root/arch/mips/kernel/entry.S

/* */

   1 /*
   2  * arch/mips/kernel/entry.S
   3  *
   4  * Copyright (C) 1994, 1995 Waldorf Electronics
   5  * written by Ralf Baechle
   6  */
   7 
   8 /*
   9  * entry.S contains the system-call and fault low-level handling routines.
  10  * This also contains the timer-interrupt handler, as well as all interrupts
  11  * and faults that can result in a task-switch.
  12  */
  13 
  14 #include <linux/sys.h>
  15 #include <linux/autoconf.h>
  16 #include <asm/segment.h>
  17 #include <asm/mipsregs.h>
  18 #include <asm/mipsconfig.h>
  19 #include <asm/page.h>
  20 #include <asm/stackframe.h>
  21 #include <asm/regdef.h>
  22 #include <asm/processor.h>
  23 
  24 /*
  25  * These are offsets into the task-struct.
  26  */
  27 state           =  0
  28 counter         =  4
  29 priority        =  8
  30 signal          = 12
  31 blocked         = 16
  32 flags           = 20
  33 errno           = 24                    #/* MIPS OK */
  34 exec_domain     = 60                    #/* ??? */
  35 
  36 ENOSYS          = 38
  37 
  38                 .globl  ret_from_sys_call
  39                 .globl  _sys_call_table
  40 
  41                 .text
  42                 .set    noreorder
  43                 .align 4
  44 handle_bottom_half:
  45                 /*
  46                  * If your assembler breaks on the next line it's
  47                  * time to update!
  48                  */
  49                 lui     s0,%hi(_intr_count)
  50                 lw      s1,%lo(_intr_count)(s0)
  51                 mfc0    s3,CP0_STATUS                   # Enable IRQs
  52                 addiu   s2,s1,1
  53                 sw      s2,%lo(_intr_count)(s0)
  54                 ori     t0,s3,0x1f
  55                 xori    t0,t0,0x1e
  56                 jal     _do_bottom_half
  57                 mtc0    t0,CP0_STATUS                   # delay slot
  58                 mtc0    s3,CP0_STATUS                   # Restore old IRQ state
  59                 j       9f
  60                 sw      s1,%lo(_intr_count)(s0)         # delay slot
  61 
  62                 .set    reorder
  63 reschedule:
  64                 la      ra,ret_from_sys_call
  65                 j       _schedule
  66                 nop
  67 
  68                 .align  5
  69                 .globl  _handle_sys
  70 _handle_sys:
  71                 .set    noreorder
  72                 .set    noat
  73                 SAVE_ALL
  74                 .set    at
  75                 STI
  76                 /*
  77                  * Compute return address. For now we assume that syscalls never
  78                  * appear in branch delay slots. For the Linux/MIPS standard
  79                  * libraries this assumption is always try.
  80                  */
  81                 lw      t3,FR_EPC(sp)
  82                 lw      s1,FR_REG2(sp)
  83                 li      t0,-ENOSYS
  84                 addiu   t3,t3,4
  85                 sw      t3,FR_EPC(sp)
  86                 li      t2,NR_syscalls
  87                 bge     s1,t2,ret_from_sys_call
  88                 sw      t0,FR_REG2(sp)          # delay slot
  89                 sll     s1,s1,2
  90                 lw      s1,_sys_call_table(s1)
  91                 lw      s0,_current
  92 
  93                 beqz    s1,ret_from_sys_call
  94                 lw      t0,flags(s0)
  95                 sll     t0,t0,2                 # PF_TRACESYS
  96                 bltz    t0,1f
  97                 sw      zero,errno(s0)          # delay slot
  98 
  99                 lw      a0,FR_REG4(sp)
 100                 lw      a1,FR_REG5(sp)
 101                 lw      a2,FR_REG6(sp)
 102                 lw      a3,FR_REG7(sp)
 103                 lw      t0,FR_REG3(sp)
 104                 jalr    s1                      # do the real work
 105                 sw      t0,16(sp)               # delay slot
 106 
 107                 lw      t0,errno(s0)
 108                 sw      v0,FR_REG2(sp)          # save the return value
 109                 subu    t0,zero,t0              # t0 = -t0
 110                 beqz    t0,ret_from_sys_call
 111                 nop
 112                 /*
 113                  * Fixme: should set error flag
 114                  */
 115                 j       ret_from_sys_call
 116                 sw      t0,FR_REG2(sp)          # delay slot
 117 
 118                 .align  4
 119 1:              jal     _syscall_trace
 120                 nop                             # delay slot
 121 
 122                 lw      a0,FR_REG4(sp)
 123                 lw      a1,FR_REG5(sp)
 124                 lw      a2,FR_REG6(sp)
 125                 lw      a3,FR_REG7(sp)
 126                 lw      t0,FR_REG3(sp)
 127                 jalr    s1                      # do the real work
 128                 sw      t0,16(sp)               # delay slot
 129 
 130                 lw      t0,errno(s0)
 131                 sw      v0,FR_REG2(sp)          # save the return value
 132                 subu    t0,zero,t0
 133                 beqz    t0,1f
 134                 nop                             # delay slot
 135                 sw      t1,FR_REG2(sp)
 136                 /*
 137                  * Fixme: should set error flag
 138                  */
 139 1:              jal     _syscall_trace
 140                 nop
 141 
 142                 .align  4
 143 ret_from_sys_call:
 144                 lw      t0,_intr_count          # bottom half
 145                 bnez    t0,2f
 146 9:
 147                 lw      t0,_bh_mask             # delay slot
 148                 lw      t1,_bh_active           # unused delay slot
 149                 and     t0,t1
 150                 bnez    t0,handle_bottom_half
 151 
 152                 lw      t0,FR_STATUS(sp)        # returning to supervisor ?
 153                 andi    t1,t0,0x10
 154                 beqz    t1,2f
 155 
 156                 mfc0    t0,CP0_STATUS           # delay slot
 157                 lw      t1,_need_resched
 158                 ori     t0,0x1f                 # enable irqs
 159                 xori    t0,0x1e
 160                 bnez    t1,reschedule
 161                 mtc0    t0,CP0_STATUS           # delay slot
 162 
 163                 lw      s0,_current
 164                 lw      t0,_task
 165                 lw      t1,state(s0)            # state
 166                 beq     s0,t0,2f                # task[0] cannot have signals
 167                 lw      t0,counter(s0)          # counter
 168                 bnez    t1,reschedule           # state == 0 ?
 169                 lw      a0,blocked(s0)
 170                                                 # save blocked in a0 for
 171                                                 # signal handling
 172                 beqz    t0,reschedule           # counter == 0 ?
 173                 lw      t0,signal(s0)
 174                 nor     t1,zero,a0
 175                 and     t1,t0,t1
 176                 beqz    t1,skip_signal_return
 177                 nop
 178 
 179                 jal     _do_signal
 180                 move    a1,sp                   # delay slot
 181                 
 182 skip_signal_return:
 183                 .set    noreorder
 184                 .set    noat
 185 2:
 186 return:         RESTORE_ALL
 187                 .set    at
 188 
 189 #ifdef CONFIG_DESKSTATION_TYNE
 190 /*
 191  * Deskstation Tyne interrupt handler
 192  */
 193                 .text
 194                 .set    noreorder
 195                 .set    noat
 196                 .globl  _deskstation_tyne_handle_int
 197                 .align  5
 198 _deskstation_tyne_handle_int:
 199                 SAVE_ALL
 200                 .set    at
 201                 CLI
 202                 lui     s0,%hi(PORT_BASE)
 203                 li      t1,0x0f
 204                 sb      t1,%lo(PORT_BASE+0x20)(s0)      # poll command
 205                 lb      t1,%lo(PORT_BASE+0x20)(s0)      # read result
 206                 li      s1,1
 207                 bgtz    t1,Lpoll_second
 208                 andi    t1,t1,7
 209                 /*
 210                  * Acknowledge first pic
 211                  */
 212                 lb      t2,%lo(PORT_BASE+0x21)(s0)
 213                 lui     s4,%hi(_cache_21)
 214                 lb      t0,%lo(_cache_21)(s4)
 215                 sllv    s1,s1,t1
 216                 or      t0,t0,s1
 217                 sb      t0,%lo(_cache_21)(s4)
 218                 sb      t0,%lo(PORT_BASE+0x21)(s0)
 219                 lui     s3,%hi(_intr_count)
 220                 lw      t0,%lo(_intr_count)(s3)
 221                 li      t2,0x20
 222                 sb      t2,%lo(PORT_BASE+0x20)(s0)
 223                 /*
 224                  * Now call the real handler
 225                  */
 226                 la      t3,_IRQ_vectors
 227                 sll     t2,t1,2
 228                 addu    t3,t3,t2
 229                 lw      t3,(t3)
 230                 addiu   t0,t0,1
 231                 jalr    t3
 232                 sw      t0,%lo(_intr_count)(s3)         # delay slot
 233                 lw      t0,%lo(_intr_count)(s3)
 234                 /*
 235                  * Unblock first pic
 236                  */
 237                 lbu     t1,%lo(PORT_BASE+0x21)(s0)
 238                 lb      t1,%lo(_cache_21)(s4)
 239                 subu    t0,t0,1
 240                 sw      t0,%lo(_intr_count)(s3)
 241                 nor     s1,zero,s1
 242                 and     t1,t1,s1
 243                 sb      t1,%lo(_cache_21)(s4)
 244                 jr      v0
 245                 sb      t1,%lo(PORT_BASE+0x21)(s0)      # delay slot
 246 
 247                 .align  5
 248 Lpoll_second:   li      t1,0x0f
 249                 sb      t1,%lo(PORT_BASE+0xa0)(s0)      # poll command
 250                 lb      t1,%lo(PORT_BASE+0xa0)(s0)      # read result
 251                 lui     s4,%hi(_cache_A1)
 252                 bgtz    t1,Lspurious_interrupt
 253                 andi    t1,t1,7
 254                 /*
 255                  * Acknowledge second pic
 256                  */
 257                 lbu     t2,%lo(PORT_BASE+0xa1)(s0)
 258                 lb      t3,%lo(_cache_A1)(s4)
 259                 sllv    s1,s1,t1
 260                 or      t3,t3,s1
 261                 sb      t3,%lo(_cache_A1)(s4)
 262                 sb      t3,%lo(PORT_BASE+0xa1)(s0)
 263                 li      t3,0x20
 264                 sb      t3,%lo(PORT_BASE+0xa0)(s0)
 265                 lui     s3,%hi(_intr_count)
 266                 lw      t0,%lo(_intr_count)(s3)
 267                 sb      t3,%lo(PORT_BASE+0x20)(s0)
 268                 /*
 269                  * Now call the real handler
 270                  */
 271                 la      t0,_IRQ_vectors
 272                 sll     t2,t1,2
 273                 addu    t0,t0,t2
 274                 lw      t0,32(t0)
 275                 addiu   t0,t0,1
 276                 jalr    t0
 277                 sw      t0,%lo(_intr_count)(s3)         # delay slot
 278                 lw      t0,%lo(_intr_count)(s3)
 279                 /*
 280                  * Unblock second pic
 281                  */
 282                 lb      t1,%lo(PORT_BASE+0xa1)(s0)
 283                 lb      t1,%lo(_cache_A1)(s4)
 284                 subu    t0,t0,1
 285                 lw      t0,%lo(_intr_count)(s3)
 286                 nor     s1,zero,s1
 287                 and     t1,t1,s1
 288                 sb      t1,%lo(_cache_A1)(s4)
 289                 jr      v0
 290                 sb      t1,%lo(PORT_BASE+0xa1)(s0)      # delay slot
 291 
 292                 .align  5
 293 Lspurious_interrupt:
 294                 /*
 295                  * Nothing happened... (whistle)
 296                  */
 297                 lui     t1,%hi(_spurious_count)
 298                 lw      t0,%lo(_spurious_count)(t1)
 299                 la      v0,return
 300                 addiu   t0,t0,1
 301                 jr      ra
 302                 sw      t0,%lo(_spurious_count)(t1)
 303 #endif /* CONFIG_DESKSTATION_TYNE */
 304                 
 305 #ifdef CONFIG_ACER_PICA_61
 306 /*
 307  * Acer PICA interrupt handler dummy
 308  */
 309                 .set    noreorder
 310                 .set    noat
 311                 .globl  _acer_pica_61_handle_int
 312                 .align  5
 313 _acer_pica_61_handle_int:
 314                 la      a0,acer_text
 315                 jal     _panic
 316                 nop
 317 1:              b       1b
 318                 nop
 319 acer_text:      .asciz  "Interrupt handler for Acer PICA not written yet"
 320                 .align  2
 321 #endif /* CONFIG_ACER_PICA_61 */
 322 
 323                 .text
 324                 .set    noreorder
 325                 .set    at
 326                 .globl  _interrupt
 327                 .align  5
 328 _interrupt:     move    s2,ra
 329                 mfc0    t0,CP0_STATUS
 330                 ori     t0,t0,0x1f
 331                 xori    t0,t0,0x1e
 332                 mtc0    t0,CP0_STATUS
 333                 move    a0,t1
 334                 jal     _do_IRQ
 335                 move    a1,sp                           # delay slot
 336                 mfc0    t0,CP0_STATUS
 337                 ori     t0,t0,1
 338                 xori    t0,t0,1
 339                 la      v0,ret_from_sys_call
 340                 jr      s2
 341                 mtc0    t0,CP0_STATUS                   # delay slot
 342 
 343                 .globl  _fast_interrupt
 344                 .align  5
 345 _fast_interrupt:
 346                 move    s2,ra
 347                 move    a0,t1
 348                 jal     _do_fast_IRQ
 349                 move    a1,sp                           # delay slot
 350                 la      v0,return
 351                 jr      s2
 352                 nop                                     # delay slot
 353 
 354                 .globl  _bad_interrupt
 355 _bad_interrupt:
 356                 /*
 357                  * Don't return & unblock the pic
 358                  */
 359                 j       return
 360                 nop
 361 
 362                 .globl  _handle_tlbl
 363                 .align  5
 364 _handle_tlbl:
 365                 .set    noreorder
 366                 .set    noat
 367                 /*
 368                  * Check whether this is a refill or an invalid exception
 369                  *
 370                  * NOTE: Some MIPS manuals say that the R4x00 sets the
 371                  * BadVAddr only when EXL == 0. This is wrong - BadVaddr
 372                  * is being set for all Reload, Invalid and Modified
 373                  * exceptions.
 374                  */
 375                 mfc0    k0,CP0_BADVADDR
 376                 mfc0    k1,CP0_ENTRYHI
 377                 ori     k0,k0,0x1fff
 378                 xori    k0,k0,0x1fff
 379                 andi    k1,k1,0xff
 380                 or      k0,k0,k1
 381                 mfc0    k1,CP0_ENTRYHI
 382                 mtc0    k0,CP0_ENTRYHI
 383                 nop                                     # for R4[04]00 pipeline
 384                 nop
 385                 nop
 386                 tlbp
 387                 nop                                     # for R4[04]00 pipeline
 388                 nop
 389                 mfc0    k0,CP0_INDEX
 390                 srl     k0,k0,31
 391                 beqz    k0,invalid_tlbl
 392                 mtc0    k1,CP0_ENTRYHI                  # delay slot
 393                 /*
 394                  * Not in tlb -> nested refill exception
 395                  * Load the missing entry and return. This is the most
 396                  * efficient way to regain the faulting address.
 397                  */
 398                 dmfc0   k1,CP0_CONTEXT
 399                 dsra    k1,k1,1
 400                 lwu     k0,(k1)                 # Never causes another exception
 401                 lwu     k1,4(k1)
 402                 dsrl    k0,k0,6                 # Convert to EntryLo format
 403                 dsrl    k1,k1,6                 # Convert to EntryLo format
 404                 dmtc0   k0,CP0_ENTRYLO0
 405                 dmtc0   k1,CP0_ENTRYLO1
 406                 nop                             # for R4[04]00 pipeline
 407                 tlbwr
 408                 eret
 409 
 410                 /*
 411                  * Handle invalid exception
 412                  *
 413                  * There are two possible causes for an invalid (tlbl)
 414                  * exception:
 415                  * 1) pages that have the present bit set but the valid bit
 416                  *    unset.
 417                  * 2) pages that don't exist
 418                  * Case one needs fast handling, therefore don't save
 419                  * registers yet.
 420                  *
 421                  * k0 now contains the bad virtual address.
 422                  */
 423 invalid_tlbl:
 424                 /*
 425                  * Remove entry so we don't need to care later
 426                  */
 427                 mfc0    k0,CP0_INDEX
 428                 lui     k1,0x0008
 429                 or      k0,k0,k1
 430                 dsll    k0,k0,13
 431                 dmtc0   k0,CP0_ENTRYHI
 432                 dmtc0   zero,CP0_ENTRYLO0
 433                 dmtc0   zero,CP0_ENTRYLO1
 434                 /*
 435                  * Test whether present bit in entry is set
 436                  */
 437                 dmfc0   k0,CP0_BADVADDR
 438                 tlbwi                                           # delayed, for R4[04]00 pipeline
 439                 srl     k0,k0,10
 440                 lui     k1,%HI(TLBMAP)
 441                 addu    k0,k0,k1
 442                 ori     k0,k0,3
 443                 xori    k0,k0,3
 444                 lw      k1,(k0)
 445                 andi    k1,k1,_PAGE_PRESENT
 446                 beqz    k1,nopage_tlbl
 447                 /*
 448                  * Present bit is set -> set valid and accessed bits
 449                  */
 450                 lw      k1,(k0)                         # delay slot
 451                 ori     k1,k1,_PAGE_ACCESSED
 452                 sw      k1,(k0)
 453                 eret
 454 
 455                 /*
 456                  * Page doesn't exist. Lots of work which is less important
 457                  * for speed needs to be done, so hand it all over to the
 458                  * kernel memory management routines.
 459                  */
 460 nopage_tlbl:
 461                 SAVE_ALL
 462                 .set    at
 463                 STI
 464                 /*
 465                  * Create a Intel-style errorcode
 466                  * Bit 0: P Present
 467                  *        0 == Page not in memory
 468                  *        1 == privilege violation
 469                  * Bit 1: R/W Read/Write
 470                  *        0 == ReadAccess
 471                  *        1 == WriteAccess
 472                  * Bit 2: U/S User/Supervisor
 473                  *        0 == User mode
 474                  *        1 == Kernel mode
 475                  *
 476                  * a0 (struct pt_regs *) regs
 477                  * a1 (unsigned long)    error_code
 478                  */
 479                 lw      a1,FR_STATUS(sp)
 480                 move    a0,sp
 481                 srl     a1,a1,4
 482                 andi    a1,a1,1
 483                 jal     _do_page_fault
 484                 xori    a1,a1,1                         # delay slot
 485                 j       ret_from_sys_call
 486                 nop                                     # delay slot
 487 
 488                 .text
 489                 .globl  _handle_tlbs
 490                 .align  5
 491 _handle_tlbs:
 492                 .set    noreorder
 493                 .set    noat
 494                 /*
 495                  * It is impossible that is a nested reload exception.
 496                  * Therefore this must be a invalid exception.
 497                  * Two possible cases:
 498                  * 1) Page not used yet
 499                  * 2) Page doesn't exist yet. Let the kernel handle the trouble.
 500                  *
 501                  * Test whether present bit in entry is set
 502                  */
 503                 dmfc0   k0,CP0_BADVADDR
 504                 srl     k0,k0,10
 505                 lui     k1,%HI(TLBMAP)
 506                 addu    k0,k0,k1
 507                 ori     k0,k0,3
 508                 xori    k0,k0,3
 509                 lw      k1,(k0)
 510                 andi    k1,k1,(_PAGE_PRESENT|_PAGE_RW)
 511                 beqz    k1,nopage_tlbs
 512                 /*
 513                  * Present and writable bits set -> set accessed and dirty bits.
 514                  */
 515                 lw      k1,(k0)                         # delay slot
 516                 ori     k1,k1,(_PAGE_ACCESSED|_PAGE_DIRTY)
 517                 sw      k1,(k0)
 518                 /*
 519                  * Now reload the entry into the tlb
 520                  */
 521                 ori     k0,k0,0x1000
 522                 xori    k0,k0,0x1000
 523                 lw      k1,4(k0)
 524                 lw      k0,(k0)
 525                 srl     k0,k0,6
 526                 srl     k1,k1,6
 527                 dmtc0   k0,CP0_ENTRYLO0
 528                 dmtc0   k1,CP0_ENTRYLO1
 529                 tlbwi
 530                 eret
 531 
 532                 /*
 533                  * Page doesn't exist. Lots of work which is less important
 534                  * for speed needs to be done, so hand it all over to the
 535                  * kernel memory management routines.
 536                  */
 537 nopage_tlbs:
 538 nowrite_mod:
 539                 /*
 540                  * Remove entry so we don't need to care later
 541                  */
 542                 mfc0    k0,CP0_INDEX
 543                 lui     k1,0x0008
 544                 or      k0,k0,k1
 545                 dsll    k0,k0,13
 546                 dmtc0   k0,CP0_ENTRYHI
 547                 dmtc0   zero,CP0_ENTRYLO0
 548                 dmtc0   zero,CP0_ENTRYLO1
 549                 tlbwi
 550                 SAVE_ALL
 551                 .set    at
 552                 STI
 553                 /*
 554                  * Create a Intel-style errorcode
 555                  * Bit 0: P Present
 556                  *        0 == Page not in memory
 557                  *        1 == privilege violation
 558                  * Bit 1: R/W Read/Write
 559                  *        0 == ReadAccess
 560                  *        1 == WriteAccess
 561                  * Bit 2: U/S User/Supervisor
 562                  *        0 == User mode
 563                  *        1 == Kernel mode
 564                  *
 565                  * a0 (struct pt_regs *) regs
 566                  * a1 (unsigned long)    error_code
 567                  */
 568                 lw      a1,FR_STATUS(sp)
 569                 move    a0,sp
 570                 srl     a1,a1,4
 571                 andi    a1,a1,1
 572                 jal     _do_page_fault
 573                 xori    a1,a1,3                         # branch delay slot
 574                 j       ret_from_sys_call
 575                 nop                                     # branch delay slot
 576 
 577                 .globl  _handle_mod
 578                 .align  5
 579 _handle_mod:
 580                 .set    noreorder
 581                 .set    noat
 582                 /*
 583                  * Two possible cases:
 584                  * 1) Page is rw but not dirty -> set dirty and return
 585                  * 2) Page is not rw -> call C handler
 586                  */
 587                 dmfc0   k0,CP0_BADVADDR
 588                 srl     k0,k0,10
 589                 lui     k1,%HI(TLBMAP)
 590                 addu    k0,k0,k1
 591                 ori     k0,k0,3
 592                 xori    k0,k0,3
 593                 lw      k1,(k0)
 594                 andi    k1,k1,_PAGE_RW
 595                 beqz    k1,nopage_tlbs
 596                 /*
 597                  * Present and writable bits set -> set accessed and dirty bits.
 598                  */
 599                 lw      k1,(k0)                         # delay slot
 600                 ori     k1,k1,(_PAGE_ACCESSED|_PAGE_DIRTY)
 601                 sw      k1,(k0)
 602                 /*
 603                  * Now reload the entry into the tlb
 604                  */
 605                 ori     k0,k0,0x1000
 606                 xori    k0,k0,0x1000
 607                 lw      k1,4(k0)
 608                 lw      k0,(k0)
 609                 srl     k0,k0,6
 610                 srl     k1,k1,6
 611                 dmtc0   k0,CP0_ENTRYLO0
 612                 dmtc0   k1,CP0_ENTRYLO1
 613                 tlbwi
 614                 eret
 615 
 616                 .globl  _handle_adel
 617                 .align  5
 618 _handle_adel:
 619                 .set    noreorder
 620                 .set    noat
 621                 SAVE_ALL
 622                 STI
 623                 li      t0,-1
 624                 sw      t0,FR_ORIG_REG2(sp)
 625                 jal     _do_adel
 626                 move    a0,sp                   # delay slot
 627                 j       ret_from_sys_call
 628                 nop                             # delay slot
 629 
 630                 .globl  _handle_ades
 631                 .align  5
 632 _handle_ades:
 633                 .set    noreorder
 634                 .set    noat
 635                 SAVE_ALL
 636                 STI
 637                 li      t0,-1
 638                 sw      t0,FR_ORIG_REG2(sp)
 639                 jal     _do_ades
 640                 move    a0,sp                   # delay slot
 641                 j       ret_from_sys_call
 642                 nop                             # delay slot
 643 
 644                 .globl  _handle_ibe
 645                 .align  5
 646 _handle_ibe:
 647                 .set    noreorder
 648                 .set    noat
 649                 SAVE_ALL
 650                 STI
 651                 li      t0,-1
 652                 sw      t0,FR_ORIG_REG2(sp)
 653                 jal     _do_ibe
 654                 move    a0,sp                   # delay slot
 655                 j       ret_from_sys_call
 656                 nop                             # delay slot
 657 
 658                 .globl  _handle_dbe
 659                 .align  5
 660 _handle_dbe:
 661                 .set    noreorder
 662                 .set    noat
 663                 SAVE_ALL
 664                 STI
 665                 li      t0,-1
 666                 sw      t0,FR_ORIG_REG2(sp)
 667                 jal     _do_dbe
 668                 move    a0,sp                   # delay slot
 669                 j       ret_from_sys_call
 670                 nop                             # delay slot
 671 
 672                 .globl  _handle_ov
 673                 .align  5
 674 _handle_ov:
 675                 .set    noreorder
 676                 .set    noat
 677                 SAVE_ALL
 678                 STI
 679                 li      t0,-1
 680                 sw      t0,FR_ORIG_REG2(sp)
 681                 jal     _do_ov
 682                 move    a0,sp                   # delay slot
 683                 j       ret_from_sys_call
 684                 nop                             # delay slot
 685 
 686                 .globl  _handle_fpe
 687                 .align  5
 688 _handle_fpe:
 689                 .set    noreorder
 690                 .set    noat
 691                 SAVE_ALL
 692                 STI
 693                 li      t0,-1
 694                 sw      t0,FR_ORIG_REG2(sp)
 695                 jal     _do_fpe
 696                 move    a0,sp                   # delay slot
 697                 j       ret_from_sys_call
 698                 nop                             # delay slot
 699 
 700                 .globl  _handle_bp
 701                 .align  5
 702 _handle_bp:
 703                 .set    noreorder
 704                 .set    noat
 705                 SAVE_ALL
 706                 STI
 707                 li      t0,-1
 708                 sw      t0,FR_ORIG_REG2(sp)
 709                 jal     _do_bp
 710                 move    a0,sp                   # delay slot
 711                 j       ret_from_sys_call
 712                 nop                             # delay slot
 713 
 714                 .globl  _handle_tr
 715                 .align  5
 716 _handle_tr:
 717                 .set    noreorder
 718                 .set    noat
 719                 SAVE_ALL
 720                 STI
 721                 li      t0,-1
 722                 sw      t0,FR_ORIG_REG2(sp)
 723                 jal     _do_tr
 724                 move    a0,sp                   # delay slot
 725                 j       ret_from_sys_call
 726                 nop                             # delay slot
 727 
 728                 .globl  _handle_ri
 729                 .align  5
 730 _handle_ri:
 731                 .set    noreorder
 732                 .set    noat
 733                 SAVE_ALL
 734                 STI
 735                 li      t0,-1
 736                 sw      t0,FR_ORIG_REG2(sp)
 737                 jal     _do_ri
 738                 move    a0,sp                   # delay slot
 739                 j       ret_from_sys_call
 740                 nop                             # delay slot
 741 
 742                 .globl  _handle_cpu
 743                 .align  5
 744 _handle_cpu:
 745                 .set    noreorder
 746                 .set    noat
 747                 SAVE_ALL
 748                 STI
 749                 li      t0,-1
 750                 sw      t0,FR_ORIG_REG2(sp)
 751                 jal     _do_cpu
 752                 move    a0,sp                   # delay slot
 753                 j       ret_from_sys_call
 754                 nop                             # delay slot
 755 
 756                 .globl  _handle_vcei
 757                 .align  5
 758 _handle_vcei:
 759                 .set    noreorder
 760                 .set    noat
 761                 SAVE_ALL
 762                 STI
 763                 li      t0,-1
 764                 sw      t0,FR_ORIG_REG2(sp)
 765                 jal     _do_vcei
 766                 move    a0,sp                   # delay slot
 767                 j       ret_from_sys_call
 768                 nop                             # delay slot
 769 
 770                 .globl  _handle_vced
 771                 .align  5
 772 _handle_vced:
 773                 .set    noreorder
 774                 .set    noat
 775                 SAVE_ALL
 776                 STI
 777                 li      t0,-1
 778                 sw      t0,FR_ORIG_REG2(sp)
 779                 jal     _do_vced
 780                 move    a0,sp                   # delay slot
 781                 j       ret_from_sys_call
 782                 nop                             # delay slot
 783 
 784                 .globl  _handle_watch
 785                 .align  5
 786 _handle_watch:
 787                 .set    noreorder
 788                 .set    noat
 789                 SAVE_ALL
 790                 STI
 791                 li      t0,-1
 792                 sw      t0,FR_ORIG_REG2(sp)
 793                 jal     _do_watch
 794                 move    a0,sp                   # delay slot
 795                 j       ret_from_sys_call
 796                 nop                             # delay slot
 797 
 798                 .globl  _handle_reserved
 799                 .align  5
 800 _handle_reserved:
 801                 .set    noreorder
 802                 .set    noat
 803                 SAVE_ALL
 804                 STI
 805                 li      t0,-1
 806                 sw      t0,FR_ORIG_REG2(sp)
 807                 jal     _do_reserved
 808                 move    a0,sp                   # delay slot
 809                 j       ret_from_sys_call
 810                 nop                             # delay slot
 811 
 812 /*
 813  * Exception handler table with 32 entries.
 814  * This might be extended to handle software exceptions
 815  */
 816                 .bss
 817                 .globl  _exception_handlers
 818                 .align  2
 819 _exception_handlers:
 820                 .fill   32,4,0
 821 
 822 /*
 823  * Table of syscalls
 824  */
 825                 .data
 826 _sys_call_table:
 827                 .word   _sys_setup              /* 0 */
 828                 .word   _sys_exit
 829                 .word   _sys_fork
 830                 .word   _sys_read
 831                 .word   _sys_write
 832                 .word   _sys_open               /* 5 */
 833                 .word   _sys_close
 834                 .word   _sys_waitpid
 835                 .word   _sys_creat
 836                 .word   _sys_link
 837                 .word   _sys_unlink             /* 10 */
 838                 .word   _sys_execve
 839                 .word   _sys_chdir
 840                 .word   _sys_time
 841                 .word   _sys_mknod
 842                 .word   _sys_chmod              /* 15 */
 843                 .word   _sys_chown
 844                 .word   _sys_break
 845                 .word   _sys_stat
 846                 .word   _sys_lseek
 847                 .word   _sys_getpid             /* 20 */
 848                 .word   _sys_mount
 849                 .word   _sys_umount
 850                 .word   _sys_setuid
 851                 .word   _sys_getuid
 852                 .word   _sys_stime              /* 25 */
 853                 .word   _sys_ptrace
 854                 .word   _sys_alarm
 855                 .word   _sys_fstat
 856                 .word   _sys_pause
 857                 .word   _sys_utime              /* 30 */
 858                 .word   _sys_stty
 859                 .word   _sys_gtty
 860                 .word   _sys_access
 861                 .word   _sys_nice
 862                 .word   _sys_ftime              /* 35 */
 863                 .word   _sys_sync
 864                 .word   _sys_kill
 865                 .word   _sys_rename
 866                 .word   _sys_mkdir
 867                 .word   _sys_rmdir              /* 40 */
 868                 .word   _sys_dup
 869                 .word   _sys_pipe
 870                 .word   _sys_times
 871                 .word   _sys_prof
 872                 .word   _sys_brk                /* 45 */
 873                 .word   _sys_setgid
 874                 .word   _sys_getgid
 875                 .word   _sys_signal
 876                 .word   _sys_geteuid
 877                 .word   _sys_getegid            /* 50 */
 878                 .word   _sys_acct
 879                 .word   _sys_phys
 880                 .word   _sys_lock
 881                 .word   _sys_ioctl
 882                 .word   _sys_fcntl              /* 55 */
 883                 .word   _sys_mpx
 884                 .word   _sys_setpgid
 885                 .word   _sys_ulimit
 886                 .word   _sys_olduname
 887                 .word   _sys_umask              /* 60 */
 888                 .word   _sys_chroot
 889                 .word   _sys_ustat
 890                 .word   _sys_dup2
 891                 .word   _sys_getppid
 892                 .word   _sys_getpgrp            /* 65 */
 893                 .word   _sys_setsid
 894                 .word   _sys_sigaction
 895                 .word   _sys_sgetmask
 896                 .word   _sys_ssetmask
 897                 .word   _sys_setreuid           /* 70 */
 898                 .word   _sys_setregid
 899                 .word   _sys_sigsuspend
 900                 .word   _sys_sigpending
 901                 .word   _sys_sethostname
 902                 .word   _sys_setrlimit          /* 75 */
 903                 .word   _sys_getrlimit
 904                 .word   _sys_getrusage
 905                 .word   _sys_gettimeofday
 906                 .word   _sys_settimeofday
 907                 .word   _sys_getgroups          /* 80 */
 908                 .word   _sys_setgroups
 909                 .word   _sys_select
 910                 .word   _sys_symlink
 911                 .word   _sys_lstat
 912                 .word   _sys_readlink           /* 85 */
 913                 .word   _sys_uselib
 914                 .word   _sys_swapon
 915                 .word   _sys_reboot
 916                 .word   _sys_readdir
 917                 .word   _sys_mmap               /* 90 */
 918                 .word   _sys_munmap
 919                 .word   _sys_truncate
 920                 .word   _sys_ftruncate
 921                 .word   _sys_fchmod
 922                 .word   _sys_fchown             /* 95 */
 923                 .word   _sys_getpriority
 924                 .word   _sys_setpriority
 925                 .word   _sys_profil
 926                 .word   _sys_statfs
 927                 .word   _sys_fstatfs            /* 100 */
 928                 .word   _sys_ioperm
 929                 .word   _sys_socketcall
 930                 .word   _sys_syslog
 931                 .word   _sys_setitimer
 932                 .word   _sys_getitimer          /* 105 */
 933                 .word   _sys_newstat
 934                 .word   _sys_newlstat
 935                 .word   _sys_newfstat
 936                 .word   _sys_uname
 937                 .word   _sys_iopl               /* 110 */
 938                 .word   _sys_vhangup
 939                 .word   _sys_idle
 940                 .word   0 #_sys_vm86
 941                 .word   _sys_wait4
 942                 .word   _sys_swapoff            /* 115 */
 943                 .word   _sys_sysinfo
 944                 .word   _sys_ipc
 945                 .word   _sys_fsync
 946                 .word   _sys_sigreturn
 947                 .word   _sys_clone              /* 120 */
 948                 .word   _sys_setdomainname
 949                 .word   _sys_newuname
 950                 .word   0 #_sys_modify_ldt
 951                 .word   _sys_adjtimex
 952                 .word   _sys_mprotect           /* 125 */
 953                 .word   _sys_sigprocmask
 954                 .word   _sys_create_module
 955                 .word   _sys_init_module
 956                 .word   _sys_delete_module
 957                 .word   _sys_get_kernel_syms    /* 130 */
 958                 .word   _sys_quotactl
 959                 .word   _sys_getpgid
 960                 .word   _sys_fchdir
 961                 .word   _sys_bdflush
 962                 .word   _sys_sysfs              /* 135 */
 963                 .word   _sys_personality
 964                 .word   0                       /* for afs_syscall */
 965                 .word   _sys_setfsuid
 966                 .word   _sys_setfsgid
 967                 .word   _sys_llseek             /* 140 */
 968                 .space  (NR_syscalls-140)*4
 969 
 970                 .bss
 971                 .globl  _IRQ_vectors
 972 _IRQ_vectors:   .fill   16,4,0
 973 

/* */