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

/* */