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/****************************************************************************
* arch/x86/src/i486/i486_utils.S
*
* Copyright (C) 2011 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Based on Bran's kernel development tutorials. Rewritten for JamesM's
* kernel development tutorials.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
.file "i486_utils.S"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define KSEG 0x10
/****************************************************************************
* Globals
****************************************************************************/
.globl gdt_flush
.globl idt_flush
/****************************************************************************
* .text
****************************************************************************/
.text
/****************************************************************************
* Name: gdt_flush
****************************************************************************/
.type gdt_flush, @function
gdt_flush:
movl %eax, 4(%esp) /* Get the pointer to the GDT, passed as a parameter */
lgdt (%eax) /* Load the new GDT pointer */
mov $KSEG, %ax /* KSEG is the offset in the GDT to our data segment */
mov %ax, %ds /* Load all data segment selectors */
mov %ax, %es
mov %ax, %fs
mov %ax, %gs
mov %ax, %ss
jmp $0x08, $.Lgflush /* 0x08 is the offset to our code segment: Far jump! */
.Lgflush:
ret
.size gdt_flush, . - gdt_flush
/****************************************************************************
* Name: idt_flush
****************************************************************************/
.type idt_flush, @function
idt_flush:
movl %eax, 4(%esp) /* Get the pointer to the IDT, passed as a parameter */
lidt (%eax) /* Load the IDT pointer */
ret
.size idt_flush, . - idt_flush
.end
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