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idt: reformat code

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This commit is contained in:
Mathieu Maret 2018-06-30 01:00:47 +02:00
parent c62f52342f
commit 6d34b7eef0
2 changed files with 95 additions and 32 deletions
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68
idt.c
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@ -1,45 +1,44 @@
#include "idt.h" #include "idt.h"
static struct idtEntry idt[IDT_NUM]; static struct idtEntry idt[IDT_NUM];
int idtSetup() int idtSetup()
{ {
struct idtRegister idtr; struct idtRegister idtr;
for (int i = 0; i < IDT_NUM; i++) { for (int i = 0; i < IDT_NUM; i++) {
struct idtEntry *idte = idt + i; struct idtEntry *idte = idt + i;
/* Setup an empty IDTE interrupt gate, see figure 5-2 in Intel /* Setup an empty IDTE interrupt gate, see figure 5-2 in Intel
x86 doc, vol 3 */ x86 doc, vol 3 */
idte->seg_sel = BUILD_SEGMENT_SELECTOR(RING_0, 0, SEGMENT_IDX_CODE); idte->seg_sel = BUILD_SEGMENT_SELECTOR(RING_0, 0, SEGMENT_IDX_CODE);
idte->reserved = 0; idte->reserved = 0;
idte->flags = 0; idte->flags = 0;
idte->type = 0x6; /* Interrupt gate (110b) */ idte->type = 0x6; /* Interrupt gate (110b) */
idte->op_size = 1; /* 32bits instructions */ idte->op_size = 1; /* 32bits instructions */
/* Disabled it for now */ /* Disabled it for now */
idte->zero = 0; idte->zero = 0;
idte->offset_low = 0; idte->offset_low = 0;
idte->offset_high = 0; idte->offset_high = 0;
idte->dpl = 0; idte->dpl = 0;
idte->present = 0; idte->present = 0;
} }
/* /*
* Setup the IDT register, see Intel x86 doc vol 3, section 5.8. * Setup the IDT register, see Intel x86 doc vol 3, section 5.8.
*/ */
/* Address of the IDT */ /* Address of the IDT */
idtr.base_addr = (uint32_t) idt; idtr.base_addr = (uint32_t)idt;
/* The limit is the maximum offset in bytes from the base address of /* The limit is the maximum offset in bytes from the base address of
the IDT */ the IDT */
idtr.limit = sizeof(idt) - 1; idtr.limit = sizeof(idt) - 1;
/* Commit the IDT into the CPU */ /* Commit the IDT into the CPU */
asm volatile ("lidt %0\n"::"m"(idtr):"memory"); asm volatile("lidt %0\n" ::"m"(idtr) : "memory");
return 0; return 0;
} }
int idt_set_handler(int index, unsigned int addr, int priviledge) int idt_set_handler(int index, unsigned int addr, int priviledge)
@ -51,13 +50,18 @@ int idt_set_handler(int index, unsigned int addr, int priviledge)
if ((priviledge < 0) || priviledge > 3) if ((priviledge < 0) || priviledge > 3)
return -1; return -1;
idte = &idt[index]; idte = idt + index;
if (addr != (unsigned int)NULL) { if (addr != (unsigned int)NULL) {
idte->offset_low = addr && 0xffff; idte->offset_low = addr && 0xffff;
idte->offset_high = (addr >> 16) && 0xffff; idte->offset_high = (addr >> 16) && 0xffff;
idte->dpl = priviledge; idte->dpl = priviledge;
idte->present = 1; idte->present = 1;
} else {
idte->offset_low = 0;
idte->offset_high = 0;
idte->dpl = 0;
idte->present = 0;
} }
return 0; return 0;

59
segment.h Normal file
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@ -0,0 +1,59 @@
/* Copyright (C) 2004 The SOS Team
Copyright (C) 1999 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
USA.
*/
#ifndef _SOS_HWSEGS_H_
#define _SOS_HWSEGS_H_
/**
* @file segments.h
*
* Global and local (GDT/LDT) segment descriptor definition and
* structure. These segments map virtual addresses (ie
* data/instruction addresses, relative to these segment descriptors)
* to linear addresses (ie addresses in the paged-memory space).
*
* @see Intel x86 doc, vol 3 chapter 3.
*/
#include "types.h"
/*
* Global segment selectors (GDT) for SOS/x86.
*
* @see gdt.h
*/
#define SOS_SEG_NULL 0 /* NULL segment, unused by the procesor */
#define SOS_SEG_KCODE 1 /* Kernel code segment */
#define SOS_SEG_KDATA 2 /* Kernel data segment */
/**
* Helper macro that builds a segment register's value
*/
#define SOS_BUILD_SEGMENT_REG_VALUE(desc_privilege,in_ldt,seg_index) \
( (((desc_privilege) & 0x3) << 0) \
| (((in_ldt)?1:0) << 2) \
| ((seg_index) << 3) )
/*
* Local segment selectors (LDT) for SOS/x86
*/
/* None */
#endif /* _SOS_HWSEGS_H_ */