WindowsNT/Int50

Int50 simplified DMMI interface

Int 0x50 interfaces for your DOS apps. See all.asm:

FORMAT MZ
HEAP 0
include "macros.asm"
include "stack.asm"
include "dmmi_data.asm"
include "dmmi_code.asm"

Install interrupt

Modes: Real

call far CODE16:F_InstallVector50

Initialize Int 0x50.

This must be called from all entry points (start, thread, protected mode, long mode functions)

Modes: Real, Protected, Long

mov eax,1
int 50h

Enable Unreal mode.

This also initializes ACPI structures.

Modes: Real

mov eax,2
int 50h

Call 32-bit protected mode function

Modes: Real

EDX = linear address of your proc

mov eax,3
linear edx,a_proc_32,MY_CODE
int 50h

Call 64-bit long mode function

Modes: Real, Protected

ECX:EDX = linear address of your proc

mov eax,4
xor ecx,ecx
linear edx,a_proc_64,MY_CODE
int 50h

Call 16-bit real mode function

Modes: Protected, Long

CD:DX = seg:ofs of real mode proc

mov eax,7
mov cx,MY_CODE
mov dx,Func_Real
int 50h

Start 16-bit thread.

This thread can call Int 50x functions to switch to protected or long mode.

Modes: Real.

EBX = cpu index EDX = linear address of the thread proc

mov eax,5
linear edx,Thread16_1,MY_CODE
mov ebx,1
int 50h

A thread must begin with 4096 NOPs for call alignment

db 4096 dup (144) ; fill NOPs for alignment

Mutex functions

Modes: Real, Protected, Long

AX = 6 BX operation 0 create 1 lock 2 unlock 3 wait 4 wait and lock ES:DI = mutex address (byte)

; Create the mutex
mov ax,MY_DATA
mov es,ax
mov di,mymut_1
mov eax,6
mov ebx,0
int 0x50

; Lock it
mov eax,6
mov ebx,1
int 0x50

; wait
mov ax,MY_DATA
mov es,ax
mov di,mymut_1
mov eax,6
mov ebx,3
int 0x50

; Another thread
; Unlock mutex and end
mov ax,MY_DATA
mov es,ax
mov di,mymut_1
mov eax,6
mov ebx,2
int 0x50
hlt 
hlt

Start 16-bit virtualized function

To call this function, first call a long mode function.

Modes: Long

CD:DX = linear address of the real mode proc.

; Is VMX supported?
mov eax,10
mov ebx, 0
int 50h; should return RAX = 1

; Run VMX
mov eax,10
mov ebx, 1
mov dx,a_virtual_64
mov cx,MY_CODE
int 50h;

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