linux/arch/powerpc/boot/virtex405-head.S
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   1#include "ppc_asm.h"
   2
   3        .text
   4        .global _zimage_start
   5_zimage_start:
   6
   7        /* PPC errata 213: needed by Virtex-4 FX */
   8        mfccr0  0
   9        oris    0,0,0x50000000@h
  10        mtccr0  0
  11
  12        /*
  13         * Invalidate the data cache if the data cache is turned off.
  14         * - The 405 core does not invalidate the data cache on power-up
  15         *   or reset but does turn off the data cache. We cannot assume
  16         *   that the cache contents are valid.
  17         * - If the data cache is turned on this must have been done by
  18         *   a bootloader and we assume that the cache contents are
  19         *   valid.
  20         */
  21        mfdccr  r9
  22        cmplwi  r9,0
  23        bne     2f
  24        lis     r9,0
  25        li      r8,256
  26        mtctr   r8
  271:      dccci   r0,r9
  28        addi    r9,r9,0x20
  29        bdnz    1b
  302:      b       _zimage_start_lib
  31