arch/s390/kernel/relocate_kernel.S

   1 /*
   2  * arch/s390/kernel/relocate_kernel.S
   3  *
   4  * (C) Copyright IBM Corp. 2005
   5  *
   6  * Author(s): Rolf Adelsberger,
   7  *            Heiko Carstens <heiko.carstens@de.ibm.com>
   8  *
   9  */
  10
  11 /*
  12  * moves the new kernel to its destination...
  13  * %r2 = pointer to first kimage_entry_t
  14  * %r3 = start address - where to jump to after the job is done...
  15  *
  16  * %r5 will be used as temp. storage
  17  * %r6 holds the destination address
  18  * %r7 = PAGE_SIZE
  19  * %r8 holds the source address
  20  * %r9 = PAGE_SIZE
  21  * %r10 is a page mask
  22  */
  23
  24         .text
  25         .globl          relocate_kernel
  26         relocate_kernel:
  27                 basr    %r13,0          # base address
  28         .base:
  29                 stnsm   sys_msk-.base(%r13),0xfb        # disable DAT
  30                 stctl   %c0,%c15,ctlregs-.base(%r13)
  31                 stm     %r0,%r15,gprregs-.base(%r13)
  32                 la      %r1,load_psw-.base(%r13)
  33                 mvc     0(8,%r0),0(%r1)
  34                 la      %r0,.back-.base(%r13)
  35                 st      %r0,4(%r0)
  36                 oi      4(%r0),0x80
  37                 mvc     0x68(8,%r0),0(%r1)
  38                 la      %r0,.back_pgm-.base(%r13)
  39                 st      %r0,0x6c(%r0)
  40                 oi      0x6c(%r0),0x80
  41                 lhi     %r0,0
  42                 diag    %r0,%r0,0x308
  43         .back:
  44                 basr    %r13,0
  45         .back_base:
  46                 oi      have_diag308-.back_base(%r13),0x01
  47                 lctl    %c0,%c15,ctlregs-.back_base(%r13)
  48                 lm      %r0,%r15,gprregs-.back_base(%r13)
  49                 j       .start_reloc
  50         .back_pgm:
  51                 lm      %r0,%r15,gprregs-.base(%r13)
  52         .start_reloc:
  53                 lhi     %r10,-1         # preparing the mask
  54                 sll     %r10,12         # shift it such that it becomes 0xf000
  55         .top:
  56                 lhi     %r7,4096        # load PAGE_SIZE in r7
  57                 lhi     %r9,4096        # load PAGE_SIZE in r9
  58                 l       %r5,0(%r2)      # read another word for indirection page
  59                 ahi     %r2,4           # increment pointer
  60                 tml     %r5,0x1         # is it a destination page?
  61                 je      .indir_check    # NO, goto "indir_check"
  62                 lr      %r6,%r5         # r6 = r5
  63                 nr      %r6,%r10        # mask it out and...
  64                 j       .top            # ...next iteration
  65         .indir_check:
  66                 tml     %r5,0x2         # is it a indirection page?
  67                 je      .done_test      # NO, goto "done_test"
  68                 nr      %r5,%r10        # YES, mask out,
  69                 lr      %r2,%r5         # move it into the right register,
  70                 j       .top            # and read next...
  71         .done_test:
  72                 tml     %r5,0x4         # is it the done indicator?
  73                 je      .source_test    # NO! Well, then it should be the source indicator...
  74                 j       .done           # ok, lets finish it here...
  75         .source_test:
  76                 tml     %r5,0x8         # it should be a source indicator...
  77                 je      .top            # NO, ignore it...
  78                 lr      %r8,%r5         # r8 = r5
  79                 nr      %r8,%r10        # masking
  80         0:      mvcle   %r6,%r8,0x0     # copy PAGE_SIZE bytes from r8 to r6 - pad with 0
  81                 jo      0b
  82                 j       .top
  83         .done:
  84                 sr      %r0,%r0         # clear register r0
  85                 la      %r4,load_psw-.base(%r13)        # load psw-address into the register
  86                 o       %r3,4(%r4)      # or load address into psw
  87                 st      %r3,4(%r4)
  88                 mvc     0(8,%r0),0(%r4) # copy psw to absolute address 0
  89                 tm      have_diag308-.base(%r13),0x01
  90                 jno     .no_diag308
  91                 diag    %r0,%r0,0x308
  92         .no_diag308:
  93                 sr      %r1,%r1         # clear %r1
  94                 sr      %r2,%r2         # clear %r2
  95                 sigp    %r1,%r2,0x12    # set cpuid to zero
  96                 lpsw    0               # hopefully start new kernel...
  97
  98                 .align  8
  99         load_psw:
 100                 .long   0x00080000,0x80000000
 101         sys_msk:
 102                 .quad   0
 103         ctlregs:
 104                 .rept   16
 105                 .long   0
 106                 .endr
 107         gprregs:
 108                 .rept   16
 109                 .long   0
 110                 .endr
 111         have_diag308:
 112                 .byte   0
 113                 .align  8
 114         relocate_kernel_end:
 115         .globl  relocate_kernel_len
 116         relocate_kernel_len:
 117                 .quad   relocate_kernel_end - relocate_kernel