arch/s390/kernel/head31.S

   1 /*
   2  * arch/s390/kernel/head31.S
   3  *
   4  * Copyright (C) IBM Corp. 2005,2006
   5  *
   6  *   Author(s): Hartmut Penner <hp@de.ibm.com>
   7  *              Martin Schwidefsky <schwidefsky@de.ibm.com>
   8  *              Rob van der Heij <rvdhei@iae.nl>
   9  *              Heiko Carstens <heiko.carstens@de.ibm.com>
  10  *
  11  */
  12
  13 #
  14 # startup-code at 0x10000, running in absolute addressing mode
  15 # this is called either by the ipl loader or directly by PSW restart
  16 # or linload or SALIPL
  17 #
  18         .org    0x10000
  19 startup:basr    %r13,0                  # get base
  20 .LPG0:  l       %r13,0f-.LPG0(%r13)
  21         b       0(%r13)
  22 0:      .long   startup_continue
  23
  24 #
  25 # params at 10400 (setup.h)
  26 #
  27         .org    PARMAREA
  28         .long   0,0                     # IPL_DEVICE
  29         .long   0,0                     # INITRD_START
  30         .long   0,0                     # INITRD_SIZE
  31
  32         .org    COMMAND_LINE
  33         .byte   "root=/dev/ram0 ro"
  34         .byte   0
  35
  36         .org    0x11000
  37
  38 startup_continue:
  39         basr    %r13,0                  # get base
  40 .LPG1:  mvi     __LC_AR_MODE_ID,0       # set ESA flag (mode 0)
  41         lctl    %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
  42         l       %r12,.Lparmaddr-.LPG1(%r13) # pointer to parameter area
  43                                         # move IPL device to lowcore
  44         mvc     __LC_IPLDEV(4),IPL_DEVICE-PARMAREA(%r12)
  45 #
  46 # Setup stack
  47 #
  48         l       %r15,.Linittu-.LPG1(%r13)
  49         mvc     __LC_CURRENT(4),__TI_task(%r15)
  50         ahi     %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union+THREAD_SIZE
  51         st      %r15,__LC_KERNEL_STACK  # set end of kernel stack
  52         ahi     %r15,-96
  53         xc      __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
  54 #
  55 # Save ipl parameters, clear bss memory, initialize storage key for kernel pages,
  56 # and create a kernel NSS if the SAVESYS= parm is defined
  57 #
  58         l       %r14,.Lstartup_init-.LPG1(%r13)
  59         basr    %r14,%r14
  60
  61         l       %r12,.Lmflags-.LPG1(%r13) # get address of machine_flags
  62 #
  63 # find out if we have an IEEE fpu
  64 #
  65         mvc     __LC_PGM_NEW_PSW(8),.Lpcfpu-.LPG1(%r13)
  66         efpc    %r0,0                   # test IEEE extract fpc instruction
  67         oi      3(%r12),2               # set IEEE fpu flag
  68 .Lchkfpu:
  69
  70 #
  71 # find out if we have the CSP instruction
  72 #
  73        mvc       __LC_PGM_NEW_PSW(8),.Lpccsp-.LPG1(%r13)
  74        la        %r0,0
  75        lr       %r1,%r0
  76        la       %r2,4
  77        csp      %r0,%r2                 # Test CSP instruction
  78        oi       3(%r12),8               # set CSP flag
  79 .Lchkcsp:
  80
  81 #
  82 # find out if we have the MVPG instruction
  83 #
  84        mvc      __LC_PGM_NEW_PSW(8),.Lpcmvpg-.LPG1(%r13)
  85        sr       %r0,%r0
  86        la       %r1,0
  87        la       %r2,0
  88        mvpg     %r1,%r2                 # Test CSP instruction
  89        oi       3(%r12),16              # set MVPG flag
  90 .Lchkmvpg:
  91
  92 #
  93 # find out if we have the IDTE instruction
  94 #
  95         mvc     __LC_PGM_NEW_PSW(8),.Lpcidte-.LPG1(%r13)
  96         .long   0xb2b10000              # store facility list
  97         tm      0xc8,0x08               # check bit for clearing-by-ASCE
  98         bno     .Lchkidte-.LPG1(%r13)
  99         lhi     %r1,2094
 100         lhi     %r2,0
 101         .long   0xb98e2001
 102         oi      3(%r12),0x80            # set IDTE flag
 103 .Lchkidte:
 104
 105 #
 106 # find out if the diag 0x9c is available
 107 #
 108         mvc     __LC_PGM_NEW_PSW(8),.Lpcdiag9c-.LPG1(%r13)
 109         stap    __LC_CPUID+4            # store cpu address
 110         lh      %r1,__LC_CPUID+4
 111         diag    %r1,0,0x9c              # test diag 0x9c
 112         oi      2(%r12),1               # set diag9c flag
 113 .Lchkdiag9c:
 114
 115         lpsw  .Lentry-.LPG1(13)         # jump to _stext in primary-space,
 116                                         # virtual and never return ...
 117         .align  8
 118 .Lentry:.long   0x00080000,0x80000000 + _stext
 119 .Lctl:  .long   0x04b50002              # cr0: various things
 120         .long   0                       # cr1: primary space segment table
 121         .long   .Lduct                  # cr2: dispatchable unit control table
 122         .long   0                       # cr3: instruction authorization
 123         .long   0                       # cr4: instruction authorization
 124         .long   0xffffffff              # cr5: primary-aste origin
 125         .long   0                       # cr6:  I/O interrupts
 126         .long   0                       # cr7:  secondary space segment table
 127         .long   0                       # cr8:  access registers translation
 128         .long   0                       # cr9:  tracing off
 129         .long   0                       # cr10: tracing off
 130         .long   0                       # cr11: tracing off
 131         .long   0                       # cr12: tracing off
 132         .long   0                       # cr13: home space segment table
 133         .long   0xc0000000              # cr14: machine check handling off
 134         .long   0                       # cr15: linkage stack operations
 135 .Lduct: .long   0,0,0,0,0,0,0,0
 136         .long   0,0,0,0,0,0,0,0
 137 .Lpcfpu:.long   0x00080000,0x80000000 + .Lchkfpu
 138 .Lpccsp:.long   0x00080000,0x80000000 + .Lchkcsp
 139 .Lpcmvpg:.long  0x00080000,0x80000000 + .Lchkmvpg
 140 .Lpcidte:.long  0x00080000,0x80000000 + .Lchkidte
 141 .Lpcdiag9c:.long 0x00080000,0x80000000 + .Lchkdiag9c
 142 .Lmchunk:.long  memory_chunk
 143 .Lmflags:.long  machine_flags
 144 .Lbss_bgn:  .long __bss_start
 145 .Lbss_end:  .long _end
 146 .Lparmaddr: .long PARMAREA
 147 .Linittu:   .long init_thread_union
 148 .Lstartup_init:
 149             .long startup_init
 150
 151         .globl ipl_schib
 152 ipl_schib:
 153         .rept 13
 154         .long 0
 155         .endr
 156
 157         .globl ipl_flags
 158 ipl_flags:
 159         .long 0
 160         .globl ipl_devno
 161 ipl_devno:
 162         .word 0
 163
 164         .org    0x12000
 165 #ifdef CONFIG_SHARED_KERNEL
 166         .org    0x100000
 167 #endif
 168
 169 #
 170 # startup-code, running in absolute addressing mode
 171 #
 172         .globl  _stext
 173 _stext: basr    %r13,0                  # get base
 174 .LPG3:
 175 # check control registers
 176         stctl   %c0,%c15,0(%r15)
 177         oi      2(%r15),0x40            # enable sigp emergency signal
 178         oi      0(%r15),0x10            # switch on low address protection
 179         lctl    %c0,%c15,0(%r15)
 180
 181 #
 182         lam     0,15,.Laregs-.LPG3(%r13) # load access regs needed by uaccess
 183         l       %r14,.Lstart-.LPG3(%r13)
 184         basr    %r14,%r14               # call start_kernel
 185 #
 186 # We returned from start_kernel ?!? PANIK
 187 #
 188         basr    %r13,0
 189         lpsw    .Ldw-.(%r13)            # load disabled wait psw
 190 #
 191         .align  8
 192 .Ldw:   .long   0x000a0000,0x00000000
 193 .Lstart:.long   start_kernel
 194 .Laregs:.long   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0