85 lines
2.6 KiB
C
85 lines
2.6 KiB
C
/* Copyright (C) 2004 David Decotigny
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License
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as published by the Free Software Foundation; either version 2
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of the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
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USA.
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*/
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#ifndef _SOS_IDT_H_
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#define _SOS_IDT_H_
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/**
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* @file idt.h
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*
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* Manage the x86 Interrupt Descriptor Table, the table which maps the
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* hardware interrupt lines, hardware exceptions, and software
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* interrupts, to software routines. We only define "interrupt gate"
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* IDT entries. Don't use it directly; refer instead to interrupt.c,
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* exceptions.c and syscall.c.
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*
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* @see Intel x86 doc, Vol 3, chapter 5
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*/
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#include <sos/errno.h>
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#include <sos/types.h>
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/* Mapping of the CPU exceptions in the IDT (imposed by Intel
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standards) */
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#define SOS_EXCEPT_BASE 0
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#define SOS_EXCEPT_NUM 32
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#define SOS_EXCEPT_MAX (SOS_HWEXCEPT_BASE + SOS_HWEXCEPT_NUM - 1)
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/* Mapping of the IRQ lines in the IDT */
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#define SOS_IRQ_BASE 32
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#define SOS_IRQ_NUM 16
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#define SOS_IRQ_MAX (SOS_IRQ_BASE + SOS_IRQ_NUM - 1)
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/**
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* Number of IDT entries.
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*
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* @note Must be large enough to map the hw interrupts, the exceptions
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* (=> total is 48 entries), and the syscall(s). Since our syscall
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* will be 0x42, it must be >= 0x43. Intel doc limits this to 256
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* entries, we use this limit.
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*/
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#define SOS_IDTE_NUM 256 /* 0x100 */
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/** Initialization routine: all the IDT entries (or "IDTE") are marked
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"not present". */
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sos_ret_t sos_idt_subsystem_setup(void);
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/**
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* Enable the IDT entry if handler_address != NULL, with the given
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* lowest_priviledge.\ Disable the IDT entry when handler_address ==
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* NULL (the lowest_priviledge parameter is then ignored). Intel doc
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* says that there must not be more than 256 entries.
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*
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* @note IRQ Unsafe
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*/
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sos_ret_t sos_idt_set_handler(int index,
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sos_vaddr_t handler_address,
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int lowest_priviledge /* 0..3 */);
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/**
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* @note IRQ Unsafe
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*
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* @return the handler address and DPL in the 2nd and 3rd
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* parameters
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*/
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sos_ret_t sos_idt_get_handler(int index,
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sos_vaddr_t *handler_address,
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int *lowest_priviledge);
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#endif /* _SOS_IDT_H_ */
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