108 lines
2.3 KiB
ArmAsm
108 lines
2.3 KiB
ArmAsm
/* -----------------------------------------------------------------------
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*
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* Copyright 2003-2009 H. Peter Anvin - All Rights Reserved
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* Copyright 2009 Intel Corporation; author: H. Peter Anvin
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
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* Boston MA 02110-1301, USA; either version 2 of the License, or
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* (at your option) any later version; incorporated herein by reference.
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*
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* ----------------------------------------------------------------------- */
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/*
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* Simple stub to get us to the right point in the 32-bit code;
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* this module must be linked first
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*/
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.section ".init", "ax"
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.globl _start
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_start:
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/* Zero the bss */
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cld
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movl $__bss_start, %edi
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movl $__bss_end, %ecx
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subl %edi, %ecx
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xorl %eax, %eax
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shrl $2, %ecx
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rep ; stosl
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/* Set up the protected-mode IDT and the interrupt jump buffers */
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movl $idt, %edi
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movl $ijb, %eax
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movl $0xee000000, %ebx /* Interrupt gate */
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movw %cs, %bx /* Target segment */
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/* Make the IDT */
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movl $256, %ecx
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1:
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stosl
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stosl
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movl %ebx, -6(%edi)
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addl $8, %eax
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loop 1b
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/*
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* Each entry in the interrupt jump buffer contains the following
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* instructions:
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*
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* 60 pushal
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* b0xx movb $xx, %al # interrupt number
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* e9xxxxxxxx jmp handle_interrupt
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*/
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movl $0xe900b060, %eax
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movl $256, %ecx
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1:
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movl %eax, (%edi)
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addl $(1 << 16), %eax
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movl $handle_interrupt-8, %edx
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subl %edi, %edx
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movl %edx, 4(%edi)
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addl $8, %edi
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loop 1b
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#if __SIZEOF_POINTER__ == 4
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lidtl idt_ptr
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#elif __SIZEOF_POINTER__ == 8
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lidt idt_ptr
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#else
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#error "unsupported architecture"
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#endif
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/* Save arguments, switch stacks */
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movl %esp, %eax /* Pointer to arguments */
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movl $__stack_end, %esp
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call setup
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jmp *(rm_args) /* First argument is return */
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.section ".text","ax"
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.globl intcall
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.type intcall, @function
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intcall:
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jmp *(rm_args+1*4) /* Intcall is argument 1 */
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.size intcall, .-intcall
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.type handle_interrupt, @function
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handle_interrupt:
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jmp *(rm_args+4*4) /* Interrupt pointer is argument 4 */
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.size handle_interrupt, .-handle_interrupt
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.section ".rodata","a"
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idt_ptr:
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.word 8*256-1
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.long idt
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.word 0
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.section ".bss.large","aw"
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.balign 2048
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idt:
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.space 8*256
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ijb:
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.space 8*256
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__stack:
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.space 65536
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__stack_end:
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