| 1 | /* |
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| 2 | * This file is subject to the terms and conditions of the GNU General Public |
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| 3 | * License. See the file "COPYING" in the main directory of this archive |
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| 4 | * for more details. |
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| 5 | * |
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| 6 | * Copyright (C) 1994, 1995 Waldorf Electronics |
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| 7 | * Written by Ralf Baechle and Andreas Busse |
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| 8 | * Copyright (C) 1994 - 99, 2003, 06 Ralf Baechle |
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| 9 | * Copyright (C) 1996 Paul M. Antoine |
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| 10 | * Modified for DECStation and hence R3000 support by Paul M. Antoine |
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| 11 | * Further modifications by David S. Miller and Harald Koerfgen |
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| 12 | * Copyright (C) 1999 Silicon Graphics, Inc. |
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| 13 | * Kevin Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com |
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| 14 | * Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved. |
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| 15 | */ |
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| 16 | #include <linux/init.h> |
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| 17 | #include <linux/threads.h> |
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| 18 | |
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| 19 | #include <asm/addrspace.h> |
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| 20 | #include <asm/asm.h> |
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| 21 | #include <asm/asmmacro.h> |
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| 22 | #include <asm/irqflags.h> |
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| 23 | #include <asm/regdef.h> |
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| 24 | #include <asm/mipsregs.h> |
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| 25 | #include <asm/stackframe.h> |
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| 26 | |
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| 27 | #include <kernel-entry-init.h> |
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| 28 | |
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| 29 | /* |
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| 30 | * For the moment disable interrupts, mark the kernel mode and |
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| 31 | * set ST0_KX so that the CPU does not spit fire when using |
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| 32 | * 64-bit addresses. A full initialization of the CPU's status |
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| 33 | * register is done later in per_cpu_trap_init(). |
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| 34 | */ |
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| 35 | .macro setup_c0_status set clr |
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| 36 | .set push |
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| 37 | mfc0 t0, CP0_STATUS |
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| 38 | or t0, ST0_KERNEL_CUMASK|\set|0x1f|\clr |
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| 39 | xor t0, 0x1f|\clr |
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| 40 | mtc0 t0, CP0_STATUS |
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| 41 | .set noreorder |
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| 42 | sll zero,3 # ehb |
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| 43 | .set pop |
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| 44 | .endm |
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| 45 | |
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| 46 | .macro setup_c0_status_pri |
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| 47 | #ifdef CONFIG_64BIT |
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| 48 | setup_c0_status ST0_KX 0 |
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| 49 | #else |
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| 50 | setup_c0_status 0 0 |
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| 51 | #endif |
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| 52 | .endm |
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| 53 | |
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| 54 | .macro setup_c0_status_sec |
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| 55 | #ifdef CONFIG_64BIT |
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| 56 | setup_c0_status ST0_KX ST0_BEV |
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| 57 | #else |
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| 58 | setup_c0_status 0 ST0_BEV |
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| 59 | #endif |
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| 60 | .endm |
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| 61 | |
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| 62 | #ifndef CONFIG_NO_EXCEPT_FILL |
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| 63 | /* |
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| 64 | * Reserved space for exception handlers. |
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| 65 | * Necessary for machines which link their kernels at KSEG0. |
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| 66 | */ |
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| 67 | .fill 0x400 |
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| 68 | #endif |
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| 69 | |
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| 70 | EXPORT(_stext) |
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| 71 | |
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| 72 | #ifdef CONFIG_BOOT_RAW |
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| 73 | /* |
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| 74 | * Give us a fighting chance of running if execution beings at the |
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| 75 | * kernel load address. This is needed because this platform does |
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| 76 | * not have a ELF loader yet. |
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| 77 | */ |
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| 78 | FEXPORT(__kernel_entry) |
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| 79 | j kernel_entry |
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| 80 | #endif /* CONFIG_BOOT_RAW */ |
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| 81 | |
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| 82 | __REF |
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| 83 | |
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| 84 | NESTED(kernel_entry, 16, sp) # kernel entry point |
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| 85 | |
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| 86 | kernel_entry_setup # cpu specific setup |
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| 87 | |
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| 88 | setup_c0_status_pri |
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| 89 | |
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| 90 | /* We might not get launched at the address the kernel is linked to, |
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| 91 | so we jump there. */ |
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| 92 | PTR_LA t0, 0f |
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| 93 | jr t0 |
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| 94 | 0: |
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| 95 | |
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| 96 | PTR_LA t0, __bss_start # clear .bss |
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| 97 | LONG_S zero, (t0) |
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| 98 | PTR_LA t1, __bss_stop - LONGSIZE |
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| 99 | 1: |
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| 100 | PTR_ADDIU t0, LONGSIZE |
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| 101 | LONG_S zero, (t0) |
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| 102 | bne t0, t1, 1b |
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| 103 | |
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| 104 | LONG_S a0, fw_arg0 # firmware arguments |
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| 105 | LONG_S a1, fw_arg1 |
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| 106 | LONG_S a2, fw_arg2 |
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| 107 | LONG_S a3, fw_arg3 |
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| 108 | |
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| 109 | MTC0 zero, CP0_CONTEXT # clear context register |
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| 110 | #ifdef CONFIG_64BIT |
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| 111 | MTC0 zero, CP0_XCONTEXT |
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| 112 | #endif |
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| 113 | PTR_LA $28, init_thread_union |
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| 114 | /* Set the SP after an empty pt_regs. */ |
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| 115 | PTR_LI sp, _THREAD_SIZE - 32 - PT_SIZE |
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| 116 | PTR_ADDU sp, $28 |
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| 117 | back_to_back_c0_hazard |
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| 118 | set_saved_sp sp, t0, t1 |
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| 119 | PTR_SUBU sp, 4 * SZREG # init stack pointer |
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| 120 | |
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| 121 | #ifdef CONFIG_RELOCATABLE |
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| 122 | /* Copy kernel and apply the relocations */ |
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| 123 | jal relocate_kernel |
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| 124 | |
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| 125 | /* Repoint the sp into the new kernel image */ |
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| 126 | PTR_LI sp, _THREAD_SIZE - 32 - PT_SIZE |
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| 127 | PTR_ADDU sp, $28 |
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| 128 | set_saved_sp sp, t0, t1 |
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| 129 | PTR_SUBU sp, 4 * SZREG # init stack pointer |
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| 130 | |
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| 131 | /* |
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| 132 | * relocate_kernel returns the entry point either |
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| 133 | * in the relocated kernel or the original if for |
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| 134 | * some reason relocation failed - jump there now |
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| 135 | * with instruction hazard barrier because of the |
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| 136 | * newly sync'd icache. |
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| 137 | */ |
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| 138 | jr.hb v0 |
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| 139 | #else /* !CONFIG_RELOCATABLE */ |
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| 140 | j start_kernel |
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| 141 | #endif /* !CONFIG_RELOCATABLE */ |
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| 142 | END(kernel_entry) |
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| 143 | |
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| 144 | #ifdef CONFIG_SMP |
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| 145 | /* |
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| 146 | * SMP slave cpus entry point. Board specific code for bootstrap calls this |
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| 147 | * function after setting up the stack and gp registers. |
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| 148 | */ |
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| 149 | NESTED(smp_bootstrap, 16, sp) |
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| 150 | smp_slave_setup |
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| 151 | setup_c0_status_sec |
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| 152 | j start_secondary |
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| 153 | END(smp_bootstrap) |
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| 154 | #endif /* CONFIG_SMP */ |
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| 155 | |
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