27b32ee02c
* also adjust BOOT_GDT_SEGMENT_COUNT for x86, the definition is used by the boot loader. * add some 32-bit definitions. * add a UserTLSDescriptor class, this will be used by 32-bit threads. Change-Id: I5b1d978969a1ce97091a16c9ec2ad7c0ca831656
171 lines
4.1 KiB
C
171 lines
4.1 KiB
C
/*
|
|
* Copyright 2002-2006, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
|
|
* Distributed under the terms of the MIT License.
|
|
*
|
|
* Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
|
|
* Distributed under the terms of the NewOS License.
|
|
*/
|
|
#ifndef _KERNEL_ARCH_X86_32_DESCRIPTORS_H
|
|
#define _KERNEL_ARCH_X86_32_DESCRIPTORS_H
|
|
|
|
|
|
// Segments common for all CPUs.
|
|
#define KERNEL_CODE_SEGMENT 1
|
|
#define KERNEL_DATA_SEGMENT 2
|
|
|
|
#define USER_CODE_SEGMENT 3
|
|
#define USER_DATA_SEGMENT 4
|
|
|
|
#define BOOT_GDT_SEGMENT_COUNT (USER_DATA_SEGMENT + 2) // match x86_64
|
|
|
|
#define APM_CODE32_SEGMENT 5
|
|
#define APM_CODE16_SEGMENT 6
|
|
#define APM_DATA_SEGMENT 7
|
|
|
|
#define BIOS_DATA_SEGMENT 8
|
|
|
|
// Per-CPU segments.
|
|
#define TSS_SEGMENT 9
|
|
#define DOUBLE_FAULT_TSS_SEGMENT 10
|
|
#define KERNEL_TLS_SEGMENT 11
|
|
#define USER_TLS_SEGMENT 12
|
|
#define APM_SEGMENT 13
|
|
|
|
#define GDT_SEGMENT_COUNT 14
|
|
|
|
|
|
#define KERNEL_CODE_SELECTOR ((KERNEL_CODE_SEGMENT << 3) | DPL_KERNEL)
|
|
#define KERNEL_DATA_SELECTOR ((KERNEL_DATA_SEGMENT << 3) | DPL_KERNEL)
|
|
|
|
#define USER_CODE_SELECTOR ((USER_CODE_SEGMENT << 3) | DPL_USER)
|
|
#define USER_DATA_SELECTOR ((USER_DATA_SEGMENT << 3) | DPL_USER)
|
|
|
|
#define KERNEL_TLS_SELECTOR ((KERNEL_TLS_SEGMENT << 3) | DPL_KERNEL)
|
|
|
|
|
|
#ifndef _ASSEMBLER
|
|
// this file can also be included from assembler as well
|
|
// (and is in arch_interrupts.S)
|
|
|
|
// defines entries in the GDT/LDT
|
|
|
|
struct segment_descriptor {
|
|
uint16 limit_00_15; // bit 0 - 15
|
|
uint16 base_00_15; // 16 - 31
|
|
uint32 base_23_16 : 8; // 0 - 7
|
|
uint32 type : 4; // 8 - 11
|
|
uint32 desc_type : 1; // 12 (0 = system, 1 = code/data)
|
|
uint32 privilege_level : 2; // 13 - 14
|
|
uint32 present : 1; // 15
|
|
uint32 limit_19_16 : 4; // 16 - 19
|
|
uint32 available : 1; // 20
|
|
uint32 zero : 1; // 21
|
|
uint32 d_b : 1; // 22
|
|
uint32 granularity : 1; // 23
|
|
uint32 base_31_24 : 8; // 24 - 31
|
|
};
|
|
|
|
struct interrupt_descriptor {
|
|
uint32 a;
|
|
uint32 b;
|
|
};
|
|
|
|
struct tss {
|
|
uint16 prev_task;
|
|
uint16 unused0;
|
|
uint32 sp0;
|
|
uint32 ss0;
|
|
uint32 sp1;
|
|
uint32 ss1;
|
|
uint32 sp2;
|
|
uint32 ss2;
|
|
uint32 cr3;
|
|
uint32 eip, eflags, eax, ecx, edx, ebx, esp, ebp, esi, edi;
|
|
uint32 es, cs, ss, ds, fs, gs;
|
|
uint32 ldt_seg_selector;
|
|
uint16 unused1;
|
|
uint16 io_map_base;
|
|
};
|
|
|
|
typedef segment_descriptor global_descriptor_table[GDT_SEGMENT_COUNT];
|
|
extern global_descriptor_table gGDTs[];
|
|
|
|
|
|
static inline void
|
|
clear_segment_descriptor(segment_descriptor* desc)
|
|
{
|
|
*(long long*)desc = 0;
|
|
}
|
|
|
|
|
|
static inline void
|
|
set_segment_descriptor_base(segment_descriptor* desc, addr_t base)
|
|
{
|
|
desc->base_00_15 = (addr_t)base & 0xffff; // base is 32 bits long
|
|
desc->base_23_16 = ((addr_t)base >> 16) & 0xff;
|
|
desc->base_31_24 = ((addr_t)base >> 24) & 0xff;
|
|
}
|
|
|
|
|
|
static inline void
|
|
set_segment_descriptor(segment_descriptor* desc, addr_t base, uint32 limit,
|
|
uint8 type, uint8 privilegeLevel)
|
|
{
|
|
set_segment_descriptor_base(desc, base);
|
|
|
|
// limit is 20 bits long
|
|
if (limit & 0xfff00000) {
|
|
desc->limit_00_15 = ((addr_t)limit >> 12) & 0x0ffff;
|
|
desc->limit_19_16 = ((addr_t)limit >> 28) & 0xf;
|
|
desc->granularity = 1; // 4 KB granularity
|
|
} else {
|
|
desc->limit_00_15 = (addr_t)limit & 0x0ffff;
|
|
desc->limit_19_16 = ((addr_t)limit >> 16) & 0xf;
|
|
desc->granularity = 0; // 1 byte granularity
|
|
}
|
|
|
|
desc->type = type;
|
|
desc->desc_type = DT_CODE_DATA_SEGMENT;
|
|
desc->privilege_level = privilegeLevel;
|
|
|
|
desc->present = 1;
|
|
desc->available = 0; // system available bit is currently not used
|
|
desc->d_b = 1; // 32-bit code
|
|
|
|
desc->zero = 0;
|
|
}
|
|
|
|
|
|
static inline void
|
|
set_tss_descriptor(segment_descriptor* desc, addr_t base, uint32 limit)
|
|
{
|
|
// the TSS descriptor has a special layout different from the standard descriptor
|
|
set_segment_descriptor_base(desc, base);
|
|
|
|
desc->limit_00_15 = (addr_t)limit & 0x0ffff;
|
|
desc->limit_19_16 = 0;
|
|
|
|
desc->type = DT_TSS;
|
|
desc->desc_type = DT_SYSTEM_SEGMENT;
|
|
desc->privilege_level = DPL_KERNEL;
|
|
|
|
desc->present = 1;
|
|
desc->granularity = 0; // 1 Byte granularity
|
|
desc->available = 0; // system available bit is currently not used
|
|
desc->d_b = 0;
|
|
|
|
desc->zero = 0;
|
|
}
|
|
|
|
|
|
static inline segment_descriptor*
|
|
get_gdt(int32 cpu)
|
|
{
|
|
return gGDTs[cpu];
|
|
}
|
|
|
|
|
|
#endif /* _ASSEMBLER */
|
|
|
|
#endif /* _KERNEL_ARCH_X86_32_DESCRIPTORS_H */
|