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 #include <asm/asm-prototypes.h>
  12
  13 /*
  14  * We're called here very early in the boot.
  15  *
  16  * Note that the kernel may be running at an address which is different
  17  * from the address that it was linked at, so we must use RELOC/PTRRELOC
  18  * to access static data (including strings).  -- paulus
  19  */
  20 notrace unsigned long __init early_init(unsigned long dt_ptr)
  21 {
  22         unsigned long kva, offset = reloc_offset();
  23
  24         kva = *PTRRELOC(&kernstart_virt_addr);
  25
  26         /* First zero the BSS */
  27         if (kva == KERNELBASE)
  28                 memset(PTRRELOC(&__bss_start), 0, __bss_stop - __bss_start);
  29
  30         /*
  31          * Identify the CPU type and fix up code sections
  32          * that depend on which cpu we have.
  33          */
  34         identify_cpu(offset, mfspr(SPRN_PVR));
  35
  36         apply_feature_fixups();
  37
  38         return kva + offset;
  39 }