ecb3fb5af2
Commit 227cc19890
"add alpha version of x64 support"
removed configure_idt_entry(), but this is used within the
lguest branch.
94 lines
2.8 KiB
C
94 lines
2.8 KiB
C
/*
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* Copyright 2010 Stefan Lankes, Chair for Operating Systems,
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* RWTH Aachen University
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* This file is part of MetalSVM.
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*/
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/**
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* @author Stefan Lankes
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* @file arch/x86/kernel/idt.c
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* @brief Definitions and functions related to IDT
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*
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*
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* This file defines the interface for interrupts as like
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* structures to describe interrupt descriptor table entries.\n
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* See idt.h for flag definitions.
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*/
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#include <metalsvm/string.h>
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#include <asm/idt.h>
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/*
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* Declare an IDT of 256 entries. Although we will only use the
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* first 32 entries in this tutorial, the rest exists as a bit
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* of a trap. If any undefined IDT entry is hit, it normally
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* will cause an "Unhandled Interrupt" exception. Any descriptor
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* for which the 'presence' bit is cleared (0) will generate an
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* "Unhandled Interrupt" exception
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*/
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#ifdef CONFIG_X86_64
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static idt_entry_t idt[256] = {[0 ... 255] = {0, 0, 0, 0, 0, 0, 0}};
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#else
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static idt_entry_t idt[256] = {[0 ... 255] = {0, 0, 0, 0, 0}};
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#endif
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static idt_ptr_t idtp;
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void configure_idt_entry(idt_entry_t *dest_entry, size_t base,
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unsigned short sel, unsigned char flags)
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{
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/* The interrupt routine's base address */
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dest_entry->base_lo = (base & 0xFFFF);
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dest_entry->base_hi = (base >> 16) & 0xFFFF;
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/* The segment or 'selector' that this IDT entry will use
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* is set here, along with any access flags */
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dest_entry->sel = sel;
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dest_entry->always0 = 0;
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dest_entry->flags = flags;
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}
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/*
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* Use this function to set an entry in the IDT. Alot simpler
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* than twiddling with the GDT ;)
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*/
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void idt_set_gate(unsigned char num, size_t base, unsigned short sel,
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unsigned char flags)
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{
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configure_idt_entry(&idt[num], base, sel, flags);
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}
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extern void isrsyscall(void);
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/* Installs the IDT */
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void idt_install(void)
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{
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static int initialized = 0;
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if (!initialized) {
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initialized = 1;
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/* Sets the special IDT pointer up, just like in 'gdt.c' */
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idtp.limit = (sizeof(idt_entry_t) * 256) - 1;
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idtp.base = (size_t)&idt;
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/* Add any new ISRs to the IDT here using idt_set_gate */
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idt_set_gate(INT_SYSCALL, (size_t)isrsyscall, KERNEL_CODE_SELECTOR,
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IDT_FLAG_PRESENT|IDT_FLAG_RING3|IDT_FLAG_32BIT|IDT_FLAG_TRAPGATE);
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}
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/* Points the processor's internal register to the new IDT */
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asm volatile("lidt %0" : : "m" (idtp));
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}
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