xref: /openbmc/linux/arch/powerpc/kernel/early_32.c (revision 2a598d0b)
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 }
39