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_KERNEL_CUMASK|\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 __HEAD 63#ifndef CONFIG_NO_EXCEPT_FILL 64 /* 65 * Reserved space for exception handlers. 66 * Necessary for machines which link their kernels at KSEG0. 67 */ 68 .fill 0x400 69#endif 70 71EXPORT(_stext) 72 73#ifdef CONFIG_BOOT_RAW 74 /* 75 * Give us a fighting chance of running if execution beings at the 76 * kernel load address. This is needed because this platform does 77 * not have a ELF loader yet. 78 */ 79FEXPORT(__kernel_entry) 80 j kernel_entry 81#endif /* CONFIG_BOOT_RAW */ 82 83 __REF 84 85NESTED(kernel_entry, 16, sp) # kernel entry point 86 87 kernel_entry_setup # cpu specific setup 88 89 setup_c0_status_pri 90 91 /* We might not get launched at the address the kernel is linked to, 92 so we jump there. */ 93 PTR_LA t0, 0f 94 jr t0 950: 96 97 PTR_LA t0, __bss_start # clear .bss 98 LONG_S zero, (t0) 99 PTR_LA t1, __bss_stop - LONGSIZE 1001: 101 PTR_ADDIU t0, LONGSIZE 102 LONG_S zero, (t0) 103 bne t0, t1, 1b 104 105 LONG_S a0, fw_arg0 # firmware arguments 106 LONG_S a1, fw_arg1 107 LONG_S a2, fw_arg2 108 LONG_S a3, fw_arg3 109 110 MTC0 zero, CP0_CONTEXT # clear context register 111#ifdef CONFIG_64BIT 112 MTC0 zero, CP0_XCONTEXT 113#endif 114 PTR_LA $28, init_thread_union 115 /* Set the SP after an empty pt_regs. */ 116 PTR_LI sp, _THREAD_SIZE - 32 - PT_SIZE 117 PTR_ADDU sp, $28 118 back_to_back_c0_hazard 119 set_saved_sp sp, t0, t1 120 PTR_SUBU sp, 4 * SZREG # init stack pointer 121 122#ifdef CONFIG_RELOCATABLE 123 /* Copy kernel and apply the relocations */ 124 jal relocate_kernel 125 126 /* Repoint the sp into the new kernel image */ 127 PTR_LI sp, _THREAD_SIZE - 32 - PT_SIZE 128 PTR_ADDU sp, $28 129 set_saved_sp sp, t0, t1 130 PTR_SUBU sp, 4 * SZREG # init stack pointer 131 132 /* 133 * relocate_kernel returns the entry point either 134 * in the relocated kernel or the original if for 135 * some reason relocation failed - jump there now 136 * with instruction hazard barrier because of the 137 * newly sync'd icache. 138 */ 139 jr.hb v0 140#else /* !CONFIG_RELOCATABLE */ 141 j start_kernel 142#endif /* !CONFIG_RELOCATABLE */ 143 END(kernel_entry) 144 145#ifdef CONFIG_SMP 146/* 147 * SMP slave cpus entry point. Board specific code for bootstrap calls this 148 * function after setting up the stack and gp registers. 149 */ 150NESTED(smp_bootstrap, 16, sp) 151 smp_slave_setup 152 setup_c0_status_sec 153 j start_secondary 154 END(smp_bootstrap) 155#endif /* CONFIG_SMP */ 156