arch/powerpc/kernel/early_32.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 /*
   4  * Early init before relocation
   5  */
   6
   7 #include <linux/init.h>
   8 #include <linux/kernel.h>
   9 #include <asm/setup.h>
  10 #include <asm/sections.h>
  11
  12 /*
  13  * We're called here very early in the boot.
  14  *
  15  * Note that the kernel may be running at an address which is different
  16  * from the address that it was linked at, so we must use RELOC/PTRRELOC
  17  * to access static data (including strings).  -- paulus
  18  */
  19 notrace unsigned long __init early_init(unsigned long dt_ptr)
  20 {
  21         unsigned long kva, offset = reloc_offset();
  22
  23         kva = *PTRRELOC(&kernstart_virt_addr);
  24
  25         /* First zero the BSS */
  26         if (kva == KERNELBASE)
  27                 memset(PTRRELOC(&__bss_start), 0, __bss_stop - __bss_start);
  28
  29         /*
  30          * Identify the CPU type and fix up code sections
  31          * that depend on which cpu we have.
  32          */
  33         identify_cpu(offset, mfspr(SPRN_PVR));
  34
  35         apply_feature_fixups();
  36
  37         return kva + offset;
  38 }