78f93cf4c7
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3351 42af7a65-404d-4744-a932-0658087f49c3
234 lines
8.0 KiB
C
Executable File
234 lines
8.0 KiB
C
Executable File
/****************************************************************************
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* arch/x86/include/i486/arch.h
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*
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* Copyright (C) 2011 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/* This file should never be included directed but, rather,
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* only indirectly through nuttx/arch.h
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*/
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#ifndef __ARCH_X86_INCLUDE_I486_ARCH_H
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#define __ARCH_X86_INCLUDE_I486_ARCH_H
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#ifndef __ASSEMBLY__
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# include <stdint.h>
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#endif
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/****************************************************************************
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* Definitions
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****************************************************************************/
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/* FLAGS bits */
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#define X86_FLAGS_CF (1 << 0) /* Bit 0: Carry Flag */
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/* Bit 1: Reserved */
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#define X86_FLAGS_PF (1 << 2) /* Bit 2: Parity Flag */
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/* Bit 3: Reserved */
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#define X86_FLAGS_AF (1 << 4) /* Bit 4: Auxillary carry Flag */
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/* Bit 5: Reserved */
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#define X86_FLAGS_ZF (1 << 6) /* Bit 6: Zero Flag */
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#define X86_FLAGS_SF (1 << 7) /* Bit 7: Sign Flag */
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#define X86_FLAGS_TF (1 << 8) /* Bit 8: Trap Flag */
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#define X86_FLAGS_IF (1 << 9) /* Bit 9: Interrupt Flag */
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#define X86_FLAGS_DF (1 << 10) /* Bit 10: Direction Flag */
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#define X86_FLAGS_OF (1 << 11) /* Bit 11: Overflow Flag */
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#define X86_FLAGS_IOPL_SHIFT (12) /* Bits 12-13: IOPL mask (286+ only)*/
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#define X86_FLAGS_IOPL_MASK (3 << X86_FLAGS_IOPL_SHIFT)
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#define X86_FLAGS_NT (1 << 14) /* Bit 14: Nested Task */
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/* Bit 15: Reserved */
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/* EFLAGS bits (Extend the basic FLAGS bit definitions) */
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#define X86_EFLAGS_RF (1 << 16) /* Bit 16: Resume Flag (386+ only) */
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#define X86_EFLAGS_VM (1 << 17) /* Bit 17: Virtual Mode (386+ only) */
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#define X86_EFLAGS_AC (1 << 18) /* Bit 18: Alignment Check (486SX+ only) */
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#define X86_EFLAGS_VIF (1 << 19) /* Bit 19: Virtual Interrupt Flag (Pentium+) */
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#define X86_EFLAGS_VIP (1 << 20) /* Bit 20: Virtual Interrupt Pending (Pentium+) */
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#define X86_EFLAGS_ID (1 << 21) /* Bit 21: CPUID detection flag (Pentium+) */
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/****************************************************************************
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* Public Types
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****************************************************************************/
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/* GDT data structures ******************************************************
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*
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* The Global Descriptor Table or GDT is a data structure used by Intel x86-
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* family processors starting with the 80286 in order to define the
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* characteristics of the various memory areas used during program execution,
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* for example the base address, the size and access privileges like
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* executability and writability. These memory areas are called segments in
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* Intel terminology.
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*/
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/* This structure defines one segment */
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struct gdt_entry_s
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{
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uint16_t lowlimit; /* The lower 16 bits of the limit */
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uint16_t lowbase; /* The lower 16 bits of the base */
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uint8_t midbase; /* The next 8 bits of the base */
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uint8_t access; /* Access flags, determine ring segment can be used in */
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uint8_t granularity;
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uint8_t hibase; /* The last 8 bits of the base */
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} __attribute__((packed));
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/* This structure refers to the array of GDT entries, and is in the format
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* required by the lgdt instruction.
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*/
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struct gdt_ptr_s
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{
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uint16_t limit; /* The upper 16 bits of all selector limits */
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uint32_t base; /* The address of the first GDT entry */
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} __attribute__((packed));
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/* IDT data structures ******************************************************
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*
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* The Interrupt Descriptor Table (IDT) is a data structure used by the x86
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* architecture to implement an interrupt vector table. The IDT is used by the
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* processor to determine the correct response to interrupts and exceptions.
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*/
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struct idt_entry_s
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{
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uint16_t lobase; /* Lower 16-bits of vector address for interrupt */
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uint16_t sel; /* Kernel segment selector */
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uint8_t zero; /* This must always be zero */
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uint8_t flags; /* (See documentation) */
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uint16_t hibase; /* Upper 16-bits of vector address for interrupt */
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} __attribute__((packed));
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/* A struct describing a pointer to an array of interrupt handlers. This is
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* in a format suitable for giving to 'lidt'.
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*/
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struct idt_ptr_s
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{
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uint16_t limit;
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uint32_t base; /* The address of the first GDT entry */
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} __attribute__((packed));
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/****************************************************************************
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* Inline functions
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****************************************************************************/
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#ifndef __ASSEMBLY__
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/* Return stack pointer */
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static inline uint32_t up_getsp()
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{
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uint32_t regval;
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asm volatile(
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"\tmovl %%esp, %0\n"
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: "=rm" (regval)
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:
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: "memory");
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return regval;
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}
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/* Get segment registers */
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static inline uint32_t up_getds()
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{
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uint32_t regval;
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asm volatile(
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"\tmov %%ds, %0\n"
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: "=rm" (regval)
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:
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: "memory");
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return regval;
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}
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static inline uint32_t up_getcs()
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{
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uint32_t regval;
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asm volatile(
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"\tmov %%cs, %0\n"
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: "=rm" (regval)
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:
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: "memory");
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return regval;
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}
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static inline uint32_t up_getss()
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{
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uint32_t regval;
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asm volatile(
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"\tmov %%ss, %0\n"
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: "=rm" (regval)
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:
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: "memory");
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return regval;
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}
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/****************************************************************************
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* Public Types
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****************************************************************************/
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/****************************************************************************
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* Public Variables
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****************************************************************************/
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/****************************************************************************
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* Public Function Prototypes
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****************************************************************************/
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#ifdef __cplusplus
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#define EXTERN extern "C"
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extern "C" {
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#else
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#define EXTERN extern
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#endif
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EXTERN void gdt_flush(uint32_t gdt_addr);
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EXTERN void idt_flush(uint32_t idt_addr);
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#undef EXTERN
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#ifdef __cplusplus
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}
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#endif
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#endif /* __ASSEMBLY__ */
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#endif /* __ARCH_X86_INCLUDE_I486_ARCH_H */
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