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;
; Copyright (c) 2006-2008 Advanced Micro Devices,Inc. ("AMD").
;
; This library is free software; you can redistribute it and/or modify
; it under the terms of the GNU Lesser General Public License as
; published by the Free Software Foundation; either version 2.1 of the
; License, or (at your option) any later version.
;
; This code is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
; Lesser General Public License for more details.
;
; You should have received a copy of the GNU Lesser General
; Public License along with this library; if not, write to the
; Free Software Foundation, Inc., 59 Temple Place, Suite 330,
; Boston, MA 02111-1307 USA
;
;********************************************************************************
;* Implementation of BIOS callbacks
;********************************************************************************
include SYSMGR.INC
include VSA2.INC
include SMIMAC.MAC
include GX2.INC
include ISA.INC
.model tiny,c
.586p
.ALPHA
DGROUP GROUP _CODE, _TEXT
_CODE SEGMENT PUBLIC use16 'CODE'
ASSUME DS:_CODE
public VSM_Buffer
SMINT_SEGMENT equ 0E000h ; Segment to store SMINT instruction & ISR stack
ALLOW_SMM_SEGMENTS equ 0 ; 1 = ES segment allowed to point to SMM memory
externdef pascal Report_VSM_Error: proc
externdef pascal Schedule_VSM: proc
externdef Sys_Exit: proc
externdef pascal Hex_8: proc
externdef pascal Hex_16: proc
externdef pascal Hex_32: proc
externdef BracketFlag: byte
externdef SchedulerStack: word
externdef INT_Vectors: dword
externdef Current_VSM: dword
externdef StartSaveArea: dword
externdef EndSaveArea: dword
externdef SysMgr_VSM: dword
externdef Header_Addr: dword
externdef SMM_Header: SmiHeader
;************************************************************************
; Implements the SYS_STATE macro
;
; Input:
; CX = Flag: 0 = Save 1 = Restore
; EDI = Offset to VSM's register buffer
; DS = System Manager's data segment
;************************************************************************
Sys_State proc
cld
mov eax, [Current_VSM] ; Create flat ptr to calling VSM
add edi, eax
push eax ; Re-schedule the calling VSM
call Schedule_VSM
lea esi, [StartSaveArea]
add esi, [SysMgr_VSM]
jcxz CopyState ; Save or Restore ?
xchg esi, edi ; Restore
; Copy the non-SMM state
CopyState:
mov ecx, OFFSET EndSaveArea
sub cx, OFFSET StartSaveArea
shr cx, 1
rep movsw [edi], fs:[esi]
jmp Sys_Exit
Sys_State endp
;************************************************************************
; Implements the SYS_SW_INTERRUPT macro
;
; Input:
; EBX = 4 * INT number
; ECX = Offset to VSM's register buffer
;************************************************************************
Sys_SW_INT proc
cld
mov esi, [Current_VSM]
push esi ; Re-schedule the calling VSM
call Schedule_VSM
cmp bx, 4*MAX_INT ; Validate INT vector
ja Unsupported_INT
mov edx, [INT_Vectors+bx]
or edx, edx
jz Illegal_INT
mov [Saved_INT], ebx ; Save current vector &
mov edi, edx ; patch with the original vector
xchg fs:[ebx], edi
mov [Saved_Vector], edi
xor edi, edi ; Don't allow calling VSM to execute
push edi
call Schedule_VSM
ASSUME di:PTR VSM_Header ; Mark the requesting VSM blocked
mov gs:[di].SysStuff.RunFlag, RUN_FLAG_BLOCKED
; Handle PIC masks
in al, PIC1_MASK ; Save PIC masks & set user-defined masks
mov ah, al
in al, PIC2_MASK
mov [Saved_PIC], ax
ASSUME di:PTR INT_REGS
mov di, cx
mov ax, word ptr gs:[di].PIC0_Mask
not ax ; PIC masks are 0=enable
cmp ah, 0FFh ; Any PIC1 IRQs enabled ?
je short SetPIC
and al, NOT 04h ; Yes, enable IRQ2
SetPIC:
or al, 01h ; Always disable IRQ0
out PIC1_MASK, al
mov al, ah
out PIC2_MASK, al
cmp ax, 0FFFFh ; Are any IRQs enabled ?
je short RealMode
or gs:[di].Flags, EFLAGS_IF ; Yes, enable interrupts
;
; Initialize real-mode state
;
RealMode:
mov ax, gs:[di].Reg_ES ; Set up ES descriptor
push OFFSET BIOS_ES
call Set_Descriptor
mov ax, gs:[di].Reg_DS ; Set up DS descriptor
push OFFSET BIOS_DS
call Set_Descriptor
add esi, ecx ; Create flat ptr to calling VSM's registers
mov [VSM_Buffer], esi
ASSUME di:PTR SmiHeader
lea edi, [BIOS_Header] ; Set up CS descriptor & Next_EIP
mov word ptr [di].SS_Flags, DATA_ATTR
mov [di].SMI_Flags, SMI_FLAGS_CS_WRITABLE + SMI_FLAGS_CS_READABLE
mov word ptr [di].Next_EIP, dx ; IP
shr edx, 16 ; Convert segment to linear address
mov [di]._CS.selector, dx ; CS selector
shl edx, 4
mov [di]._CS.base, edx ; CS descriptor
mov [di]._CS.limit, 0FFFFh
mov [di]._CS.attr, CODE_ATTR ; CS attribute
mov eax, CR0 ; Preserve the CD & NW bits
and eax, 60000000h
or eax, VSM_CR0
mov [di].r_CR0, eax
if ALLOW_SMM_SEGMENTS
mov ecx, MSR_RCONF_SMM ; Make SMM memory writeable by interrupt code
rdmsr
mov [OldRCONF], al
and al, NOT REGION_WP
wrmsr
endif
ASSUME DI: NOTHING
mov ecx, 1000002Ch ; Save P2D_SC value & make UMBs R/W
rdmsr
mov [ShadowMSR], dx
or dx, 0FFFFh
wrmsr
mov ebx, SMINT_SEGMENT ; Patch SS descriptor
mov word ptr [BIOS_SS+8], bx
shl ebx, 4
mov dword ptr [BIOS_SS+2], ebx
mov byte ptr [BIOS_SS+5], DATA_ATTR
add ebx, 0FFF0h
mov [ShadowAddr], ebx
mov word ptr [BIOS_ESP], bx
; Build a stack frame:
; SMINT_SEGMENT:FFF0 SMINT_SEGMENT:FFF6 - return addresss
; SMINT_SEGMENT:FFF4 Flags
; SMINT_SEGMENT:FFF6 SMINT instruction
mov eax, SMINT_SEGMENT SHL 16 ; Segment
lea ax, [bx+6] ; Offset (SP+6)
xchg eax, dword ptr fs:[ebx]
mov [ShadowMemory], eax
mov eax, 380F0000h ; FLAGS & SMINT
xchg eax, fs:[ebx+4]
mov [ShadowMemory+4], eax
mov eax, [Header_Addr] ; Copy top-level header address
mov [Hdr_Address], eax
call VSM_Registers ; Get registers for ISR
call Swap_States ; S wap top-level state with BIOS state
Exit: jmp Sys_Exit
Unsupported_INT:
Illegal_INT:
mov ax, ERR_BAD_INTERRUPT
push ax ; Push error code
shr ebx, 2
push ebx ; Info1 = Interrupt #
push dword ptr 0 ; Info2 = 0x00000000
call Report_VSM_Error
jmp Exit
Sys_SW_INT endp
;********************************************************************************
; Returns here from INT callback
;********************************************************************************
INT_Return proc
mov ebx, [Saved_INT] ; Restore the INT vector
mov edx, [Saved_Vector]
mov fs:[ebx], edx
if ALLOW_SMM_SEGMENTS
mov ecx, MSR_RCONF_SMM ; Restore SMM region properties
rdmsr
mov al, [OldRCONF]
wrmsr
endif
mov esi, [Current_VSM] ; Mark the requesting VSM ready to run
mov fs:(VSM_Header PTR [esi]).SysStuff.RunFlag, RUN_FLAG_READY
call Swap_States ; Restore the original non-SMM state
call VSM_Registers ; Return register values & flags
xor eax, eax
mov [VSM_Buffer], eax
sub [SchedulerStack], 4 ; Pop the scheduler sentinel
mov ebx, [ShadowAddr] ; Restore shadow memory
mov eax, [ShadowMemory]
mov fs:[ebx], eax
mov eax, [ShadowMemory+4]
mov fs:[ebx+4], eax
mov ecx, 1000002Ch ; Restore R/W attributes of UMBs
rdmsr
mov dx, [ShadowMSR]
wrmsr
mov ax, [Saved_PIC] ; Restore PIC masks
out PIC2_MASK, al
mov al, ah
out PIC1_MASK, al
ret
INT_Return endp
;************************************************************************
; Swaps the top-level state with the BIOS callback state.
; Info to be saved:
; - SMM header & pointer
; - Descriptors
; - GP registers
; - IDT ptr
; - PCI config address
;************************************************************************
Swap_States proc
lea si, [StartSaveArea] ; Swap thread states
lea di, [Saved_State]
mov cx, OFFSET EndSaveArea ; Compute # dwords of state
sub cx, si
shr cx, 2
StateLoop:
lodsd ; Exchange a dword
xchg [di], eax
mov dword ptr [si-4], eax
add di, 4
loop StateLoop
lea si, [SMM_Header] ; Now do the top-level SMM header
lea di, [BIOS_Header]
mov cl, sizeof(SmiHeader)/4
Hdr_Loop:
lodsd
xchg [di], eax
mov [si-4], eax
add di, 4
loop Hdr_Loop
ret
Swap_States endp
;************************************************************************
; Swaps the VSM's registers with the local state
;************************************************************************
VSM_Registers proc
mov esi, [VSM_Buffer] ; Caller's register buffer
mov ax, word ptr [BIOS_Header].EFLAGS
xchg fs:(INT_REGS PTR [esi]).Flags, ax
mov word ptr [BIOS_Header].EFLAGS, ax
lea bx, [Reg_Table]
mov cx, (End_Reg_Table-Reg_Table)/2
Reg_Loop:
mov di, [bx] ; Get offset of register
mov eax, [di] ; Swap with register structure
xchg eax, fs:[esi]
mov [di], eax
add bx, 2 ; Increment ptrs
add esi, 4
loop Reg_Loop
ret
; This table translates between a INT_REGS structure and the PUSHA/POPA ordering
Reg_Table:
dw OFFSET BIOS_EAX
dw OFFSET BIOS_EBX
dw OFFSET BIOS_ECX
dw OFFSET BIOS_EDX
dw OFFSET BIOS_EBP
dw OFFSET BIOS_ESI
dw OFFSET BIOS_EDI
End_Reg_Table:
VSM_Registers endp
;************************************************************************
; Sets a descriptor to a real-mode descriptor
; Input:
; AX = selector
; If selector = 0x0000, a 4 GB descriptor (big-real) is used
; If selector = 0xFFFF, the calling VSM's base/limit is used
; DI = ptr to descriptor
;************************************************************************
Set_Descriptor proc pascal uses di \
DescrPtr: PTR Descriptor
ASSUME di: PTR Descriptor
mov di, [DescrPtr]
mov ebx, 0FFFFh ; 64K limit
or ax, ax ; Selector = 0000h?
jnz short SetSelector
mov ebx, 008FFFFFh ; Yes, then use 4 GB limit (big-real mode)
SetSelector:
movzx eax, ax
mov [di].selector, ax
shl eax, 4
if ALLOW_SMM_SEGMENTS
; If ES == 0xFFFF, use VSM's base
cmp ax, bx
jne short Set_Limit
mov eax, [Current_VSM] ; No, use VSM's base & limit
mov bx, ax
shr bx, 4
mov [di].selector, bx
mov ebx, (VSM_Header PTR fs:[eax]).DS_Limit
endif
Set_Limit:
; EAX = base
; EBX = limit
mov [di].limit_15_0, bx ; Store 24-bit limit
shr ebx, 16
mov [di].limit_19_16, bl
mov [di].base_15_0, ax ; Store 32-bit base
shr eax, 16
mov [di].base_23_16, al
mov [di].base_31_24, ah
ret
ASSUME di: NOTHING
Set_Descriptor endp
align 4
Saved_State:
;******************************************************************************
; The following must match the structure at StartSaveArea in SYSMGR.ASM
BIOS_PCI dd 80000000h
BIOS_EDI dd 0
BIOS_ESI dd 0
BIOS_EBP dd 0
dd 0 ; ESP (not used)
BIOS_EBX dd 0
BIOS_EDX dd 0
BIOS_ECX dd 0
BIOS_EAX dd 0
BIOS_ESP dd 0
BIOS_SS Descriptor {0FFFFh, 0, 0, DATA_ATTR, 0, 0, 0}
BIOS_DS Descriptor {0FFFFh, 0, 0, DATA_ATTR, 0, 0, 0}
BIOS_ES Descriptor {0FFFFh, 0, 0, DATA_ATTR, 0, 0, 0}
BIOS_FS Descriptor {0FFFFh, 0, 0, DATA_ATTR, 0, 0, 0}
BIOS_GS Descriptor {0FFFFh, 0, 0, DATA_ATTR, 0, 0, 0}
Hdr_Address dd 0
IDT_Selector dd 00920000h
IDT_Base dd 00000000h
IDT_Limit dd 0000FFFFh
dw 0 ; Pad
;******************************************************************************
SMM_CONTROL equ EXTL_SMI_EN + INTL_SMI_EN + SMM_INST_EN + NEST_SMI_EN
BIOS_Header SmiHeader {,SMM_CONTROL,,,,,,,,,VSM_CR0, VSM_EFLAGS, VSM_DR7}
ShadowMemory dd 0, 0
ShadowAddr dd 0
ShadowMSR dw 0
VSM_Buffer dd 0
Saved_PIC dw 0
Saved_INT dd 0
Saved_Vector dd 0
OldRCONF db 0
_CODE ENDS
END
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