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