1/* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (C) 1994, 1995 Waldorf Electronics 7 * Written by Ralf Baechle and Andreas Busse 8 * Copyright (C) 1994 - 99, 2003, 06 Ralf Baechle 9 * Copyright (C) 1996 Paul M. Antoine 10 * Modified for DECStation and hence R3000 support by Paul M. Antoine 11 * Further modifications by David S. Miller and Harald Koerfgen 12 * Copyright (C) 1999 Silicon Graphics, Inc. 13 * Kevin Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com 14 * Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved. 15 */ 16#include <linux/init.h> 17#include <linux/threads.h> 18 19#include <asm/addrspace.h> 20#include <asm/asm.h> 21#include <asm/asmmacro.h> 22#include <asm/irqflags.h> 23#include <asm/regdef.h> 24#include <asm/mipsregs.h> 25#include <asm/stackframe.h> 26 27#include <kernel-entry-init.h> 28 29 /* 30 * For the moment disable interrupts, mark the kernel mode and 31 * set ST0_KX so that the CPU does not spit fire when using 32 * 64-bit addresses. A full initialization of the CPU's status 33 * register is done later in per_cpu_trap_init(). 34 */ 35 .macro setup_c0_status set clr 36 .set push 37 mfc0 t0, CP0_STATUS 38 or t0, ST0_CU0|\set|0x1f|\clr 39 xor t0, 0x1f|\clr 40 mtc0 t0, CP0_STATUS 41 .set noreorder 42 sll zero,3 # ehb 43 .set pop 44 .endm 45 46 .macro setup_c0_status_pri 47#ifdef CONFIG_64BIT 48 setup_c0_status ST0_KX 0 49#else 50 setup_c0_status 0 0 51#endif 52 .endm 53 54 .macro setup_c0_status_sec 55#ifdef CONFIG_64BIT 56 setup_c0_status ST0_KX ST0_BEV 57#else 58 setup_c0_status 0 ST0_BEV 59#endif 60 .endm 61 62#ifndef CONFIG_NO_EXCEPT_FILL 63 /* 64 * Reserved space for exception handlers. 65 * Necessary for machines which link their kernels at KSEG0. 66 */ 67 .fill 0x400 68#endif 69 70EXPORT(_stext) 71 72#ifdef CONFIG_BOOT_RAW 73 /* 74 * Give us a fighting chance of running if execution beings at the 75 * kernel load address. This is needed because this platform does 76 * not have a ELF loader yet. 77 */ 78FEXPORT(__kernel_entry) 79 j kernel_entry 80#endif 81 82 __REF 83 84NESTED(kernel_entry, 16, sp) # kernel entry point 85 86 kernel_entry_setup # cpu specific setup 87 88 setup_c0_status_pri 89 90 /* We might not get launched at the address the kernel is linked to, 91 so we jump there. */ 92 PTR_LA t0, 0f 93 jr t0 940: 95 96#ifdef CONFIG_MIPS_RAW_APPENDED_DTB 97 PTR_LA t0, __appended_dtb 98 99#ifdef CONFIG_CPU_BIG_ENDIAN 100 li t1, 0xd00dfeed 101#else 102 li t1, 0xedfe0dd0 103#endif 104 lw t2, (t0) 105 bne t1, t2, not_found 106 nop 107 108 move a1, t0 109 PTR_LI a0, -2 110not_found: 111#endif 112 PTR_LA t0, __bss_start # clear .bss 113 LONG_S zero, (t0) 114 PTR_LA t1, __bss_stop - LONGSIZE 1151: 116 PTR_ADDIU t0, LONGSIZE 117 LONG_S zero, (t0) 118 bne t0, t1, 1b 119 120 LONG_S a0, fw_arg0 # firmware arguments 121 LONG_S a1, fw_arg1 122 LONG_S a2, fw_arg2 123 LONG_S a3, fw_arg3 124 125 MTC0 zero, CP0_CONTEXT # clear context register 126 PTR_LA $28, init_thread_union 127 /* Set the SP after an empty pt_regs. */ 128 PTR_LI sp, _THREAD_SIZE - 32 - PT_SIZE 129 PTR_ADDU sp, $28 130 back_to_back_c0_hazard 131 set_saved_sp sp, t0, t1 132 PTR_SUBU sp, 4 * SZREG # init stack pointer 133 134#ifdef CONFIG_RELOCATABLE 135 /* Copy kernel and apply the relocations */ 136 jal relocate_kernel 137 138 /* Repoint the sp into the new kernel image */ 139 PTR_LI sp, _THREAD_SIZE - 32 - PT_SIZE 140 PTR_ADDU sp, $28 141 set_saved_sp sp, t0, t1 142 PTR_SUBU sp, 4 * SZREG # init stack pointer 143 144 /* 145 * relocate_kernel returns the entry point either 146 * in the relocated kernel or the original if for 147 * some reason relocation failed - jump there now 148 * with instruction hazard barrier because of the 149 * newly sync'd icache. 150 */ 151 jr.hb v0 152#else 153 j start_kernel 154#endif 155 END(kernel_entry) 156 157#ifdef CONFIG_SMP 158/* 159 * SMP slave cpus entry point. Board specific code for bootstrap calls this 160 * function after setting up the stack and gp registers. 161 */ 162NESTED(smp_bootstrap, 16, sp) 163 smp_slave_setup 164 setup_c0_status_sec 165 j start_secondary 166 END(smp_bootstrap) 167#endif /* CONFIG_SMP */ 168