LXR linux/arch/powerpc/kernel/early

   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 */
  20notrace 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}
  40