git.oblomov.eu Git - linux-2.6/blob - arch/s390/kernel/head64.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   0x78(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         larl  %r12,_pstart                     # pointer to parameter area
 268         st    %r1,IPL_DEVICE+4-PARMAREA(%r12)  # store ipl device number
 269
 270 #
 271 # load parameter file from ipl device
 272 #
 273 .Lagain1:
 274         l     %r2,INITRD_START+4-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+4-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+4-PARMAREA(%r12)# load adr. of ramdisk
 326         bas   %r14,.Lloader                    # load ramdisk
 327         st    %r2,INITRD_SIZE+4-PARMAREA(%r12) # store size of ramdisk
 328         ltr   %r2,%r2
 329         bnz   .Lrdcont
 330         st    %r2,INITRD_START+4-PARMAREA(%r12)# no ramdisk found, null it
 331 .Lrdcont:
 332         l     %r2,INITRD_START+4-PARMAREA(%r12)
 333         clc   0(3,%r2),.L_hdr                  # skip HDRx and EOFx
 334         bz    .Lagain2
 335         clc   0(3,%r2),.L_eof
 336         bz    .Lagain2
 337
 338 #ifdef CONFIG_IPL_VM
 339 #
 340 # reset files in VM reader
 341 #
 342         stidp __LC_CPUID                       # store cpuid
 343         tm    __LC_CPUID,0xff                  # running VM ?
 344         bno   .Lnoreset
 345         la    %r2,.Lreset
 346         lhi   %r3,26
 347         diag  %r2,%r3,8
 348         la    %r5,.Lirb
 349         stsch 0(%r5)                           # check if irq is pending
 350         tm    30(%r5),0x0f                     # by verifying if any of the
 351         bnz   .Lwaitforirq                     # activity or status control
 352         tm    31(%r5),0xff                     # bits is set in the schib
 353         bz    .Lnoreset
 354 .Lwaitforirq:
 355         mvc   0x78(8),.Lrdrnewpsw              # set up IO interrupt psw
 356 .Lwaitrdrirq:
 357         lpsw  .Lrdrwaitpsw
 358 .Lrdrint:
 359         c     %r1,0xb8                         # compare subchannel number
 360         bne   .Lwaitrdrirq
 361         la    %r5,.Lirb
 362         tsch  0(%r5)
 363 .Lnoreset:
 364         b     .Lnoload
 365
 366         .align 8
 367 .Lrdrnewpsw:
 368         .long  0x00080000,0x80000000+.Lrdrint
 369 .Lrdrwaitpsw:
 370         .long  0x020a0000,0x80000000+.Lrdrint
 371 #endif
 372
 373 #
 374 # everything loaded, go for it
 375 #
 376 .Lnoload:
 377         l     %r1,.Lstartup
 378         br    %r1
 379
 380 .Lstartup: .long startup
 381 .Lcvtab:.long  _ebcasc                         # ebcdic to ascii table
 382 .Lreset:.byte  0xc3,0xc8,0xc1,0xd5,0xc7,0xc5,0x40,0xd9,0xc4,0xd9,0x40
 383         .byte  0xc1,0xd3,0xd3,0x40,0xd2,0xc5,0xc5,0xd7,0x40,0xd5,0xd6
 384         .byte  0xc8,0xd6,0xd3,0xc4             # "change rdr all keep nohold"
 385 .L_eof: .long  0xc5d6c600       /* C'EOF' */
 386 .L_hdr: .long  0xc8c4d900       /* C'HDR' */
 387 #endif  /* CONFIG_IPL */
 388
 389 #
 390 # SALIPL loader support. Based on a patch by Rob van der Heij.
 391 # This entry point is called directly from the SALIPL loader and
 392 # doesn't need a builtin ipl record.
 393 #
 394         .org  0x800
 395         .globl start
 396 start:
 397         stm   %r0,%r15,0x07b0           # store registers
 398         basr  %r12,%r0
 399 .base:
 400         l     %r11,.parm
 401         l     %r8,.cmd                  # pointer to command buffer
 402
 403         ltr   %r9,%r9                   # do we have SALIPL parameters?
 404         bp    .sk8x8
 405
 406         mvc   0(64,%r8),0x00b0          # copy saved registers
 407         xc    64(240-64,%r8),0(%r8)     # remainder of buffer
 408         tr    0(64,%r8),.lowcase
 409         b     .gotr
 410 .sk8x8:
 411         mvc   0(240,%r8),0(%r9)         # copy iplparms into buffer
 412 .gotr:
 413         l     %r10,.tbl                 # EBCDIC to ASCII table
 414         tr    0(240,%r8),0(%r10)
 415         stidp __LC_CPUID                # Are we running on VM maybe
 416         cli   __LC_CPUID,0xff
 417         bnz   .test
 418         .long 0x83300060                # diag 3,0,x'0060' - storage size
 419         b     .done
 420 .test:
 421         mvc   0x68(8),.pgmnw            # set up pgm check handler
 422         l     %r2,.fourmeg
 423         lr    %r3,%r2
 424         bctr  %r3,%r0                   # 4M-1
 425 .loop:  iske  %r0,%r3
 426         ar    %r3,%r2
 427 .pgmx:
 428         sr    %r3,%r2
 429         la    %r3,1(%r3)
 430 .done:
 431         l     %r1,.memsize
 432         st    %r3,4(%r1)
 433         slr   %r0,%r0
 434         st    %r0,INITRD_SIZE+4-PARMAREA(%r11)
 435         st    %r0,INITRD_START+4-PARMAREA(%r11)
 436         j     startup                   # continue with startup
 437 .tbl:   .long _ebcasc                   # translate table
 438 .cmd:   .long COMMAND_LINE              # address of command line buffer
 439 .parm:  .long PARMAREA
 440 .fourmeg: .long 0x00400000              # 4M
 441 .pgmnw: .long 0x00080000,.pgmx
 442 .memsize: .long memory_size
 443 .lowcase:
 444         .byte 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07
 445         .byte 0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f
 446         .byte 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17
 447         .byte 0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f
 448         .byte 0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27
 449         .byte 0x28,0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f
 450         .byte 0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37
 451         .byte 0x38,0x39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f
 452         .byte 0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47
 453         .byte 0x48,0x49,0x4a,0x4b,0x4c,0x4d,0x4e,0x4f
 454         .byte 0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57
 455         .byte 0x58,0x59,0x5a,0x5b,0x5c,0x5d,0x5e,0x5f
 456         .byte 0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67
 457         .byte 0x68,0x69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f
 458         .byte 0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77
 459         .byte 0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f
 460
 461         .byte 0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87
 462         .byte 0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f
 463         .byte 0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97
 464         .byte 0x98,0x99,0x9a,0x9b,0x9c,0x9d,0x9e,0x9f
 465         .byte 0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7
 466         .byte 0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf
 467         .byte 0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7
 468         .byte 0xb8,0xb9,0xba,0xbb,0xbc,0xbd,0xbe,0xbf
 469         .byte 0xc0,0x81,0x82,0x83,0x84,0x85,0x86,0x87   # .abcdefg
 470         .byte 0x88,0x89,0xca,0xcb,0xcc,0xcd,0xce,0xcf   # hi
 471         .byte 0xd0,0x91,0x92,0x93,0x94,0x95,0x96,0x97   # .jklmnop
 472         .byte 0x98,0x99,0xda,0xdb,0xdc,0xdd,0xde,0xdf   # qr
 473         .byte 0xe0,0xe1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7   # ..stuvwx
 474         .byte 0xa8,0xa9,0xea,0xeb,0xec,0xed,0xee,0xef   # yz
 475         .byte 0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7
 476         .byte 0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff
 477
 478 #
 479 # startup-code at 0x10000, running in real mode
 480 # this is called either by the ipl loader or directly by PSW restart
 481 # or linload or SALIPL
 482 #
 483         .org  0x10000
 484 startup:basr  %r13,0                     # get base
 485 .LPG1:  sll   %r13,1                     # remove high order bit
 486         srl   %r13,1
 487         lhi   %r1,1                      # mode 1 = esame
 488         slr   %r0,%r0                    # set cpuid to zero
 489         sigp  %r1,%r0,0x12               # switch to esame mode
 490         sam64                            # switch to 64 bit mode
 491         lctlg %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
 492         larl  %r12,_pstart               # pointer to parameter area
 493                                          # move IPL device to lowcore
 494         mvc   __LC_IPLDEV(4),IPL_DEVICE+4-PARMAREA(%r12)
 495
 496 #
 497 # clear bss memory
 498 #
 499         larl  %r2,__bss_start           # start of bss segment
 500         larl  %r3,_end                  # end of bss segment
 501         sgr   %r3,%r2                   # length of bss
 502         sgr   %r4,%r4                   #
 503         sgr   %r5,%r5                   # set src,length and pad to zero
 504         mvcle %r2,%r4,0                 # clear mem
 505         jo    .-4                       # branch back, if not finish
 506
 507         l     %r2,.Lrcp-.LPG1(%r13)     # Read SCP forced command word
 508 .Lservicecall:
 509         stosm .Lpmask-.LPG1(%r13),0x01  # authorize ext interrupts
 510
 511         stctg %r0,%r0,.Lcr-.LPG1(%r13)  # get cr0
 512         la    %r1,0x200                 # set bit 22
 513         og    %r1,.Lcr-.LPG1(%r13)      # or old cr0 with r1
 514         stg   %r1,.Lcr-.LPG1(%r13)
 515         lctlg %r0,%r0,.Lcr-.LPG1(%r13)  # load modified cr0
 516
 517         mvc   __LC_EXT_NEW_PSW(8),.Lpcmsk-.LPG1(%r13) # set postcall psw
 518         larl  %r1,.Lsclph
 519         stg   %r1,__LC_EXT_NEW_PSW+8    # set handler
 520
 521         larl  %r4,_pstart               # %r4 is our index for sccb stuff
 522         la    %r1,.Lsccb-PARMAREA(%r4)  # our sccb
 523         .insn rre,0xb2200000,%r2,%r1    # service call
 524         ipm   %r1
 525         srl   %r1,28                    # get cc code
 526         xr    %r3,%r3
 527         chi   %r1,3
 528         be    .Lfchunk-.LPG1(%r13)      # leave
 529         chi   %r1,2
 530         be    .Lservicecall-.LPG1(%r13)
 531         lpsw  .Lwaitsclp-.LPG1(%r13)
 532 .Lsclph:
 533         lh    %r1,.Lsccbr-PARMAREA(%r4)
 534         chi   %r1,0x10                  # 0x0010 is the sucess code
 535         je    .Lprocsccb                # let's process the sccb
 536         chi   %r1,0x1f0
 537         bne   .Lfchunk-.LPG1(%r13)      # unhandled error code
 538         c     %r2,.Lrcp-.LPG1(%r13)     # Did we try Read SCP forced
 539         bne   .Lfchunk-.LPG1(%r13)      # if no, give up
 540         l     %r2,.Lrcp2-.LPG1(%r13)    # try with Read SCP
 541         b     .Lservicecall-.LPG1(%r13)
 542 .Lprocsccb:
 543         lghi  %r1,0
 544         icm   %r1,3,.Lscpincr1-PARMAREA(%r4) # use this one if != 0
 545         jnz   .Lscnd
 546         lg    %r1,.Lscpincr2-PARMAREA(%r4) # otherwise use this one
 547 .Lscnd:
 548         xr    %r3,%r3                   # same logic
 549         ic    %r3,.Lscpa1-PARMAREA(%r4)
 550         chi   %r3,0x00
 551         jne   .Lcompmem
 552         l     %r3,.Lscpa2-PARMAREA(%r13)
 553 .Lcompmem:
 554         mlgr  %r2,%r1                   # mem in MB on 128-bit
 555         l     %r1,.Lonemb-.LPG1(%r13)
 556         mlgr  %r2,%r1                   # mem size in bytes in %r3
 557         b     .Lfchunk-.LPG1(%r13)
 558
 559 .Lpmask:
 560         .byte 0
 561         .align 8
 562 .Lcr:
 563         .quad 0x00  # place holder for cr0
 564 .Lwaitsclp:
 565         .long 0x020A0000
 566         .quad .Lsclph
 567 .Lrcp:
 568         .int 0x00120001 # Read SCP forced code
 569 .Lrcp2:
 570         .int 0x00020001 # Read SCP code
 571 .Lonemb:
 572         .int 0x100000
 573
 574 .Lfchunk:
 575                                          # set program check new psw mask
 576         mvc   __LC_PGM_NEW_PSW(8),.Lpcmsk-.LPG1(%r13)
 577
 578 #
 579 # find memory chunks.
 580 #
 581         lgr   %r9,%r3                    # end of mem
 582         larl  %r1,.Lchkmem               # set program check address
 583         stg   %r1,__LC_PGM_NEW_PSW+8
 584         la    %r1,1                      # test in increments of 128KB
 585         sllg  %r1,%r1,17
 586         larl  %r3,memory_chunk
 587         slgr  %r4,%r4                    # set start of chunk to zero
 588         slgr  %r5,%r5                    # set end of chunk to zero
 589         slr  %r6,%r6                     # set access code to zero
 590         la    %r10,MEMORY_CHUNKS         # number of chunks
 591 .Lloop:
 592         tprot 0(%r5),0                   # test protection of first byte
 593         ipm   %r7
 594         srl   %r7,28
 595         clr   %r6,%r7                    # compare cc with last access code
 596         je    .Lsame
 597         j     .Lchkmem
 598 .Lsame:
 599         algr  %r5,%r1                    # add 128KB to end of chunk
 600                                          # no need to check here,
 601         brc   12,.Lloop                  # this is the same chunk
 602 .Lchkmem:                                # > 16EB or tprot got a program check
 603         clgr  %r4,%r5                    # chunk size > 0?
 604         je    .Lchkloop
 605         stg   %r4,0(%r3)                 # store start address of chunk
 606         lgr   %r0,%r5
 607         slgr  %r0,%r4
 608         stg   %r0,8(%r3)                 # store size of chunk
 609         st    %r6,20(%r3)                # store type of chunk
 610         la    %r3,24(%r3)
 611         larl  %r8,memory_size
 612         stg   %r5,0(%r8)                 # store memory size
 613         ahi   %r10,-1                    # update chunk number
 614 .Lchkloop:
 615         lr    %r6,%r7                    # set access code to last cc
 616         # we got an exception or we're starting a new
 617         # chunk , we must check if we should
 618         # still try to find valid memory (if we detected
 619         # the amount of available storage), and if we
 620         # have chunks left
 621         lghi  %r4,1
 622         sllg  %r4,%r4,31
 623         clgr  %r5,%r4
 624         je    .Lhsaskip
 625         xr    %r0, %r0
 626         clgr  %r0, %r9                   # did we detect memory?
 627         je    .Ldonemem                  # if not, leave
 628         chi   %r10, 0                    # do we have chunks left?
 629         je    .Ldonemem
 630 .Lhsaskip:
 631         algr  %r5,%r1                    # add 128KB to end of chunk
 632         lgr   %r4,%r5                    # potential new chunk
 633         clgr  %r5,%r9                    # should we go on?
 634         jl    .Lloop
 635 .Ldonemem:
 636
 637         larl  %r12,machine_flags
 638 #
 639 # find out if we are running under VM
 640 #
 641         stidp  __LC_CPUID               # store cpuid
 642         tm     __LC_CPUID,0xff          # running under VM ?
 643         bno    0f-.LPG1(%r13)
 644         oi     7(%r12),1                # set VM flag
 645 0:      lh     %r0,__LC_CPUID+4         # get cpu version
 646         chi    %r0,0x7490               # running on a P/390 ?
 647         bne    1f-.LPG1(%r13)
 648         oi     7(%r12),4                # set P/390 flag
 649 1:
 650
 651 #
 652 # find out if we have the MVPG instruction
 653 #
 654         la     %r1,0f-.LPG1(%r13)       # set program check address
 655         stg    %r1,__LC_PGM_NEW_PSW+8
 656         sgr    %r0,%r0
 657         lghi   %r1,0
 658         lghi   %r2,0
 659         mvpg   %r1,%r2                  # test MVPG instruction
 660         oi     7(%r12),16               # set MVPG flag
 661 0:
 662
 663 #
 664 # find out if the diag 0x44 works in 64 bit mode
 665 #
 666         la     %r1,0f-.LPG1(%r13)       # set program check address
 667         stg    %r1,__LC_PGM_NEW_PSW+8
 668         diag   0,0,0x44                 # test diag 0x44
 669         oi     7(%r12),32               # set diag44 flag
 670 0:
 671
 672 #
 673 # find out if we have the IDTE instruction
 674 #
 675         la     %r1,0f-.LPG1(%r13)       # set program check address
 676         stg    %r1,__LC_PGM_NEW_PSW+8
 677         .long   0xb2b10000              # store facility list
 678         tm      0xc8,0x08               # check bit for clearing-by-ASCE
 679         bno     0f-.LPG1(%r13)
 680         lhi     %r1,2094
 681         lhi     %r2,0
 682         .long   0xb98e2001
 683         oi      7(%r12),0x80            # set IDTE flag
 684 0:
 685
 686         lpswe .Lentry-.LPG1(13)         # jump to _stext in primary-space,
 687                                         # virtual and never return ...
 688         .align 16
 689 .Lentry:.quad  0x0000000180000000,_stext
 690 .Lctl:  .quad  0x04b50002               # cr0: various things
 691         .quad  0                        # cr1: primary space segment table
 692         .quad  .Lduct                   # cr2: dispatchable unit control table
 693         .quad  0                        # cr3: instruction authorization
 694         .quad  0                        # cr4: instruction authorization
 695         .quad  0xffffffffffffffff       # cr5: primary-aste origin
 696         .quad  0                        # cr6:  I/O interrupts
 697         .quad  0                        # cr7:  secondary space segment table
 698         .quad  0                        # cr8:  access registers translation
 699         .quad  0                        # cr9:  tracing off
 700         .quad  0                        # cr10: tracing off
 701         .quad  0                        # cr11: tracing off
 702         .quad  0                        # cr12: tracing off
 703         .quad  0                        # cr13: home space segment table
 704         .quad  0xc0000000               # cr14: machine check handling off
 705         .quad  0                        # cr15: linkage stack operations
 706 .Lpcmsk:.quad  0x0000000180000000
 707 .L4malign:.quad 0xffffffffffc00000
 708 .Lscan2g:.quad 0x80000000 + 0x20000 - 8 # 2GB + 128K - 8
 709 .Lnop:  .long  0x07000700
 710
 711         .org PARMAREA-64
 712 .Lduct: .long 0,0,0,0,0,0,0,0
 713         .long 0,0,0,0,0,0,0,0
 714
 715 #
 716 # params at 10400 (setup.h)
 717 #
 718         .org   PARMAREA
 719         .global _pstart
 720 _pstart:
 721         .quad  0                        # IPL_DEVICE
 722         .quad  RAMDISK_ORIGIN           # INITRD_START
 723         .quad  RAMDISK_SIZE             # INITRD_SIZE
 724
 725         .org   COMMAND_LINE
 726         .byte  "root=/dev/ram0 ro"
 727         .byte  0
 728         .org   0x11000
 729 .Lsccb:
 730         .hword 0x1000                   # length, one page
 731         .byte 0x00,0x00,0x00
 732         .byte 0x80                      # variable response bit set
 733 .Lsccbr:
 734         .hword 0x00                     # response code
 735 .Lscpincr1:
 736         .hword 0x00
 737 .Lscpa1:
 738         .byte 0x00
 739         .fill 89,1,0
 740 .Lscpa2:
 741         .int 0x00
 742 .Lscpincr2:
 743         .quad 0x00
 744         .fill 3984,1,0
 745         .org 0x12000
 746         .global _pend
 747 _pend:
 748
 749 #ifdef CONFIG_SHARED_KERNEL
 750         .org   0x100000
 751 #endif
 752
 753 #
 754 # startup-code, running in virtual mode
 755 #
 756         .globl _stext
 757 _stext: basr  %r13,0                    # get base
 758 .LPG2:
 759 #
 760 # Setup stack
 761 #
 762         larl  %r15,init_thread_union
 763         lg    %r14,__TI_task(%r15)      # cache current in lowcore
 764         stg   %r14,__LC_CURRENT
 765         aghi  %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE
 766         stg   %r15,__LC_KERNEL_STACK    # set end of kernel stack
 767         aghi  %r15,-160
 768         xc    __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
 769
 770 # check control registers
 771         stctg  %c0,%c15,0(%r15)
 772         oi     6(%r15),0x40             # enable sigp emergency signal
 773         oi     4(%r15),0x10             # switch on low address proctection
 774         lctlg  %c0,%c15,0(%r15)
 775
 776 #
 777         lam    0,15,.Laregs-.LPG2(%r13) # load access regs needed by uaccess
 778         brasl  %r14,start_kernel        # go to C code
 779 #
 780 # We returned from start_kernel ?!? PANIK
 781 #
 782         basr  %r13,0
 783         lpswe .Ldw-.(%r13)           # load disabled wait psw
 784 #
 785             .align 8
 786 .Ldw:       .quad  0x0002000180000000,0x0000000000000000
 787 .Laregs:    .long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
 788