax, 4
; mov ebx, 0x1000 ; start with address 0x1000 (second page)
; mov edi, [esi+V86_machine.tables]
;.l:
; mov ecx, ebx
; shr ecx, 12
; mov edx, [edi+0x1000+ecx*4] ; get linear address
; test edx, edx ; page allocated?
; jz .unalloc
; mov ecx, ebx
; and ecx, 0xFFF
; add edx, ecx
; cmp dword [edx], 0 ; free block?
; jnz .n
; cmp dword [edx+4],
; and [esi+V86_machine.mutex], 0
; pop edi edx ecx ebx
; ret
uglobal
sys_v86_machine dd ?
endg
; Called from kernel.asm at first stages of loading
; Initialize system V86 machine (used to simulate BIOS int 13h)
init_sys_v86:
call v86_create
mov [sys_v86_machine], eax
test eax, eax
jz .ret
mov esi, eax
if ~DEBUG_SHOW_IO
; allow access to all ports
mov ecx, [esi + V86_machine.iopm]
xor eax, eax
mov edi, ecx
mov ecx, 10000h/8/4
rep stosd
end if
.ret:
ret
struct v86_regs
; don't change the order, it is important
edi dd ?
esi dd ?
ebp dd ?
dd ? ; ignored
ebx dd ?
edx dd ?
ecx dd ?
eax dd ?
eip dd ?
cs dd ?
eflags dd ? ; VM flag must be set!
esp dd ?
ss dd ?
es dd ?
ds dd ?
fs dd ?
gs dd ?
ends
; Run V86 machine
; in: ebx -> registers for V86 (two structures: in and out)
; esi = handle
; ecx = expected end address (CS:IP)
; edx = IRQ to hook or -1 if not required
; out: structure pointed to by ebx is filled with new values
; eax = 1 - exception has occured, cl contains code
; eax = 2 - access to disabled i/o port, ecx contains port address
; eax = 3 - IRQ is already hooked by another VM
; destroys: nothing
v86_start:
pushad
cli
mov ecx, [current_slot]
push dword [ecx + APPDATA.io_map]
push dword [ecx + APPDATA.io_map+4]
push [ecx + APPDATA.process]
push [ecx + APPDATA.saved_esp0]
mov [ecx + APPDATA.saved_esp0], esp
mov [tss._esp0], esp
mov eax, [esi + V86_machine.iopm]
call get_pg_addr
inc eax
mov dword [ecx + APPDATA.io_map], eax
mov dword [page_tabs + (tss._io_map_0 shr 10)], eax
mov eax, [esi + V86_machine.iopm]
add eax, 0x1000
call get_pg_addr
inc eax
mov dword [ecx + APPDATA.io_map + 4], eax
mov dword [page_tabs + (tss._io_map_1 shr 10)], eax
mov eax, [esi + V86_machine.process]
mov [ecx + APPDATA.process], eax
mov [current_process], eax
mov eax, [eax + PROC.pdt_0_phys]
mov cr3, eax
; We do not enable interrupts, because V86 IRQ redirector assumes that
; machine is running
; They will be enabled by IRET.
; sti
mov eax, esi
sub esp, sizeof.v86_regs
mov esi, ebx
mov edi, esp
mov ecx, sizeof.v86_regs/4
rep movsd
cmp edx, -1
jz .noirqhook
uglobal
v86_irqhooks rd IRQ_RESERVED * 2
endg
cmp [v86_irqhooks + edx*8], 0
jz @f
cmp [v86_irqhooks + edx*8], eax
jz @f
mov esi, v86_irqerr
call sys_msg_board_str
inc [v86_irqhooks + edx*8 + 4]
mov eax, 3
jmp v86_exc_c.exit
@@:
mov [v86_irqhooks + edx*8], eax
inc [v86_irqhooks + edx*8 + 4]
.noirqhook:
popad
iretd
; It is only possible to leave virtual-8086 mode by faulting to
; a protected-mode interrupt handler (typically the general-protection
; exception handler, which in turn calls the virtual 8086-mode monitor).
iglobal
v86_exc_str1 db 'V86 : unexpected exception ',0
v86_exc_str2 db ' at ',0
v86_exc_str3 db ':',0
v86_exc_str4 db 13,10,'V86 : faulted code:',0
v86_exc_str5 db ' (unavailable)',0
v86_newline db 13,10,0
v86_io_str1 db 'V86 : access to disabled i/o port ',0
v86_io_byte db ' (byte)',13,10,0
v86_io_word db ' (word)',13,10,0
v86_io_dword db ' (dword)',13,10,0
v86_irqerr db 'V86 : IRQ already hooked',13,10,0
endg
v86_exc_c:
; Did we all that we have wanted to do?
cmp bl, 1
jne @f
xor eax, eax
mov dr6, eax
@@:
mov eax, [esp + sizeof.v86_regs + 10h+18h]
cmp word [esp + v86_regs.eip], ax
jnz @f
shr eax, 16
cmp word [esp + v86_regs.cs], ax
jz .done
@@:
; Various system events, which must be handled, result in #GP
cmp bl, 13
jnz .nogp
; If faulted EIP exceeds 0xFFFF, we have #GP and it is an error
cmp word [esp + v86_regs.eip+2], 0
jnz .nogp
; Otherwise we can safely access byte at CS:IP
; (because it is #GP, not #PF handler)
; If we could get an exception just because of reading code bytes,
; we would have got it already and it wouldn't be #GP
movzx esi, word [esp + v86_regs.cs]
shl esi, 4
add esi, [esp + v86_regs.eip]
lodsb
cmp al, 0xCD ; int xx command = CD xx
jz .handle_int
cmp al, 0xCF
jz .handle_iret
cmp al, 0xF3
jz .handle_rep
cmp al, 0xEC
jz .handle_in
cmp al, 0xED
jz .handle_in_word
cmp al, 0xEE
jz .handle_out
cmp al, 0xEF
jz .handle_out_word
cmp al, 0xE4
jz .handle_in_imm
cmp al, 0xE6
jz .handle_out_imm
cmp al, 0x9C
jz .handle_pushf
cmp al, 0x9D
jz .handle_popf
cmp al, 0xFA
jz .handle_cli
cmp al, 0xFB
jz .handle_sti
cmp al, 0x66
jz .handle_66
jmp .nogp
.handle_int:
cmp word [esp + v86_regs.eip], 0xFFFF
jae .nogp
xor eax, eax
lodsb
; call sys_msg_board_byte
; simulate INT command
; N.B. It is possible that some checks need to be corrected,
; but at least in case of normal execution the code works.
.simulate_int:
cmp word [esp + v86_regs.esp], 6
jae @f
mov bl, 12 ; #SS exception
jmp .nogp
@@:
movzx edx, word [esp + v86_regs.ss]
shl edx, 4
push eax
movzx eax, word [esp + 4 + v86_regs.esp]
sub eax, 6
add edx, eax
mov eax, edx
mov esi, [esp + 4 + sizeof.v86_regs + 10h+4]
call v86_get_lin_addr
cmp eax, 0x1000
jae @f
mov bl, 14 ; #PF exception
jmp .nogp
@@:
lea eax, [edx+5]
call v86_get_lin_addr
cmp eax, 0x1000
jae @f
mov bl, 14 ; #PF exception
jmp .nogp
@@:
sub word [esp+4+v86_regs.esp], 6
mov eax, [esp+4+v86_regs.eip]
cmp byte [esp+1], 0
jnz @f
inc eax
inc eax
@@:
mov word [edx], ax
mov eax, [esp + 4 + v86_regs.cs]
mov word [edx+2], ax
mov eax, [esp + 4 + v86_regs.eflags]
mov word [edx+4], ax
pop eax
mov ah, 0
mov cx, [eax*4]
mov word [esp + v86_regs.eip], cx
mov cx, [eax*4+2]
mov word [esp + v86_regs.cs], cx
; note that interrupts will be disabled globally at IRET
and byte [esp + v86_regs.eflags+1], not 3 ; clear IF and TF flags
; continue V86 execution
popad
iretd
.handle_iret:
cmp word [esp + v86_regs.esp], 0x10000 - 6
jbe @f
mov bl, 12
jmp .nogp
@@:
movzx edx, word [esp + v86_regs.ss]
shl edx, 4
movzx eax, word [esp + v86_regs.esp]
add edx, eax
mov eax, edx
mov esi, [esp + sizeof.v86_regs + 10h+4]
call v86_get_lin_addr
cmp eax, 0x1000
jae @f
mov bl, 14
jmp .nogp
@@:
lea eax, [edx+5]
call v86_get_lin_addr
cmp eax, 0x1000
jae @f
mov bl, 14
jmp .nogp
@@:
mov ax, [edx]
mov word [esp + v86_regs.eip], ax
mov ax, [edx+2]
mov word [esp + v86_regs.cs], ax
mov ax, [edx+4]
mov word [esp + v86_regs.eflags], ax
add word [esp + v86_regs.esp], 6
popad
iretd
.handle_pushf:
cmp word [esp + v86_regs.esp], 1
jnz @f
mov bl, 12
jmp .nogp
@@:
movzx edx, word [esp + v86_regs.ss]
shl edx, 4
mov eax, [esp + v86_regs.esp]
sub eax, 2
movzx eax, ax
add edx, eax
mov eax, edx
mov esi, [esp + sizeof.v86_regs + 10h+4]
call v86_get_lin_addr
cmp eax, 0x1000
jae @f
mov bl, 14 ; #PF exception
jmp .nogp
@@:
lea eax, [edx+1]
call v86_get_lin_addr
cmp eax, 0x1000
jae @f
mov bl, 14
jmp .nogp
@@:
sub word [esp + v86_regs.esp], 2
mov eax, [esp + v86_regs.eflags]
mov [edx], ax
inc word [esp + v86_regs.eip]
popad
iretd
.handle_pushfd:
cmp word [esp + v86_regs.esp], 4
jae @f
mov bl, 12 ; #SS exception
jmp .nogp
@@:
movzx edx, word [esp + v86_regs.ss]
shl edx, 4
movzx eax, word [esp + v86_regs.esp]
sub eax, 4
add edx, eax
mov eax, edx
mov esi, [esp + sizeof.v86_regs + 10h+4]
call v86_get_lin_addr
cmp eax, 0x1000
jae @f
mov bl, 14 ; #PF exception
jmp .nogp
@@:
lea eax, [edx+3]
call v86_get_lin_addr
cmp eax, 0x1000
jae @f
mov bl, 14 ; #PF exception
jmp .nogp
@@:
sub word [esp + v86_regs.esp], 4
movzx eax, word [esp + v86_regs.eflags]
mov [edx], eax
add word [esp + v86_regs.eip], 2
popad
iretd
.handle_popf:
cmp word [esp + v86_regs.esp], 0xFFFF
jnz @f
mov bl, 12
jmp .nogp
@@:
movzx edx, word [esp + v86_regs.ss]
shl edx, 4
movzx eax, word [esp + v86_regs.esp]
add edx, eax
mov eax, edx
mov esi, [esp + sizeof.v86_regs+10h+4]
call v86_get_lin_addr
cmp eax, 0x1000
jae @f
mov bl, 14 ; #PF exception
jmp .nogp
@@:
lea eax, [edx+1]
call v86_get_lin_addr
cmp eax, 0x1000
jae @f
mov bl, 14
jmp .nogp
@@:
mov ax, [edx]
mov word [esp + v86_regs.eflags], ax
add word [esp + v86_regs.esp], 2
inc word [esp + v86_regs.eip]
popad
iretd
.handle_popfd:
cmp word [esp + v86_regs.esp], 0x10000 - 4
jbe @f
mov bl, 12
jmp .nogp
@@:
movzx edx, word [esp + v86_regs.ss]
shl edx, 4
movzx eax, word [esp + v86_regs.esp]
add edx, eax
mov eax, edx
mov esi, [esp + sizeof.v86_regs + 10h+4]
call v86_get_lin_addr
cmp eax, 0x1000
jae @f
mov bl, 14
jmp .nogp
@@:
lea eax, [edx+3]
call v86_get_lin_addr
cmp eax, 0x1000
jae @f
mov bl, 14
jmp .nogp
@@:
mov eax, [edx]
mov word [esp + v86_regs.eflags], ax
add word [esp + v86_regs.esp], 4
add word [esp + v86_regs.eip], 2
popad
iretd
.handle_cli:
and byte [esp + v86_regs.eflags+1], not 2
inc word [esp + v86_regs.eip]
popad
iretd
.handle_sti:
or byte [esp + v86_regs.eflags+1], 2
inc word [esp + v86_regs.eip]
popad
iretd
.handle_rep:
cmp word [esp + v86_regs.eip], 0xFFFF
jae .nogp
lodsb
cmp al, 6Eh
jz .handle_rep_outsb
jmp .nogp
.handle_rep_outsb:
.handle_in:
.handle_out:
.invalid_io_byte:
movzx ebx, word [esp + v86_regs.edx]
mov ecx, 1
jmp .invalid_io
.handle_in_imm:
.handle_out_imm:
cmp word [esp + v86_regs.eip], 0xFFFF
jae .nogp
lodsb
movzx ebx, al
mov ecx, 1
jmp .invalid_io
.handle_66:
cmp word [esp + v86_regs.eip], 0xFFFF
jae .nogp
lodsb
cmp al, 0x9C
jz .handle_pushfd
cmp al, 0x9D
jz .handle_popfd
cmp al, 0xEF
jz .handle_out_dword
cmp al, 0xED
jz .handle_in_dword
jmp .nogp
.handle_in_word:
.handle_out_word:
movzx ebx, word [esp + v86_regs.edx]
mov ecx, 2
jmp .invalid_io
.handle_in_dword:
.handle_out_dword:
.invalid_io_dword:
movzx ebx, word [esp + v86_regs.edx]
mov ecx, 4
.invalid_io:
mov esi, v86_io_str1
call sys_msg_board_str
mov eax, ebx
call sys_msg_board_dword
mov esi, v86_io_byte
cmp ecx, 1
jz @f
mov esi, v86_io_word
cmp ecx, 2
jz @f
mov esi, v86_io_dword
@@:
call sys_msg_board_str
if DEBUG_SHOW_IO
mov edx, ebx
mov ebx, 200
call delay_hs
mov esi, [esp + v86_regs.size + 10h+4]
mov eax, [esi + V86_machine.iopm]
@@:
btr [eax], edx
inc edx
loop @b
popad
iretd
else
mov eax, 2
jmp .exit
end if
.nogp:
mov esi, v86_exc_str1
call sys_msg_board_str
mov al, bl
call sys_msg_board_byte
mov esi, v86_exc_str2
call sys_msg_board_str
mov ax, [esp+32+4]
call sys_msg_board_word
mov esi, v86_exc_str3
call sys_msg_board_str
mov ax, [esp+32]
call sys_msg_board_word
mov esi, v86_exc_str4
call sys_msg_board_str
mov ecx, 8
movzx edx, word [esp+32+4]
shl edx, 4
add edx, [esp+32]
@@:
mov esi, [esp+sizeof.v86_regs + 10h+4]
mov eax, edx
call v86_get_lin_addr
cmp eax, 0x1000
jb .nopage
mov esi, v86_exc_str3 - 2
call sys_msg_board_str
mov al, [edx]
call sys_msg_board_byte
inc edx
loop @b
jmp @f
.nopage:
mov esi, v86_exc_str5
call sys_msg_board_str
@@:
mov esi, v86_newline
call sys_msg_board_str
mov eax, 1
jmp .exit
.done:
xor eax, eax
.exit:
mov [esp + sizeof.v86_regs + 10h+1Ch], eax
mov [esp + sizeof.v86_regs + 10h+18h], ebx
mov edx, [esp + sizeof.v86_regs + 10h+14h]
cmp edx, -1
jz @f
dec [v86_irqhooks + edx*8 + 4]
jnz @f
and [v86_irqhooks + edx*8], 0
@@:
mov esi, esp
mov edi, [esi + sizeof.v86_regs + 10h+10h]
add edi, sizeof.v86_regs
mov ecx, sizeof.v86_regs/4
rep movsd
mov esp, esi
cli
mov ecx, [current_slot]
pop eax
mov [ecx + APPDATA.saved_esp0], eax
mov [tss._esp0], eax
pop eax
mov [ecx + APPDATA.process], eax
mov [current_process], eax
pop ebx
mov dword [ecx + APPDATA.io_map+4], ebx
mov dword [page_tabs + (tss._io_map_1 shr 10)], ebx
pop ebx
mov dword [ecx + APPDATA.io_map], ebx
mov dword [page_tabs + (tss._io_map_0 shr 10)], ebx
mov eax, [eax+PROC.pdt_0_phys]
mov cr3, eax
sti
popad
ret
;my05:
; mov dx, 30C2h
; mov cx, 4
;.0:
; in al, dx
; cmp al, 0FFh
; jz @f
; test al, 4
; jnz .1
;@@:
; add dx, 8
; in al, dx
; cmp al, 0FFh
; jz @f
; test al, 4
; jnz .1
;@@:
; loop .0
; ret
;.1:
; or al, 84h
; out dx, al
;.2:
; mov dx, 30F7h
; in al, dx
; mov byte [BOOT_VAR + 48Eh], 0FFh
; ret
align 4
v86_irq:
; push irq/pushad/jmp v86_irq
; ebp = irq
lea esi, [esp + 1Ch]
lea edi, [esi+4]
mov ecx, 8
std
rep movsd
cld
mov edi, ebp
pop eax
v86_irq2:
mov esi, [v86_irqhooks + edi*8] ; get VM handle
mov eax, [esi + V86_machine.process]
mov ecx, [current_slot]
cmp [ecx + APPDATA.process], eax
jnz .notcurrent
lea eax, [edi+8]
cmp al, 10h
mov ah, 1
jb @f
add al, 60h
@@:
jmp v86_exc_c.simulate_int
.notcurrent:
mov ebx, SLOT_BASE + sizeof.APPDATA
mov ecx, [thread_count]
.scan:
cmp [ebx + APPDATA.process], eax
jnz .cont
push ecx
mov ecx, [ebx + APPDATA.saved_esp0]
cmp word [ecx - sizeof.v86_regs + v86_regs.esp], 6
jb .cont2
movzx edx, word [ecx - sizeof.v86_regs + v86_regs.ss]
shl edx, 4
push eax
movzx eax, word [ecx - sizeof.v86_regs + v86_regs.esp]
sub eax, 6
add edx, eax
mov eax, edx
call v86_get_lin_addr
cmp eax, 0x1000
jb .cont3
lea eax, [edx+5]
call v86_get_lin_addr
cmp eax, 0x1000
jb .cont3
pop eax
pop ecx
jmp .found
.cont3:
pop eax
.cont2:
pop ecx
.cont:
add ebx, 0x100
loop .scan
mov ecx, edi
call irq_eoi
popad
iretd
.found:
mov eax, [eax + PROC.pdt_0_phys]
mov cr3, eax
mov esi, [ebx + APPDATA.saved_esp0]
sub word [esi - sizeof.v86_regs + v86_regs.esp], 6
mov ecx, [esi - sizeof.v86_regs + v86_regs.eip]
mov word [edx], cx
mov ecx, [esi - sizeof.v86_regs + v86_regs.cs]
mov word [edx+2], cx
mov ecx, [esi - sizeof.v86_regs + v86_regs.eflags]
mov word [edx+4], cx
lea eax, [edi+8]
cmp al, 10h
jb @f
add al, 60h
@@:
mov cx, [eax*4]
mov word [esi - sizeof.v86_regs + v86_regs.eip], cx
mov cx, [eax*4+2]
mov word [esi - sizeof.v86_regs + v86_regs.cs], cx
and byte [esi - sizeof.v86_regs + v86_regs.eflags + 1], not 3
call update_counters
call find_next_task.found
call do_change_task
popad
iretd