mirror of
https://gitlab.os-k.eu/os-k-team/os-k.git
synced 2023-08-25 14:03:10 +02:00
116 lines
3.7 KiB
C
116 lines
3.7 KiB
C
//----------------------------------------------------------------------------//
|
|
// GNU GPL OS/K //
|
|
// //
|
|
// Desc: GDT related functions //
|
|
// //
|
|
// //
|
|
// Copyright © 2018-2019 The OS/K Team //
|
|
// //
|
|
// This file is part of OS/K. //
|
|
// //
|
|
// OS/K 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 3 of the License, or //
|
|
// any later version. //
|
|
// //
|
|
// OS/K 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 OS/K. If not, see <https://www.gnu.org/licenses/>. //
|
|
//----------------------------------------------------------------------------//
|
|
|
|
#ifndef _KERNEL_H
|
|
#include <kernel.h>
|
|
#endif
|
|
|
|
#ifndef _MM_GDT_H
|
|
#define _MM_GDT_H
|
|
|
|
//----------------------------------------------------------------------------//
|
|
|
|
#define IOMAP_SIZE (8 * 1024)
|
|
|
|
//----------------------------------------------------------------------------//
|
|
|
|
// The gdt entry
|
|
struct GdtEntry_t
|
|
{
|
|
ushort lowLimit; // lower 16 bits
|
|
ushort lowBase; // lower 16 bits
|
|
uchar middleBase; // next 8 bits
|
|
uchar access; // determine what ring this segment can be used in
|
|
uchar flags;
|
|
uchar highBase; // last 8 bits
|
|
} __attribute__((__packed__));
|
|
|
|
struct TssDescriptor_t
|
|
{
|
|
ushort lowLimit;
|
|
ushort lowBase;
|
|
uchar middleBase;
|
|
uchar access;
|
|
uchar flags;
|
|
uchar highBase;
|
|
uint veryHighBase;
|
|
uint reserved;
|
|
} __attribute__ ((packed));
|
|
|
|
struct Tss_t
|
|
{
|
|
uint reserved1;
|
|
|
|
// Stack pointers (RSP) for privilege levels 0-2
|
|
ulong rsp0;
|
|
ulong rsp1;
|
|
ulong rsp2;
|
|
ulong reserved2;
|
|
|
|
// Interrupt stack table pointers
|
|
ulong ist1;
|
|
ulong ist2;
|
|
ulong ist3;
|
|
ulong ist4;
|
|
ulong ist5;
|
|
ulong ist6;
|
|
ulong ist7;
|
|
ulong reserved3;
|
|
ushort reserved4;
|
|
|
|
// Offset to the I/O permission bit map from the 64-bit TSS base
|
|
ushort iomap_base;
|
|
uchar iomap[IOMAP_SIZE];
|
|
|
|
} __attribute__ ((packed)) __attribute__((aligned(8)));
|
|
|
|
// The gdt pointer
|
|
struct GdtPtr_t
|
|
{
|
|
ushort limit; // upper 16 bits
|
|
ulong base; // address of the first entry
|
|
} __attribute__((__packed__));
|
|
|
|
//----------------------------------------------------------------------------//
|
|
|
|
//
|
|
// Initializes the descriptor table
|
|
//
|
|
void MmInitGdt(void);
|
|
|
|
//
|
|
// Loads the descriptor table
|
|
//
|
|
extern void MmLoadGdt(GdtPtr_t *gdtPtr, ushort tssOffset);
|
|
|
|
|
|
//
|
|
// Stores the descriptor table
|
|
//
|
|
extern void MmStoreGdt(void);
|
|
|
|
//----------------------------------------------------------------------------//
|
|
|
|
#endif
|