.section .data
    .align 4
# The DPMI Register Structure (50 bytes total)
# This holds the register states injected into Real Mode.
dpmi_regs:
    .long 0         # edi  (offset 0)
    .long 0         # esi  (offset 4)
    .long 0         # ebp  (offset 8)
    .long 0         # esp / reserved (offset 12)
    .long 0         # ebx  (offset 16)
    .long 0         # edx  (offset 20)
    .long 0         # ecx  (offset 24)
dpmi_eax:
    .long 0         # eax  (offset 28)
    .short 0        # flags(offset 32)
    .short 0        # es   (offset 34)
    .short 0        # ds   (offset 36)
    .short 0        # fs   (offset 38)
    .short 0        # gs   (offset 40)
    .short 0        # ip   (offset 42)
    .short 0        # cs   (offset 44)
    .short 0        # sp   (offset 46)
    .short 0        # ss   (offset 48)

.section .text
.global _start

_start:
    call plr_display_dos_main

    # 1. Set up the Real-Mode registers inside the DPMI structure
    # AH = 4Ch (DOS Exit Function), AL = 00h (Return Code 0)
    movl $0x00004C00, dpmi_eax

    # 2. Call DPMI Simulate Real Mode Interrupt
    movw $0x0300, %ax    # DPMI Function: Simulate Real Mode Interrupt
    movb $0x21, %bl      # Interrupt number to trigger (INT 21h)
    movb $0x00, %bh      # Flags (Must be 0)
    movw $0x0000, %cx    # Number of words to copy to RM stack (0)
    
    # ES:EDI points to our DPMI register block. 
    # In WDOSX flat model, %es already targets the flat data descriptor.
    movl $dpmi_regs, %edi
    
    int $0x31            # Trigger DPMI host to execute the RM interrupt

    # --- Execution halts here as DOS terminates the program ---