NAME BU_ASM
TITLE BU_ASM.ASM -- ASM support for DOS BU_LIB
;****************************************************************************
;* Copyright (C) Intel Corporation 1994-1999
;*
;* All rights reserved. No part of this program or publication
;* may be reproduced, transmitted, transcribed, stored in a
;* retrieval system, or translated into any language or computer
;* language, in any form or by any means, electronic, mechanical,
;* magnetic, optical, chemical, manual, or otherwise, without
;* the prior written permission of Intel Corporation.
;****************************************************************************
;
; To assemble with MASM61 -- ml /c a16utils.asm
;
;****************************************************************************
.286
.MODEL large, c
IFDEF MODEL_S
.MODEL small, c
ENDIF
IFDEF MODEL_M
.MODEL medium, c
ENDIF
IFDEF MODEL_L
.MODEL large, c
ENDIF
IFDEF MODEL_C
.MODEL compact, c
ENDIF
IFDEF MODEL_H
.MODEL huge, c
ENDIF
;--------------------------------------------------------------------
GOREAL MACRO
LOCAL here
mov eax, cr0
and eax, 0fffffffeh
mov cr0, eax
jmp here
here:
ENDM
;--------------------------------------------------------------------
GOPROT MACRO
LOCAL here
xor eax, eax
xor edx, edx
mov ax, ds
shl eax, 4
lea edx, _gdt
add eax, edx
mov [_gdt_ptr+2], ax
shr eax, 16
mov [_gdt_ptr+4], ax
lgdt FWORD PTR _gdt_ptr
mov eax, cr0
or eax, 1
mov cr0, eax
jmp here
here:
ENDM
;--------------------------------------------------------------------
.STACK
.DATA
PUBLIC _dAPAwake, _dAPDone, _dAPFuncPtr, _wProcNumber, _bSPValid
PUBLIC _wCSegDS, _wCSegES, _wCSegSS, _wCSegSP, _wASegDS, _wASegES
PUBLIC _dAPHltJmp
emsfilename DB 'EMMXXXX0',0
_dAPAwake DD 0
_dAPDone DD 0
_dAPFuncPtr DD 0
_wProcNumber DW 0
_bSPValid DB 0
_wASegDS DW 0
_wASegES DW 0
_wCSegDS DW 0
_wCSegES DW 0
_wCSegSS DW 0
_wCSegSP DW 0
_block DW 0
_gdt_ptr DW 23
DD 0
_gdt DD 0 ; NULL descriptor
DD 0 ; NULL descriptor
; 64K real mode style data segment
DD 0ffffh ; base 0, limit 0xffff
DD 00009200h ; data, CPL=0, 16-bit, 1 byte granularity, r/w
; 4G flat data segment
DD 0ffffh ; base 0, limit 0xfffff
DD 008f9200h ; data, CPL=0, 16-bit, 4K granularity, r/w
_old_es DW 0
_old_ds DW 0
_old_fs DW 0
_old_gs DW 0
_dAPHltJmp DD 0 ; jump to halt location
.CODE
EXTERNDEF pascal cprint:proc
PUBLIC ems_present
ems_present PROC C
mov ah,3dh ; open file
xor al,al ; read only operation
mov dx,offset emsfilename ; look for EMMXXXX0
int 21h
jc emserror1 ; if carry flag set, then no EMM driver
mov di,ax ; save file handle
mov bx,ax ; set up handle
mov ax,4400h ; get device (channel) info
int 21h
mov ah,3eh ; close file
mov bx,di ; close the file handle up
int 21h
jc emserror1 ; if carry flag set, then no driver is present
test dx,10000000b ; if bit 7 not set, then the channel is a file
jz emserror1 ; otherwise the channel is a device driver
mov ax,1 ; 1 = EMS present
ret
emserror1:
xor ax,ax ; 0 = EMS not present
ret
ems_present ENDP
PUBLIC vm86
vm86 PROC C
smsw ax
and ax, 1
ret
vm86 ENDP
PUBLIC _set_rows
_set_rows PROC C rows:WORD
cmp rows, 25
je set_25
cmp rows, 50
je set_50
cmp rows, 132
je set_132
jmp invalid_input
set_25:
mov ah, 00
mov al, 03
int 10h
mov ax, rows
jmp end_set_rows
set_50:
mov ah, 00
mov al, 03
int 10h
xor bx, bx
mov ah, 11h
mov al, 12h
int 10h
mov ax, rows
jmp end_set_rows
set_132:
mov ah, 00
mov al, 14h
int 10h
xor bx, bx
mov ah, 11h
mov al, 12h
int 10h
mov ax, rows
jmp end_set_rows
invalid_input:
xor ax, ax
jmp end_set_rows
end_set_rows:
ret
_set_rows ENDP
PUBLIC _cpuid_asm
_cpuid_asm PROC C hv:DWORD, regs:PTR DWORD
check_8086:
.8086
pushf
pop ax
mov cx, ax
and ax, 0fffh
push ax
popf
pushf
pop ax
and ax, 0f000h
cmp ax, 0f000h
mov ax, 10h
je end_cpuid
check_80286:
.286
or cx, 0f000h
push cx
popf
pushf
pop ax
and ax, 0f000h
mov ax, 20h
jz end_cpuid
check_80386:
.386
mov bx, sp
and sp, not 3
pushfd
pop eax
mov ecx, eax
xor eax, 40000h
push eax
popfd
pushfd
pop eax
cmp ecx, eax
jne check_80486
mov ax, 30h
mov sp, bx
jmp end_cpuid
check_80486:
.486
pushfd
pop ecx
mov ecx, eax
xor eax, 200000h
push eax
popfd
pushfd
pop eax
xor eax, ecx
mov ax, 40h
je end_cpuid
check_cpuid:
.586
mov eax, hv
cpuid
push ebx
IF @DataSize ; segment is far
les bx, regs
mov dword ptr es:[bx], eax
pop eax
mov dword ptr es:[bx + 4], eax
mov dword ptr es:[bx + 8], ecx
mov dword ptr es:[bx + 12], edx
ELSE ; segment is near
mov bx, regs
mov dword ptr [bx], eax
pop eax
mov dword ptr [bx + 4], eax
mov dword ptr [bx + 8], ecx
mov dword ptr [bx + 12], edx
ENDIF
mov ax, 5
end_cpuid:
ret
_cpuid_asm ENDP
.386p
;--------------------------------------------------------------------
; Pentium Pro MSRs - from Pentium Pro Developer's Manual
; January 1996 - Appendix C
;
; MTRRs: 200h - 20Fh, 250h, 258h - 259h, 268h - 26Fh, 2FFh
;--------------------------------------------------------------------
PUBLIC _read_msr
_read_msr PROC C dmsr:DWORD, pqmsr:PTR DWORD
pushad
mov ecx, dmsr
dw 320fh ; RDMSR
les bx, pqmsr
mov DWORD ptr es:[bx], eax
mov DWORD ptr es:[bx + 4], edx
popad
ret
_read_msr ENDP
;--------------------------------------------------------------------
PUBLIC _write_msr
_write_msr PROC C dmsr:DWORD, pqmsr:PTR DWORD
pushad
les bx, pqmsr
mov eax, DWORD ptr es:[bx]
mov edx, DWORD ptr es:[bx + 4]
mov ecx, dmsr
dw 300fh ; WRMSR
popad
ret
_write_msr ENDP
;----------------------------------------------------------------------------
; Procedure: dReadCR0 - Reads CR0 CPU Register
;
; Output: dx:ax and eax - Contents of CR0
;
; Registers: All registers preserved except EAX and EDX
;----------------------------------------------------------------------------
PUBLIC dReadCR0
dReadCR0 PROC C
mov eax, cr0
mov edx, eax
shr edx, 16 ; upper 16 bits in dx
ret
dReadCR0 ENDP
;----------------------------------------------------------------------------
; Procedure: dReadCR2 - Reads CR2 CPU Register
;
; Output: dx:ax and eax - Contents of CR2
;
; Registers: All registers preserved except EAX and EDX
;----------------------------------------------------------------------------
PUBLIC dReadCR2
dReadCR2 PROC C
mov eax, cr2
mov edx, eax
shr edx, 16 ; upper 16 bits in dx
ret
dReadCR2 ENDP
;----------------------------------------------------------------------------
; Procedure: dReadCR3 - Reads CR3 CPU Register
;
; Output: dx:ax and eax - Contents of CR3
;
; Registers: All registers preserved except EAX and EDX
;----------------------------------------------------------------------------
PUBLIC dReadCR3
dReadCR3 PROC C
mov eax, cr3
mov edx, eax
shr edx, 16 ; upper 16 bits in dx
ret
dReadCR3 ENDP
.586
;----------------------------------------------------------------------------
; Procedure: dGetProcUpdateRev_asm - Reads PPP Update Revision via an MSR
;
; Output: dx:ax and eax - PPP Update Revision
;
; Registers: All registers preserved except EAX, ECX, and EDX
;----------------------------------------------------------------------------
PUBLIC _dGetProcUpdateRev_asm
_dGetProcUpdateRev_asm PROC C
mov ecx, 08Bh ; model specific register to write
xor eax, eax
xor edx, edx
dw 300Fh ; WRMSR ==> load 0 to MSR at 8Bh
mov eax, 1
cpuid
mov ecx, 08Bh ; model specific register to read
dw 320Fh ; RDMSR ==> EDX = (read) MSR 8Bh
mov eax, edx ; return EAX
shr edx, 16 ; return DX:AX
ret
_dGetProcUpdateRev_asm ENDP
;--------------------------------------------------------------------
PUBLIC iInterruptFlagState
iInterruptFlagState PROC
pushf
pop ax
and ax, 200h
shr ax, 9
ret
iInterruptFlagState ENDP
;--------------------------------------------------------------------
.586P
PUBLIC vRealFsGs
vRealFsGs PROC C
; TBD: verify this on an AMD K6-2 266 MHz
; Assert A20M# via system control port A (This is a
; system dependent feature).
in al, 92h
and al, 0fdh
out 92h, al ; re-assert A20M#
GOPROT
mov ax, 8
mov gs, ax
GOREAL
mov ax, [_old_fs] ; restore original
mov fs, ax
mov ax, [_old_gs] ; restore original
mov gs, ax
sti
ret
vRealFsGs ENDP
;--------------------------------------------------------------------
PUBLIC vFlatFsGs
vFlatFsGs PROC C
cli
mov ax, fs
mov [_old_fs], ax ; save original fs
mov ax, gs
mov [_old_gs], ax ; save original gs
; Deassert A20M# via system control port A (This is a
; system dependent feature)
in al, 92h
or al, 2
out 92h, al ; de-assert A20M#
GOPROT
mov ax, 10h
mov fs, ax
mov gs, ax
GOREAL
ret
vFlatFsGs ENDP
PUBLIC vRealEsDs
vRealEsDs PROC C
; TBD: verify this on an AMD K6-2 266 MHz
; Assert A20M# via system control port A (This is a
; system dependent feature).
in al, 92h
and al, 0fdh
out 92h, al ; re-assert A20M#
GOPROT
mov ax, 8
mov gs, ax
GOREAL
mov ax, [_old_es] ; restore original
mov es, ax
mov ax, [_old_gs] ; restore original
mov gs, ax
sti
ret
vRealEsDs ENDP
;--------------------------------------------------------------------
PUBLIC vFlatEsDs
vFlatEsDs PROC C
cli
mov ax, es
mov [_old_es], ax ; save original
mov ax, gs
mov [_old_gs], ax ; save original
; Deassert A20M# via system control port A (This is a
; system dependent feature)
in al, 92h
or al, 2
out 92h, al ; de-assert A20M#
GOPROT
mov ax, 10h
mov es, ax
mov gs, ax
GOREAL
ret
vFlatEsDs ENDP
PUBLIC print
print PROC PASCAL Seq:DWORD
pushad
mov eax, Seq
push eax
call cprint
popad
ret
print ENDP
PUBLIC DoMove
DoMove PROC
push edx
; GOPROT
pop edx
mov ecx, edx
shr ecx, 2 ; byte count / 4 = dword count
cmp ecx, 0
je DoBytes
NextDword:
xor eax, eax
lock or eax, gs:[esi]
; mov eax, gs:[esi]
mov gs:[edi], eax
add esi, 4
add edi, 4
loop NextDword
DoBytes:
mov ecx, edx
and ecx, 3
cmp ecx, 0
je Exit ; no extra bytes to move
NextByte:
mov al, byte ptr gs:[esi]
mov byte ptr gs:[edi], al
inc esi
inc edi
loop NextByte
Exit:
; GOREAL
ret
DoMove ENDP
.586
;--------------------------------------------------------------------
PUBLIC _WriteApic
_WriteApic PROC C
call vFlatFsGs
xor ecx, ecx
xor edx, edx
mov cx, [esp+6] ; high word of apic address
shl ecx, 16
mov cx, [esp+4] ; low word of apic address
mov dx, [esp+10] ; high word of apic command
shl edx, 16
mov dx, [esp+8] ; low word of apic command
mov gs:[ecx], edx
call vRealFsGs
ret
_WriteApic ENDP
;--------------------------------------------------------------------
PUBLIC _ReadApic
_ReadApic PROC C
call vFlatFsGs
xor ecx, ecx
mov cx, [esp+6] ; low word of apic address
shl ecx, 16
mov cx, [esp+4] ; high word of apic address
mov eax, gs:[ecx]
push eax ; save eax
call vRealFsGs
pop eax ; restore eax
mov edx, eax
shr edx, 16
ret
_ReadApic ENDP
;--------------------------------------------------------------------
; Since the AP shares the BSP's stack, coordination is needed to avoid
; simultaneous usage by both processors, which would cause corruption.
;
; While the AP is executing here, the BSP is executing the code
; which follows the call to vAPStartupAll() or vAPStartupOne()
; in bu_apic.c:vExecuteOnAPs(). After disabling interrupts,
; the BSP stores the sp value in _wCSegSP, sets _bSPValid to 1,
; and spins while _dAPDone != _dAPAwake. (Both are initially zero;
; the code below increments _dAPAwake before spinning on _bSPValid.)
;
; XXX - There is a race condition here: if the BSP makes it all
; XXX - the way to its spin loop on _dAPDone != _dAPAwake before
; XXX - the AP increments _dAPAwake, the BSP will exit the spin
; XXX - loop without actually having waited for the AP to finish.
PUBLIC _vSetupAP
_vSetupAP PROC C
cli
mov ax, @data
mov ds, ax
mov esp, 0
lock inc dword ptr [_dAPAwake]
spin1:
mov al, [_bSPValid]
cmp al, 1
jne spin1
; XXX - The following line is supposed to provide some validity checking,
; XXX - but it does not entirely succeed. It is possible for > 1 AP to
; XXX - see _bSPValid == 1, and exit the spin1 loop just above, before
; XXX - the first one out has had time to decrement _bSPValid; this race
; XXX - defeats the purpose of decrementing it. The decrement is likely
; XXX - not needed anyway due to the exclusion provided by the spin2 loop
; XXX - below.
lock dec byte ptr[_bSPValid]
mov ax, [_wCSegSS]
mov ss, ax
mov sp, [_wCSegSP]
; critical section - determining unique cpu signatures
spin2:
mov eax, 1
; XXX - Should the following line have a 'lock' prefix?
xchg word ptr [_block], ax
test ax, ax
jne spin2
mov ax, ds ; Save ASM DS and ES in global vars
mov [_wASegDS], ax
mov ax, es
mov [_wASegES], ax
mov ax, [_wCSegES]
mov es, ax
mov ax, [_wCSegDS] ; Restore C DS and ES from global vars
mov ds, ax
; Update Current Processor Number. Mutual exclusion from other AP's is
; guaranteed by the spin2 loop above.
; Note that the "processor number" determined here represents the order
; in which the processors happened to get through the spin2 lock, and
; has nothing to do with APIC numbers. A system having > 1 AP will not
; necessarily number the AP's consistently from one run to the next.
mov eax, [_dAPDone]
inc eax
mov [_wProcNumber], ax
call [_dAPFuncPtr] ; _dAPFuncPtr needs to point to a void function
mov ax, [_wASegDS] ; Restore ASM DS and ES from global vars
mov ds, ax
mov ax, [_wASegES]
mov es, ax
lock inc dword ptr [_dAPDone]
lock inc byte ptr [_bSPValid]
xor eax, eax
; A simple 'mov' would serve as well as the following 'xchg'.
xchg word ptr [_block], ax
wbinvd
mov si, offset _dAPHltJmp
jmp dword ptr [si] ; Jump to HLT, JMP $-1 in F000 segment
hlt ; Should never get here
_vSetupAP ENDP
;--------------------------------------------------------------------
PUBLIC bIn8
bIn8 PROC C wPort:WORD
xor ax, ax
mov dx, wPort
in al, dx
ret
bIn8 ENDP
;--------------------------------------------------------------------
PUBLIC wIn16
wIn16 PROC C wPort:WORD
mov dx, wPort
in ax, dx
ret
wIn16 ENDP
;--------------------------------------------------------------------
PUBLIC dIn32
dIn32 PROC C wPort:WORD
mov dx, wPort
in eax, dx
mov edx, eax
shr edx, 16
ret
dIn32 ENDP
;--------------------------------------------------------------------
PUBLIC vOut8
vOut8 PROC C wPort:WORD, bValue:BYTE
mov dx, wPort
mov al, bValue
out dx, al
ret
vOut8 ENDP
;--------------------------------------------------------------------
PUBLIC vOut16
vOut16 PROC C wPort:WORD, wValue:WORD
mov dx, wPort
mov ax, wValue
out dx, ax
ret
vOut16 ENDP
;--------------------------------------------------------------------
PUBLIC vOut32
vOut32 PROC C wPort:WORD, dValue:DWORD
mov dx, wPort
mov eax, dValue
out dx, eax
ret
vOut32 ENDP
;--------------------------------------------------------------------
; int FlatMove (DWORD dPhysicalDestination, DWORD dPhysicalSource, size_t sSize)
PUBLIC FlatMoveX
FlatMoveX PROC C dDest:DWORD, dSrc:DWORD, sSize:WORD
call vm86 ; check if VM86 mode
cmp ax, 0
jne NotRealMode ; skip memory move if not in real mode
call vFlatFsGs ; set up FS and GS as 4GB limit selectors with
; base 0:0 and de-assert A20M#
movzx ecx, sSize
cmp ecx, 0
je SKipMemoryMove ; skip memory move if 0==sSize
mov eax, dDest
cmp eax, 400h
jbe SkipMemoryMove ; skip memory move if destination is 40:0
; BIOS Data Area or less (IVT)
mov ebx, dSrc
NextByte:
mov dl, gs:[ebx][ecx - 1]
mov gs:[eax][ecx - 1], dl
loop NextByte
call vRealFsGs
xor ax, ax
NotRealMode:
ret
SkipMemoryMove:
mov ax, 1 ; return error code
ret
FlatMoveX ENDP
; int FlatMove32 (DWORD dPhysicalDestination, DWORD dPhysicalSource, size_t sSize)
PUBLIC FlatMove32
FlatMove32 PROC C dDest:DWORD, dSrc:DWORD, sSize:WORD
call vm86 ; check if VM86 mode
cmp ax, 0
jne NotRealMode ; skip memory move if not in real mode
call vFlatFsGs ; set up FS and GS as 4GB limit selectors with
; base 0:0 and de-assert A20M#
movzx edx, sSize
mov esi, dSrc
mov edi, dDest
push edx
call print
push esi
call print
push edi
call print
cmp edx, 0
je SkipMemoryMove ; skip memory move if 0==sSize
cmp edi, 400h
jbe SkipMemoryMove ; skip memory move if destination is 40:0
; BIOS Data Area or less (IVT)
call DoMove ; edx=Count, esi=src, edi=dst
movzx ecx, sSize
shr ecx, 2
mov edi, dDest
PrintLoop:
mov eax, gs:[edi]
push eax
call print
add edi, 4
loop PrintLoop
call vRealFsGs
xor ax, ax
NotRealMode:
ret
SkipMemoryMove:
call print
call vRealEsDs
mov ax, 1 ; return error code
ret
FlatMove32 ENDP
; int FlatMove32 (DWORD dPhysicalDestination, DWORD dPhysicalSource, size_t sSize)
PUBLIC FlatMove32x
FlatMove32x PROC C dDest:DWORD, dSrc:DWORD, sSize:WORD
call vm86 ; check if VM86 mode
cmp ax, 0
jne NotRealMode ; skip memory move if not in real mode
call vFlatFsGs ; set up FS and GS as 4GB limit selectors with
; base 0:0 and de-assert A20M#
movzx ecx, sSize
cmp ecx, 0
je SKipMemoryMove ; skip memory move if 0==sSize
mov eax, dDest
cmp eax, 400h
jbe SkipMemoryMove ; skip memory move if destination is 40:0
; BIOS Data Area or less (IVT)
mov ebx, dSrc
mov esi, 0
push ecx
call print
push ebx
call print
push eax
call print
shr ecx, 2 ; byte count / 4 = dword count
cmp ecx, 0
je DoBytes
NextDword:
mov edx, dword ptr gs:[ebx][esi]
mov dword ptr gs:[eax][esi], edx
push edx
call print
add esi, 4
loop NextDword
DoBytes:
movzx ecx, sSize
and ecx, 3
cmp ecx, 0
je Exit ; no extra bytes to move
NextByte:
mov dl, gs:[ebx][esi]
mov gs:[eax][esi], dl
inc esi
loop NextByte
Exit:
call vRealFsGs
xor ax, ax
NotRealMode:
ret
SkipMemoryMove:
mov ax, 1 ; return error code
ret
FlatMove32x ENDP
END
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