最近用到的中断

Category: BIOS

INT 15 - SYSTEM - GET EXTENDED MEMORY SIZE (286+)

	AH = 88h
Return: CF clear if successful
	    AX = number of contiguous KB starting at absolute address 100000h
	CF set on error
	    AH = status
		80h invalid command (PC,PCjr)
		86h unsupported function (XT,PS30)
Notes:	TSRs which wish to allocate extended memory to themselves often hook
	  this call, and return a reduced memory size.	They are then free to
	  use the memory between the new and old sizes at will.
	the standard BIOS only returns memory between 1MB and 16MB; use AH=C7h
	  for memory beyond 16MB
	not all BIOSes correctly return the carry flag, making this call
	  unreliable unless one first checks whether it is supported through
	  a mechanism other than calling the function and testing CF
	Due to applications not dealing with more than 24-bit descriptors
	  (286), Windows 3.0 has problems when this function reports more
	  than 15 MB. Some releases of HIMEM.SYS are therefore limited to use
	  only 15 MB, even when this function reports more.
SeeAlso: AH=87h,AH=8Ah"Phoenix",AH=C7h,AX=DA88h,AX=E801h,AX=E820h

Category: BIOS
INT 15 - SYSTEM - COPY EXTENDED MEMORY

	AH = 87h
	CX = number of words to copy (max 8000h)
	ES:SI -> global descriptor table (see )
Return: CF set on error
	CF clear if successful
	AH = status (see )
Notes:	copy is done in protected mode with interrupts disabled by the default
	  BIOS handler; many 386 memory managers perform the copy with
	  interrupts enabled
	on the PS/2 30-286 & "Tortuga" this function does not use the port 92h
	  for A20 control, but instead uses the keyboard controller (8042).
	  Reportedly this may cause the system to crash when access to the
	  8042 is disabled in password server mode (see also PORT 0064h,#P0398)
	this function is incompatible with the OS/2 compatibility box
SeeAlso: AH=88h,AH=89h,INT 1F/AH=90h

Format of global descriptor table:
Offset	Size	Description	)
 00h 16 BYTEs	zeros (used by BIOS)
 10h	WORD	source segment length in bytes (2*CX-1 or greater)
 12h  3 BYTEs	24-bit linear source address, low byte first
 15h	BYTE	source segment access rights (93h)
 16h	WORD	(286) zero
		(386+) extended access rights and high byte of source address
 18h	WORD	destination segment length in bytes (2*CX-1 or greater)
 1Ah  3 BYTEs	24-bit linear destination address, low byte first
 1Dh	BYTE	destination segment access rights (93h)
 1Eh	WORD	(286) zero
		(386+) extended access rights and high byte of destin. address
 20h 16 BYTEs	zeros (used by BIOS to build CS and SS descriptors)

Values for extended-memory copy status:
 00h	source copied into destination
 01h	parity error
 02h	interrupt error
 03h	address line 20 gating failed
 80h	invalid command (PC,PCjr)
 86h	unsupported function (XT,PS30)