arch/s390/kernel/head.S

   1 /*
   2  *  arch/s390/kernel/head.S
   3  *
   4  *  S390 version
   5  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
   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  *
  10  * There are 5 different IPL methods
  11  *  1) load the image directly into ram at address 0 and do an PSW restart
  12  *  2) linload will load the image from address 0x10000 to memory 0x10000
  13  *     and start the code thru LPSW 0x0008000080010000 (VM only, deprecated)
  14  *  3) generate the tape ipl header, store the generated image on a tape
  15  *     and ipl from it
  16  *     In case of SL tape you need to IPL 5 times to get past VOL1 etc
  17  *  4) generate the vm reader ipl header, move the generated image to the
  18  *     VM reader (use option NOH!) and do a ipl from reader (VM only)
  19  *  5) direct call of start by the SALIPL loader
  20  *  We use the cpuid to distinguish between VM and native ipl
  21  *  params for kernel are pushed to 0x10400 (see setup.h)
  22
  23     Changes:
  24     Okt 25 2000 <rvdheij@iae.nl>
  25         added code to skip HDR and EOF to allow SL tape IPL (5 retries)
  26         changed first CCW from rewind to backspace block
  27
  28  */
  29
  30 #include <linux/config.h>
  31 #include <asm/setup.h>
  32 #include <asm/lowcore.h>
  33 #include <asm/offsets.h>
  34 #include <asm/thread_info.h>
  35 #include <asm/page.h>
  36
  37 #ifndef CONFIG_IPL
  38         .org   0
  39         .long  0x00080000,0x80000000+startup   # Just a restart PSW
  40 #else
  41 #ifdef CONFIG_IPL_TAPE
  42 #define IPL_BS 1024
  43         .org   0
  44         .long  0x00080000,0x80000000+iplstart  # The first 24 bytes are loaded
  45         .long  0x27000000,0x60000001           # by ipl to addresses 0-23.
  46         .long  0x02000000,0x20000000+IPL_BS    # (a PSW and two CCWs).
  47         .long  0x00000000,0x00000000           # external old psw
  48         .long  0x00000000,0x00000000           # svc old psw
  49         .long  0x00000000,0x00000000           # program check old psw
  50         .long  0x00000000,0x00000000           # machine check old psw
  51         .long  0x00000000,0x00000000           # io old psw
  52         .long  0x00000000,0x00000000
  53         .long  0x00000000,0x00000000
  54         .long  0x00000000,0x00000000
  55         .long  0x000a0000,0x00000058           # external new psw
  56         .long  0x000a0000,0x00000060           # svc new psw
  57         .long  0x000a0000,0x00000068           # program check new psw
  58         .long  0x000a0000,0x00000070           # machine check new psw
  59         .long  0x00080000,0x80000000+.Lioint   # io new psw
  60
  61         .org   0x100
  62 #
  63 # subroutine for loading from tape
  64 # Paramters:
  65 #  R1 = device number
  66 #  R2 = load address
  67 .Lloader:
  68         st    %r14,.Lldret
  69         la    %r3,.Lorbread                    # r3 = address of orb
  70         la    %r5,.Lirb                        # r5 = address of irb
  71         st    %r2,.Lccwread+4                  # initialize CCW data addresses
  72         lctl  %c6,%c6,.Lcr6
  73         slr   %r2,%r2
  74 .Lldlp:
  75         la    %r6,3                            # 3 retries
  76 .Lssch:
  77         ssch  0(%r3)                           # load chunk of IPL_BS bytes
  78         bnz   .Llderr
  79 .Lw4end:
  80         bas   %r14,.Lwait4io
  81         tm    8(%r5),0x82                      # do we have a problem ?
  82         bnz   .Lrecov
  83         slr   %r7,%r7
  84         icm   %r7,3,10(%r5)                    # get residual count
  85         lcr   %r7,%r7
  86         la    %r7,IPL_BS(%r7)                  # IPL_BS-residual=#bytes read
  87         ar    %r2,%r7                          # add to total size
  88         tm    8(%r5),0x01                      # found a tape mark ?
  89         bnz   .Ldone
  90         l     %r0,.Lccwread+4                  # update CCW data addresses
  91         ar    %r0,%r7
  92         st    %r0,.Lccwread+4
  93         b     .Lldlp
  94 .Ldone:
  95         l     %r14,.Lldret
  96         br    %r14                             # r2 contains the total size
  97 .Lrecov:
  98         bas   %r14,.Lsense                     # do the sensing
  99         bct   %r6,.Lssch                       # dec. retry count & branch
 100         b     .Llderr
 101 #
 102 # Sense subroutine
 103 #
 104 .Lsense:
 105         st    %r14,.Lsnsret
 106         la    %r7,.Lorbsense
 107         ssch  0(%r7)                           # start sense command
 108         bnz   .Llderr
 109         bas   %r14,.Lwait4io
 110         l     %r14,.Lsnsret
 111         tm    8(%r5),0x82                      # do we have a problem ?
 112         bnz   .Llderr
 113         br    %r14
 114 #
 115 # Wait for interrupt subroutine
 116 #
 117 .Lwait4io:
 118         lpsw  .Lwaitpsw
 119 .Lioint:
 120         c     %r1,0xb8                         # compare subchannel number
 121         bne   .Lwait4io
 122         tsch  0(%r5)
 123         slr   %r0,%r0
 124         tm    8(%r5),0x82                      # do we have a problem ?
 125         bnz   .Lwtexit
 126         tm    8(%r5),0x04                      # got device end ?
 127         bz    .Lwait4io
 128 .Lwtexit:
 129         br    %r14
 130 .Llderr:
 131         lpsw  .Lcrash
 132
 133         .align 8
 134 .Lorbread:
 135         .long  0x00000000,0x0080ff00,.Lccwread
 136         .align 8
 137 .Lorbsense:
 138         .long  0x00000000,0x0080ff00,.Lccwsense
 139         .align 8
 140 .Lccwread:
 141         .long  0x02200000+IPL_BS,0x00000000
 142 .Lccwsense:
 143         .long  0x04200001,0x00000000
 144 .Lwaitpsw:
 145         .long  0x020a0000,0x80000000+.Lioint
 146
 147 .Lirb:  .long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
 148 .Lcr6:  .long  0xff000000
 149         .align 8
 150 .Lcrash:.long  0x000a0000,0x00000000
 151 .Lldret:.long  0
 152 .Lsnsret: .long 0
 153 #endif  /* CONFIG_IPL_TAPE */
 154
 155 #ifdef CONFIG_IPL_VM
 156 #define IPL_BS 0x730
 157         .org   0
 158         .long  0x00080000,0x80000000+iplstart  # The first 24 bytes are loaded
 159         .long  0x02000018,0x60000050           # by ipl to addresses 0-23.
 160         .long  0x02000068,0x60000050           # (a PSW and two CCWs).
 161         .fill  80-24,1,0x40                    # bytes 24-79 are discarded !!
 162         .long  0x020000f0,0x60000050           # The next 160 byte are loaded
 163         .long  0x02000140,0x60000050           # to addresses 0x18-0xb7
 164         .long  0x02000190,0x60000050           # They form the continuation
 165         .long  0x020001e0,0x60000050           # of the CCW program started
 166         .long  0x02000230,0x60000050           # by ipl and load the range
 167         .long  0x02000280,0x60000050           # 0x0f0-0x730 from the image
 168         .long  0x020002d0,0x60000050           # to the range 0x0f0-0x730
 169         .long  0x02000320,0x60000050           # in memory. At the end of
 170         .long  0x02000370,0x60000050           # the channel program the PSW
 171         .long  0x020003c0,0x60000050           # at location 0 is loaded.
 172         .long  0x02000410,0x60000050           # Initial processing starts
 173         .long  0x02000460,0x60000050           # at 0xf0 = iplstart.
 174         .long  0x020004b0,0x60000050
 175         .long  0x02000500,0x60000050
 176         .long  0x02000550,0x60000050
 177         .long  0x020005a0,0x60000050
 178         .long  0x020005f0,0x60000050
 179         .long  0x02000640,0x60000050
 180         .long  0x02000690,0x60000050
 181         .long  0x020006e0,0x20000050
 182
 183         .org   0xf0
 184 #
 185 # subroutine for loading cards from the reader
 186 #
 187 .Lloader:
 188         la    %r3,.Lorb                        # r2 = address of orb into r2
 189         la    %r5,.Lirb                        # r4 = address of irb
 190         la    %r6,.Lccws
 191         la    %r7,20
 192 .Linit:
 193         st    %r2,4(%r6)                       # initialize CCW data addresses
 194         la    %r2,0x50(%r2)
 195         la    %r6,8(%r6)
 196         bct   7,.Linit
 197
 198         lctl  %c6,%c6,.Lcr6                    # set IO subclass mask
 199         slr   %r2,%r2
 200 .Lldlp:
 201         ssch  0(%r3)                           # load chunk of 1600 bytes
 202         bnz   .Llderr
 203 .Lwait4irq:
 204         mvc   __LC_IO_NEW_PSW(8),.Lnewpsw      # set up IO interrupt psw
 205         lpsw  .Lwaitpsw
 206 .Lioint:
 207         c     %r1,0xb8                         # compare subchannel number
 208         bne   .Lwait4irq
 209         tsch  0(%r5)
 210
 211         slr   %r0,%r0
 212         ic    %r0,8(%r5)                       # get device status
 213         chi   %r0,8                            # channel end ?
 214         be    .Lcont
 215         chi   %r0,12                           # channel end + device end ?
 216         be    .Lcont
 217
 218         l     %r0,4(%r5)
 219         s     %r0,8(%r3)                       # r0/8 = number of ccws executed
 220         mhi   %r0,10                           # *10 = number of bytes in ccws
 221         lh    %r3,10(%r5)                      # get residual count
 222         sr    %r0,%r3                          # #ccws*80-residual=#bytes read
 223         ar    %r2,%r0
 224
 225         br    %r14                             # r2 contains the total size
 226
 227 .Lcont:
 228         ahi   %r2,0x640                        # add 0x640 to total size
 229         la    %r6,.Lccws
 230         la    %r7,20
 231 .Lincr:
 232         l     %r0,4(%r6)                       # update CCW data addresses
 233         ahi   %r0,0x640
 234         st    %r0,4(%r6)
 235         ahi   %r6,8
 236         bct   7,.Lincr
 237
 238         b     .Lldlp
 239 .Llderr:
 240         lpsw  .Lcrash
 241
 242         .align 8
 243 .Lorb:  .long  0x00000000,0x0080ff00,.Lccws
 244 .Lirb:  .long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
 245 .Lcr6:  .long  0xff000000
 246 .Lloadp:.long  0,0
 247         .align 8
 248 .Lcrash:.long  0x000a0000,0x00000000
 249 .Lnewpsw:
 250         .long  0x00080000,0x80000000+.Lioint
 251 .Lwaitpsw:
 252         .long  0x020a0000,0x80000000+.Lioint
 253
 254         .align 8
 255 .Lccws: .rept  19
 256         .long  0x02600050,0x00000000
 257         .endr
 258         .long  0x02200050,0x00000000
 259 #endif  /* CONFIG_IPL_VM */
 260
 261 iplstart:
 262         lh    %r1,0xb8                         # test if subchannel number
 263         bct   %r1,.Lnoload                     #  is valid
 264         l     %r1,0xb8                         # load ipl subchannel number
 265         la    %r2,IPL_BS                       # load start address
 266         bas   %r14,.Lloader                    # load rest of ipl image
 267         l     %r12,.Lparm                      # pointer to parameter area
 268         st    %r1,IPL_DEVICE-PARMAREA(%r12)    # store ipl device number
 269
 270 #
 271 # load parameter file from ipl device
 272 #
 273 .Lagain1:
 274         l     %r2,INITRD_START-PARMAREA(%r12)  # use ramdisk location as temp
 275         bas   %r14,.Lloader                    # load parameter file
 276         ltr   %r2,%r2                          # got anything ?
 277         bz    .Lnopf
 278         chi   %r2,895
 279         bnh   .Lnotrunc
 280         la    %r2,895
 281 .Lnotrunc:
 282         l     %r4,INITRD_START-PARMAREA(%r12)
 283         clc   0(3,%r4),.L_hdr                  # if it is HDRx
 284         bz    .Lagain1                         # skip dataset header
 285         clc   0(3,%r4),.L_eof                  # if it is EOFx
 286         bz    .Lagain1                         # skip dateset trailer
 287         la    %r5,0(%r4,%r2)
 288         lr    %r3,%r2
 289 .Lidebc:
 290         tm    0(%r5),0x80                      # high order bit set ?
 291         bo    .Ldocv                           #  yes -> convert from EBCDIC
 292         ahi   %r5,-1
 293         bct   %r3,.Lidebc
 294         b     .Lnocv
 295 .Ldocv:
 296         l     %r3,.Lcvtab
 297         tr    0(256,%r4),0(%r3)                # convert parameters to ascii
 298         tr    256(256,%r4),0(%r3)
 299         tr    512(256,%r4),0(%r3)
 300         tr    768(122,%r4),0(%r3)
 301 .Lnocv: la    %r3,COMMAND_LINE-PARMAREA(%r12)  # load adr. of command line
 302         mvc   0(256,%r3),0(%r4)
 303         mvc   256(256,%r3),256(%r4)
 304         mvc   512(256,%r3),512(%r4)
 305         mvc   768(122,%r3),768(%r4)
 306         slr   %r0,%r0
 307         b     .Lcntlp
 308 .Ldelspc:
 309         ic    %r0,0(%r2,%r3)
 310         chi   %r0,0x20                         # is it a space ?
 311         be    .Lcntlp
 312         ahi   %r2,1
 313         b     .Leolp
 314 .Lcntlp:
 315         brct  %r2,.Ldelspc
 316 .Leolp:
 317         slr   %r0,%r0
 318         stc   %r0,0(%r2,%r3)                   # terminate buffer
 319 .Lnopf:
 320
 321 #
 322 # load ramdisk from ipl device
 323 #
 324 .Lagain2:
 325         l     %r2,INITRD_START-PARMAREA(%r12)  # load adr. of ramdisk
 326         bas   %r14,.Lloader                    # load ramdisk
 327         st    %r2,INITRD_SIZE-PARMAREA(%r12)   # store size of ramdisk
 328         ltr   %r2,%r2
 329         bnz   .Lrdcont
 330         st    %r2,INITRD_START-PARMAREA(%r12)  # no ramdisk found, null it
 331 .Lrdcont:
 332         l     %r2,INITRD_START-PARMAREA(%r12)
 333
 334         clc   0(3,%r2),.L_hdr                  # skip HDRx and EOFx
 335         bz    .Lagain2
 336         clc   0(3,%r2),.L_eof
 337         bz    .Lagain2
 338
 339 #ifdef CONFIG_IPL_VM
 340 #
 341 # reset files in VM reader
 342 #
 343         stidp __LC_CPUID                       # store cpuid
 344         tm    __LC_CPUID,0xff                  # running VM ?
 345         bno   .Lnoreset
 346         la    %r2,.Lreset
 347         lhi   %r3,26
 348         .long 0x83230008
 349 .Lnoreset:
 350 #endif
 351
 352 #
 353 # everything loaded, go for it
 354 #
 355 .Lnoload:
 356         l     %r1,.Lstartup
 357         br    %r1
 358
 359 .Lparm: .long  PARMAREA
 360 .Lstartup: .long startup
 361 .Lcvtab:.long  _ebcasc                         # ebcdic to ascii table
 362 .Lreset:.byte  0xc3,0xc8,0xc1,0xd5,0xc7,0xc5,0x40,0xd9,0xc4,0xd9,0x40
 363         .byte  0xc1,0xd3,0xd3,0x40,0xd2,0xc5,0xc5,0xd7,0x40,0xd5,0xd6
 364         .byte  0xc8,0xd6,0xd3,0xc4             # "change rdr all keep nohold"
 365 .L_eof: .long  0xc5d6c600       /* C'EOF' */
 366 .L_hdr: .long  0xc8c4d900       /* C'HDR' */
 367
 368 #endif  /* CONFIG_IPL */
 369
 370 #
 371 # SALIPL loader support. Based on a patch by Rob van der Heij.
 372 # This entry point is called directly from the SALIPL loader and
 373 # doesn't need a builtin ipl record.
 374 #
 375         .org  0x800
 376         .globl start
 377 start:
 378         stm   %r0,%r15,0x07b0           # store registers
 379         basr  %r12,%r0
 380 .base:
 381         l     %r11,.parm
 382         l     %r8,.cmd                  # pointer to command buffer
 383
 384         ltr   %r9,%r9                   # do we have SALIPL parameters?
 385         bp    .sk8x8
 386
 387         mvc   0(64,%r8),0x00b0          # copy saved registers
 388         xc    64(240-64,%r8),0(%r8)     # remainder of buffer
 389         tr    0(64,%r8),.lowcase
 390         b     .gotr
 391 .sk8x8:
 392         mvc   0(240,%r8),0(%r9)         # copy iplparms into buffer
 393 .gotr:
 394         l     %r10,.tbl                 # EBCDIC to ASCII table
 395         tr    0(240,%r8),0(%r10)
 396         stidp __LC_CPUID                # Are we running on VM maybe
 397         cli   __LC_CPUID,0xff
 398         bnz   .test
 399         .long 0x83300060                # diag 3,0,x'0060' - storage size
 400         b     .done
 401 .test:
 402         mvc   0x68(8),.pgmnw            # set up pgm check handler
 403         l     %r2,.fourmeg
 404         lr    %r3,%r2
 405         bctr  %r3,%r0                   # 4M-1
 406 .loop:  iske  %r0,%r3
 407         ar    %r3,%r2
 408 .pgmx:
 409         sr    %r3,%r2
 410         la    %r3,1(%r3)
 411 .done:
 412         l     %r1,.memsize
 413         st    %r3,0(%r1)
 414         slr   %r0,%r0
 415         st    %r0,INITRD_SIZE-PARMAREA(%r11)
 416         st    %r0,INITRD_START-PARMAREA(%r11)
 417         j     startup                   # continue with startup
 418 .tbl:   .long _ebcasc                   # translate table
 419 .cmd:   .long COMMAND_LINE              # address of command line buffer
 420 .parm:  .long PARMAREA
 421 .memsize: .long memory_size
 422 .fourmeg: .long 0x00400000              # 4M
 423 .pgmnw: .long 0x00080000,.pgmx
 424 .lowcase:
 425         .byte 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07
 426         .byte 0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f
 427         .byte 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17
 428         .byte 0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f
 429         .byte 0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27
 430         .byte 0x28,0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f
 431         .byte 0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37
 432         .byte 0x38,0x39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f
 433         .byte 0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47
 434         .byte 0x48,0x49,0x4a,0x4b,0x4c,0x4d,0x4e,0x4f
 435         .byte 0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57
 436         .byte 0x58,0x59,0x5a,0x5b,0x5c,0x5d,0x5e,0x5f
 437         .byte 0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67
 438         .byte 0x68,0x69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f
 439         .byte 0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77
 440         .byte 0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f
 441
 442         .byte 0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87
 443         .byte 0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f
 444         .byte 0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97
 445         .byte 0x98,0x99,0x9a,0x9b,0x9c,0x9d,0x9e,0x9f
 446         .byte 0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7
 447         .byte 0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf
 448         .byte 0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7
 449         .byte 0xb8,0xb9,0xba,0xbb,0xbc,0xbd,0xbe,0xbf
 450         .byte 0xc0,0x81,0x82,0x83,0x84,0x85,0x86,0x87   # .abcdefg
 451         .byte 0x88,0x89,0xca,0xcb,0xcc,0xcd,0xce,0xcf   # hi
 452         .byte 0xd0,0x91,0x92,0x93,0x94,0x95,0x96,0x97   # .jklmnop
 453         .byte 0x98,0x99,0xda,0xdb,0xdc,0xdd,0xde,0xdf   # qr
 454         .byte 0xe0,0xe1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7   # ..stuvwx
 455         .byte 0xa8,0xa9,0xea,0xeb,0xec,0xed,0xee,0xef   # yz
 456         .byte 0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7
 457         .byte 0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff
 458
 459 #
 460 # startup-code at 0x10000, running in real mode
 461 # this is called either by the ipl loader or directly by PSW restart
 462 # or linload or SALIPL
 463 #
 464         .org  0x10000
 465 startup:basr  %r13,0                     # get base
 466 .LPG1:  lctl  %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
 467         la    %r12,_pstart-.LPG1(%r13)   # pointer to parameter area
 468                                          # move IPL device to lowcore
 469         mvc   __LC_IPLDEV(4),IPL_DEVICE-PARMAREA(%r12)
 470
 471 #
 472 # clear bss memory
 473 #
 474         l     %r2,.Lbss_bgn-.LPG1(%r13) # start of bss
 475         l     %r3,.Lbss_end-.LPG1(%r13) # end of bss
 476         sr    %r3,%r2                   # length of bss
 477         sr    %r4,%r4                   #
 478         sr    %r5,%r5                   # set src,length and pad to zero
 479         sr    %r0,%r0                   #
 480         mvcle %r2,%r4,0                 # clear mem
 481         jo    .-4                       # branch back, if not finish
 482
 483         l     %r2,.Lrcp-.LPG1(%r13)     # Read SCP forced command word
 484 .Lservicecall:
 485         stosm .Lpmask-.LPG1(%r13),0x01  # authorize ext interrupts
 486
 487         stctl %r0, %r0,.Lcr-.LPG1(%r13) # get cr0
 488         la    %r1,0x200                 # set bit 22
 489         o     %r1,.Lcr-.LPG1(%r13)      # or old cr0 with r1
 490         st    %r1,.Lcr-.LPG1(%r13)
 491         lctl  %r0, %r0,.Lcr-.LPG1(%r13) # load modified cr0
 492
 493         mvc   __LC_EXT_NEW_PSW(8),.Lpcext-.LPG1(%r13) # set postcall psw
 494         la    %r1, .Lsclph-.LPG1(%r13)
 495         a     %r1,__LC_EXT_NEW_PSW+4    # set handler
 496         st    %r1,__LC_EXT_NEW_PSW+4
 497
 498         la    %r4,_pstart-.LPG1(%r13)   # %r4 is our index for sccb stuff
 499         la    %r1, .Lsccb-PARMAREA(%r4) # our sccb
 500         .insn rre,0xb2200000,%r2,%r1    # service call
 501         ipm   %r1
 502         srl   %r1,28                    # get cc code
 503         xr    %r3, %r3
 504         chi   %r1,3
 505         be    .Lfchunk-.LPG1(%r13)      # leave
 506         chi   %r1,2
 507         be    .Lservicecall-.LPG1(%r13)
 508         lpsw  .Lwaitsclp-.LPG1(%r13)
 509 .Lsclph:
 510         lh    %r1,.Lsccbr-PARMAREA(%r4)
 511         chi   %r1,0x10                  # 0x0010 is the sucess code
 512         je    .Lprocsccb                # let's process the sccb
 513         chi   %r1,0x1f0
 514         bne   .Lfchunk-.LPG1(%r13)      # unhandled error code
 515         c     %r2, .Lrcp-.LPG1(%r13)    # Did we try Read SCP forced
 516         bne   .Lfchunk-.LPG1(%r13)      # if no, give up
 517         l     %r2, .Lrcp2-.LPG1(%r13)   # try with Read SCP
 518         b     .Lservicecall-.LPG1(%r13)
 519 .Lprocsccb:
 520         lh    %r1,.Lscpincr1-PARMAREA(%r4) # use this one if != 0
 521         chi   %r1,0x00
 522         jne   .Lscnd
 523         l     %r1,.Lscpincr2-PARMAREA(%r4) # otherwise use this one
 524 .Lscnd:
 525         xr    %r3,%r3                   # same logic
 526         ic    %r3,.Lscpa1-PARMAREA(%r4)
 527         chi   %r3,0x00
 528         jne   .Lcompmem
 529         l     %r3,.Lscpa2-PARMAREA(%r13)
 530 .Lcompmem:
 531         mr    %r2,%r1                   # mem in MB on 128-bit
 532         l     %r1,.Lonemb-.LPG1(%r13)
 533         mr    %r2,%r1                   # mem size in bytes in %r3
 534         b     .Lfchunk-.LPG1(%r13)
 535
 536 .Lpmask:
 537         .byte 0
 538 .align 8
 539 .Lpcext:.long  0x00080000,0x80000000
 540 .Lcr:
 541         .long 0x00                      # place holder for cr0
 542 .Lwaitsclp:
 543         .long 0x020A0000
 544         .long .Lsclph
 545 .Lrcp:
 546         .int 0x00120001                 # Read SCP forced code
 547 .Lrcp2:
 548         .int 0x00020001                 # Read SCP code
 549 .Lonemb:
 550         .int 0x100000
 551 .Lfchunk:
 552
 553 #
 554 # find memory chunks.
 555 #
 556         lr    %r9,%r3                    # end of mem
 557         mvc   __LC_PGM_NEW_PSW(8),.Lpcmem-.LPG1(%r13)
 558         la    %r1,1                      # test in increments of 128KB
 559         sll   %r1,17
 560         l     %r3,.Lmchunk-.LPG1(%r13)   # get pointer to memory_chunk array
 561         slr   %r4,%r4                    # set start of chunk to zero
 562         slr   %r5,%r5                    # set end of chunk to zero
 563         slr   %r6,%r6                    # set access code to zero
 564         la    %r10, MEMORY_CHUNKS        # number of chunks
 565 .Lloop:
 566         tprot 0(%r5),0                   # test protection of first byte
 567         ipm   %r7
 568         srl   %r7,28
 569         clr   %r6,%r7                    # compare cc with last access code
 570         be    .Lsame-.LPG1(%r13)
 571         b     .Lchkmem-.LPG1(%r13)
 572 .Lsame:
 573         ar    %r5,%r1                    # add 128KB to end of chunk
 574         bno   .Lloop-.LPG1(%r13)         # r1 < 0x80000000 -> loop
 575 .Lchkmem:                                # > 2GB or tprot got a program check
 576         clr   %r4,%r5                    # chunk size > 0?
 577         be    .Lchkloop-.LPG1(%r13)
 578         st    %r4,0(%r3)                 # store start address of chunk
 579         lr    %r0,%r5
 580         slr   %r0,%r4
 581         st    %r0,4(%r3)                 # store size of chunk
 582         st    %r6,8(%r3)                 # store type of chunk
 583         la    %r3,12(%r3)
 584         l     %r4,.Lmemsize-.LPG1(%r13)  # address of variable memory_size
 585         st    %r5,0(%r4)                 # store last end to memory size
 586         ahi   %r10,-1                    # update chunk number
 587 .Lchkloop:
 588         lr    %r6,%r7                    # set access code to last cc
 589         # we got an exception or we're starting a new
 590         # chunk , we must check if we should
 591         # still try to find valid memory (if we detected
 592         # the amount of available storage), and if we
 593         # have chunks left
 594         xr    %r0,%r0
 595         clr   %r0,%r9                    # did we detect memory?
 596         je    .Ldonemem                  # if not, leave
 597         chi   %r10,0                     # do we have chunks left?
 598         je    .Ldonemem
 599         alr   %r5,%r1                    # add 128KB to end of chunk
 600         lr    %r4,%r5                    # potential new chunk
 601         clr    %r5,%r9                   # should we go on?
 602         jl     .Lloop
 603 .Ldonemem:
 604         l      %r12,.Lmflags-.LPG1(%r13) # get address of machine_flags
 605 #
 606 # find out if we are running under VM
 607 #
 608         stidp  __LC_CPUID               # store cpuid
 609         tm     __LC_CPUID,0xff          # running under VM ?
 610         bno    .Lnovm-.LPG1(%r13)
 611         oi     3(%r12),1                # set VM flag
 612 .Lnovm:
 613         lh     %r0,__LC_CPUID+4         # get cpu version
 614         chi    %r0,0x7490               # running on a P/390 ?
 615         bne    .Lnop390-.LPG1(%r13)
 616         oi     3(%r12),4                # set P/390 flag
 617 .Lnop390:
 618
 619 #
 620 # find out if we have an IEEE fpu
 621 #
 622         mvc    __LC_PGM_NEW_PSW(8),.Lpcfpu-.LPG1(%r13)
 623         efpc   %r0,0                    # test IEEE extract fpc instruction
 624         oi     3(%r12),2                # set IEEE fpu flag
 625 .Lchkfpu:
 626
 627 #
 628 # find out if we have the CSP instruction
 629 #
 630        mvc    __LC_PGM_NEW_PSW(8),.Lpccsp-.LPG1(%r13)
 631        la     %r0,0
 632        lr     %r1,%r0
 633        la     %r2,4
 634        csp    %r0,%r2                   # Test CSP instruction
 635        oi     3(%r12),8                 # set CSP flag
 636 .Lchkcsp:
 637
 638 #
 639 # find out if we have the MVPG instruction
 640 #
 641        mvc    __LC_PGM_NEW_PSW(8),.Lpcmvpg-.LPG1(%r13)
 642        sr     %r0,%r0
 643        la     %r1,0
 644        la     %r2,0
 645        mvpg   %r1,%r2                   # Test CSP instruction
 646        oi     3(%r12),16                # set MVPG flag
 647 .Lchkmvpg:
 648
 649 #
 650 # find out if we have the IDTE instruction
 651 #
 652         mvc     __LC_PGM_NEW_PSW(8),.Lpcidte-.LPG1(%r13)
 653         .long   0xb2b10000              # store facility list
 654         tm      0xc8,0x08               # check bit for clearing-by-ASCE
 655         bno     .Lchkidte-.LPG1(%r13)
 656         lhi     %r1,2094
 657         lhi     %r2,0
 658         .long   0xb98e2001
 659         oi      3(%r12),0x80            # set IDTE flag
 660 .Lchkidte:
 661
 662         lpsw  .Lentry-.LPG1(13)         # jump to _stext in primary-space,
 663                                         # virtual and never return ...
 664         .align 8
 665 .Lentry:.long  0x00080000,0x80000000 + _stext
 666 .Lctl:  .long  0x04b50002               # cr0: various things
 667         .long  0                        # cr1: primary space segment table
 668         .long  .Lduct                   # cr2: dispatchable unit control table
 669         .long  0                        # cr3: instruction authorization
 670         .long  0                        # cr4: instruction authorization
 671         .long  0xffffffff               # cr5: primary-aste origin
 672         .long  0                        # cr6:  I/O interrupts
 673         .long  0                        # cr7:  secondary space segment table
 674         .long  0                        # cr8:  access registers translation
 675         .long  0                        # cr9:  tracing off
 676         .long  0                        # cr10: tracing off
 677         .long  0                        # cr11: tracing off
 678         .long  0                        # cr12: tracing off
 679         .long  0                        # cr13: home space segment table
 680         .long  0xc0000000               # cr14: machine check handling off
 681         .long  0                        # cr15: linkage stack operations
 682 .Lpcmem:.long  0x00080000,0x80000000 + .Lchkmem
 683 .Lpcfpu:.long  0x00080000,0x80000000 + .Lchkfpu
 684 .Lpccsp:.long  0x00080000,0x80000000 + .Lchkcsp
 685 .Lpcmvpg:.long 0x00080000,0x80000000 + .Lchkmvpg
 686 .Lpcidte:.long 0x00080000,0x80000000 + .Lchkidte
 687 .Lmemsize:.long memory_size
 688 .Lmchunk:.long memory_chunk
 689 .Lmflags:.long machine_flags
 690 .Lbss_bgn:  .long  __bss_start
 691 .Lbss_end:  .long  _end
 692
 693         .org PARMAREA-64
 694 .Lduct: .long 0,0,0,0,0,0,0,0
 695         .long 0,0,0,0,0,0,0,0
 696
 697 #
 698 # params at 10400 (setup.h)
 699 #
 700         .org   PARMAREA
 701         .global _pstart
 702 _pstart:
 703         .long  0,0                      # IPL_DEVICE
 704         .long  0,RAMDISK_ORIGIN         # INITRD_START
 705         .long  0,RAMDISK_SIZE           # INITRD_SIZE
 706
 707         .org   COMMAND_LINE
 708         .byte  "root=/dev/ram0 ro"
 709         .byte  0
 710         .org   0x11000
 711 .Lsccb:
 712         .hword 0x1000                   # length, one page
 713         .byte 0x00,0x00,0x00
 714         .byte 0x80                      # variable response bit set
 715 .Lsccbr:
 716         .hword 0x00                     # response code
 717 .Lscpincr1:
 718         .hword 0x00
 719 .Lscpa1:
 720         .byte 0x00
 721         .fill 89,1,0
 722 .Lscpa2:
 723         .int 0x00
 724 .Lscpincr2:
 725         .quad 0x00
 726         .fill 3984,1,0
 727         .org 0x12000
 728         .global _pend
 729 _pend:
 730
 731 #ifdef CONFIG_SHARED_KERNEL
 732         .org   0x100000
 733 #endif
 734
 735 #
 736 # startup-code, running in virtual mode
 737 #
 738         .globl _stext
 739 _stext: basr  %r13,0                    # get base
 740 .LPG2:
 741 #
 742 # Setup stack
 743 #
 744         l     %r15,.Linittu-.LPG2(%r13)
 745         mvc   __LC_CURRENT(4),__TI_task(%r15)
 746         ahi   %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE
 747         st    %r15,__LC_KERNEL_STACK    # set end of kernel stack
 748         ahi   %r15,-96
 749         xc    __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
 750
 751 # check control registers
 752         stctl  %c0,%c15,0(%r15)
 753         oi     2(%r15),0x20             # enable sigp external interrupts
 754         oi     0(%r15),0x10             # switch on low address protection
 755         lctl   %c0,%c15,0(%r15)
 756
 757 #
 758         lam    0,15,.Laregs-.LPG2(%r13) # load access regs needed by uaccess
 759         l      %r14,.Lstart-.LPG2(%r13)
 760         basr   %r14,%r14                # call start_kernel
 761 #
 762 # We returned from start_kernel ?!? PANIK
 763 #
 764         basr  %r13,0
 765         lpsw  .Ldw-.(%r13)           # load disabled wait psw
 766 #
 767             .align 8
 768 .Ldw:       .long  0x000a0000,0x00000000
 769 .Linittu:   .long  init_thread_union
 770 .Lstart:    .long  start_kernel
 771 .Laregs:    .long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
 772