arch/mips/boot/compressed/head.S

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1994, 1995 Waldorf Electronics
   7  * Written by Ralf Baechle and Andreas Busse
   8  * Copyright (C) 1995 - 1999 Ralf Baechle
   9  * Copyright (C) 1996 Paul M. Antoine
  10  * Modified for DECStation and hence R3000 support by Paul M. Antoine
  11  * Further modifications by David S. Miller and Harald Koerfgen
  12  * Copyright (C) 1999 Silicon Graphics, Inc.
  13  */
  14
  15 #include <asm/asm.h>
  16 #include <asm/regdef.h>
  17
  18         .set noreorder
  19         .cprestore
  20         LEAF(start)
  21 start:
  22         /* Save boot rom start args */
  23         move    s0, a0
  24         move    s1, a1
  25         move    s2, a2
  26         move    s3, a3
  27
  28 #ifdef CONFIG_MIPS_ZBOOT_APPENDED_DTB
  29         PTR_LA  t0, __appended_dtb
  30 #ifdef CONFIG_CPU_BIG_ENDIAN
  31         li      t1, 0xd00dfeed
  32 #else
  33         li      t1, 0xedfe0dd0
  34 #endif
  35         lw      t2, (t0)
  36         bne     t1, t2, not_found
  37          nop
  38
  39         move    s1, t0
  40         PTR_LI  s0, -2
  41 not_found:
  42 #endif
  43
  44         /* Clear BSS */
  45         PTR_LA  a0, _edata
  46         PTR_LA  a2, _end
  47 1:      sw      zero, 0(a0)
  48         bne     a2, a0, 1b
  49          addiu  a0, a0, 4
  50
  51         PTR_LA  a0, (.heap)          /* heap address */
  52         PTR_LA  sp, (.stack + 8192)  /* stack address */
  53
  54         PTR_LA  ra, 2f
  55         PTR_LA  k0, decompress_kernel
  56         jr      k0
  57          nop
  58 2:
  59         move    a0, s0
  60         move    a1, s1
  61         move    a2, s2
  62         move    a3, s3
  63         PTR_LI  k0, KERNEL_ENTRY
  64         jr      k0
  65          nop
  66 3:
  67         b       3b
  68          nop
  69         END(start)
  70
  71         .comm .heap,BOOT_HEAP_SIZE,4
  72         .comm .stack,4096*2,4