/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* PowerPC version
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
* Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
* Adapted for Power Macintosh by Paul Mackerras.
* Low-level exception handlers and MMU support
* rewritten by Paul Mackerras.
* Copyright (C) 1996 Paul Mackerras.
* MPC8xx modifications Copyright (C) 1997 Dan Malek (dmalek@jlc.net).
*
* This file contains the low-level support and setup for the
* PowerPC platform, including trap and interrupt dispatch.
* (The PPC 8xx embedded CPUs use head_8xx.S instead.)
*/
#include <linux/init.h>
#include <linux/pgtable.h>
#include <asm/reg.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/cputable.h>
#include <asm/cache.h>
#include <asm/thread_info.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/ptrace.h>
#include <asm/bug.h>
#include <asm/kvm_book3s_asm.h>
#include <asm/export.h>
#include <asm/feature-fixups.h>
#include "head_32.h"
#define LOAD_BAT(n, reg, RA, RB) \
/* see the comment for clear_bats() -- Cort */ \
li RA,0; \
mtspr SPRN_IBAT##n##U,RA; \
mtspr SPRN_DBAT##n##U,RA; \
lwz RA,(n*16)+0(reg); \
lwz RB,(n*16)+4(reg); \
mtspr SPRN_IBAT##n##U,RA; \
mtspr SPRN_IBAT##n##L,RB; \
lwz RA,(n*16)+8(reg); \
lwz RB,(n*16)+12(reg); \
mtspr SPRN_DBAT##n##U,RA; \
mtspr SPRN_DBAT##n##L,RB
__HEAD
.stabs "arch/powerpc/kernel/",N_SO,0,0,0f
.stabs "head_book3s_32.S",N_SO,0,0,0f
0:
_ENTRY(_stext);
/*
* _start is defined this way because the XCOFF loader in the OpenFirmware
* on the powermac expects the entry point to be a procedure descriptor.
*/
_ENTRY(_start);
/*
* These are here for legacy reasons, the kernel used to
* need to look like a coff function entry for the pmac
* but we're always started by some kind of bootloader now.
* -- Cort
*/
nop /* used by __secondary_hold on prep (mtx) and chrp smp */
nop /* used by __secondary_hold on prep (mtx) and chrp smp */
nop
/* PMAC
* Enter here with the kernel text, data and bss loaded starting at
* 0, running with virtual == physical mapping.
* r5 points to the prom entry point (the client interface handler
* address). Address translation is turned on, with the prom
* managing the hash table. Interrupts are disabled. The stack
* pointer (r1) points to just below the end of the half-meg region
* from 0x380000 - 0x400000, which is mapped in already.
*
* If we are booted from MacOS via BootX, we enter with the kernel
* image loaded somewhere, and the following values in registers:
* r3: 'BooX' (0x426f6f58)
* r4: virtual address of boot_infos_t
* r5: 0
*
* PREP
* This is jumped to on prep systems right after the kernel is relocated
* to its proper place in memory by the boot loader. The expected layout
* of the regs is:
* r3: ptr to residual data
* r4: initrd_start or if no initrd then 0
* r5: initrd_end - unused if r4 is 0
* r6: Start of command line string
* r7: End of command line string
*
* This just gets a minimal mmu environment setup so we can call
* start_here() to do the real work.
* -- Cort
*/
.globl __start
__start:
/*
* We have to do any OF calls before we map ourselves to KERNELBASE,
* because OF may have I/O devices mapped into that area
* (particularly on CHRP).
*/
cmpwi 0,r5,0
beq 1f
#ifdef CONFIG_PPC_OF_BOOT_TRAMPOLINE
/* find out where we are now */
bcl 20,31,$+4
0: mflr r8 /* r8 = runtime addr here */
addis r8,r8,(_stext - 0b)@ha
addi r8,r8,(_stext - 0b)@l /* current runtime base