btx.S revision 52202
143561Skato# 243561Skato# Copyright (c) 1998 Robert Nordier 343561Skato# All rights reserved. 443561Skato# 543561Skato# Redistribution and use in source and binary forms are freely 643561Skato# permitted provided that the above copyright notice and this 743561Skato# paragraph and the following disclaimer are duplicated in all 843561Skato# such forms. 943561Skato# 1043561Skato# This software is provided "AS IS" and without any express or 1143561Skato# implied warranties, including, without limitation, the implied 1243561Skato# warranties of merchantability and fitness for a particular 1343561Skato# purpose. 1443561Skato# 1543561Skato 1650477Speter# $FreeBSD: head/sys/boot/pc98/btx/btx/btx.S 52202 1999-10-13 10:55:56Z kato $ 1743561Skato 1843561Skato# 1943561Skato# Memory layout. 2043561Skato# 2143561Skato .set MEM_BTX,0x1000 # Start of BTX memory 2243561Skato .set MEM_ESP0,0x1800 # Supervisor stack 2343561Skato .set MEM_BUF,0x1800 # Scratch buffer 2443561Skato .set MEM_ESP1,0x1e00 # Link stack 2543561Skato .set MEM_IDT,0x1e00 # IDT 2643561Skato .set MEM_TSS,0x1f98 # TSS 2743561Skato .set MEM_MAP,0x2000 # I/O bit map 2843561Skato .set MEM_DIR,0x4000 # Page directory 2943561Skato .set MEM_TBL,0x5000 # Page tables 3043561Skato .set MEM_ORG,0x9000 # BTX code 3143561Skato .set MEM_USR,0xa000 # Start of user memory 3243561Skato# 3343561Skato# Paging control. 3443561Skato# 3543561Skato .set PAG_SIZ,0x1000 # Page size 3643561Skato .set PAG_CNT,0x1000 # Pages to map 3743561Skato# 3843561Skato# Segment selectors. 3943561Skato# 4043561Skato .set SEL_SCODE,0x8 # Supervisor code 4143561Skato .set SEL_SDATA,0x10 # Supervisor data 4243561Skato .set SEL_RCODE,0x18 # Real mode code 4343561Skato .set SEL_RDATA,0x20 # Real mode data 4443561Skato .set SEL_UCODE,0x28|3 # User code 4543561Skato .set SEL_UDATA,0x30|3 # User data 4643561Skato .set SEL_TSS,0x38 # TSS 4743561Skato# 4843561Skato# Task state segment fields. 4943561Skato# 5043561Skato .set TSS_ESP0,0x4 # PL 0 ESP 5143561Skato .set TSS_SS0,0x8 # PL 0 SS 5243561Skato .set TSS_ESP1,0xc # PL 1 ESP 5343561Skato .set TSS_MAP,0x66 # I/O bit map base 5443561Skato# 5543561Skato# System calls. 5643561Skato# 5743561Skato .set SYS_EXIT,0x0 # Exit 5843561Skato .set SYS_EXEC,0x1 # Exec 5943561Skato# 6043561Skato# V86 constants. 6143561Skato# 6243561Skato .set V86_FLG,0x208eff # V86 flag mask 6343561Skato .set V86_STK,0x400 # V86 stack allowance 6443561Skato# 6543561Skato# Dump format control bytes. 6643561Skato# 6743561Skato .set DMP_X16,0x1 # Word 6843561Skato .set DMP_X32,0x2 # Long 6943561Skato .set DMP_MEM,0x4 # Memory 7043561Skato .set DMP_EOL,0x8 # End of line 7143561Skato# 7243561Skato# Screen defaults and assumptions. 7343561Skato# 7443561Skato.`ifdef' PC98 7543561Skato .set SCR_MAT,0xe1 # Mode/attribute 7643561Skato.else 7743561Skato .set SCR_MAT,0x7 # Mode/attribute 7843561Skato.endif 7943561Skato .set SCR_COL,0x50 # Columns per row 8043561Skato .set SCR_ROW,0x19 # Rows per screen 8143561Skato# 8243561Skato# BIOS Data Area locations. 8343561Skato# 8443561Skato.`ifdef' PC98 8543561Skato .set BDA_MEM,0xa1501 # Free memory 8643561Skato .set BDA_POS,0xa153e # Cursor position 8743561Skato.else 8843561Skato .set BDA_MEM,0x413 # Free memory 8943561Skato .set BDA_SCR,0x449 # Video mode 9043561Skato .set BDA_POS,0x450 # Cursor position 9143561Skato.endif 9243561Skato# 9343561Skato# Derivations, for brevity. 9443561Skato# 9543561Skato .set _ESP0H,MEM_ESP0>>0x8 # Byte 1 of ESP0 9643561Skato .set _ESP1H,MEM_ESP1>>0x8 # Byte 1 of ESP1 9743561Skato .set _TSSIO,MEM_MAP-MEM_TSS # TSS I/O base 9843561Skato .set _TSSLM,MEM_DIR-MEM_TSS-1 # TSS limit 9943561Skato .set _IDTLM,MEM_TSS-MEM_IDT-1 # IDT limit 10043561Skato# 10143561Skato# Code segment. 10243561Skato# 10343561Skato .globl start 10443561Skatostart: # Start of code 10543561Skato# 10643561Skato# BTX header. 10743561Skato# 10843561Skatobtx_hdr: .byte 0xeb # Machine ID 10943561Skato .byte 0xe # Header size 11043561Skato .ascii "BTX" # Magic 11143561Skato .byte 0x1 # Major version 11244368Skato .byte 0x1 # Minor version 11343561Skato .byte 0x0 # Flags 11443561Skato .word PAG_CNT-MEM_ORG>>0xc # Paging control 11543561Skato .word break-start # Text size 11643561Skato .long 0x0 # Entry address 11743561Skato# 11843561Skato# Initialization routine. 11943561Skato# 12043561Skatoinit: cli # Disable interrupts 12143561Skato xorl %eax,%eax # Zero/segment 12243561Skato movl %ax,%ss # Set up 12343561Skato movwir(MEM_ESP0,_sp) # stack 12443561Skato movl %ax,%es # Address 12543561Skato movl %ax,%ds # data 12643561Skato pushw $0x2 # Clear 12743561Skato popfw # flags 12843561Skato# 12943561Skato# Initialize memory. 13043561Skato# 13143561Skato movwir(MEM_IDT,_di) # Memory to initialize 13243561Skato movwir((MEM_ORG-MEM_IDT)/2,_cx) # Words to zero 13343561Skato pushl %edi # Save 13443561Skato rep # Zero-fill 13543561Skato stosl # memory 13643561Skato popl %edi # Restore 13743561Skato# 13843561Skato# Create IDT. 13943561Skato# 14043561Skato movwir(idtctl,_si) # Control string 14143561Skatoinit.1: lodsb # Get entry 14243561Skato cwde # count 14343561Skato xchgl %eax,%ecx # as word 14443561Skato jecxz init.4 # If done 14543561Skato lodsb # Get segment 14643561Skato xchgl %eax,%edx # P:DPL:type 14743561Skato lodsl # Get control 14843561Skato xchgl %eax,%ebx # set 14943561Skato lodsl # Get handler offset 15043561Skato movb $SEL_SCODE,%dh # Segment selector 15143561Skatoinit.2: shrl %ebx # Handle this int? 15243561Skato jnc init.3 # No 15343561Skato movwr0(_ax,_di_) # Set handler offset 15443561Skato movbr1(_dh,0x2,_di_) # and selector 15543561Skato movbr1(_dl,0x5,_di_) # Set P:DPL:type 15643561Skato addwia(0x4) # Next handler 15743561Skatoinit.3: leaw1r(0x8,_di_,_di) # Next entry 15843561Skato loop init.2 # Till set done 15943561Skato jmp init.1 # Continue 16043561Skato# 16143561Skato# Initialize TSS. 16243561Skato# 16343561Skatoinit.4: movbi1(_ESP0H,TSS_ESP0+1,_di_) # Set ESP0 16443561Skato movbi1(SEL_SDATA,TSS_SS0,_di_) # Set SS0 16543561Skato movbi1(_ESP1H,TSS_ESP1+1,_di_) # Set ESP1 16643561Skato movbi1(_TSSIO,TSS_MAP,_di_) # Set I/O bit map base 16752202Skatoifdef(`PAGING',` 16843561Skato# 16943561Skato# Create page directory. 17043561Skato# 17143561Skato xorw %dx,%dx # Page 17243561Skato movb $PAG_SIZ>>0x8,%dh # size 17343561Skato xorw %ax,%ax # Zero 17443561Skato movwir(MEM_DIR,_di) # Page directory 17543561Skato movb $PAG_CNT>>0xa,%cl # Entries 17643561Skato movwir(MEM_TBL|0x7,_ax) # First entry 17743561Skatoinit.5: stosw # Write entry 17843561Skato addl %edx,%eax # To next 17943561Skato loop init.5 # Till done 18043561Skato# 18143561Skato# Create page tables. 18243561Skato# 18343561Skato movwir(MEM_TBL,_di) # Page table 18443561Skato movb $PAG_CNT>>0x8,%ch # Entries 18543561Skato xorl %eax,%eax # Start address 18643561Skatoinit.6: movb $0x7,%al # Set U:W:P flags 18743561Skato cmpwmr(btx_hdr+0x8,_cx) # Standard user page? 18843561Skato jb init.7 # Yes 18943561Skato cmpwir(PAG_CNT-MEM_BTX>>0xc,_cx)# BTX memory? 19043561Skato jae init.7 # No or first page 19143561Skato andb $~0x2,%al # Clear W flag 19243561Skato cmpwir(PAG_CNT-MEM_USR>>0xc,_cx)# User page zero? 19343561Skato jne init.7 # No 19443561Skato tstbim(0x80,btx_hdr+0x7) # Unmap it? 19543561Skato jz init.7 # No 19643561Skato andb $~0x1,%al # Clear P flag 19743561Skatoinit.7: stosw # Set entry 19843561Skato addw %dx,%ax # Next address 19943561Skato loop init.6 # Till done 20052202Skato') 20143561Skato# 20243561Skato# Bring up the system. 20343561Skato# 20443561Skato movwir(0x2820,_bx) # Set protected mode 20543561Skato callwi(setpic) # IRQ offsets 20643561Skato lidtwm(idtdesc) # Set IDT 20752202Skatoifdef(`PAGING',` 20843561Skato xorw %ax,%ax # Set base 20943561Skato movb $MEM_DIR>>0x8,%ah # of page 21043561Skato movl %eax,%cr3 # directory 21152202Skato') 21243561Skato lgdtwm(gdtdesc) # Set GDT 21343561Skato movl %cr0,%eax # Switch to 21443561Skato o16 # protected mode 21552202Skato orl $0x01,%eax # 21652202Skato movl %eax,%cr0 # 21743561Skato jmpfwi(SEL_SCODE,init.8) # To 32-bit code 21843561Skatoinit.8: xorl %ecx,%ecx # Zero 21943561Skato movb $SEL_SDATA,%cl # To 32-bit 22043561Skato movl %cx,%ss # stack 22143561Skato# 22243561Skato# Launch user task. 22343561Skato# 22443561Skato movb $SEL_TSS,%cl # Set task 22543561Skato ltrl %ecx # register 22643561Skato movl $MEM_USR,%edx # User base address 22743561Skato movzwl %ss:BDA_MEM,%eax # Get free memory 22843561Skato.`ifdef' PC98 22943561Skato andl $0x7,%eax 23043561Skato incl %eax 23143561Skato shll $0x11,%eax # To bytes 23243561Skato.else 23343561Skato shll $0xa,%eax # To bytes 23443561Skato.endif 23543561Skato subl $0x1000,%eax # Less arg space 23643561Skato subl %edx,%eax # Less base 23743561Skato movb $SEL_UDATA,%cl # User data selector 23843561Skato pushl %ecx # Set SS 23943561Skato pushl %eax # Set ESP 24043561Skato pushl $0x202 # Set flags (IF set) 24143561Skato pushl $SEL_UCODE # Set CS 24243561Skato pushl btx_hdr+0xc # Set EIP 24343561Skato pushl %ecx # Set GS 24443561Skato pushl %ecx # Set FS 24543561Skato pushl %ecx # Set DS 24643561Skato pushl %ecx # Set ES 24743561Skato pushl %edx # Set EAX 24843561Skato movb $0x7,%cl # Set remaining 24943561Skatoinit.9: pushb $0x0 # general 25043561Skato loop init.9 # registers 25143561Skato popa # and initialize 25243561Skato popl %es # Initialize 25343561Skato popl %ds # user 25443561Skato popl %fs # segment 25543561Skato popl %gs # registers 25643561Skato iret # To user mode 25743561Skato# 25843561Skato# Exit routine. 25943561Skato# 26043561Skatoexit: cli # Disable interrupts 26143561Skato movl $MEM_ESP0,%esp # Clear stack 26252202Skatoifdef(`PAGING',` 26343561Skato# 26443561Skato# Turn off paging. 26543561Skato# 26643561Skato movl %cr0,%eax # Get CR0 26743561Skato andl $~0x80000000,%eax # Disable 26843561Skato movl %eax,%cr0 # paging 26952202Skato') 27043561Skato xorl %ecx,%ecx # Zero 27152202Skatoifdef(`PAGING',` 27243561Skato movl %ecx,%cr3 # Flush TLB 27352202Skato') 27443561Skato# 27543561Skato# To 16 bits. 27643561Skato# 27743561Skato o16 # Reload 27843561Skato jmpfwi(SEL_RCODE,exit.1) # CS 27943561Skatoexit.1: movb $SEL_RDATA,%cl # 16-bit selector 28043561Skato movl %cx,%ss # Reload SS 28143561Skato movl %cx,%ds # Load 28243561Skato movl %cx,%es # remaining 28343561Skato movl %cx,%fs # segment 28443561Skato movl %cx,%gs # registers 28543561Skato# 28643561Skato# To real-address mode. 28743561Skato# 28843561Skato decl %eax # Switch to 28943561Skato movl %eax,%cr0 # real mode 29043561Skato jmpfwi(0x0,exit.2) # Reload CS 29143561Skatoexit.2: xorl %eax,%eax # Real mode segment 29243561Skato movl %ax,%ss # Reload SS 29343561Skato movl %ax,%ds # Address data 29443561Skato.`ifdef' PC98 29543561Skato movwir(0x1008,_bx) # Set real mode 29643561Skato.else 29743561Skato movwir(0x7008,_bx) # Set real mode 29843561Skato.endif 29943561Skato callwi(setpic) # IRQ offsets 30043561Skato lidtwm(ivtdesc) # Set IVT 30143561Skato# 30243561Skato# Reboot or await reset. 30343561Skato# 30443561Skato sti # Enable interrupts 30543561Skato tstbim(0x1,btx_hdr+0x7) # Reboot? 30643561Skatoexit.3: jz exit.3 # No 30743561Skato.`ifdef' PC98 30843561Skato movb $0xa0,%al 30943561Skato outb %al,$0x35 31043561Skato movb 0,%al 31143561Skato outb %al,$0xf0 31243561Skatoexit.4: jmp exit.4 31343561Skato.else 31443561Skato int $0x19 # BIOS: Reboot 31543561Skato.endif 31643561Skato# 31743561Skato# Set IRQ offsets by reprogramming 8259A PICs. 31843561Skato# 31943561Skato.`ifdef' PC98 32043561Skatosetpic: inb $0x02,%al # Save master 32143561Skato pushl %eax # IMR 32243561Skato inb $0x0a,%al # Save slave 32343561Skato pushl %eax # IMR 32443561Skato movb $0x11,%al # ICW1 to 32543561Skato outb %al,$0x00 # master, 32643561Skato outb %al,$0x08 # slave 32743561Skato movb %bl,%al # ICW2 to 32843561Skato outb %al,$0x02 # master 32943561Skato movb %bh,%al # ICW2 to 33043561Skato outb %al,$0x0a # slave 33143561Skato movb $0x80,%al # ICW3 to 33243561Skato outb %al,$0x02 # master 33343561Skato movb $0x7,%al # ICW3 to 33443561Skato outb %al,$0x0a # slave 33543561Skato movb $0x1d,%al # ICW4 to 33643561Skato outb %al,$0x02 # master, 33743561Skato movb $0x9,%al # ICW4 to 33843561Skato outb %al,$0x0a # slave 33943561Skato popl %eax # Restore slave 34043561Skato outb %al,$0x0a # IMR 34143561Skato popl %eax # Restore master 34243561Skato outb %al,$0x02 # IMR 34343561Skato.else 34443561Skatosetpic: inb $0x21,%al # Save master 34543561Skato pushl %eax # IMR 34643561Skato inb $0xa1,%al # Save slave 34743561Skato pushl %eax # IMR 34843561Skato movb $0x11,%al # ICW1 to 34943561Skato outb %al,$0x20 # master, 35043561Skato outb %al,$0xa0 # slave 35143561Skato movb %bl,%al # ICW2 to 35243561Skato outb %al,$0x21 # master 35343561Skato movb %bh,%al # ICW2 to 35443561Skato outb %al,$0xa1 # slave 35543561Skato movb $0x4,%al # ICW3 to 35643561Skato outb %al,$0x21 # master 35743561Skato movb $0x2,%al # ICW3 to 35843561Skato outb %al,$0xa1 # slave 35943561Skato movb $0x1,%al # ICW4 to 36043561Skato outb %al,$0x21 # master, 36143561Skato outb %al,$0xa1 # slave 36243561Skato popl %eax # Restore slave 36343561Skato outb %al,$0xa1 # IMR 36443561Skato popl %eax # Restore master 36543561Skato outb %al,$0x21 # IMR 36643561Skato.endif 36743561Skato ret # To caller 36843561Skato# 36943561Skato# Initiate return from V86 mode to user mode. 37043561Skato# 37143561Skatointhlt: hlt # To supervisor mode 37243561Skato# 37343561Skato# Exception jump table. 37443561Skato# 37543561Skatointx00: pushb $0x0 # Int 0x0: #DE 37643561Skato jmp ex_noc # Divide error 37743561Skato pushb $0x1 # Int 0x1: #DB 37843561Skato jmp ex_noc # Debug 37943561Skato pushb $0x3 # Int 0x3: #BP 38043561Skato jmp ex_noc # Breakpoint 38143561Skato pushb $0x4 # Int 0x4: #OF 38243561Skato jmp ex_noc # Overflow 38343561Skato pushb $0x5 # Int 0x5: #BR 38443561Skato jmp ex_noc # BOUND range exceeded 38543561Skato pushb $0x6 # Int 0x6: #UD 38643561Skato jmp ex_noc # Invalid opcode 38743561Skato pushb $0x7 # Int 0x7: #NM 38843561Skato jmp ex_noc # Device not available 38943561Skato pushb $0x8 # Int 0x8: #DF 39043561Skato jmp except # Double fault 39143561Skato pushb $0xa # Int 0xa: #TS 39243561Skato jmp except # Invalid TSS 39343561Skato pushb $0xb # Int 0xb: #NP 39443561Skato jmp except # Segment not present 39543561Skato pushb $0xc # Int 0xc: #SS 39643561Skato jmp except # Stack segment fault 39743561Skato pushb $0xd # Int 0xd: #GP 39843561Skato jmp ex_v86 # General protection 39943561Skato pushb $0xe # Int 0xe: #PF 40043561Skato jmp except # Page fault 40143561Skatointx10: pushb $0x10 # Int 0x10: #MF 40243561Skato jmp ex_noc # Floating-point error 40343561Skato# 40443561Skato# Handle #GP exception. 40543561Skato# 40643561Skatoex_v86: testb $0x2,0x12(%esp,1) # V86 mode? 40743561Skato jz except # No 40843561Skato jmp v86mon # To monitor 40943561Skato# 41043561Skato# Save a zero error code. 41143561Skato# 41243561Skatoex_noc: pushl (%esp,1) # Duplicate int no 41343561Skato movb $0x0,0x4(%esp,1) # Fake error code 41443561Skato# 41543561Skato# Handle exception. 41643561Skato# 41743561Skatoexcept: cld # String ops inc 41843561Skato pushl %ds # Save 41943561Skato pushl %es # most 42043561Skato pusha # registers 42143561Skato movb $0x6,%al # Push loop count 42243561Skato testb $0x2,0x3a(%esp,1) # V86 mode? 42343561Skato jnz except.1 # Yes 42443561Skato pushl %gs # Set GS 42543561Skato pushl %fs # Set FS 42643561Skato pushl %ds # Set DS 42743561Skato pushl %es # Set ES 42843561Skato movb $0x2,%al # Push loop count 42943561Skato cmpw $SEL_SCODE,0x44(%esp,1) # Supervisor mode? 43043561Skato jne except.1 # No 43143561Skato pushl %ss # Set SS 43243561Skato leal 0x50(%esp,1),%eax # Set 43343561Skato pushl %eax # ESP 43443561Skato jmp except.2 # Join common code 43543561Skatoexcept.1: pushl 0x50(%esp,1) # Set GS, FS, DS, ES 43643561Skato decb %al # (if V86 mode), and 43743561Skato jne except.1 # SS, ESP 43843561Skatoexcept.2: pushl $SEL_SDATA # Set up 43943561Skato popl %ds # to 44043561Skato pushl %ds # address 44143561Skato popl %es # data 44243561Skato movl %esp,%ebx # Stack frame 44343561Skato movl $dmpfmt,%esi # Dump format string 44443561Skato movl $MEM_BUF,%edi # Buffer 44543561Skato.`ifdef' PC98 44643561Skato pushl %eax 44743561Skato pushl %edx 44843561Skatowait.1: 44943561Skato inb $0x60,%al 45043561Skato testb $0x04,%al 45143561Skato jz wait.1 45243561Skato movb $0xe0,%al 45343561Skato outb %al,$0x62 45443561Skatowait.2: 45543561Skato inb $0x60,%al 45643561Skato testb $0x01,%al 45743561Skato jz wait.2 45843561Skato xorl %edx,%edx 45943561Skato inb $0x62,%al 46043561Skato movb %al,%dl 46143561Skato inb $0x62,%al 46243561Skato movb %al,%dh 46343561Skato inb $0x62,%al 46443561Skato inb $0x62,%al 46543561Skato inb $0x62,%al 46643561Skato movl %edx,%eax 46743561Skato shlw $1,%ax 46843561Skato movl $BDA_POS,%edx 46943561Skato movw %ax,(%edx) 47043561Skato popl %edx 47143561Skato popl %eax 47243561Skato.endif 47343561Skato pushl %edi # Dump to 47443561Skato call dump # buffer 47543561Skato popl %esi # and 47643561Skato call putstr # display 47743561Skato leal 0x18(%esp,1),%esp # Discard frame 47843561Skato popa # Restore 47943561Skato popl %es # registers 48043561Skato popl %ds # saved 48143561Skato cmpb $0x3,(%esp,1) # Breakpoint? 48243561Skato je except.3 # Yes 48343561Skato jmp exit # Exit 48443561Skatoexcept.3: leal 0x8(%esp,1),%esp # Discard err, int no 48543561Skato iret # From interrupt 48643561Skato# 48743561Skato# Return to user mode from V86 mode. 48843561Skato# 48943561Skatointrtn: cld # String ops inc 49043561Skato pushl %ds # Address 49143561Skato popl %es # data 49243561Skato leal 0x3c(%ebp),%edx # V86 Segment registers 49343561Skato movl MEM_TSS+TSS_ESP1,%esi # Link stack pointer 49443561Skato lodsl # INT_V86 args pointer 49543561Skato movl %esi,%ebx # Saved exception frame 49643561Skato testl %eax,%eax # INT_V86 args? 49743561Skato jz intrtn.2 # No 49843561Skato movl $MEM_USR,%edi # User base 49943561Skato movl 0x1c(%esi),%ebx # User ESP 50043561Skato movl %eax,(%edi,%ebx,1) # Restore to user stack 50143561Skato leal 0x8(%edi,%eax,1),%edi # Arg segment registers 50243561Skato testb $0x4,-0x6(%edi) # Return flags? 50343561Skato jz intrtn.1 # No 50443561Skato movl 0x30(%ebp),%eax # Get V86 flags 50543561Skato movw %ax,0x18(%esi) # Set user flags 50643561Skatointrtn.1: leal 0x10(%esi),%ebx # Saved exception frame 50743561Skato xchgl %edx,%esi # Segment registers 50843561Skato movb $0x4,%cl # Update seg regs 50943561Skato rep # in INT_V86 51043561Skato movsl # args 51143561Skatointrtn.2: movl %edx,%esi # Segment registers 51243561Skato leal 0x28(%ebp),%edi # Set up seg 51343561Skato movb $0x4,%cl # regs for 51443561Skato rep # later 51543561Skato movsl # pop 51643561Skato movl %ebx,%esi # Restore exception 51743561Skato movb $0x5,%cl # frame to 51843561Skato rep # supervisor 51943561Skato movsl # stack 52043561Skato movl %esi,MEM_TSS+TSS_ESP1 # Link stack pointer 52143561Skato popa # Restore 52243561Skato leal 0x8(%esp,1),%esp # Discard err, int no 52343561Skato popl %es # Restore 52443561Skato popl %ds # user 52543561Skato popl %fs # segment 52643561Skato popl %gs # registers 52743561Skato iret # To user mode 52843561Skato# 52943561Skato# V86 monitor. 53043561Skato# 53143561Skatov86mon: cld # String ops inc 53243561Skato pushl $SEL_SDATA # Set up for 53343561Skato popl %ds # flat addressing 53443561Skato pusha # Save registers 53543561Skato movl %esp,%ebp # Address stack frame 53643561Skato movzwl 0x2c(%ebp),%edi # Load V86 CS 53743561Skato shll $0x4,%edi # To linear 53843561Skato movl 0x28(%ebp),%esi # Load V86 IP 53943561Skato addl %edi,%esi # Code pointer 54043561Skato xorl %ecx,%ecx # Zero 54143561Skato movb $0x2,%cl # 16-bit operands 54243561Skato xorl %eax,%eax # Zero 54343561Skatov86mon.1: lodsb # Get opcode 54443561Skato cmpb $0x66,%al # Operand size prefix? 54543561Skato jne v86mon.2 # No 54643561Skato movb $0x4,%cl # 32-bit operands 54743561Skato jmp v86mon.1 # Continue 54843561Skatov86mon.2: cmpb $0xf4,%al # HLT? 54943561Skato jne v86mon.3 # No 55043561Skato cmpl $inthlt+0x1,%esi # Is inthlt? 55144368Skato jne v86mon.7 # No (ignore) 55243561Skato jmp intrtn # Return to user mode 55344368Skatov86mon.3: cmpb $0xf,%al # Is 55444368Skato jne v86mon.4 # this 55544368Skato cmpb $0x20,(%esi) # a 55644368Skato jne v86mon.4 # MOV EAX,CR0 55744368Skato cmpb $0xc0,0x1(%esi) # instruction? 55844368Skato je v86mov # Yes 55944368Skatov86mon.4: cmpb $0xfa,%al # CLI? 56043561Skato je v86cli # Yes 56143561Skato cmpb $0xfb,%al # STI? 56243561Skato je v86sti # Yes 56343561Skato movzwl 0x38(%ebp),%ebx # Load V86 SS 56443561Skato shll $0x4,%ebx # To offset 56543561Skato pushl %ebx # Save 56643561Skato addl 0x34(%ebp),%ebx # Add V86 SP 56743561Skato movl 0x30(%ebp),%edx # Load V86 flags 56843561Skato cmpb $0x9c,%al # PUSHF/PUSHFD? 56943561Skato je v86pushf # Yes 57043561Skato cmpb $0x9d,%al # POPF/POPFD? 57143561Skato je v86popf # Yes 57243561Skato cmpb $0xcd,%al # INT imm8? 57343561Skato je v86intn # Yes 57443561Skato cmpb $0xcf,%al # IRET/IRETD? 57543561Skato je v86iret # Yes 57643561Skato popl %ebx # Restore 57743561Skato popa # Restore 57843561Skato jmp except # Handle exception 57944368Skatov86mon.5: movl %edx,0x30(%ebp) # Save V86 flags 58044368Skatov86mon.6: popl %edx # V86 SS adjustment 58143561Skato subl %edx,%ebx # Save V86 58243561Skato movl %ebx,0x34(%ebp) # SP 58344368Skatov86mon.7: subl %edi,%esi # From linear 58443561Skato movl %esi,0x28(%ebp) # Save V86 IP 58543561Skato popa # Restore 58643561Skato leal 0x8(%esp,1),%esp # Discard int no, error 58743561Skato iret # To V86 mode 58843561Skato# 58944368Skato# Emulate MOV EAX,CR0. 59044368Skato# 59144368Skatov86mov: movl %cr0,%eax # CR0 to 59244368Skato movl %eax,0x1c(%ebp) # saved EAX 59344368Skato incl %esi # Adjust 59444368Skato incl %esi # IP 59544368Skato jmp v86mon.7 # Finish up 59644368Skato# 59743561Skato# Emulate CLI. 59843561Skato# 59943561Skatov86cli: andb $~0x2,0x31(%ebp) # Clear IF 60044368Skato jmp v86mon.7 # Finish up 60143561Skato# 60243561Skato# Emulate STI. 60343561Skato# 60443561Skatov86sti: orb $0x2,0x31(%ebp) # Set IF 60544368Skato jmp v86mon.7 # Finish up 60643561Skato# 60743561Skato# Emulate PUSHF/PUSHFD. 60843561Skato# 60943561Skatov86pushf: subl %ecx,%ebx # Adjust SP 61043561Skato cmpb $0x4,%cl # 32-bit 61143561Skato je v86pushf.1 # Yes 61243561Skato o16 # 16-bit 61343561Skatov86pushf.1: movl %edx,(%ebx) # Save flags 61444368Skato jmp v86mon.6 # Finish up 61543561Skato# 61643561Skato# Emulate IRET/IRETD. 61743561Skato# 61843561Skatov86iret: movzwl (%ebx),%esi # Load V86 IP 61943561Skato movzwl 0x2(%ebx),%edi # Load V86 CS 62043561Skato leal 0x4(%ebx),%ebx # Adjust SP 62143561Skato movl %edi,0x2c(%ebp) # Save V86 CS 62243561Skato xorl %edi,%edi # No ESI adjustment 62343561Skato# 62443561Skato# Emulate POPF/POPFD (and remainder of IRET/IRETD). 62543561Skato# 62643561Skatov86popf: cmpb $0x4,%cl # 32-bit? 62743561Skato je v86popf.1 # Yes 62843561Skato movl %edx,%eax # Initialize 62943561Skato o16 # 16-bit 63043561Skatov86popf.1: movl (%ebx),%eax # Load flags 63143561Skato addl %ecx,%ebx # Adjust SP 63243561Skato andl $V86_FLG,%eax # Merge 63343561Skato andl $~V86_FLG,%edx # the 63443561Skato orl %eax,%edx # flags 63544368Skato jmp v86mon.5 # Finish up 63643561Skato# 63752202Skato# trap int 15, function 87 63852202Skato# reads %es:%si from saved registers on stack to find a GDT containing 63952202Skato# source and destination locations 64052202Skato# reads count of words from saved %cx 64152202Skato# returns success by setting %ah to 0 64243561Skato# 64352202Skatoint15_87: pushl %eax # Save 64452202Skato pushl %ebx # some information 64552202Skato pushl %esi # onto the stack. 64652202Skato pushl %edi 64752202Skato xorl %eax,%eax # clean EAX 64852202Skato xorl %ebx,%ebx # clean EBX 64952202Skato movl 0x4(%ebp),%esi # Get user's ESI 65052202Skato movl 0x3C(%ebp),%ebx # store ES 65152202Skato movw %si,%ax # store SI 65252202Skato shll $0x4,%ebx # Make it a seg. 65352202Skato addl %eax,%ebx # ebx=(es<<4)+si 65452202Skato movb 0x14(%ebx),%al # Grab the 65552202Skato movb 0x17(%ebx),%ah # necessary 65652202Skato shll $0x10,%eax # information 65752202Skato movw 0x12(%ebx),%ax # from 65852202Skato movl %eax,%esi # the 65952202Skato movb 0x1c(%ebx),%al # GDT in order to 66052202Skato movb 0x1f(%ebx),%ah # have %esi offset 66152202Skato shll $0x10,%eax # of source and %edi 66252202Skato movw 0x1a(%ebx),%ax # of destination. 66352202Skato movl %eax,%edi 66452202Skato pushl %ds # Make: 66552202Skato popl %es # es = ds 66652202Skato pushl %ecx # stash ECX 66752202Skato xorl %ecx,%ecx # highw of ECX is clear 66852202Skato movw 0x18(%ebp),%cx # Get user's ECX 66952202Skato rep # repeat... 67052202Skato movsb # perform copy. 67152202Skato popl %ecx # Restore 67252202Skato popl %edi 67352202Skato popl %esi # previous 67452202Skato popl %ebx # register 67552202Skato popl %eax # values. 67652202Skato movb $0x0,0x1d(%ebp) # set ah = 0 to indicate 67752202Skato # success 67852202Skato andb $0xfe,%dl # clear CF 67952202Skato jmp v86mon.5 # Finish up 68052202Skato 68152202Skato# 68252202Skato# Emulate INT imm8... also make sure to check if it's int 15/87 68352202Skato# 68443561Skatov86intn: lodsb # Get int no 68552202Skato cmpb $0x15,%al # is it int 15? 68652202Skato jne v86intn.2 # no, skip parse 68752202Skato pushl %eax # stash EAX 68852202Skato movl 0x1c(%ebp),%eax # user's saved EAX 68952202Skato cmpb $0x87,%ah # is it our sub function? 69052202Skato jne v86intn.1 # no, don't handle it 69152202Skato popl %eax # get the stack straight 69252202Skato jmp int15_87 # it's our cue 69352202Skatov86intn.1: popl %eax # restore EAX 69452202Skatov86intn.2: subl %edi,%esi # From 69543561Skato shrl $0x4,%edi # linear 69643561Skato movw %dx,-0x2(%ebx) # Save flags 69743561Skato movw %di,-0x4(%ebx) # Save CS 69843561Skato leal -0x6(%ebx),%ebx # Adjust SP 69943561Skato movw %si,(%ebx) # Save IP 70043561Skato shll $0x2,%eax # Scale 70143561Skato movzwl (%eax),%esi # Load IP 70243561Skato movzwl 0x2(%eax),%edi # Load CS 70343561Skato movl %edi,0x2c(%ebp) # Save CS 70443561Skato xorl %edi,%edi # No ESI adjustment 70543561Skato andb $~0x3,%dh # Clear IF and TF 70644368Skato jmp v86mon.5 # Finish up 70743561Skato# 70843561Skato# Hardware interrupt jump table. 70943561Skato# 71043561Skatointx20: pushb $0x8 # Int 0x20: IRQ0 71143561Skato jmp int_hw # V86 int 0x8 71243561Skato pushb $0x9 # Int 0x21: IRQ1 71343561Skato jmp int_hw # V86 int 0x9 71443561Skato pushb $0xa # Int 0x22: IRQ2 71543561Skato jmp int_hw # V86 int 0xa 71643561Skato pushb $0xb # Int 0x23: IRQ3 71743561Skato jmp int_hw # V86 int 0xb 71843561Skato pushb $0xc # Int 0x24: IRQ4 71943561Skato jmp int_hw # V86 int 0xc 72043561Skato pushb $0xd # Int 0x25: IRQ5 72143561Skato jmp int_hw # V86 int 0xd 72243561Skato pushb $0xe # Int 0x26: IRQ6 72343561Skato jmp int_hw # V86 int 0xe 72443561Skato pushb $0xf # Int 0x27: IRQ7 72543561Skato jmp int_hw # V86 int 0xf 72643561Skato.`ifdef' PC98 72743561Skato pushb $0x10 # Int 0x28: IRQ8 72843561Skato jmp int_hw # V86 int 0x10 72943561Skato pushb $0x11 # Int 0x29: IRQ9 73043561Skato jmp int_hw # V86 int 0x11 73143561Skato pushb $0x12 # Int 0x2a: IRQ10 73243561Skato jmp int_hw # V86 int 0x12 73343561Skato pushb $0x13 # Int 0x2b: IRQ11 73443561Skato jmp int_hw # V86 int 0x13 73543561Skato pushb $0x14 # Int 0x2c: IRQ12 73643561Skato jmp int_hw # V86 int 0x14 73743561Skato pushb $0x15 # Int 0x2d: IRQ13 73843561Skato jmp int_hw # V86 int 0x15 73943561Skato pushb $0x16 # Int 0x2e: IRQ14 74043561Skato jmp int_hw # V86 int 0x16 74143561Skato pushb $0x17 # Int 0x2f: IRQ15 74243561Skato jmp int_hw # V86 int 0x17 74343561Skato.else 74443561Skato pushb $0x70 # Int 0x28: IRQ8 74543561Skato jmp int_hw # V86 int 0x70 74643561Skato pushb $0x71 # Int 0x29: IRQ9 74743561Skato jmp int_hw # V86 int 0x71 74843561Skato pushb $0x72 # Int 0x2a: IRQ10 74943561Skato jmp int_hw # V86 int 0x72 75043561Skato pushb $0x73 # Int 0x2b: IRQ11 75143561Skato jmp int_hw # V86 int 0x73 75243561Skato pushb $0x74 # Int 0x2c: IRQ12 75343561Skato jmp int_hw # V86 int 0x74 75443561Skato pushb $0x75 # Int 0x2d: IRQ13 75543561Skato jmp int_hw # V86 int 0x75 75643561Skato pushb $0x76 # Int 0x2e: IRQ14 75743561Skato jmp int_hw # V86 int 0x76 75843561Skato pushb $0x77 # Int 0x2f: IRQ15 75943561Skato jmp int_hw # V86 int 0x77 76043561Skato.endif 76143561Skato# 76243561Skato# Reflect hardware interrupts. 76343561Skato# 76443561Skatoint_hw: testb $0x2,0xe(%esp,1) # V86 mode? 76543561Skato jz intusr # No 76643561Skato pushl $SEL_SDATA # Address 76743561Skato popl %ds # data 76843561Skato xchgl %eax,(%esp,1) # Swap EAX, int no 76943561Skato pushl %ebp # Address 77043561Skato movl %esp,%ebp # stack frame 77143561Skato pushl %ebx # Save 77243561Skato shll $0x2,%eax # Get int 77343561Skato movl (%eax),%eax # vector 77443561Skato subl $0x6,0x14(%ebp) # Adjust V86 ESP 77543561Skato movzwl 0x18(%ebp),%ebx # V86 SS 77643561Skato shll $0x4,%ebx # * 0x10 77743561Skato addl 0x14(%ebp),%ebx # + V86 ESP 77843561Skato xchgw %ax,0x8(%ebp) # Swap V86 IP 77943561Skato rorl $0x10,%eax # Swap words 78043561Skato xchgw %ax,0xc(%ebp) # Swap V86 CS 78143561Skato roll $0x10,%eax # Swap words 78243561Skato movl %eax,(%ebx) # CS:IP for IRET 78343561Skato movl 0x10(%ebp),%eax # V86 flags 78443561Skato movw %ax,0x4(%ebx) # Flags for IRET 78543561Skato andb $~0x3,0x11(%ebp) # Clear IF, TF 78643561Skato popl %ebx # Restore 78743561Skato popl %ebp # saved 78843561Skato popl %eax # registers 78943561Skato iret # To V86 mode 79043561Skato# 79143561Skato# Invoke V86 interrupt from user mode, with arguments. 79243561Skato# 79343561Skatointx31: stc # Have btx_v86 79443561Skato pushl %eax # Missing int no 79543561Skato# 79643561Skato# Invoke V86 interrupt from user mode. 79743561Skato# 79843561Skatointusr: std # String ops dec 79943561Skato pushl %eax # Expand 80043561Skato pushl %eax # stack 80143561Skato pushl %eax # frame 80243561Skato pusha # Save 80343561Skato pushl %gs # Save 80443561Skato movl %esp,%eax # seg regs 80543561Skato pushl %fs # and 80643561Skato pushl %ds # point 80743561Skato pushl %es # to them 80843561Skato pushb $SEL_SDATA # Set up 80943561Skato popl %ds # to 81043561Skato pushl %ds # address 81143561Skato popl %es # data 81243561Skato movl $MEM_USR,%ebx # User base 81343561Skato movl %ebx,%edx # address 81443561Skato jc intusr.1 # If btx_v86 81543561Skato xorl %edx,%edx # Control flags 81643561Skato xorl %ebp,%ebp # btx_v86 pointer 81743561Skatointusr.1: leal 0x50(%esp,1),%esi # Base of frame 81843561Skato pushl %esi # Save 81943561Skato addl -0x4(%esi),%ebx # User ESP 82043561Skato movl MEM_TSS+TSS_ESP1,%edi # Link stack pointer 82143561Skato leal -0x4(%edi),%edi # Adjust for push 82243561Skato xorl %ecx,%ecx # Zero 82343561Skato movb $0x5,%cl # Push exception 82443561Skato rep # frame on 82543561Skato movsl # link stack 82643561Skato xchgl %eax,%esi # Saved seg regs 82743561Skato movl 0x40(%esp,1),%eax # Get int no 82843561Skato testl %edx,%edx # Have btx_v86? 82943561Skato jz intusr.2 # No 83043561Skato movl (%ebx),%ebp # btx_v86 pointer 83143561Skato movb $0x4,%cl # Count 83243561Skato addl %ecx,%ebx # Adjust for pop 83343561Skato rep # Push saved seg regs 83443561Skato movsl # on link stack 83543561Skato addl %ebp,%edx # Flatten btx_v86 ptr 83643561Skato leal 0x14(%edx),%esi # Seg regs pointer 83743561Skato movl 0x4(%edx),%eax # Get int no/address 83843561Skato movzwl 0x2(%edx),%edx # Get control flags 83943561Skatointusr.2: movl %ebp,(%edi) # Push btx_v86 and 84043561Skato movl %edi,MEM_TSS+TSS_ESP1 # save link stack ptr 84143561Skato popl %edi # Base of frame 84243561Skato xchgl %eax,%ebp # Save intno/address 84343561Skato movl 0x48(%esp,1),%eax # Get flags 84443561Skato testb $0x2,%dl # Simulate CALLF? 84543561Skato jnz intusr.3 # Yes 84643561Skato decl %ebx # Push flags 84743561Skato decl %ebx # on V86 84843561Skato movw %ax,(%ebx) # stack 84943561Skatointusr.3: movb $0x4,%cl # Count 85043561Skato subl %ecx,%ebx # Push return address 85143561Skato movl $inthlt,(%ebx) # on V86 stack 85243561Skato rep # Copy seg regs to 85343561Skato movsl # exception frame 85443561Skato xchgl %eax,%ecx # Save flags 85543561Skato movl %ebx,%eax # User ESP 85643561Skato subl $V86_STK,%eax # Less bytes 85743561Skato ja intusr.4 # to 85843561Skato xorl %eax,%eax # keep 85943561Skatointusr.4: shrl $0x4,%eax # Gives segment 86043561Skato stosl # Set SS 86143561Skato shll $0x4,%eax # To bytes 86243561Skato xchgl %eax,%ebx # Swap 86343561Skato subl %ebx,%eax # Gives offset 86443561Skato stosl # Set ESP 86543561Skato xchgl %eax,%ecx # Get flags 86643561Skato btsl $0x11,%eax # Set VM 86743561Skato andb $~0x3,%ah # Clear IF and TF 86843561Skato stosl # Set EFL 86943561Skato xchgl %eax,%ebp # Get int no/address 87043561Skato testb $0x1,%dl # Address? 87143561Skato jnz intusr.5 # Yes 87243561Skato shll $0x2,%eax # Scale 87343561Skato movl (%eax),%eax # Load int vector 87443561Skatointusr.5: movl %eax,%ecx # Save 87543561Skato shrl $0x10,%eax # Gives segment 87643561Skato stosl # Set CS 87743561Skato movw %cx,%ax # Restore 87843561Skato stosl # Set EIP 87943561Skato leal 0x10(%esp,1),%esp # Discard seg regs 88043561Skato popa # Restore 88143561Skato iret # To V86 mode 88243561Skato# 88343561Skato# System Call. 88443561Skato# 88543561Skatointx30: cmpl $SYS_EXEC,%eax # Exec system call? 88643561Skato jne intx30.1 # No 88743561Skato pushl %ss # Set up 88843561Skato popl %es # all 88943561Skato pushl %es # segment 89043561Skato popl %ds # registers 89143561Skato pushl %ds # for the 89243561Skato popl %fs # program 89343561Skato pushl %fs # we're 89443561Skato popl %gs # invoking 89543561Skato movl $MEM_USR,%eax # User base address 89643561Skato addl 0xc(%esp,1),%eax # Change to user 89743561Skato leal 0x4(%eax),%esp # stack 89843561Skato movl %cr0,%eax # Turn 89943561Skato andl $~0x80000000,%eax # off 90043561Skato movl %eax,%cr0 # paging 90143561Skato xorl %eax,%eax # Flush 90243561Skato movl %eax,%cr3 # TLB 90343561Skato popl %eax # Call 90443561Skato call *%eax # program 90543561Skatointx30.1: incb %ss:btx_hdr+0x7 # Flag reboot 90643561Skato jmp exit # Exit 90743561Skato# 90843561Skato# Dump structure [EBX] to [EDI], using format string [ESI]. 90943561Skato# 91043561Skatodump.0: stosb # Save char 91143561Skatodump: lodsb # Load char 91243561Skato testb %al,%al # End of string? 91343561Skato jz dump.10 # Yes 91443561Skato testb $0x80,%al # Control? 91543561Skato jz dump.0 # No 91643561Skato movb %al,%ch # Save control 91743561Skato movb $'=',%al # Append 91843561Skato stosb # '=' 91943561Skato lodsb # Get offset 92043561Skato pushl %esi # Save 92143561Skato movsbl %al,%esi # To 92243561Skato addl %ebx,%esi # pointer 92343561Skato testb $DMP_X16,%ch # Dump word? 92443561Skato jz dump.1 # No 92543561Skato lodsw # Get and 92643561Skato call hex16 # dump it 92743561Skatodump.1: testb $DMP_X32,%ch # Dump long? 92843561Skato jz dump.2 # No 92943561Skato lodsl # Get and 93043561Skato call hex32 # dump it 93143561Skatodump.2: testb $DMP_MEM,%ch # Dump memory? 93243561Skato jz dump.8 # No 93343561Skato pushl %ds # Save 93443561Skato testb $0x2,0x52(%ebx) # V86 mode? 93543561Skato jnz dump.3 # Yes 93643561Skato verrl 0x4(%esi) # Readable selector? 93743561Skato jnz dump.3 # No 93843561Skato ldsl (%esi),%esi # Load pointer 93943561Skato jmp dump.4 # Join common code 94043561Skatodump.3: lodsl # Set offset 94143561Skato xchgl %eax,%edx # Save 94243561Skato lodsl # Get segment 94343561Skato shll $0x4,%eax # * 0x10 94443561Skato addl %edx,%eax # + offset 94543561Skato xchgl %eax,%esi # Set pointer 94643561Skatodump.4: movb $0x10,%cl # Bytes to dump 94743561Skatodump.5: lodsb # Get byte and 94843561Skato call hex8 # dump it 94943561Skato decb %cl # Keep count 95043561Skato jz dump.7 # If done 95143561Skato movb $'-',%al # Separator 95243561Skato cmpb $0x8,%cl # Half way? 95343561Skato je dump.6 # Yes 95443561Skato movb $' ',%al # Use space 95543561Skatodump.6: stosb # Save separator 95643561Skato jmp dump.5 # Continue 95743561Skatodump.7: popl %ds # Restore 95843561Skatodump.8: popl %esi # Restore 95943561Skato movb $0xa,%al # Line feed 96043561Skato testb $DMP_EOL,%ch # End of line? 96143561Skato jnz dump.9 # Yes 96243561Skato movb $' ',%al # Use spaces 96343561Skato stosb # Save one 96443561Skatodump.9: jmp dump.0 # Continue 96543561Skatodump.10: stosb # Terminate string 96643561Skato ret # To caller 96743561Skato# 96843561Skato# Convert EAX, AX, or AL to hex, saving the result to [EDI]. 96943561Skato# 97043561Skatohex32: pushl %eax # Save 97143561Skato shrl $0x10,%eax # Do upper 97243561Skato call hex16 # 16 97343561Skato popl %eax # Restore 97443561Skatohex16: call hex16.1 # Do upper 8 97543561Skatohex16.1: xchgb %ah,%al # Save/restore 97643561Skatohex8: pushl %eax # Save 97743561Skato shrb $0x4,%al # Do upper 97843561Skato call hex8.1 # 4 97943561Skato popl %eax # Restore 98043561Skatohex8.1: andb $0xf,%al # Get lower 4 98143561Skato cmpb $0xa,%al # Convert 98243561Skato sbbb $0x69,%al # to hex 98343561Skato das # digit 98443561Skato orb $0x20,%al # To lower case 98543561Skato stosb # Save char 98643561Skato ret # (Recursive) 98743561Skato# 98843561Skato# Output zero-terminated string [ESI] to the console. 98943561Skato# 99043561Skatoputstr.0: call putchr # Output char 99143561Skatoputstr: lodsb # Load char 99243561Skato testb %al,%al # End of string? 99343561Skato jnz putstr.0 # No 99443561Skato ret # To caller 99543561Skato# 99643561Skato# Output character AL to the console. 99743561Skato# 99843561Skatoputchr: pusha # Save 99943561Skato xorl %ecx,%ecx # Zero for loops 100043561Skato movb $SCR_MAT,%ah # Mode/attribute 100143561Skato movl $BDA_POS,%ebx # BDA pointer 100243561Skato movw (%ebx),%dx # Cursor position 100343561Skato.`ifdef' PC98 100443561Skato movl $0xa0000,%edi 100543561Skato.else 100643561Skato movl $0xb8000,%edi # Regen buffer (color) 100743561Skato cmpb %ah,BDA_SCR-BDA_POS(%ebx) # Mono mode? 100843561Skato jne putchr.1 # No 100943561Skato xorw %di,%di # Regen buffer (mono) 101043561Skato.endif 101143561Skatoputchr.1: cmpb $0xa,%al # New line? 101243561Skato je putchr.2 # Yes 101343561Skato.`ifdef' PC98 101443561Skato movw %dx,%cx 101543561Skato movb %al,(%edi,%ecx,1) # Write char 101643561Skato addl $0x2000,%ecx 101743561Skato movb %ah,(%edi,%ecx,1) # Write attr 101843561Skato addw $0x02,%dx 101943561Skato jmp putchr.3 102043561Skatoputchr.2: movw %dx,%ax 102143561Skato movb $SCR_COL*2,%dl 102243561Skato div %dl 102343561Skato incb %al 102443561Skato mul %dl 102543561Skato movw %ax,%dx 102643561Skatoputchr.3: cmpw $SCR_ROW*SCR_COL*2,%dx 102743561Skato.else 102843561Skato xchgl %eax,%ecx # Save char 102943561Skato movb $SCR_COL,%al # Columns per row 103043561Skato mulb %dh # * row position 103143561Skato addb %dl,%al # + column 103243561Skato adcb $0x0,%ah # position 103343561Skato shll %eax # * 2 103443561Skato xchgl %eax,%ecx # Swap char, offset 103543561Skato movw %ax,(%edi,%ecx,1) # Write attr:char 103643561Skato incl %edx # Bump cursor 103743561Skato cmpb $SCR_COL,%dl # Beyond row? 103843561Skato jb putchr.3 # No 103943561Skatoputchr.2: xorb %dl,%dl # Zero column 104043561Skato incb %dh # Bump row 104143561Skatoputchr.3: cmpb $SCR_ROW,%dh # Beyond screen? 104243561Skato.endif 104343561Skato jb putchr.4 # No 104443561Skato leal 2*SCR_COL(%edi),%esi # New top line 104543561Skato movw $(SCR_ROW-1)*SCR_COL/2,%cx # Words to move 104643561Skato rep # Scroll 104743561Skato movsl # screen 104843561Skato movb $' ',%al # Space 104943561Skato.`ifdef' PC98 105043561Skato xorb %ah,%ah 105143561Skato.endif 105243561Skato movb $SCR_COL,%cl # Columns to clear 105343561Skato rep # Clear 105443561Skato stosw # line 105543561Skato.`ifdef' PC98 105643561Skato movw $(SCR_ROW-1)*SCR_COL*2,%dx 105743561Skato.else 105843561Skato movb $SCR_ROW-1,%dh # Bottom line 105943561Skato.endif 106043561Skatoputchr.4: movw %dx,(%ebx) # Update position 106143561Skato popa # Restore 106243561Skato ret # To caller 106343561Skato 106443561Skato .p2align 4 106543561Skato# 106643561Skato# Global descriptor table. 106743561Skato# 106843561Skatogdt: .word 0x0,0x0,0x0,0x0 # Null entry 106943561Skato .word 0xffff,0x0,0x9a00,0xcf # SEL_SCODE 107043561Skato .word 0xffff,0x0,0x9200,0xcf # SEL_SDATA 107143561Skato .word 0xffff,0x0,0x9a00,0x0 # SEL_RCODE 107243561Skato .word 0xffff,0x0,0x9200,0x0 # SEL_RDATA 107343561Skato .word 0xffff,MEM_USR,0xfa00,0xcf# SEL_UCODE 107443561Skato .word 0xffff,MEM_USR,0xf200,0xcf# SEL_UDATA 107543561Skato .word _TSSLM,MEM_TSS,0x8900,0x0 # SEL_TSS 107643561Skatogdt.1: 107743561Skato# 107843561Skato# Pseudo-descriptors. 107943561Skato# 108043561Skatogdtdesc: .word gdt.1-gdt-1,gdt,0x0 # GDT 108143561Skatoidtdesc: .word _IDTLM,MEM_IDT,0x0 # IDT 108243561Skatoivtdesc: .word 0x400-0x0-1,0x0,0x0 # IVT 108343561Skato# 108443561Skato# IDT construction control string. 108543561Skato# 108643561Skatoidtctl: .byte 0x10, 0x8e # Int 0x0-0xf 108743561Skato .word 0x7dfb,intx00 # (exceptions) 108843561Skato .byte 0x10, 0x8e # Int 0x10 108943561Skato .word 0x1, intx10 # (exception) 109043561Skato .byte 0x10, 0x8e # Int 0x20-0x2f 109143561Skato .word 0xffff,intx20 # (hardware) 109243561Skato .byte 0x1, 0xee # int 0x30 109343561Skato .word 0x1, intx30 # (system call) 109443561Skato .byte 0x2, 0xee # Int 0x31-0x32 109543561Skato .word 0x1, intx31 # (V86, null) 109643561Skato .byte 0x0 # End of string 109743561Skato# 109843561Skato# Dump format string. 109943561Skato# 110043561Skatodmpfmt: .byte '\n' # "\n" 110143561Skato .ascii "int" # "int=" 110243561Skato .byte 0x80|DMP_X32, 0x40 # "00000000 " 110343561Skato .ascii "err" # "err=" 110443561Skato .byte 0x80|DMP_X32, 0x44 # "00000000 " 110543561Skato .ascii "efl" # "efl=" 110643561Skato .byte 0x80|DMP_X32, 0x50 # "00000000 " 110743561Skato .ascii "eip" # "eip=" 110843561Skato .byte 0x80|DMP_X32|DMP_EOL,0x48 # "00000000\n" 110943561Skato .ascii "eax" # "eax=" 111043561Skato .byte 0x80|DMP_X32, 0x34 # "00000000 " 111143561Skato .ascii "ebx" # "ebx=" 111243561Skato .byte 0x80|DMP_X32, 0x28 # "00000000 " 111343561Skato .ascii "ecx" # "ecx=" 111443561Skato .byte 0x80|DMP_X32, 0x30 # "00000000 " 111543561Skato .ascii "edx" # "edx=" 111643561Skato .byte 0x80|DMP_X32|DMP_EOL,0x2c # "00000000\n" 111743561Skato .ascii "esi" # "esi=" 111843561Skato .byte 0x80|DMP_X32, 0x1c # "00000000 " 111943561Skato .ascii "edi" # "edi=" 112043561Skato .byte 0x80|DMP_X32, 0x18 # "00000000 " 112143561Skato .ascii "ebp" # "ebp=" 112243561Skato .byte 0x80|DMP_X32, 0x20 # "00000000 " 112343561Skato .ascii "esp" # "esp=" 112443561Skato .byte 0x80|DMP_X32|DMP_EOL,0x0 # "00000000\n" 112543561Skato .ascii "cs" # "cs=" 112643561Skato .byte 0x80|DMP_X16, 0x4c # "0000 " 112743561Skato .ascii "ds" # "ds=" 112843561Skato .byte 0x80|DMP_X16, 0xc # "0000 " 112943561Skato .ascii "es" # "es=" 113043561Skato .byte 0x80|DMP_X16, 0x8 # "0000 " 113143561Skato .ascii " " # " " 113243561Skato .ascii "fs" # "fs=" 113343561Skato .byte 0x80|DMP_X16, 0x10 # "0000 " 113443561Skato .ascii "gs" # "gs=" 113543561Skato .byte 0x80|DMP_X16, 0x14 # "0000 " 113643561Skato .ascii "ss" # "ss=" 113743561Skato .byte 0x80|DMP_X16|DMP_EOL,0x4 # "0000\n" 113843561Skato .ascii "cs:eip" # "cs:eip=" 113943561Skato .byte 0x80|DMP_MEM|DMP_EOL,0x48 # "00 00 ... 00 00\n" 114043561Skato .ascii "ss:esp" # "ss:esp=" 114143561Skato .byte 0x80|DMP_MEM|DMP_EOL,0x0 # "00 00 ... 00 00\n" 114243561Skato .asciz "System halted" # End 114343561Skato# 114443561Skato# End of BTX memory. 114543561Skato# 114643561Skato .p2align 4 114743561Skatobreak: 1148