I currently disassembled NTLDR of Windows XP. During the process of booting, NTLDR uses the following interrupt:
INT 10H, AX=2000H, BX=0301H, CX=0H, DX=0H
I don't know the meaning of this interrupt. What does it mean?
Understanding the answer is going to require a bit of assembly language to understand.
Of the multipurpose registers used by x86 and x64 processors, EAX, EBX, ECX, and EDX can be divided into to halves. So EAX breaks down into AX and AH. The same holds true for EBX and so on. AX, BX, CX, and DX are the lower halves of the EAX, EBX, ECX, and EDX registers. The interrupt 10H is the video interrupt code.