git.oblomov.eu Git - linux-2.6/blob - arch/s390/kernel/head.S

   1 /*
   2  *  arch/s390/kernel/head.S
   3  *
   4  * (C) Copyright IBM Corp. 1999, 2005
   5  *
   6  *    Author(s): Hartmut Penner <hp@de.ibm.com>
   7  *               Martin Schwidefsky <schwidefsky@de.ibm.com>
   8  *               Rob van der Heij <rvdhei@iae.nl>
   9  *               Heiko Carstens <heiko.carstens@de.ibm.com>
  10  *
  11  * There are 5 different IPL methods
  12  *  1) load the image directly into ram at address 0 and do an PSW restart
  13  *  2) linload will load the image from address 0x10000 to memory 0x10000
  14  *     and start the code thru LPSW 0x0008000080010000 (VM only, deprecated)
  15  *  3) generate the tape ipl header, store the generated image on a tape
  16  *     and ipl from it
  17  *     In case of SL tape you need to IPL 5 times to get past VOL1 etc
  18  *  4) generate the vm reader ipl header, move the generated image to the
  19  *     VM reader (use option NOH!) and do a ipl from reader (VM only)
  20  *  5) direct call of start by the SALIPL loader
  21  *  We use the cpuid to distinguish between VM and native ipl
  22  *  params for kernel are pushed to 0x10400 (see setup.h)
  23  *
  24  */
  25
  26 #include <linux/config.h>
  27 #include <asm/setup.h>
  28 #include <asm/lowcore.h>
  29 #include <asm/asm-offsets.h>
  30 #include <asm/thread_info.h>
  31 #include <asm/page.h>
  32
  33 #ifdef CONFIG_ARCH_S390X
  34 #define ARCH_OFFSET     4
  35 #else
  36 #define ARCH_OFFSET     0
  37 #endif
  38
  39 #ifndef CONFIG_IPL
  40         .org   0
  41         .long  0x00080000,0x80000000+startup   # Just a restart PSW
  42 #else
  43 #ifdef CONFIG_IPL_TAPE
  44 #define IPL_BS 1024
  45         .org   0
  46         .long  0x00080000,0x80000000+iplstart  # The first 24 bytes are loaded
  47         .long  0x27000000,0x60000001           # by ipl to addresses 0-23.
  48         .long  0x02000000,0x20000000+IPL_BS    # (a PSW and two CCWs).
  49         .long  0x00000000,0x00000000           # external old psw
  50         .long  0x00000000,0x00000000           # svc old psw
  51         .long  0x00000000,0x00000000           # program check old psw
  52         .long  0x00000000,0x00000000           # machine check old psw
  53         .long  0x00000000,0x00000000           # io old psw
  54         .long  0x00000000,0x00000000
  55         .long  0x00000000,0x00000000
  56         .long  0x00000000,0x00000000
  57         .long  0x000a0000,0x00000058           # external new psw
  58         .long  0x000a0000,0x00000060           # svc new psw
  59         .long  0x000a0000,0x00000068           # program check new psw
  60         .long  0x000a0000,0x00000070           # machine check new psw
  61         .long  0x00080000,0x80000000+.Lioint   # io new psw
  62
  63         .org   0x100
  64 #
  65 # subroutine for loading from tape
  66 # Paramters:
  67 #  R1 = device number
  68 #  R2 = load address
  69 .Lloader:
  70         st    %r14,.Lldret
  71         la    %r3,.Lorbread                    # r3 = address of orb
  72         la    %r5,.Lirb                        # r5 = address of irb
  73         st    %r2,.Lccwread+4                  # initialize CCW data addresses
  74         lctl  %c6,%c6,.Lcr6
  75         slr   %r2,%r2
  76 .Lldlp:
  77         la    %r6,3                            # 3 retries
  78 .Lssch:
  79         ssch  0(%r3)                           # load chunk of IPL_BS bytes
  80         bnz   .Llderr
  81 .Lw4end:
  82         bas   %r14,.Lwait4io
  83         tm    8(%r5),0x82                      # do we have a problem ?
  84         bnz   .Lrecov
  85         slr   %r7,%r7
  86         icm   %r7,3,10(%r5)                    # get residual count
  87         lcr   %r7,%r7
  88         la    %r7,IPL_BS(%r7)                  # IPL_BS-residual=#bytes read
  89         ar    %r2,%r7                          # add to total size
  90         tm    8(%r5),0x01                      # found a tape mark ?
  91         bnz   .Ldone
  92         l     %r0,.Lccwread+4                  # update CCW data addresses
  93         ar    %r0,%r7
  94         st    %r0,.Lccwread+4
  95         b     .Lldlp
  96 .Ldone:
  97         l     %r14,.Lldret
  98         br    %r14                             # r2 contains the total size
  99 .Lrecov:
 100         bas   %r14,.Lsense                     # do the sensing
 101         bct   %r6,.Lssch                       # dec. retry count & branch
 102         b     .Llderr
 103 #
 104 # Sense subroutine
 105 #
 106 .Lsense:
 107         st    %r14,.Lsnsret
 108         la    %r7,.Lorbsense
 109         ssch  0(%r7)                           # start sense command
 110         bnz   .Llderr
 111         bas   %r14,.Lwait4io
 112         l     %r14,.Lsnsret
 113         tm    8(%r5),0x82                      # do we have a problem ?
 114         bnz   .Llderr
 115         br    %r14
 116 #
 117 # Wait for interrupt subroutine
 118 #
 119 .Lwait4io:
 120         lpsw  .Lwaitpsw
 121 .Lioint:
 122         c     %r1,0xb8                         # compare subchannel number
 123         bne   .Lwait4io
 124         tsch  0(%r5)
 125         slr   %r0,%r0
 126         tm    8(%r5),0x82                      # do we have a problem ?
 127         bnz   .Lwtexit
 128         tm    8(%r5),0x04                      # got device end ?
 129         bz    .Lwait4io
 130 .Lwtexit:
 131         br    %r14
 132 .Llderr:
 133         lpsw  .Lcrash
 134
 135         .align 8
 136 .Lorbread:
 137         .long  0x00000000,0x0080ff00,.Lccwread
 138         .align 8
 139 .Lorbsense:
 140         .long  0x00000000,0x0080ff00,.Lccwsense
 141         .align 8
 142 .Lccwread:
 143         .long  0x02200000+IPL_BS,0x00000000
 144 .Lccwsense:
 145         .long  0x04200001,0x00000000
 146 .Lwaitpsw:
 147         .long  0x020a0000,0x80000000+.Lioint
 148
 149 .Lirb:  .long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
 150 .Lcr6:  .long  0xff000000
 151         .align 8
 152 .Lcrash:.long  0x000a0000,0x00000000
 153 .Lldret:.long  0
 154 .Lsnsret: .long 0
 155 #endif  /* CONFIG_IPL_TAPE */
 156
 157 #ifdef CONFIG_IPL_VM
 158 #define IPL_BS 0x730
 159         .org   0
 160         .long  0x00080000,0x80000000+iplstart  # The first 24 bytes are loaded
 161         .long  0x02000018,0x60000050           # by ipl to addresses 0-23.
 162         .long  0x02000068,0x60000050           # (a PSW and two CCWs).
 163         .fill  80-24,1,0x40                    # bytes 24-79 are discarded !!
 164         .long  0x020000f0,0x60000050           # The next 160 byte are loaded
 165         .long  0x02000140,0x60000050           # to addresses 0x18-0xb7
 166         .long  0x02000190,0x60000050           # They form the continuation
 167         .long  0x020001e0,0x60000050           # of the CCW program started
 168         .long  0x02000230,0x60000050           # by ipl and load the range
 169         .long  0x02000280,0x60000050           # 0x0f0-0x730 from the image
 170         .long  0x020002d0,0x60000050           # to the range 0x0f0-0x730
 171         .long  0x02000320,0x60000050           # in memory. At the end of
 172         .long  0x02000370,0x60000050           # the channel program the PSW
 173         .long  0x020003c0,0x60000050           # at location 0 is loaded.
 174         .long  0x02000410,0x60000050           # Initial processing starts
 175         .long  0x02000460,0x60000050           # at 0xf0 = iplstart.
 176         .long  0x020004b0,0x60000050
 177         .long  0x02000500,0x60000050
 178         .long  0x02000550,0x60000050
 179         .long  0x020005a0,0x60000050
 180         .long  0x020005f0,0x60000050
 181         .long  0x02000640,0x60000050
 182         .long  0x02000690,0x60000050
 183         .long  0x020006e0,0x20000050
 184
 185         .org   0xf0
 186 #
 187 # subroutine for loading cards from the reader
 188 #
 189 .Lloader:
 190         la    %r3,.Lorb                        # r2 = address of orb into r2
 191         la    %r5,.Lirb                        # r4 = address of irb
 192         la    %r6,.Lccws
 193         la    %r7,20
 194 .Linit:
 195         st    %r2,4(%r6)                       # initialize CCW data addresses
 196         la    %r2,0x50(%r2)
 197         la    %r6,8(%r6)
 198         bct   7,.Linit
 199
 200         lctl  %c6,%c6,.Lcr6                    # set IO subclass mask
 201         slr   %r2,%r2
 202 .Lldlp:
 203         ssch  0(%r3)                           # load chunk of 1600 bytes
 204         bnz   .Llderr
 205 .Lwait4irq:
 206         mvc   0x78(8),.Lnewpsw                 # set up IO interrupt psw
 207         lpsw  .Lwaitpsw
 208 .Lioint:
 209         c     %r1,0xb8                         # compare subchannel number
 210         bne   .Lwait4irq
 211         tsch  0(%r5)
 212
 213         slr   %r0,%r0
 214         ic    %r0,8(%r5)                       # get device status
 215         chi   %r0,8                            # channel end ?
 216         be    .Lcont
 217         chi   %r0,12                           # channel end + device end ?
 218         be    .Lcont
 219
 220         l     %r0,4(%r5)
 221         s     %r0,8(%r3)                       # r0/8 = number of ccws executed
 222         mhi   %r0,10                           # *10 = number of bytes in ccws
 223         lh    %r3,10(%r5)                      # get residual count
 224         sr    %r0,%r3                          # #ccws*80-residual=#bytes read
 225         ar    %r2,%r0
 226
 227         br    %r14                             # r2 contains the total size
 228
 229 .Lcont:
 230         ahi   %r2,0x640                        # add 0x640 to total size
 231         la    %r6,.Lccws
 232         la    %r7,20
 233 .Lincr:
 234         l     %r0,4(%r6)                       # update CCW data addresses
 235         ahi   %r0,0x640
 236         st    %r0,4(%r6)
 237         ahi   %r6,8
 238         bct   7,.Lincr
 239
 240         b     .Lldlp
 241 .Llderr:
 242         lpsw  .Lcrash
 243
 244         .align 8
 245 .Lorb:  .long  0x00000000,0x0080ff00,.Lccws
 246 .Lirb:  .long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
 247 .Lcr6:  .long  0xff000000
 248 .Lloadp:.long  0,0
 249         .align 8
 250 .Lcrash:.long  0x000a0000,0x00000000
 251 .Lnewpsw:
 252         .long  0x00080000,0x80000000+.Lioint
 253 .Lwaitpsw:
 254         .long  0x020a0000,0x80000000+.Lioint
 255
 256         .align 8
 257 .Lccws: .rept  19
 258         .long  0x02600050,0x00000000
 259         .endr
 260         .long  0x02200050,0x00000000
 261 #endif  /* CONFIG_IPL_VM */
 262
 263 iplstart:
 264         lh    %r1,0xb8                         # test if subchannel number
 265         bct   %r1,.Lnoload                     #  is valid
 266         l     %r1,0xb8                         # load ipl subchannel number
 267         la    %r2,IPL_BS                       # load start address
 268         bas   %r14,.Lloader                    # load rest of ipl image
 269         l     %r12,.Lparm                      # pointer to parameter area
 270         st    %r1,IPL_DEVICE+ARCH_OFFSET-PARMAREA(%r12) # save ipl device number
 271
 272 #
 273 # load parameter file from ipl device
 274 #
 275 .Lagain1:
 276         l     %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12) # ramdisk loc. is temp
 277         bas   %r14,.Lloader                    # load parameter file
 278         ltr   %r2,%r2                          # got anything ?
 279         bz    .Lnopf
 280         chi   %r2,895
 281         bnh   .Lnotrunc
 282         la    %r2,895
 283 .Lnotrunc:
 284         l     %r4,INITRD_START+ARCH_OFFSET-PARMAREA(%r12)
 285         clc   0(3,%r4),.L_hdr                  # if it is HDRx
 286         bz    .Lagain1                         # skip dataset header
 287         clc   0(3,%r4),.L_eof                  # if it is EOFx
 288         bz    .Lagain1                         # skip dateset trailer
 289         la    %r5,0(%r4,%r2)
 290         lr    %r3,%r2
 291 .Lidebc:
 292         tm    0(%r5),0x80                      # high order bit set ?
 293         bo    .Ldocv                           #  yes -> convert from EBCDIC
 294         ahi   %r5,-1
 295         bct   %r3,.Lidebc
 296         b     .Lnocv
 297 .Ldocv:
 298         l     %r3,.Lcvtab
 299         tr    0(256,%r4),0(%r3)                # convert parameters to ascii
 300         tr    256(256,%r4),0(%r3)
 301         tr    512(256,%r4),0(%r3)
 302         tr    768(122,%r4),0(%r3)
 303 .Lnocv: la    %r3,COMMAND_LINE-PARMAREA(%r12)  # load adr. of command line
 304         mvc   0(256,%r3),0(%r4)
 305         mvc   256(256,%r3),256(%r4)
 306         mvc   512(256,%r3),512(%r4)
 307         mvc   768(122,%r3),768(%r4)
 308         slr   %r0,%r0
 309         b     .Lcntlp
 310 .Ldelspc:
 311         ic    %r0,0(%r2,%r3)
 312         chi   %r0,0x20                         # is it a space ?
 313         be    .Lcntlp
 314         ahi   %r2,1
 315         b     .Leolp
 316 .Lcntlp:
 317         brct  %r2,.Ldelspc
 318 .Leolp:
 319         slr   %r0,%r0
 320         stc   %r0,0(%r2,%r3)                   # terminate buffer
 321 .Lnopf:
 322
 323 #
 324 # load ramdisk from ipl device
 325 #
 326 .Lagain2:
 327         l     %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12) # addr of ramdisk
 328         bas   %r14,.Lloader                    # load ramdisk
 329         st    %r2,INITRD_SIZE+ARCH_OFFSET-PARMAREA(%r12) # store size of ramdisk
 330         ltr   %r2,%r2
 331         bnz   .Lrdcont
 332         st    %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12) # no ramdisk found
 333 .Lrdcont:
 334         l     %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12)
 335
 336         clc   0(3,%r2),.L_hdr                  # skip HDRx and EOFx
 337         bz    .Lagain2
 338         clc   0(3,%r2),.L_eof
 339         bz    .Lagain2
 340
 341 #ifdef CONFIG_IPL_VM
 342 #
 343 # reset files in VM reader
 344 #
 345         stidp __LC_CPUID                       # store cpuid
 346         tm    __LC_CPUID,0xff                  # running VM ?
 347         bno   .Lnoreset
 348         la    %r2,.Lreset
 349         lhi   %r3,26
 350         diag  %r2,%r3,8
 351         la    %r5,.Lirb
 352         stsch 0(%r5)                           # check if irq is pending
 353         tm    30(%r5),0x0f                     # by verifying if any of the
 354         bnz   .Lwaitforirq                     # activity or status control
 355         tm    31(%r5),0xff                     # bits is set in the schib
 356         bz    .Lnoreset
 357 .Lwaitforirq:
 358         mvc   0x78(8),.Lrdrnewpsw              # set up IO interrupt psw
 359 .Lwaitrdrirq:
 360         lpsw  .Lrdrwaitpsw
 361 .Lrdrint:
 362         c     %r1,0xb8                         # compare subchannel number
 363         bne   .Lwaitrdrirq
 364         la    %r5,.Lirb
 365         tsch  0(%r5)
 366 .Lnoreset:
 367         b     .Lnoload
 368
 369         .align 8
 370 .Lrdrnewpsw:
 371         .long  0x00080000,0x80000000+.Lrdrint
 372 .Lrdrwaitpsw:
 373         .long  0x020a0000,0x80000000+.Lrdrint
 374 #endif
 375
 376 #
 377 # everything loaded, go for it
 378 #
 379 .Lnoload:
 380         l     %r1,.Lstartup
 381         br    %r1
 382
 383 .Lparm: .long  PARMAREA
 384 .Lstartup: .long startup
 385 .Lcvtab:.long  _ebcasc                         # ebcdic to ascii table
 386 .Lreset:.byte  0xc3,0xc8,0xc1,0xd5,0xc7,0xc5,0x40,0xd9,0xc4,0xd9,0x40
 387         .byte  0xc1,0xd3,0xd3,0x40,0xd2,0xc5,0xc5,0xd7,0x40,0xd5,0xd6
 388         .byte  0xc8,0xd6,0xd3,0xc4             # "change rdr all keep nohold"
 389 .L_eof: .long  0xc5d6c600       /* C'EOF' */
 390 .L_hdr: .long  0xc8c4d900       /* C'HDR' */
 391
 392 #endif  /* CONFIG_IPL */
 393
 394 #
 395 # SALIPL loader support. Based on a patch by Rob van der Heij.
 396 # This entry point is called directly from the SALIPL loader and
 397 # doesn't need a builtin ipl record.
 398 #
 399         .org  0x800
 400         .globl start
 401 start:
 402         stm   %r0,%r15,0x07b0           # store registers
 403         basr  %r12,%r0
 404 .base:
 405         l     %r11,.parm
 406         l     %r8,.cmd                  # pointer to command buffer
 407
 408         ltr   %r9,%r9                   # do we have SALIPL parameters?
 409         bp    .sk8x8
 410
 411         mvc   0(64,%r8),0x00b0          # copy saved registers
 412         xc    64(240-64,%r8),0(%r8)     # remainder of buffer
 413         tr    0(64,%r8),.lowcase
 414         b     .gotr
 415 .sk8x8:
 416         mvc   0(240,%r8),0(%r9)         # copy iplparms into buffer
 417 .gotr:
 418         l     %r10,.tbl                 # EBCDIC to ASCII table
 419         tr    0(240,%r8),0(%r10)
 420         stidp __LC_CPUID                # Are we running on VM maybe
 421         cli   __LC_CPUID,0xff
 422         bnz   .test
 423         .long 0x83300060                # diag 3,0,x'0060' - storage size
 424         b     .done
 425 .test:
 426         mvc   0x68(8),.pgmnw            # set up pgm check handler
 427         l     %r2,.fourmeg
 428         lr    %r3,%r2
 429         bctr  %r3,%r0                   # 4M-1
 430 .loop:  iske  %r0,%r3
 431         ar    %r3,%r2
 432 .pgmx:
 433         sr    %r3,%r2
 434         la    %r3,1(%r3)
 435 .done:
 436         l     %r1,.memsize
 437         st    %r3,ARCH_OFFSET(%r1)
 438         slr   %r0,%r0
 439         st    %r0,INITRD_SIZE+ARCH_OFFSET-PARMAREA(%r11)
 440         st    %r0,INITRD_START+ARCH_OFFSET-PARMAREA(%r11)
 441         j     startup                   # continue with startup
 442 .tbl:   .long _ebcasc                   # translate table
 443 .cmd:   .long COMMAND_LINE              # address of command line buffer
 444 .parm:  .long PARMAREA
 445 .memsize: .long memory_size
 446 .fourmeg: .long 0x00400000              # 4M
 447 .pgmnw: .long 0x00080000,.pgmx
 448 .lowcase:
 449         .byte 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07
 450         .byte 0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f
 451         .byte 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17
 452         .byte 0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f
 453         .byte 0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27
 454         .byte 0x28,0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f
 455         .byte 0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37
 456         .byte 0x38,0x39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f
 457         .byte 0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47
 458         .byte 0x48,0x49,0x4a,0x4b,0x4c,0x4d,0x4e,0x4f
 459         .byte 0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57
 460         .byte 0x58,0x59,0x5a,0x5b,0x5c,0x5d,0x5e,0x5f
 461         .byte 0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67
 462         .byte 0x68,0x69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f
 463         .byte 0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77
 464         .byte 0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f
 465
 466         .byte 0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87
 467         .byte 0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f
 468         .byte 0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97
 469         .byte 0x98,0x99,0x9a,0x9b,0x9c,0x9d,0x9e,0x9f
 470         .byte 0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7
 471         .byte 0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf
 472         .byte 0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7
 473         .byte 0xb8,0xb9,0xba,0xbb,0xbc,0xbd,0xbe,0xbf
 474         .byte 0xc0,0x81,0x82,0x83,0x84,0x85,0x86,0x87   # .abcdefg
 475         .byte 0x88,0x89,0xca,0xcb,0xcc,0xcd,0xce,0xcf   # hi
 476         .byte 0xd0,0x91,0x92,0x93,0x94,0x95,0x96,0x97   # .jklmnop
 477         .byte 0x98,0x99,0xda,0xdb,0xdc,0xdd,0xde,0xdf   # qr
 478         .byte 0xe0,0xe1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7   # ..stuvwx
 479         .byte 0xa8,0xa9,0xea,0xeb,0xec,0xed,0xee,0xef   # yz
 480         .byte 0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7
 481         .byte 0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff
 482
 483 .macro GET_IPL_DEVICE
 484 .Lget_ipl_device:
 485         basr  %r12,0
 486 .LGID:  l     %r1,0xb8                  # get sid
 487         sll   %r1,15                    # test if subchannel is enabled
 488         srl   %r1,31
 489         ltr   %r1,%r1
 490         bz    0(%r14)                   # subchannel disabled
 491         l     %r1,0xb8
 492         la    %r5,.Lipl_schib-.LGID(%r12)
 493         stsch 0(%r5)                    # get schib of subchannel
 494         bnz   0(%r14)                   # schib not available
 495         tm    5(%r5),0x01               # devno valid?
 496         bno   0(%r14)
 497         la    %r6,ipl_parameter_flags-.LGID(%r12)
 498         oi    3(%r6),0x01               # set flag
 499         la    %r2,ipl_devno-.LGID(%r12)
 500         mvc   0(2,%r2),6(%r5)           # store devno
 501         tm    4(%r5),0x80               # qdio capable device?
 502         bno   0(%r14)
 503         oi    3(%r6),0x02               # set flag
 504
 505         # copy ipl parameters
 506
 507         lhi   %r0,4096
 508         l     %r2,20(%r0)               # get address of parameter list
 509         lhi   %r3,IPL_PARMBLOCK_ORIGIN
 510         st    %r3,20(%r0)
 511         lhi   %r4,1
 512         cr    %r2,%r3                   # start parameters < destination ?
 513         jl    0f
 514         lhi   %r1,1                     # copy direction is upwards
 515         j     1f
 516 0:      lhi   %r1,-1                    # copy direction is downwards
 517         ar    %r2,%r0
 518         ar    %r3,%r0
 519         ar    %r2,%r1
 520         ar    %r3,%r1
 521 1:      mvc   0(1,%r3),0(%r2)           # finally copy ipl parameters
 522         ar    %r3,%r1
 523         ar    %r2,%r1
 524         sr    %r0,%r4
 525         jne   1b
 526         b     0(%r14)
 527
 528         .align 4
 529 .Lipl_schib:
 530         .rept 13
 531         .long 0
 532         .endr
 533
 534         .globl ipl_parameter_flags
 535 ipl_parameter_flags:
 536         .long 0
 537         .globl ipl_devno
 538 ipl_devno:
 539         .word 0
 540 .endm
 541
 542 #ifdef CONFIG_ARCH_S390X
 543 #include "head64.S"
 544 #else
 545 #include "head31.S"
 546 #endif