sys/boot/i386/btx/btx/btx.S

   1 #
   2 # Copyright (c) 1998 Robert Nordier
   3 # All rights reserved.
   4 #
   5 # Redistribution and use in source and binary forms are freely
   6 # permitted provided that the above copyright notice and this
   7 # paragraph and the following disclaimer are duplicated in all
   8 # such forms.
   9 #
  10 # This software is provided "AS IS" and without any express or
  11 # implied warranties, including, without limitation, the implied
  12 # warranties of merchantability and fitness for a particular
  13 # purpose.
  14 #
  15
  16 # $FreeBSD: src/sys/boot/i386/btx/btx/btx.s,v 1.15.2.4 2000/12/28 12:08:22 ps Exp $
  17
  18 #
  19 # Memory layout.
  20 #
  21                 .set MEM_BTX,0x1000             # Start of BTX memory
  22                 .set MEM_ESP0,0x1800            # Supervisor stack
  23                 .set MEM_BUF,0x1800             # Scratch buffer
  24                 .set MEM_ESP1,0x1e00            # Link stack
  25                 .set MEM_IDT,0x1e00             # IDT
  26                 .set MEM_TSS,0x1f98             # TSS
  27                 .set MEM_MAP,0x2000             # I/O bit map
  28                 .set MEM_DIR,0x4000             # Page directory
  29                 .set MEM_TBL,0x5000             # Page tables
  30                 .set MEM_ORG,0x9000             # BTX code
  31                 .set MEM_USR,0xa000             # Start of user memory
  32 #
  33 # Paging control.
  34 #
  35                 .set PAG_SIZ,0x1000             # Page size
  36                 .set PAG_CNT,0x1000             # Pages to map
  37 #
  38 # Segment selectors.
  39 #
  40                 .set SEL_SCODE,0x8              # Supervisor code
  41                 .set SEL_SDATA,0x10             # Supervisor data
  42                 .set SEL_RCODE,0x18             # Real mode code
  43                 .set SEL_RDATA,0x20             # Real mode data
  44                 .set SEL_UCODE,0x28|3           # User code
  45                 .set SEL_UDATA,0x30|3           # User data
  46                 .set SEL_TSS,0x38               # TSS
  47 #
  48 # Task state segment fields.
  49 #
  50                 .set TSS_ESP0,0x4               # PL 0 ESP
  51                 .set TSS_SS0,0x8                # PL 0 SS
  52                 .set TSS_ESP1,0xc               # PL 1 ESP
  53                 .set TSS_MAP,0x66               # I/O bit map base
  54 #
  55 # System calls.
  56 #
  57                 .set SYS_EXIT,0x0               # Exit
  58                 .set SYS_EXEC,0x1               # Exec
  59 #
  60 # V86 constants.
  61 #
  62                 .set V86_FLG,0x208eff           # V86 flag mask
  63                 .set V86_STK,0x400              # V86 stack allowance
  64 #
  65 # Dump format control bytes.
  66 #
  67                 .set DMP_X16,0x1                # Word
  68                 .set DMP_X32,0x2                # Long
  69                 .set DMP_MEM,0x4                # Memory
  70                 .set DMP_EOL,0x8                # End of line
  71 #
  72 # Screen defaults and assumptions.
  73 #
  74                 .set SCR_MAT,0x7                # Mode/attribute
  75                 .set SCR_COL,0x50               # Columns per row
  76                 .set SCR_ROW,0x19               # Rows per screen
  77 #
  78 # BIOS Data Area locations.
  79 #
  80                 .set BDA_MEM,0x413              # Free memory
  81                 .set BDA_KEYFLAGS,0x417         # Keyboard shift-state flags
  82                 .set BDA_SCR,0x449              # Video mode
  83                 .set BDA_POS,0x450              # Cursor position
  84                 .set BDA_BOOT,0x472             # Boot howto flag
  85 #
  86 # Derivations, for brevity.
  87 #
  88                 .set _ESP0H,MEM_ESP0>>0x8       # Byte 1 of ESP0
  89                 .set _ESP1H,MEM_ESP1>>0x8       # Byte 1 of ESP1
  90                 .set _TSSIO,MEM_MAP-MEM_TSS     # TSS I/O base
  91                 .set _TSSLM,MEM_DIR-MEM_TSS-1   # TSS limit
  92                 .set _IDTLM,MEM_TSS-MEM_IDT-1   # IDT limit
  93 #
  94 # Code segment.
  95 #
  96                 .globl start
  97                 .code16
  98 start:                                          # Start of code
  99 #
 100 # BTX header.
 101 #
 102 btx_hdr:        .byte 0xeb                      # Machine ID
 103                 .byte 0xe                       # Header size
 104                 .ascii "BTX"                    # Magic
 105                 .byte 0x1                       # Major version
 106                 .byte 0x1                       # Minor version
 107                 .byte BTX_FLAGS                 # Flags
 108                 .word PAG_CNT-MEM_ORG>>0xc      # Paging control
 109                 .word break-start               # Text size
 110                 .long 0x0                       # Entry address
 111 #
 112 # Initialization routine.
 113 #
 114 init:           cli                             # Disable interrupts
 115                 xor %ax,%ax                     # Zero/segment
 116                 mov %ax,%ss                     # Set up
 117                 mov $MEM_ESP0,%sp               #  stack
 118                 mov %ax,%es                     # Address
 119                 mov %ax,%ds                     #  data
 120                 pushl $0x2                      # Clear
 121                 popfl                           #  flags
 122 #
 123 # Initialize memory.
 124 #
 125                 mov $MEM_IDT,%di                # Memory to initialize
 126                 mov $(MEM_ORG-MEM_IDT)/2,%cx    # Words to zero
 127                 push %di                        # Save
 128                 rep                             # Zero-fill
 129                 stosw                           #  memory
 130                 pop %di                         # Restore
 131 #
 132 # Create IDT.
 133 #
 134                 mov $idtctl,%si                 # Control string
 135 init.1:         lodsb                           # Get entry
 136                 cbw                             #  count
 137                 xchg %ax,%cx                    #  as word
 138                 jcxz init.4                     # If done
 139                 lodsb                           # Get segment
 140                 xchg %ax,%dx                    #  P:DPL:type
 141                 lodsw                           # Get control
 142                 xchg %ax,%bx                    #  set
 143                 lodsw                           # Get handler offset
 144                 mov $SEL_SCODE,%dh              # Segment selector
 145 init.2:         shr %bx                         # Handle this int?
 146                 jnc init.3                      # No
 147                 mov %ax,(%di)                   # Set handler offset
 148                 mov %dh,0x2(%di)                #  and selector
 149                 mov %dl,0x5(%di)                # Set P:DPL:type
 150                 add $0x4,%ax                    # Next handler
 151 init.3:         lea 0x8(%di),%di                # Next entry
 152                 loop init.2                     # Till set done
 153                 jmp init.1                      # Continue
 154 #
 155 # Initialize TSS.
 156 #
 157 init.4:         movb $_ESP0H,TSS_ESP0+1(%di)    # Set ESP0
 158                 movb $SEL_SDATA,TSS_SS0(%di)    # Set SS0
 159                 movb $_ESP1H,TSS_ESP1+1(%di)    # Set ESP1
 160                 movb $_TSSIO,TSS_MAP(%di)       # Set I/O bit map base
 161 ifdef(`PAGING',`
 162 #
 163 # Create page directory.
 164 #
 165                 xor %edx,%edx                   # Page
 166                 mov $PAG_SIZ>>0x8,%dh           #  size
 167                 xor %eax,%eax                   # Zero
 168                 mov $MEM_DIR,%di                # Page directory
 169                 mov $PAG_CNT>>0xa,%cl           # Entries
 170                 mov $MEM_TBL|0x7,%ax            # First entry
 171 init.5:         stosl                           # Write entry
 172                 add %dx,%ax                     # To next
 173                 loop init.5                     # Till done
 174 #
 175 # Create page tables.
 176 #
 177                 mov $MEM_TBL,%di                # Page table
 178                 mov $PAG_CNT>>0x8,%ch           # Entries
 179                 xor %ax,%ax                     # Start address
 180 init.6:         mov $0x7,%al                    # Set U:W:P flags
 181                 cmp btx_hdr+0x8,%cx             # Standard user page?
 182                 jb init.7                       # Yes
 183                 cmp $PAG_CNT-MEM_BTX>>0xc,%cx   # BTX memory?
 184                 jae init.7                      # No or first page
 185                 and $~0x2,%al                   # Clear W flag
 186                 cmp $PAG_CNT-MEM_USR>>0xc,%cx   # User page zero?
 187                 jne init.7                      # No
 188                 testb $0x80,btx_hdr+0x7         # Unmap it?
 189                 jz init.7                       # No
 190                 and $~0x1,%al                   # Clear P flag
 191 init.7:         stosl                           # Set entry
 192                 add %edx,%eax                   # Next address
 193                 loop init.6                     # Till done
 194 ')
 195 #
 196 # Bring up the system.
 197 #
 198                 mov $0x2820,%bx                 # Set protected mode
 199                 callw setpic                    #  IRQ offsets
 200                 lidt idtdesc                    # Set IDT
 201 ifdef(`PAGING',`
 202                 xor %eax,%eax                   # Set base
 203                 mov $MEM_DIR>>0x8,%ah           #  of page
 204                 mov %eax,%cr3                   #  directory
 205 ')
 206                 lgdt gdtdesc                    # Set GDT
 207                 mov %cr0,%eax                   # Switch to protected
 208 ifdef(`PAGING',`
 209                 or $0x80000001,%eax             #  mode and enable paging
 210 ',`
 211                 or $0x01,%eax                   #  mode
 212 ')
 213                 mov %eax,%cr0                   #
 214                 ljmp $SEL_SCODE,$init.8         # To 32-bit code
 215                 .code32
 216 init.8:         xorl %ecx,%ecx                  # Zero
 217                 movb $SEL_SDATA,%cl             # To 32-bit
 218                 movw %cx,%ss                    #  stack
 219 #
 220 # Launch user task.
 221 #
 222                 movb $SEL_TSS,%cl               # Set task
 223                 ltr %cx                         #  register
 224                 movl $MEM_USR,%edx              # User base address
 225                 movzwl %ss:BDA_MEM,%eax         # Get free memory
 226                 shll $0xa,%eax                  # To bytes
 227                 subl $0x1000,%eax               # Less arg space
 228                 subl %edx,%eax                  # Less base
 229                 movb $SEL_UDATA,%cl             # User data selector
 230                 pushl %ecx                      # Set SS
 231                 pushl %eax                      # Set ESP
 232                 push $0x202                     # Set flags (IF set)
 233                 push $SEL_UCODE                 # Set CS
 234                 pushl btx_hdr+0xc               # Set EIP
 235                 pushl %ecx                      # Set GS
 236                 pushl %ecx                      # Set FS
 237                 pushl %ecx                      # Set DS
 238                 pushl %ecx                      # Set ES
 239                 pushl %edx                      # Set EAX
 240                 movb $0x7,%cl                   # Set remaining
 241 init.9:         push $0x0                       #  general
 242                 loop init.9                     #  registers
 243                 popa                            #  and initialize
 244                 popl %es                        # Initialize
 245                 popl %ds                        #  user
 246                 popl %fs                        #  segment
 247                 popl %gs                        #  registers
 248                 iret                            # To user mode
 249 #
 250 # Exit routine.
 251 #
 252 exit:           cli                             # Disable interrupts
 253                 movl $MEM_ESP0,%esp             # Clear stack
 254 #
 255 # Turn off paging.
 256 #
 257                 movl %cr0,%eax                  # Get CR0
 258 ifdef(`PAGING',`
 259                 andl $~0x80000000,%eax          # Disable
 260                 movl %eax,%cr0                  #  paging
 261 ')
 262                 xorl %ecx,%ecx                  # Zero
 263 ifdef(`PAGING',`
 264                 movl %ecx,%cr3                  # Flush TLB
 265 ')
 266 #
 267 # To 16 bits.
 268 #
 269                 ljmpw $SEL_RCODE,$exit.1        # Reload CS
 270                 .code16
 271 exit.1:         mov $SEL_RDATA,%cl              # 16-bit selector
 272                 mov %cx,%ss                     # Reload SS
 273                 mov %cx,%ds                     # Load
 274                 mov %cx,%es                     #  remaining
 275                 mov %cx,%fs                     #  segment
 276                 mov %cx,%gs                     #  registers
 277 #
 278 # To real-address mode.
 279 #
 280                 dec %ax                         # Switch to
 281                 mov %eax,%cr0                   #  real mode
 282                 ljmp $0x0,$exit.2               # Reload CS
 283 exit.2:         xor %ax,%ax                     # Real mode segment
 284                 mov %ax,%ss                     # Reload SS
 285                 mov %ax,%ds                     # Address data
 286                 mov $0x7008,%bx                 # Set real mode
 287                 callw setpic                    #  IRQ offsets
 288                 lidt ivtdesc                    # Set IVT
 289 #
 290 # Reboot or await reset.
 291 #
 292                 sti                             # Enable interrupts
 293                 testb $0x1,btx_hdr+0x7          # Reboot?
 294 exit.3:         jz exit.3                       # No
 295                 movw $0x1234, BDA_BOOT          # Do a warm boot
 296                 ljmp $0xffff,$0x0               # reboot the machine
 297 #
 298 # Set IRQ offsets by reprogramming 8259A PICs.
 299 #
 300 setpic:         in $0x21,%al                    # Save master
 301                 push %ax                        #  IMR
 302                 in $0xa1,%al                    # Save slave
 303                 push %ax                        #  IMR
 304                 movb $0x11,%al                  # ICW1 to
 305                 outb %al,$0x20                  #  master,
 306                 outb %al,$0xa0                  #  slave
 307                 movb %bl,%al                    # ICW2 to
 308                 outb %al,$0x21                  #  master
 309                 movb %bh,%al                    # ICW2 to
 310                 outb %al,$0xa1                  #  slave
 311                 movb $0x4,%al                   # ICW3 to
 312                 outb %al,$0x21                  #  master
 313                 movb $0x2,%al                   # ICW3 to
 314                 outb %al,$0xa1                  #  slave
 315                 movb $0x1,%al                   # ICW4 to
 316                 outb %al,$0x21                  #  master,
 317                 outb %al,$0xa1                  #  slave
 318                 pop %ax                         # Restore slave
 319                 outb %al,$0xa1                  #  IMR
 320                 pop %ax                         # Restore master
 321                 outb %al,$0x21                  #  IMR
 322                 retw                            # To caller
 323                 .code32
 324 #
 325 # Initiate return from V86 mode to user mode.
 326 #
 327 inthlt:         hlt                             # To supervisor mode
 328 #
 329 # Exception jump table.
 330 #
 331 intx00:         push $0x0                       # Int 0x0: #DE
 332                 jmp ex_noc                      # Divide error
 333                 push $0x1                       # Int 0x1: #DB
 334                 jmp ex_noc                      # Debug
 335                 push $0x3                       # Int 0x3: #BP
 336                 jmp ex_noc                      # Breakpoint
 337                 push $0x4                       # Int 0x4: #OF
 338                 jmp ex_noc                      # Overflow
 339                 push $0x5                       # Int 0x5: #BR
 340                 jmp ex_noc                      # BOUND range exceeded
 341                 push $0x6                       # Int 0x6: #UD
 342                 jmp ex_noc                      # Invalid opcode
 343                 push $0x7                       # Int 0x7: #NM
 344                 jmp ex_noc                      # Device not available
 345                 push $0x8                       # Int 0x8: #DF
 346                 jmp except                      # Double fault
 347                 push $0xa                       # Int 0xa: #TS
 348                 jmp except                      # Invalid TSS
 349                 push $0xb                       # Int 0xb: #NP
 350                 jmp except                      # Segment not present
 351                 push $0xc                       # Int 0xc: #SS
 352                 jmp except                      # Stack segment fault
 353                 push $0xd                       # Int 0xd: #GP
 354                 jmp ex_v86                      # General protection
 355                 push $0xe                       # Int 0xe: #PF
 356                 jmp except                      # Page fault
 357 intx10:         push $0x10                      # Int 0x10: #MF
 358                 jmp ex_noc                      # Floating-point error
 359 #
 360 # Handle #GP exception.
 361 #
 362 ex_v86:         testb $0x2,0x12(%esp,1)         # V86 mode?
 363                 jz except                       # No
 364                 jmp v86mon                      # To monitor
 365 #
 366 # Save a zero error code.
 367 #
 368 ex_noc:         pushl (%esp,1)                  # Duplicate int no
 369                 movb $0x0,0x4(%esp,1)           # Fake error code
 370 #
 371 # Handle exception.
 372 #
 373 except:         cld                             # String ops inc
 374                 pushl %ds                       # Save
 375                 pushl %es                       #  most
 376                 pusha                           #  registers
 377                 movb $0x6,%al                   # Push loop count
 378                 testb $0x2,0x3a(%esp,1)         # V86 mode?
 379                 jnz except.1                    # Yes
 380                 pushl %gs                       # Set GS
 381                 pushl %fs                       # Set FS
 382                 pushl %ds                       # Set DS
 383                 pushl %es                       # Set ES
 384                 movb $0x2,%al                   # Push loop count
 385                 cmpw $SEL_SCODE,0x44(%esp,1)    # Supervisor mode?
 386                 jne except.1                    # No
 387                 pushl %ss                       # Set SS
 388                 leal 0x50(%esp,1),%eax          # Set
 389                 pushl %eax                      #  ESP
 390                 jmp except.2                    # Join common code
 391 except.1:       pushl 0x50(%esp,1)              # Set GS, FS, DS, ES
 392                 decb %al                        #  (if V86 mode), and
 393                 jne except.1                    #  SS, ESP
 394 except.2:       push $SEL_SDATA                 # Set up
 395                 popl %ds                        #  to
 396                 pushl %ds                       #  address
 397                 popl %es                        #  data
 398                 movl %esp,%ebx                  # Stack frame
 399                 movl $dmpfmt,%esi               # Dump format string
 400                 movl $MEM_BUF,%edi              # Buffer
 401                 pushl %edi                      # Dump to
 402                 call dump                       #  buffer
 403                 popl %esi                       #  and
 404                 call putstr                     #  display
 405                 leal 0x18(%esp,1),%esp          # Discard frame
 406                 popa                            # Restore
 407                 popl %es                        #  registers
 408                 popl %ds                        #  saved
 409                 cmpb $0x3,(%esp,1)              # Breakpoint?
 410                 je except.3                     # Yes
 411                 jmp exit                        # Exit
 412 except.3:       leal 0x8(%esp,1),%esp           # Discard err, int no
 413                 iret                            # From interrupt
 414 #
 415 # Return to user mode from V86 mode.
 416 #
 417 intrtn:         cld                             # String ops inc
 418                 pushl %ds                       # Address
 419                 popl %es                        #  data
 420                 leal 0x3c(%ebp),%edx            # V86 Segment registers
 421                 movl MEM_TSS+TSS_ESP1,%esi      # Link stack pointer
 422                 lodsl                           # INT_V86 args pointer
 423                 movl %esi,%ebx                  # Saved exception frame
 424                 testl %eax,%eax                 # INT_V86 args?
 425                 jz intrtn.2                     # No
 426                 movl $MEM_USR,%edi              # User base
 427                 movl 0x1c(%esi),%ebx            # User ESP
 428                 movl %eax,(%edi,%ebx,1)         # Restore to user stack
 429                 leal 0x8(%edi,%eax,1),%edi      # Arg segment registers
 430                 testb $0x4,-0x6(%edi)           # Return flags?
 431                 jz intrtn.1                     # No
 432                 movl 0x30(%ebp),%eax            # Get V86 flags
 433                 movw %ax,0x18(%esi)             # Set user flags
 434 intrtn.1:       leal 0x10(%esi),%ebx            # Saved exception frame
 435                 xchgl %edx,%esi                 # Segment registers
 436                 movb $0x4,%cl                   # Update seg regs
 437                 rep                             #  in INT_V86
 438                 movsl                           #  args
 439 intrtn.2:       movl %edx,%esi                  # Segment registers
 440                 leal 0x28(%ebp),%edi            # Set up seg
 441                 movb $0x4,%cl                   #  regs for
 442                 rep                             #  later
 443                 movsl                           #  pop
 444                 movl %ebx,%esi                  # Restore exception
 445                 movb $0x5,%cl                   #  frame to
 446                 rep                             #  supervisor
 447                 movsl                           #  stack
 448                 movl %esi,MEM_TSS+TSS_ESP1      # Link stack pointer
 449                 popa                            # Restore
 450                 leal 0x8(%esp,1),%esp           # Discard err, int no
 451                 popl %es                        # Restore
 452                 popl %ds                        #  user
 453                 popl %fs                        #  segment
 454                 popl %gs                        #  registers
 455                 iret                            # To user mode
 456 #
 457 # V86 monitor.
 458 #
 459 v86mon:         cld                             # String ops inc
 460                 pushl $SEL_SDATA                # Set up for
 461                 popl %ds                        #  flat addressing
 462                 pusha                           # Save registers
 463                 movl %esp,%ebp                  # Address stack frame
 464                 movzwl 0x2c(%ebp),%edi          # Load V86 CS
 465                 shll $0x4,%edi                  # To linear
 466                 movl 0x28(%ebp),%esi            # Load V86 IP
 467                 addl %edi,%esi                  # Code pointer
 468                 xorl %ecx,%ecx                  # Zero
 469                 movb $0x2,%cl                   # 16-bit operands
 470                 xorl %eax,%eax                  # Zero
 471 v86mon.1:       lodsb                           # Get opcode
 472                 cmpb $0x66,%al                  # Operand size prefix?
 473                 jne v86mon.2                    # No
 474                 movb $0x4,%cl                   # 32-bit operands
 475                 jmp v86mon.1                    # Continue
 476 v86mon.2:       cmpb $0xf4,%al                  # HLT?
 477                 jne v86mon.3                    # No
 478                 cmpl $inthlt+0x1,%esi           # Is inthlt?
 479                 jne v86mon.7                    # No (ignore)
 480                 jmp intrtn                      # Return to user mode
 481 v86mon.3:       cmpb $0xf,%al                   # Prefixed instruction?
 482                 jne v86mon.4                    # No
 483                 cmpb $0x09,(%esi)               # Is it a WBINVD?
 484                 je v86wbinvd                    # Yes
 485                 cmpb $0x30,(%esi)               # Is it a WRMSR?
 486                 je v86wrmsr                     # Yes
 487                 cmpb $0x32,(%esi)               # Is it a RDMSR?
 488                 je v86rdmsr                     # Yes
 489                 cmpb $0x20,(%esi)               # Is this a
 490                 jne v86mon.4                    #  MOV EAX,CR0
 491                 cmpb $0xc0,0x1(%esi)            #  instruction?
 492                 je v86mov                       # Yes
 493 v86mon.4:       cmpb $0xfa,%al                  # CLI?
 494                 je v86cli                       # Yes
 495                 cmpb $0xfb,%al                  # STI?
 496                 je v86sti                       # Yes
 497                 movzwl 0x38(%ebp),%ebx          # Load V86 SS
 498                 shll $0x4,%ebx                  # To offset
 499                 pushl %ebx                      # Save
 500                 addl 0x34(%ebp),%ebx            # Add V86 SP
 501                 movl 0x30(%ebp),%edx            # Load V86 flags
 502                 cmpb $0x9c,%al                  # PUSHF/PUSHFD?
 503                 je v86pushf                     # Yes
 504                 cmpb $0x9d,%al                  # POPF/POPFD?
 505                 je v86popf                      # Yes
 506                 cmpb $0xcd,%al                  # INT imm8?
 507                 je v86intn                      # Yes
 508                 cmpb $0xcf,%al                  # IRET/IRETD?
 509                 je v86iret                      # Yes
 510                 popl %ebx                       # Restore
 511                 popa                            # Restore
 512                 jmp except                      # Handle exception
 513 v86mon.5:       movl %edx,0x30(%ebp)            # Save V86 flags
 514 v86mon.6:       popl %edx                       # V86 SS adjustment
 515                 subl %edx,%ebx                  # Save V86
 516                 movl %ebx,0x34(%ebp)            #  SP
 517 v86mon.7:       subl %edi,%esi                  # From linear
 518                 movl %esi,0x28(%ebp)            # Save V86 IP
 519                 popa                            # Restore
 520                 leal 0x8(%esp,1),%esp           # Discard int no, error
 521                 iret                            # To V86 mode
 522 #
 523 # Emulate MOV EAX,CR0.
 524 #
 525 v86mov:         movl %cr0,%eax                  # CR0 to
 526                 movl %eax,0x1c(%ebp)            #  saved EAX
 527                 incl %esi                       # Adjust IP
 528 #
 529 # Return from emulating a 0x0f prefixed instruction
 530 #
 531 v86preret:      incl %esi                       # Adjust IP
 532                 jmp v86mon.7                    # Finish up
 533 #
 534 # Emulate WBINVD
 535 #
 536 v86wbinvd:      wbinvd                          # Write back and invalidate
 537                                                 #  cache
 538                 jmp v86preret                   # Finish up
 539 #
 540 # Emulate WRMSR
 541 #
 542 v86wrmsr:       movl 0x18(%ebp),%ecx            # Get user's %ecx (MSR to write)
 543                 movl 0x14(%ebp),%edx            # Load the value
 544                 movl 0x1c(%ebp),%eax            #  to write
 545                 wrmsr                           # Write MSR
 546                 jmp v86preret                   # Finish up
 547 #
 548 # Emulate RDMSR
 549 #
 550 v86rdmsr:       movl 0x18(%ebp),%ecx            # MSR to read
 551                 rdmsr                           # Read the MSR
 552                 movl %eax,0x1c(%ebp)            # Return the value of
 553                 movl %edx,0x14(%ebp)            #  the MSR to the user
 554                 jmp v86preret                   # Finish up
 555 #
 556 # Emulate CLI.
 557 #
 558 v86cli:         andb $~0x2,0x31(%ebp)           # Clear IF
 559                 jmp v86mon.7                    # Finish up
 560 #
 561 # Emulate STI.
 562 #
 563 v86sti:         orb $0x2,0x31(%ebp)             # Set IF
 564                 jmp v86mon.7                    # Finish up
 565 #
 566 # Emulate PUSHF/PUSHFD.
 567 #
 568 v86pushf:       subl %ecx,%ebx                  # Adjust SP
 569                 cmpb $0x4,%cl                   # 32-bit
 570                 je v86pushf.1                   # Yes
 571                 data16                          # 16-bit
 572 v86pushf.1:     movl %edx,(%ebx)                # Save flags
 573                 jmp v86mon.6                    # Finish up
 574 #
 575 # Emulate IRET/IRETD.
 576 #
 577 v86iret:        movzwl (%ebx),%esi              # Load V86 IP
 578                 movzwl 0x2(%ebx),%edi           # Load V86 CS
 579                 leal 0x4(%ebx),%ebx             # Adjust SP
 580                 movl %edi,0x2c(%ebp)            # Save V86 CS
 581                 xorl %edi,%edi                  # No ESI adjustment
 582 #
 583 # Emulate POPF/POPFD (and remainder of IRET/IRETD).
 584 #
 585 v86popf:        cmpb $0x4,%cl                   # 32-bit?
 586                 je v86popf.1                    # Yes
 587                 movl %edx,%eax                  # Initialize
 588                 data16                          # 16-bit
 589 v86popf.1:      movl (%ebx),%eax                # Load flags
 590                 addl %ecx,%ebx                  # Adjust SP
 591                 andl $V86_FLG,%eax              # Merge
 592                 andl $~V86_FLG,%edx             #  the
 593                 orl %eax,%edx                   #  flags
 594                 jmp v86mon.5                    # Finish up
 595 #
 596 # trap int 15, function 87
 597 # reads %es:%si from saved registers on stack to find a GDT containing
 598 # source and destination locations
 599 # reads count of words from saved %cx
 600 # returns success by setting %ah to 0
 601 #
 602 int15_87:       pushl %eax                      # Save
 603                 pushl %ebx                      #  some information
 604                 pushl %esi                      #  onto the stack.
 605                 pushl %edi
 606                 xorl %eax,%eax                  # clean EAX
 607                 xorl %ebx,%ebx                  # clean EBX
 608                 movl 0x4(%ebp),%esi             # Get user's ESI
 609                 movl 0x3C(%ebp),%ebx            # store ES
 610                 movw %si,%ax                    # store SI
 611                 shll $0x4,%ebx                  # Make it a seg.
 612                 addl %eax,%ebx                  # ebx=(es<<4)+si
 613                 movb 0x14(%ebx),%al             # Grab the
 614                 movb 0x17(%ebx),%ah             #  necessary
 615                 shll $0x10,%eax                 #  information
 616                 movw 0x12(%ebx),%ax             #  from
 617                 movl %eax,%esi                  #  the
 618                 movb 0x1c(%ebx),%al             #  GDT in order to
 619                 movb 0x1f(%ebx),%ah             #  have %esi offset
 620                 shll $0x10,%eax                 #  of source and %edi
 621                 movw 0x1a(%ebx),%ax             #  of destination.
 622                 movl %eax,%edi
 623                 pushl %ds                       # Make:
 624                 popl %es                        # es = ds
 625                 pushl %ecx                      # stash ECX
 626                 xorl %ecx,%ecx                  # highw of ECX is clear
 627                 movw 0x18(%ebp),%cx             # Get user's ECX
 628                 shll $0x1,%ecx                  # Convert from num words to num
 629                                                 #  bytes
 630                 rep                             # repeat...
 631                 movsb                           #  perform copy.
 632                 popl %ecx                       # Restore
 633                 popl %edi
 634                 popl %esi                       #  previous
 635                 popl %ebx                       #  register
 636                 popl %eax                       #  values.
 637                 movb $0x0,0x1d(%ebp)            # set ah = 0 to indicate
 638                                                 #  success
 639                 andb $0xfe,%dl                  # clear CF
 640                 jmp v86mon.5                    # Finish up
 641
 642 #
 643 # Reboot the machine by setting the reboot flag and exiting
 644 #
 645 reboot:         orb $0x1,btx_hdr+0x7            # Set the reboot flag
 646                 jmp exit                        # Terminate BTX and reboot
 647
 648 #
 649 # Emulate INT imm8... also make sure to check if it's int 15/87
 650 #
 651 v86intn:        lodsb                           # Get int no
 652                 cmpb $0x19,%al                  # is it int 19?
 653                 je reboot                       #  yes, reboot the machine
 654                 cmpb $0x15,%al                  # is it int 15?
 655                 jne v86intn.3                   #  no, skip parse
 656                 pushl %eax                      # stash EAX
 657                 movl 0x1c(%ebp),%eax            # user's saved EAX
 658                 cmpb $0x87,%ah                  # is it the memcpy subfunction?
 659                 jne v86intn.1                   #  no, keep checking
 660                 popl %eax                       # get the stack straight
 661                 jmp int15_87                    # it's our cue
 662 v86intn.1:      cmpw $0x4f53,%ax                # is it the delete key callout?
 663                 jne v86intn.2                   #  no, handle the int normally
 664                 movb BDA_KEYFLAGS,%al           # get the shift key state
 665                 andb $0xc,%al                   # mask off just Ctrl and Alt
 666                 cmpb $0xc,%al                   # are both Ctrl and Alt down?
 667                 jne v86intn.2                   #  no, handle the int normally
 668                 popl %eax                       # restore EAX
 669                 jmp reboot                      # reboot the machine
 670 v86intn.2:      popl %eax                       # restore EAX
 671 v86intn.3:      subl %edi,%esi                  # From
 672                 shrl $0x4,%edi                  #  linear
 673                 movw %dx,-0x2(%ebx)             # Save flags
 674                 movw %di,-0x4(%ebx)             # Save CS
 675                 leal -0x6(%ebx),%ebx            # Adjust SP
 676                 movw %si,(%ebx)                 # Save IP
 677                 shll $0x2,%eax                  # Scale
 678                 movzwl (%eax),%esi              # Load IP
 679                 movzwl 0x2(%eax),%edi           # Load CS
 680                 movl %edi,0x2c(%ebp)            # Save CS
 681                 xorl %edi,%edi                  # No ESI adjustment
 682                 andb $~0x1,%dh                  # Clear TF
 683                 jmp v86mon.5                    # Finish up
 684 #
 685 # Hardware interrupt jump table.
 686 #
 687 intx20:         push $0x8                       # Int 0x20: IRQ0
 688                 jmp int_hw                      # V86 int 0x8
 689                 push $0x9                       # Int 0x21: IRQ1
 690                 jmp int_hw                      # V86 int 0x9
 691                 push $0xa                       # Int 0x22: IRQ2
 692                 jmp int_hw                      # V86 int 0xa
 693                 push $0xb                       # Int 0x23: IRQ3
 694                 jmp int_hw                      # V86 int 0xb
 695                 push $0xc                       # Int 0x24: IRQ4
 696                 jmp int_hw                      # V86 int 0xc
 697                 push $0xd                       # Int 0x25: IRQ5
 698                 jmp int_hw                      # V86 int 0xd
 699                 push $0xe                       # Int 0x26: IRQ6
 700                 jmp int_hw                      # V86 int 0xe
 701                 push $0xf                       # Int 0x27: IRQ7
 702                 jmp int_hw                      # V86 int 0xf
 703                 push $0x70                      # Int 0x28: IRQ8
 704                 jmp int_hw                      # V86 int 0x70
 705                 push $0x71                      # Int 0x29: IRQ9
 706                 jmp int_hw                      # V86 int 0x71
 707                 push $0x72                      # Int 0x2a: IRQ10
 708                 jmp int_hw                      # V86 int 0x72
 709                 push $0x73                      # Int 0x2b: IRQ11
 710                 jmp int_hw                      # V86 int 0x73
 711                 push $0x74                      # Int 0x2c: IRQ12
 712                 jmp int_hw                      # V86 int 0x74
 713                 push $0x75                      # Int 0x2d: IRQ13
 714                 jmp int_hw                      # V86 int 0x75
 715                 push $0x76                      # Int 0x2e: IRQ14
 716                 jmp int_hw                      # V86 int 0x76
 717                 push $0x77                      # Int 0x2f: IRQ15
 718                 jmp int_hw                      # V86 int 0x77
 719 #
 720 # Reflect hardware interrupts.
 721 #
 722 int_hw:         testb $0x2,0xe(%esp,1)          # V86 mode?
 723                 jz intusr                       # No
 724                 pushl $SEL_SDATA                # Address
 725                 popl %ds                        #  data
 726                 xchgl %eax,(%esp,1)             # Swap EAX, int no
 727                 pushl %ebp                      # Address
 728                 movl %esp,%ebp                  #  stack frame
 729                 pushl %ebx                      # Save
 730                 shll $0x2,%eax                  # Get int
 731                 movl (%eax),%eax                #  vector
 732                 subl $0x6,0x14(%ebp)            # Adjust V86 ESP
 733                 movzwl 0x18(%ebp),%ebx          # V86 SS
 734                 shll $0x4,%ebx                  #  * 0x10
 735                 addl 0x14(%ebp),%ebx            #  + V86 ESP
 736                 xchgw %ax,0x8(%ebp)             # Swap V86 IP
 737                 rorl $0x10,%eax                 # Swap words
 738                 xchgw %ax,0xc(%ebp)             # Swap V86 CS
 739                 roll $0x10,%eax                 # Swap words
 740                 movl %eax,(%ebx)                # CS:IP for IRET
 741                 movl 0x10(%ebp),%eax            # V86 flags
 742                 movw %ax,0x4(%ebx)              # Flags for IRET
 743                 andb $~0x3,0x11(%ebp)           # Clear IF, TF
 744                 popl %ebx                       # Restore
 745                 popl %ebp                       #  saved
 746                 popl %eax                       #  registers
 747                 iret                            # To V86 mode
 748 #
 749 # Invoke V86 interrupt from user mode, with arguments.
 750 #
 751 intx31:         stc                             # Have btx_v86
 752                 pushl %eax                      # Missing int no
 753 #
 754 # Invoke V86 interrupt from user mode.
 755 #
 756 intusr:         std                             # String ops dec
 757                 pushl %eax                      # Expand
 758                 pushl %eax                      #  stack
 759                 pushl %eax                      #  frame
 760                 pusha                           # Save
 761                 pushl %gs                       # Save
 762                 movl %esp,%eax                  #  seg regs
 763                 pushl %fs                       #  and
 764                 pushl %ds                       #  point
 765                 pushl %es                       #  to them
 766                 push $SEL_SDATA                 # Set up
 767                 popl %ds                        #  to
 768                 pushl %ds                       #  address
 769                 popl %es                        #  data
 770                 movl $MEM_USR,%ebx              # User base
 771                 movl %ebx,%edx                  #  address
 772                 jc intusr.1                     # If btx_v86
 773                 xorl %edx,%edx                  # Control flags
 774                 xorl %ebp,%ebp                  # btx_v86 pointer
 775 intusr.1:       leal 0x50(%esp,1),%esi          # Base of frame
 776                 pushl %esi                      # Save
 777                 addl -0x4(%esi),%ebx            # User ESP
 778                 movl MEM_TSS+TSS_ESP1,%edi      # Link stack pointer
 779                 leal -0x4(%edi),%edi            # Adjust for push
 780                 xorl %ecx,%ecx                  # Zero
 781                 movb $0x5,%cl                   # Push exception
 782                 rep                             #  frame on
 783                 movsl                           #  link stack
 784                 xchgl %eax,%esi                 # Saved seg regs
 785                 movl 0x40(%esp,1),%eax          # Get int no
 786                 testl %edx,%edx                 # Have btx_v86?
 787                 jz intusr.2                     # No
 788                 movl (%ebx),%ebp                # btx_v86 pointer
 789                 movb $0x4,%cl                   # Count
 790                 addl %ecx,%ebx                  # Adjust for pop
 791                 rep                             # Push saved seg regs
 792                 movsl                           #  on link stack
 793                 addl %ebp,%edx                  # Flatten btx_v86 ptr
 794                 leal 0x14(%edx),%esi            # Seg regs pointer
 795                 movl 0x4(%edx),%eax             # Get int no/address
 796                 movzwl 0x2(%edx),%edx           # Get control flags
 797 intusr.2:       movl %ebp,(%edi)                # Push btx_v86 and
 798                 movl %edi,MEM_TSS+TSS_ESP1      #  save link stack ptr
 799                 popl %edi                       # Base of frame
 800                 xchgl %eax,%ebp                 # Save intno/address
 801                 movl 0x48(%esp,1),%eax          # Get flags
 802                 testb $0x2,%dl                  # Simulate CALLF?
 803                 jnz intusr.3                    # Yes
 804                 decl %ebx                       # Push flags
 805                 decl %ebx                       #  on V86
 806                 movw %ax,(%ebx)                 #  stack
 807 intusr.3:       movb $0x4,%cl                   # Count
 808                 subl %ecx,%ebx                  # Push return address
 809                 movl $inthlt,(%ebx)             #  on V86 stack
 810                 rep                             # Copy seg regs to
 811                 movsl                           #  exception frame
 812                 xchgl %eax,%ecx                 # Save flags
 813                 movl %ebx,%eax                  # User ESP
 814                 subl $V86_STK,%eax              # Less bytes
 815                 ja intusr.4                     #  to
 816                 xorl %eax,%eax                  #  keep
 817 intusr.4:       shrl $0x4,%eax                  # Gives segment
 818                 stosl                           # Set SS
 819                 shll $0x4,%eax                  # To bytes
 820                 xchgl %eax,%ebx                 # Swap
 821                 subl %ebx,%eax                  # Gives offset
 822                 stosl                           # Set ESP
 823                 xchgl %eax,%ecx                 # Get flags
 824                 btsl $0x11,%eax                 # Set VM
 825                 andb $~0x1,%ah                  # Clear TF
 826                 stosl                           # Set EFL
 827                 xchgl %eax,%ebp                 # Get int no/address
 828                 testb $0x1,%dl                  # Address?
 829                 jnz intusr.5                    # Yes
 830                 shll $0x2,%eax                  # Scale
 831                 movl (%eax),%eax                # Load int vector
 832 intusr.5:       movl %eax,%ecx                  # Save
 833                 shrl $0x10,%eax                 # Gives segment
 834                 stosl                           # Set CS
 835                 movw %cx,%ax                    # Restore
 836                 stosl                           # Set EIP
 837                 leal 0x10(%esp,1),%esp          # Discard seg regs
 838                 popa                            # Restore
 839                 iret                            # To V86 mode
 840 #
 841 # System Call.
 842 #
 843 intx30:         cmpl $SYS_EXEC,%eax             # Exec system call?
 844                 jne intx30.1                    # No
 845                 pushl %ss                       # Set up
 846                 popl %es                        #  all
 847                 pushl %es                       #  segment
 848                 popl %ds                        #  registers
 849                 pushl %ds                       #  for the
 850                 popl %fs                        #  program
 851                 pushl %fs                       #  we're
 852                 popl %gs                        #  invoking
 853                 movl $MEM_USR,%eax              # User base address
 854                 addl 0xc(%esp,1),%eax           # Change to user
 855                 leal 0x4(%eax),%esp             #  stack
 856 ifdef(`PAGING',`
 857                 movl %cr0,%eax                  # Turn
 858                 andl $~0x80000000,%eax          #  off
 859                 movl %eax,%cr0                  #  paging
 860                 xorl %eax,%eax                  # Flush
 861                 movl %eax,%cr3                  #  TLB
 862 ')
 863                 popl %eax                       # Call
 864                 call *%eax                      #  program
 865 intx30.1:       incb %ss:btx_hdr+0x7            # Flag reboot
 866                 jmp exit                        # Exit
 867 #
 868 # Dump structure [EBX] to [EDI], using format string [ESI].
 869 #
 870 dump.0:         stosb                           # Save char
 871 dump:           lodsb                           # Load char
 872                 testb %al,%al                   # End of string?
 873                 jz dump.10                      # Yes
 874                 testb $0x80,%al                 # Control?
 875                 jz dump.0                       # No
 876                 movb %al,%ch                    # Save control
 877                 movb $'=',%al                   # Append
 878                 stosb                           #  '='
 879                 lodsb                           # Get offset
 880                 pushl %esi                      # Save
 881                 movsbl %al,%esi                 # To
 882                 addl %ebx,%esi                  #  pointer
 883                 testb $DMP_X16,%ch              # Dump word?
 884                 jz dump.1                       # No
 885                 lodsw                           # Get and
 886                 call hex16                      #  dump it
 887 dump.1:         testb $DMP_X32,%ch              # Dump long?
 888                 jz dump.2                       # No
 889                 lodsl                           # Get and
 890                 call hex32                      #  dump it
 891 dump.2:         testb $DMP_MEM,%ch              # Dump memory?
 892                 jz dump.8                       # No
 893                 pushl %ds                       # Save
 894                 testb $0x2,0x52(%ebx)           # V86 mode?
 895                 jnz dump.3                      # Yes
 896                 verr 0x4(%esi)                  # Readable selector?
 897                 jnz dump.3                      # No
 898                 ldsl (%esi),%esi                # Load pointer
 899                 jmp dump.4                      # Join common code
 900 dump.3:         lodsl                           # Set offset
 901                 xchgl %eax,%edx                 # Save
 902                 lodsl                           # Get segment
 903                 shll $0x4,%eax                  #  * 0x10
 904                 addl %edx,%eax                  #  + offset
 905                 xchgl %eax,%esi                 # Set pointer
 906 dump.4:         movb $0x10,%cl                  # Bytes to dump
 907 dump.5:         lodsb                           # Get byte and
 908                 call hex8                       #  dump it
 909                 decb %cl                        # Keep count
 910                 jz dump.7                       # If done
 911                 movb $'-',%al                   # Separator
 912                 cmpb $0x8,%cl                   # Half way?
 913                 je dump.6                       # Yes
 914                 movb $' ',%al                   # Use space
 915 dump.6:         stosb                           # Save separator
 916                 jmp dump.5                      # Continue
 917 dump.7:         popl %ds                        # Restore
 918 dump.8:         popl %esi                       # Restore
 919                 movb $0xa,%al                   # Line feed
 920                 testb $DMP_EOL,%ch              # End of line?
 921                 jnz dump.9                      # Yes
 922                 movb $' ',%al                   # Use spaces
 923                 stosb                           # Save one
 924 dump.9:         jmp dump.0                      # Continue
 925 dump.10:        stosb                           # Terminate string
 926                 ret                             # To caller
 927 #
 928 # Convert EAX, AX, or AL to hex, saving the result to [EDI].
 929 #
 930 hex32:          pushl %eax                      # Save
 931                 shrl $0x10,%eax                 # Do upper
 932                 call hex16                      #  16
 933                 popl %eax                       # Restore
 934 hex16:          call hex16.1                    # Do upper 8
 935 hex16.1:        xchgb %ah,%al                   # Save/restore
 936 hex8:           pushl %eax                      # Save
 937                 shrb $0x4,%al                   # Do upper
 938                 call hex8.1                     #  4
 939                 popl %eax                       # Restore
 940 hex8.1:         andb $0xf,%al                   # Get lower 4
 941                 cmpb $0xa,%al                   # Convert
 942                 sbbb $0x69,%al                  #  to hex
 943                 das                             #  digit
 944                 orb $0x20,%al                   # To lower case
 945                 stosb                           # Save char
 946                 ret                             # (Recursive)
 947 #
 948 # Output zero-terminated string [ESI] to the console.
 949 #
 950 putstr.0:       call putchr                     # Output char
 951 putstr:         lodsb                           # Load char
 952                 testb %al,%al                   # End of string?
 953                 jnz putstr.0                    # No
 954                 ret                             # To caller
 955 #
 956 # Output character AL to the console.
 957 #
 958 putchr:         pusha                           # Save
 959                 xorl %ecx,%ecx                  # Zero for loops
 960                 movb $SCR_MAT,%ah               # Mode/attribute
 961                 movl $BDA_POS,%ebx              # BDA pointer
 962                 movw (%ebx),%dx                 # Cursor position
 963                 movl $0xb8000,%edi              # Regen buffer (color)
 964                 cmpb %ah,BDA_SCR-BDA_POS(%ebx)  # Mono mode?
 965                 jne putchr.1                    # No
 966                 xorw %di,%di                    # Regen buffer (mono)
 967 putchr.1:       cmpb $0xa,%al                   # New line?
 968                 je putchr.2                     # Yes
 969                 xchgl %eax,%ecx                 # Save char
 970                 movb $SCR_COL,%al               # Columns per row
 971                 mulb %dh                        #  * row position
 972                 addb %dl,%al                    #  + column
 973                 adcb $0x0,%ah                   #  position
 974                 shll %eax                       #  * 2
 975                 xchgl %eax,%ecx                 # Swap char, offset
 976                 movw %ax,(%edi,%ecx,1)          # Write attr:char
 977                 incl %edx                       # Bump cursor
 978                 cmpb $SCR_COL,%dl               # Beyond row?
 979                 jb putchr.3                     # No
 980 putchr.2:       xorb %dl,%dl                    # Zero column
 981                 incb %dh                        # Bump row
 982 putchr.3:       cmpb $SCR_ROW,%dh               # Beyond screen?
 983                 jb putchr.4                     # No
 984                 leal 2*SCR_COL(%edi),%esi       # New top line
 985                 movw $(SCR_ROW-1)*SCR_COL/2,%cx # Words to move
 986                 rep                             # Scroll
 987                 movsl                           #  screen
 988                 movb $' ',%al                   # Space
 989                 movb $SCR_COL,%cl               # Columns to clear
 990                 rep                             # Clear
 991                 stosw                           #  line
 992                 movb $SCR_ROW-1,%dh             # Bottom line
 993 putchr.4:       movw %dx,(%ebx)                 # Update position
 994                 popa                            # Restore
 995                 ret                             # To caller
 996
 997                 .p2align 4
 998 #
 999 # Global descriptor table.
1000 #
1001 gdt:            .word 0x0,0x0,0x0,0x0           # Null entry
1002                 .word 0xffff,0x0,0x9a00,0xcf    # SEL_SCODE
1003                 .word 0xffff,0x0,0x9200,0xcf    # SEL_SDATA
1004                 .word 0xffff,0x0,0x9a00,0x0     # SEL_RCODE
1005                 .word 0xffff,0x0,0x9200,0x0     # SEL_RDATA
1006                 .word 0xffff,MEM_USR,0xfa00,0xcf# SEL_UCODE
1007                 .word 0xffff,MEM_USR,0xf200,0xcf# SEL_UDATA
1008                 .word _TSSLM,MEM_TSS,0x8900,0x0 # SEL_TSS
1009 gdt.1:
1010 #
1011 # Pseudo-descriptors.
1012 #
1013 gdtdesc:        .word gdt.1-gdt-1,gdt,0x0       # GDT
1014 idtdesc:        .word _IDTLM,MEM_IDT,0x0        # IDT
1015 ivtdesc:        .word 0x400-0x0-1,0x0,0x0       # IVT
1016 #
1017 # IDT construction control string.
1018 #
1019 idtctl:         .byte 0x10,  0x8e               # Int 0x0-0xf
1020                 .word 0x7dfb,intx00             #  (exceptions)
1021                 .byte 0x10,  0x8e               # Int 0x10
1022                 .word 0x1,   intx10             #  (exception)
1023                 .byte 0x10,  0x8e               # Int 0x20-0x2f
1024                 .word 0xffff,intx20             #  (hardware)
1025                 .byte 0x1,   0xee               # int 0x30
1026                 .word 0x1,   intx30             #  (system call)
1027                 .byte 0x2,   0xee               # Int 0x31-0x32
1028                 .word 0x1,   intx31             #  (V86, null)
1029                 .byte 0x0                       # End of string
1030 #
1031 # Dump format string.
1032 #
1033 dmpfmt:         .byte '\n'                      # "\n"
1034                 .ascii "int"                    # "int="
1035                 .byte 0x80|DMP_X32,        0x40 # "00000000  "
1036                 .ascii "err"                    # "err="
1037                 .byte 0x80|DMP_X32,        0x44 # "00000000  "
1038                 .ascii "efl"                    # "efl="
1039                 .byte 0x80|DMP_X32,        0x50 # "00000000  "
1040                 .ascii "eip"                    # "eip="
1041                 .byte 0x80|DMP_X32|DMP_EOL,0x48 # "00000000\n"
1042                 .ascii "eax"                    # "eax="
1043                 .byte 0x80|DMP_X32,        0x34 # "00000000  "
1044                 .ascii "ebx"                    # "ebx="
1045                 .byte 0x80|DMP_X32,        0x28 # "00000000  "
1046                 .ascii "ecx"                    # "ecx="
1047                 .byte 0x80|DMP_X32,        0x30 # "00000000  "
1048                 .ascii "edx"                    # "edx="
1049                 .byte 0x80|DMP_X32|DMP_EOL,0x2c # "00000000\n"
1050                 .ascii "esi"                    # "esi="
1051                 .byte 0x80|DMP_X32,        0x1c # "00000000  "
1052                 .ascii "edi"                    # "edi="
1053                 .byte 0x80|DMP_X32,        0x18 # "00000000  "
1054                 .ascii "ebp"                    # "ebp="
1055                 .byte 0x80|DMP_X32,        0x20 # "00000000  "
1056                 .ascii "esp"                    # "esp="
1057                 .byte 0x80|DMP_X32|DMP_EOL,0x0  # "00000000\n"
1058                 .ascii "cs"                     # "cs="
1059                 .byte 0x80|DMP_X16,        0x4c # "0000  "
1060                 .ascii "ds"                     # "ds="
1061                 .byte 0x80|DMP_X16,        0xc  # "0000  "
1062                 .ascii "es"                     # "es="
1063                 .byte 0x80|DMP_X16,        0x8  # "0000  "
1064                 .ascii "  "                     # "  "
1065                 .ascii "fs"                     # "fs="
1066                 .byte 0x80|DMP_X16,        0x10 # "0000  "
1067                 .ascii "gs"                     # "gs="
1068                 .byte 0x80|DMP_X16,        0x14 # "0000  "
1069                 .ascii "ss"                     # "ss="
1070                 .byte 0x80|DMP_X16|DMP_EOL,0x4  # "0000\n"
1071                 .ascii "cs:eip"                 # "cs:eip="
1072                 .byte 0x80|DMP_MEM|DMP_EOL,0x48 # "00 00 ... 00 00\n"
1073                 .ascii "ss:esp"                 # "ss:esp="
1074                 .byte 0x80|DMP_MEM|DMP_EOL,0x0  # "00 00 ... 00 00\n"
1075                 .asciz "BTX halted"             # End
1076 #
1077 # End of BTX memory.
1078 #
1079                 .p2align 4
1080 break: