arch/powerpc/boot/virtex405-head.S

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #include "ppc_asm.h"
   3
   4         .text
   5         .global _zimage_start
   6 _zimage_start:
   7
   8         /* PPC errata 213: needed by Virtex-4 FX */
   9         mfccr0  0
  10         oris    0,0,0x50000000@h
  11         mtccr0  0
  12
  13         /*
  14          * Invalidate the data cache if the data cache is turned off.
  15          * - The 405 core does not invalidate the data cache on power-up
  16          *   or reset but does turn off the data cache. We cannot assume
  17          *   that the cache contents are valid.
  18          * - If the data cache is turned on this must have been done by
  19          *   a bootloader and we assume that the cache contents are
  20          *   valid.
  21          */
  22         mfdccr  r9
  23         cmplwi  r9,0
  24         bne     2f
  25         lis     r9,0
  26         li      r8,256
  27         mtctr   r8
  28 1:      dccci   r0,r9
  29         addi    r9,r9,0x20
  30         bdnz    1b
  31 2:      b       _zimage_start_lib