System-Management Mode   	Release 62    	Last Change 04apr26 12:01
Original RBIL Copyright (c) 1997,1998,1999,2000 Ralf Brown
Modifications Copyright (c) 2026 The List Project and its contributors
--------!---SMM:AM486------------------------
SMM Am486
Format of Am486 SMM State-Save Map:
Offset	Size	Description	(Table S0001)
FE00h		reserved
FEE4h	DWORD	DR3
FEE8h	DWORD	DR2
FEECh	DWORD	DR1
FEF0h	DWORD	DR0
FEF4h	DWORD	CR2
FEF8h	DWORD	SMM state dump base address
fEFCh	DWORD	SMM revision ID (see #S0004)
FF00h	WORD	I/O restart
		(set to 00FFh to re-execute trapped I/O)
FF02h	WORD	halt auto restart
		(bit 0 set on entry if SMI during HLT)
		(set to 00FFh to restart from HLT)
FF04h	DWORD	I/O trap word (see #S0002)
FF08h	DWORD	reserved
FF0Ch	DWORD	reserved
FF10h	DWORD	previous EIP
FF14h 5 DWORDs	???
FF28h	DWORD	reserved
FF2Ch	DWORD	reserved
FF30h	DWORD	ES limit
FF34h	DWORD	ES base
FF38h	DWORD	ES attributes
FF3Ch	DWORD	CS limit
FF40h	DWORD	CS base
FF44h	DWORD	CS attributes
FF48h	DWORD	SS limit
FF4Ch	DWORD	SS base
FF50h	DWORD	SS attributes
FF54h	DWORD	DS limit
FF58h	DWORD	DS base
FF5Ch	DWORD	DS attributes
FF60h	DWORD	FS limit
FF64h	DWORD	FS base
FF68h	DWORD	FS attributes
FF6Ch	DWORD	GS limit
FF70h	DWORD	GS base
FF74h	DWORD	GS attributes
FF78h	DWORD	LDT limit
FF7Ch	DWORD	LDT base
FF80h	DWORD	LDT attribute
FF84h	DWORD	GDT limit
FF88h	DWORD	GDT base
FF8Ch	DWORD	GDT attribute
FF90h	DWORD	IDT limit
FF94h	DWORD	IDT base
FF98h	DWORD	IDT attribute
FF9Ch	DWORD	TSS limit
FFA0h	DWORD	TSS base
FFA4h	DWORD	TSS attribute
FFA8h	WORD	ES
FFAAh	WORD	unused???
FFACh	WORD	CS
FFAEh	WORD	unused???
FFB0h	WORD	SS
FFB2h	WORD	unused???
FFB4h	WORD	DS
FFB6h	WORD	unused???
FFB8h	WORD	FS
FFBAh	WORD	unused???
FFBCh	WORD	GS
FFBEh	WORD	unused???
FFC0h	DWORD	LDTR
FFC4h	DWORD	TR
FFC8h	DWORD	DR7
FFCCh	DWORD	DR6
FFD0h	DWORD	EAX
FFD4h	DWORD	ECX
FFD8h	DWORD	EDX
FFDCh	DWORD	EBX
FFE0h	DWORD	ESP
FFE4h	DWORD	EBP
FFE8h	DWORD	ESI
FFECh	DWORD	EDI
FFF0h	DWORD	EIP
FFF4h	DWORD	EFLAGS
FFF8h	DWORD	CR3
FFFCh	DWORD	CR0
SeeAlso: #S0003

Bitfields for AMD Am486 I/O trap word:
Bit(s)	Description	(Table S0002)
 31-16	I/O address
 15-2	reserved
 1	valid I/O instruction
 0	direction
SeeAlso: #S0001
--------!---SMM:AMD-K5-----------------------
SMM AMD-K5
Format of AMD K5 SMM State-Save Area:
Offset	Size	Description	(Table S0003)
FE00h		reserved
FEF8h	DWORD	SMM base address
		(may be set to any multiple of 32K; initially 00030000h)
FEFCh	DWORD	SMM revision identifier (see #S0004)
FF00h	WORD	I/O trap restart slot (see #S0007)
FF02h	WORD	HLT restart slot (see #S0005)
FF04h	DWORD	I/O restart EDI
FF08h	DWORD	I/O restart ECX
FF0Ch	DWORD	I/O restart ESI
FF10h	DWORD	CR4
FF14h	DWORD	CR2
FF18h 3 DWORDs	reserved
FF24h	DWORD	ES limit
FF28h	DWORD	ES base
FF2Ch	DWORD	ES attributes
FF30h	DWORD	CS limit
FF34h	DWORD	CS base
FF38h	DWORD	CS attributes
FF3Ch	DWORD	SS limit
FF40h	DWORD	SS base
FF44h	DWORD	SS attributes
FF48h	DWORD	DS limit
FF4Ch	DWORD	DS base
FF50h	DWORD	DS attributes
FF54h	DWORD	FS limit
FF58h	DWORD	FS base
FF5Ch	DWORD	FS attributes
FF60h	DWORD	GS limit
FF64h	DWORD	GS base
FF68h	DWORD	GS attributes
FF6Ch	DWORD	LDT limit
FF70h	DWORD	LDT base
FF74h	DWORD	LDT attributes
FF78h	DWORD	TSS limit
FF7Ch	DWORD	TSS base
FF80h	DWORD	TSS attributes
FF84h	DWORD	GDT limit
FF88h	DWORD	GDT base
FF8Ch	DWORD	IDT limit
FF90h	DWORD	IDT base
FF94h 2 DWORDs	reserved
FF9Ch	DWORD	I/O trap EIP
FFA0h	DWORD	reserved
FFA4h	DWORD	I/O trap DWORD (see #S0006)
FFA8h	WORD	ES
FFAAh	WORD	unused???
FFACh	WORD	CS
FFAEh	WORD	unused???
FFB0h	WORD	SS
FFB2h	WORD	unused???
FFB4h	WORD	DS
FFB6h	WORD	unused???
FFB8h	WORD	FS
FFBAh	WORD	unused???
FFBCh	WORD	GS
FFBEh	WORD	unused???
FFC0h	DWORD	LDTR
FFC4h	DWORD	TR
FFC8h	DWORD	DR7
FFCCh	DWORD	DR6
FFD0h	DWORD	EAX
FFD4h	DWORD	ECX
FFD8h	DWORD	EDX
FFDCh	DWORD	EBX
FFE0h	DWORD	ESP
FFE4h	DWORD	EBP
FFE8h	DWORD	ESI
FFECh	DWORD	EDI
FFF0h	DWORD	EIP
FFF4h	DWORD	EFLAGS
FFF8h	DWORD	CR3
FFFCh	DWORD	CR0
SeeAlso: #S0001

Bitfields for AMD K5 SMM Revision Identifier:
Bit(s)	Description	(Table S0004)
 31-18	reserved (0)
 17	SMM base address relocation available (always 1 [enabled] on K5)
 16	I/O trap restart supported (always 1 on K5)
 15-0	SMM revision level (currently 0000h)
SeeAlso: #S0003

Bitfields for AMD K5 Halt Restart Slot:
Bit(s)	Description	(Table S0005)
 15-1	undefined
 0	(on SMM entry) entered SMM from Halt state
	(at RSM) return to Halt state instead of state in SMM state-save area
SeeAlso: #S0003

Bitfields for AMD K5 I/O Trap DWORD:
Bit(s)	Description	(Table S0006)
 31-16	I/O port address
 15	I/O was string operation (INS,OUTS,etc.)
 14-2	reserved
 1	valid I/O instruction
 0	direction (0 = output, 1 = input)
SeeAlso: #S0003,#S0007

Bitfields for AMD K5 I/O Trap Restart Slot:
Bit(s)	Description	(Table S0007)
 31-16	reserved
 15-0	I/O instruction restart on RSM
	0000h resume at next instruction following trapped I/O instruction
		(default on SMM entry)
	00FFh re-execute the trapped I/O instruction
Note:	before changing the restart value, check that the I/O instruction is
	  actually valid (see #S0006)
SeeAlso: #S0003,#S0006
--------!---SMM:PENTIUM----------------------
SMM Pentium
Format of Pentium State Dump record:
Offset	Size	Description	(Table S0008)
FE00h 248 BYTEs	officially reserved, actually unused
FEF8h	DWORD	state dump base address (must be multiple of 32K)
FEFCh	DWORD	SMM revision identifier
		bits 15-0: SMM revision level
		bit 16: I/O trap extension is present (offset FF00h)
		bit 17: SMM base relocation supported (offset FEF8h)
		bits 31-18: reserved
FF00h	WORD	I/O Trap restart
		(set to 00FFh to re-execute trapped I/O)
FF02h	WORD	Halt auto-restart
		(bit 0 set on entry if SMI during HLT; if handler clears it,
		  the CPU returns to the instruction after the interrupted HLT
		  rather than to the HLT instruction)
FF04h	DWORD	(undoc) I/O restart EDI / CR0
FF08h	DWORD	(undoc) I/O restart ECX
FF0Ch	DWORD	(undoc) I/O restart ESI
FF10h	DWORD	(undoc) I/O restart EIP
FF14h 16 BYTEs	unused
FF24h	WORD	(undoc) alternate DR6
FF26h	WORD	(undoc) RSM control
		if bit 0 set on return, the low word of DR6 is loaded from FF26h
		  instead of FFCCh
FF28h	DWORD	(undoc) CR4
FF2Ch	DWORD	unused
FF30h 12 BYTEs	(undoc) ES descriptor cache
		DWORD limit
		DWORD base address
		DWORD type
FF3Ch 12 BYTEs	(undoc) CS descriptor cache
FF48h 12 BYTEs	(undoc) SS descriptor cache
FF54h 12 BYTEs	(undoc) DS descriptor cache
FF60h 12 BYTEs	(undoc) FS descriptor cache
FF6Ch 12 BYTEs	(undoc) GS descriptor cache
FF78h 12 BYTEs	(undoc) LDT descriptor cache
FF84h 12 BYTEs	(undoc) GDT descriptor cache
FF90h 12 BYTEs	(undoc) IDT descriptor cache
FF9Ch 12 BYTEs	(undoc) TSS descriptor cache
FFA8h	WORD	ES
FFAAh	WORD	reserved
FFACh	WORD	CS
FFAEh	WORD	reserved
FFB0h	WORD	SS
FFB2h	WORD	reserved
FFB4h	WORD	DS
FFB6h	WORD	reserved
FFB8h	WORD	FS
FFBAh	WORD	reserved
FFBCh	WORD	GS
FFBEh	WORD	reserved
FFC0h	DWORD	LDTR
FFC4h	DWORD	TR
FFC8h	DWORD	DR7
FFCCh	DWORD	DR6
FFD0h	DWORD	EAX
FFD4h	DWORD	ECX
FFD8h	DWORD	EDX
FFDCh	DWORD	EBX
FFE0h	DWORD	ESP
FFE4h	DWORD	EBP
FFE8h	DWORD	ESI
FFECh	DWORD	EDI
FFF0h	DWORD	EIP
FFF4h	DWORD	EFLAGS
FFF8h	DWORD	CR3
FFFCh	DWORD	CR0
SeeAlso: #S0003
--------!---CONTACT_INFO---------------------
The List Project is in not affiliated with Ralf Brown or his original
Interrupt List, which he maintained up to July 2000 as the Release 61.
We are very grateful for his efforts and intend to continue improving and
adding to that work as The List Project. All contact to The List Project
should be performed through GitHub at: https://github.com/LoopZ/TheList

To find a copy of the original Ralf Brown's Interrupt List or to contact him,
please visit his webpage at http://www.cs.cmu.edu/~ralf/
