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         .long 0x83230008
 348 .Lnoreset:
 349 #endif
 350
 351 #
 352 # everything loaded, go for it
 353 #
 354 .Lnoload:
 355         l     %r1,.Lstartup
 356         br    %r1
 357
 358 .Lstartup: .long startup
 359 .Lcvtab:.long  _ebcasc                         # ebcdic to ascii table
 360 .Lreset:.byte  0xc3,0xc8,0xc1,0xd5,0xc7,0xc5,0x40,0xd9,0xc4,0xd9,0x40
 361         .byte  0xc1,0xd3,0xd3,0x40,0xd2,0xc5,0xc5,0xd7,0x40,0xd5,0xd6
 362         .byte  0xc8,0xd6,0xd3,0xc4             # "change rdr all keep nohold"
 363 .L_eof: .long  0xc5d6c600       /* C'EOF' */
 364 .L_hdr: .long  0xc8c4d900       /* C'HDR' */
 365 #endif  /* CONFIG_IPL */
 366
 367 #
 368 # SALIPL loader support. Based on a patch by Rob van der Heij.
 369 # This entry point is called directly from the SALIPL loader and
 370 # doesn't need a builtin ipl record.
 371 #
 372         .org  0x800
 373         .globl start
 374 start:
 375         stm   %r0,%r15,0x07b0           # store registers
 376         basr  %r12,%r0
 377 .base:
 378         l     %r11,.parm
 379         l     %r8,.cmd                  # pointer to command buffer
 380
 381         ltr   %r9,%r9                   # do we have SALIPL parameters?
 382         bp    .sk8x8
 383
 384         mvc   0(64,%r8),0x00b0          # copy saved registers
 385         xc    64(240-64,%r8),0(%r8)     # remainder of buffer
 386         tr    0(64,%r8),.lowcase
 387         b     .gotr
 388 .sk8x8:
 389         mvc   0(240,%r8),0(%r9)         # copy iplparms into buffer
 390 .gotr:
 391         l     %r10,.tbl                 # EBCDIC to ASCII table
 392         tr    0(240,%r8),0(%r10)
 393         stidp __LC_CPUID                # Are we running on VM maybe
 394         cli   __LC_CPUID,0xff
 395         bnz   .test
 396         .long 0x83300060                # diag 3,0,x'0060' - storage size
 397         b     .done
 398 .test:
 399         mvc   0x68(8),.pgmnw            # set up pgm check handler
 400         l     %r2,.fourmeg
 401         lr    %r3,%r2
 402         bctr  %r3,%r0                   # 4M-1
 403 .loop:  iske  %r0,%r3
 404         ar    %r3,%r2
 405 .pgmx:
 406         sr    %r3,%r2
 407         la    %r3,1(%r3)
 408 .done:
 409         l     %r1,.memsize
 410         st    %r3,4(%r1)
 411         slr   %r0,%r0
 412         st    %r0,INITRD_SIZE+4-PARMAREA(%r11)
 413         st    %r0,INITRD_START+4-PARMAREA(%r11)
 414         j     startup                   # continue with startup
 415 .tbl:   .long _ebcasc                   # translate table
 416 .cmd:   .long COMMAND_LINE              # address of command line buffer
 417 .parm:  .long PARMAREA
 418 .fourmeg: .long 0x00400000              # 4M
 419 .pgmnw: .long 0x00080000,.pgmx
 420 .memsize: .long memory_size
 421 .lowcase:
 422         .byte 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07
 423         .byte 0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f
 424         .byte 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17
 425         .byte 0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f
 426         .byte 0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27
 427         .byte 0x28,0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f
 428         .byte 0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37
 429         .byte 0x38,0x39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f
 430         .byte 0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47
 431         .byte 0x48,0x49,0x4a,0x4b,0x4c,0x4d,0x4e,0x4f
 432         .byte 0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57
 433         .byte 0x58,0x59,0x5a,0x5b,0x5c,0x5d,0x5e,0x5f
 434         .byte 0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67
 435         .byte 0x68,0x69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f
 436         .byte 0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77
 437         .byte 0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f
 438
 439         .byte 0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87
 440         .byte 0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f
 441         .byte 0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97
 442         .byte 0x98,0x99,0x9a,0x9b,0x9c,0x9d,0x9e,0x9f
 443         .byte 0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7
 444         .byte 0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf
 445         .byte 0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7
 446         .byte 0xb8,0xb9,0xba,0xbb,0xbc,0xbd,0xbe,0xbf
 447         .byte 0xc0,0x81,0x82,0x83,0x84,0x85,0x86,0x87   # .abcdefg
 448         .byte 0x88,0x89,0xca,0xcb,0xcc,0xcd,0xce,0xcf   # hi
 449         .byte 0xd0,0x91,0x92,0x93,0x94,0x95,0x96,0x97   # .jklmnop
 450         .byte 0x98,0x99,0xda,0xdb,0xdc,0xdd,0xde,0xdf   # qr
 451         .byte 0xe0,0xe1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7   # ..stuvwx
 452         .byte 0xa8,0xa9,0xea,0xeb,0xec,0xed,0xee,0xef   # yz
 453         .byte 0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7
 454         .byte 0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff
 455
 456 #
 457 # startup-code at 0x10000, running in real mode
 458 # this is called either by the ipl loader or directly by PSW restart
 459 # or linload or SALIPL
 460 #
 461         .org  0x10000
 462 startup:basr  %r13,0                     # get base
 463 .LPG1:  sll   %r13,1                     # remove high order bit
 464         srl   %r13,1
 465         lhi   %r1,1                      # mode 1 = esame
 466         slr   %r0,%r0                    # set cpuid to zero
 467         sigp  %r1,%r0,0x12               # switch to esame mode
 468         sam64                            # switch to 64 bit mode
 469         lctlg %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
 470         larl  %r12,_pstart               # pointer to parameter area
 471                                          # move IPL device to lowcore
 472         mvc   __LC_IPLDEV(4),IPL_DEVICE+4-PARMAREA(%r12)
 473
 474 #
 475 # clear bss memory
 476 #
 477         larl  %r2,__bss_start           # start of bss segment
 478         larl  %r3,_end                  # end of bss segment
 479         sgr   %r3,%r2                   # length of bss
 480         sgr   %r4,%r4                   #
 481         sgr   %r5,%r5                   # set src,length and pad to zero
 482         mvcle %r2,%r4,0                 # clear mem
 483         jo    .-4                       # branch back, if not finish
 484
 485         l     %r2,.Lrcp-.LPG1(%r13)     # Read SCP forced command word
 486 .Lservicecall:
 487         stosm .Lpmask-.LPG1(%r13),0x01  # authorize ext interrupts
 488
 489         stctg %r0,%r0,.Lcr-.LPG1(%r13)  # get cr0
 490         la    %r1,0x200                 # set bit 22
 491         og    %r1,.Lcr-.LPG1(%r13)      # or old cr0 with r1
 492         stg   %r1,.Lcr-.LPG1(%r13)
 493         lctlg %r0,%r0,.Lcr-.LPG1(%r13)  # load modified cr0
 494
 495         mvc   __LC_EXT_NEW_PSW(8),.Lpcmsk-.LPG1(%r13) # set postcall psw
 496         larl  %r1,.Lsclph
 497         stg   %r1,__LC_EXT_NEW_PSW+8    # set handler
 498
 499         larl  %r4,_pstart               # %r4 is our index for sccb stuff
 500         la    %r1,.Lsccb-PARMAREA(%r4)  # our sccb
 501         .insn rre,0xb2200000,%r2,%r1    # service call
 502         ipm   %r1
 503         srl   %r1,28                    # get cc code
 504         xr    %r3,%r3
 505         chi   %r1,3
 506         be    .Lfchunk-.LPG1(%r13)      # leave
 507         chi   %r1,2
 508         be    .Lservicecall-.LPG1(%r13)
 509         lpsw  .Lwaitsclp-.LPG1(%r13)
 510 .Lsclph:
 511         lh    %r1,.Lsccbr-PARMAREA(%r4)
 512         chi   %r1,0x10                  # 0x0010 is the sucess code
 513         je    .Lprocsccb                # let's process the sccb
 514         chi   %r1,0x1f0
 515         bne   .Lfchunk-.LPG1(%r13)      # unhandled error code
 516         c     %r2,.Lrcp-.LPG1(%r13)     # Did we try Read SCP forced
 517         bne   .Lfchunk-.LPG1(%r13)      # if no, give up
 518         l     %r2,.Lrcp2-.LPG1(%r13)    # try with Read SCP
 519         b     .Lservicecall-.LPG1(%r13)
 520 .Lprocsccb:
 521         lh    %r1,.Lscpincr1-PARMAREA(%r4) # use this one if != 0
 522         chi   %r1,0x00
 523         jne   .Lscnd
 524         lg    %r1,.Lscpincr2-PARMAREA(%r4) # otherwise use this one
 525 .Lscnd:
 526         xr    %r3,%r3                   # same logic
 527         ic    %r3,.Lscpa1-PARMAREA(%r4)
 528         chi   %r3,0x00
 529         jne   .Lcompmem
 530         l     %r3,.Lscpa2-PARMAREA(%r13)
 531 .Lcompmem:
 532         mlgr  %r2,%r1                   # mem in MB on 128-bit
 533         l     %r1,.Lonemb-.LPG1(%r13)
 534         mlgr  %r2,%r1                   # mem size in bytes in %r3
 535         b     .Lfchunk-.LPG1(%r13)
 536
 537 .Lpmask:
 538         .byte 0
 539         .align 8
 540 .Lcr:
 541         .quad 0x00  # place holder for cr0
 542 .Lwaitsclp:
 543         .long 0x020A0000
 544         .quad .Lsclph
 545 .Lrcp:
 546         .int 0x00120001 # Read SCP forced code
 547 .Lrcp2:
 548         .int 0x00020001 # Read SCP code
 549 .Lonemb:
 550         .int 0x100000
 551
 552 .Lfchunk:
 553                                          # set program check new psw mask
 554         mvc   __LC_PGM_NEW_PSW(8),.Lpcmsk-.LPG1(%r13)
 555
 556 #
 557 # find memory chunks.
 558 #
 559         lgr   %r9,%r3                    # end of mem
 560         larl  %r1,.Lchkmem               # set program check address
 561         stg   %r1,__LC_PGM_NEW_PSW+8
 562         la    %r1,1                      # test in increments of 128KB
 563         sllg  %r1,%r1,17
 564         larl  %r3,memory_chunk
 565         slgr  %r4,%r4                    # set start of chunk to zero
 566         slgr  %r5,%r5                    # set end of chunk to zero
 567         slr  %r6,%r6                     # set access code to zero
 568         la    %r10,MEMORY_CHUNKS         # number of chunks
 569 .Lloop:
 570         tprot 0(%r5),0                   # test protection of first byte
 571         ipm   %r7
 572         srl   %r7,28
 573         clr   %r6,%r7                    # compare cc with last access code
 574         je    .Lsame
 575         j     .Lchkmem
 576 .Lsame:
 577         algr  %r5,%r1                    # add 128KB to end of chunk
 578                                          # no need to check here,
 579         brc   12,.Lloop                  # this is the same chunk
 580 .Lchkmem:                                # > 16EB or tprot got a program check
 581         clgr  %r4,%r5                    # chunk size > 0?
 582         je    .Lchkloop
 583         stg   %r4,0(%r3)                 # store start address of chunk
 584         lgr   %r0,%r5
 585         slgr  %r0,%r4
 586         stg   %r0,8(%r3)                 # store size of chunk
 587         st    %r6,20(%r3)                # store type of chunk
 588         la    %r3,24(%r3)
 589         larl  %r8,memory_size
 590         stg   %r5,0(%r8)                 # store memory size
 591         ahi   %r10,-1                    # update chunk number
 592 .Lchkloop:
 593         lr    %r6,%r7                    # set access code to last cc
 594         # we got an exception or we're starting a new
 595         # chunk , we must check if we should
 596         # still try to find valid memory (if we detected
 597         # the amount of available storage), and if we
 598         # have chunks left
 599         lghi  %r4,1
 600         sllg  %r4,%r4,31
 601         clgr  %r5,%r4
 602         je    .Lhsaskip
 603         xr    %r0, %r0
 604         clgr  %r0, %r9                   # did we detect memory?
 605         je    .Ldonemem                  # if not, leave
 606         chi   %r10, 0                    # do we have chunks left?
 607         je    .Ldonemem
 608 .Lhsaskip:
 609         algr  %r5,%r1                    # add 128KB to end of chunk
 610         lgr   %r4,%r5                    # potential new chunk
 611         clgr  %r5,%r9                    # should we go on?
 612         jl    .Lloop
 613 .Ldonemem:
 614
 615         larl  %r12,machine_flags
 616 #
 617 # find out if we are running under VM
 618 #
 619         stidp  __LC_CPUID               # store cpuid
 620         tm     __LC_CPUID,0xff          # running under VM ?
 621         bno    0f-.LPG1(%r13)
 622         oi     7(%r12),1                # set VM flag
 623 0:      lh     %r0,__LC_CPUID+4         # get cpu version
 624         chi    %r0,0x7490               # running on a P/390 ?
 625         bne    1f-.LPG1(%r13)
 626         oi     7(%r12),4                # set P/390 flag
 627 1:
 628
 629 #
 630 # find out if we have the MVPG instruction
 631 #
 632         la     %r1,0f-.LPG1(%r13)       # set program check address
 633         stg    %r1,__LC_PGM_NEW_PSW+8
 634         sgr    %r0,%r0
 635         lghi   %r1,0
 636         lghi   %r2,0
 637         mvpg   %r1,%r2                  # test MVPG instruction
 638         oi     7(%r12),16               # set MVPG flag
 639 0:
 640
 641 #
 642 # find out if the diag 0x44 works in 64 bit mode
 643 #
 644         la     %r1,0f-.LPG1(%r13)       # set program check address
 645         stg    %r1,__LC_PGM_NEW_PSW+8
 646         mvc    __LC_DIAG44_OPCODE(8),.Lnop-.LPG1(%r13)
 647         diag   0,0,0x44                 # test diag 0x44
 648         oi     7(%r12),32               # set diag44 flag
 649         mvc    __LC_DIAG44_OPCODE(8),.Ldiag44-.LPG1(%r13)
 650 0:
 651
 652 #
 653 # find out if we have the IDTE instruction
 654 #
 655         la     %r1,0f-.LPG1(%r13)       # set program check address
 656         stg    %r1,__LC_PGM_NEW_PSW+8
 657         .long   0xb2b10000              # store facility list
 658         tm      0xc8,0x08               # check bit for clearing-by-ASCE
 659         bno     0f-.LPG1(%r13)
 660         lhi     %r1,2094
 661         lhi     %r2,0
 662         .long   0xb98e2001
 663         oi      7(%r12),0x80            # set IDTE flag
 664 0:
 665
 666         lpswe .Lentry-.LPG1(13)         # jump to _stext in primary-space,
 667                                         # virtual and never return ...
 668         .align 16
 669 .Lentry:.quad  0x0000000180000000,_stext
 670 .Lctl:  .quad  0x04b50002               # cr0: various things
 671         .quad  0                        # cr1: primary space segment table
 672         .quad  .Lduct                   # cr2: dispatchable unit control table
 673         .quad  0                        # cr3: instruction authorization
 674         .quad  0                        # cr4: instruction authorization
 675         .quad  0xffffffffffffffff       # cr5: primary-aste origin
 676         .quad  0                        # cr6:  I/O interrupts
 677         .quad  0                        # cr7:  secondary space segment table
 678         .quad  0                        # cr8:  access registers translation
 679         .quad  0                        # cr9:  tracing off
 680         .quad  0                        # cr10: tracing off
 681         .quad  0                        # cr11: tracing off
 682         .quad  0                        # cr12: tracing off
 683         .quad  0                        # cr13: home space segment table
 684         .quad  0xc0000000               # cr14: machine check handling off
 685         .quad  0                        # cr15: linkage stack operations
 686 .Lpcmsk:.quad  0x0000000180000000
 687 .L4malign:.quad 0xffffffffffc00000
 688 .Lscan2g:.quad 0x80000000 + 0x20000 - 8 # 2GB + 128K - 8
 689 .Lnop:  .long  0x07000700
 690 .Ldiag44:.long 0x83000044
 691
 692         .org PARMAREA-64
 693 .Lduct: .long 0,0,0,0,0,0,0,0
 694         .long 0,0,0,0,0,0,0,0
 695
 696 #
 697 # params at 10400 (setup.h)
 698 #
 699         .org   PARMAREA
 700         .global _pstart
 701 _pstart:
 702         .quad  0                        # IPL_DEVICE
 703         .quad  RAMDISK_ORIGIN           # INITRD_START
 704         .quad  RAMDISK_SIZE             # INITRD_SIZE
 705
 706         .org   COMMAND_LINE
 707         .byte  "root=/dev/ram0 ro"
 708         .byte  0
 709         .org   0x11000
 710 .Lsccb:
 711         .hword 0x1000                   # length, one page
 712         .byte 0x00,0x00,0x00
 713         .byte 0x80                      # variable response bit set
 714 .Lsccbr:
 715         .hword 0x00                     # response code
 716 .Lscpincr1:
 717         .hword 0x00
 718 .Lscpa1:
 719         .byte 0x00
 720         .fill 89,1,0
 721 .Lscpa2:
 722         .int 0x00
 723 .Lscpincr2:
 724         .quad 0x00
 725         .fill 3984,1,0
 726         .org 0x12000
 727         .global _pend
 728 _pend:
 729
 730 #ifdef CONFIG_SHARED_KERNEL
 731         .org   0x100000
 732 #endif
 733
 734 #
 735 # startup-code, running in virtual mode
 736 #
 737         .globl _stext
 738 _stext: basr  %r13,0                    # get base
 739 .LPG2:
 740 #
 741 # Setup stack
 742 #
 743         larl  %r15,init_thread_union
 744         lg    %r14,__TI_task(%r15)      # cache current in lowcore
 745         stg   %r14,__LC_CURRENT
 746         aghi  %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE
 747         stg   %r15,__LC_KERNEL_STACK    # set end of kernel stack
 748         aghi  %r15,-160
 749         xc    __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
 750
 751 # check control registers
 752         stctg  %c0,%c15,0(%r15)
 753         oi     6(%r15),0x20             # enable sigp external interrupts
 754         oi     4(%r15),0x10             # switch on low address proctection
 755         lctlg  %c0,%c15,0(%r15)
 756
 757 #
 758         lam    0,15,.Laregs-.LPG2(%r13) # load access regs needed by uaccess
 759         brasl  %r14,start_kernel        # go to C code
 760 #
 761 # We returned from start_kernel ?!? PANIK
 762 #
 763         basr  %r13,0
 764         lpswe .Ldw-.(%r13)           # load disabled wait psw
 765 #
 766             .align 8
 767 .Ldw:       .quad  0x0002000180000000,0x0000000000000000
 768 .Laregs:    .long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
 769