/*
This file is part of Fennix Kernel.
Fennix Kernel 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 (at your option) any later version.
Fennix Kernel 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 Fennix Kernel. If not, see .
*/
#include "gdt.hpp"
#include
#include
#include
#include
namespace GlobalDescriptorTable
{
static GlobalDescriptorTableEntries GDTEntriesTemplate = {
.Null =
{
.Limit0 = 0x0,
.BaseLow = 0x0,
.BaseMiddle = 0x0,
.Access = {.Raw = 0x0},
// .Limit1 = 0x0,
.Flags = {.Raw = 0x0},
.BaseHigh = 0x0,
},
.Code =
{
.Limit0 = 0xFFFF,
.BaseLow = 0x0,
.BaseMiddle = 0x0,
.Access = {
.A = 0,
.RW = 1,
.DC = 0,
.E = 1,
.S = 1,
.DPL = 0,
.P = 1,
},
// .Limit1 = 0xF,
.Flags = {
.Reserved = 0xF, /* Workaround for Limit1 */
.AVL = 0,
.L = 0,
.DB = 1,
.G = 1,
},
.BaseHigh = 0x0,
},
.Data = {
.Limit0 = 0xFFFF,
.BaseLow = 0x0,
.BaseMiddle = 0x0,
.Access = {
.A = 0,
.RW = 1,
.DC = 0,
.E = 0,
.S = 1,
.DPL = 0,
.P = 1,
},
// .Limit1 = 0xF,
.Flags = {
.Reserved = 0xF, /* Workaround for Limit1 */
.AVL = 0,
.L = 0,
.DB = 1,
.G = 1,
},
.BaseHigh = 0x0,
},
.UserData = {
.Limit0 = 0xFFFF,
.BaseLow = 0x0,
.BaseMiddle = 0x0,
.Access = {
.A = 0,
.RW = 1,
.DC = 0,
.E = 0,
.S = 1,
.DPL = 3,
.P = 1,
},
// .Limit1 = 0xF,
.Flags = {
.Reserved = 0xF, /* Workaround for Limit1 */
.AVL = 0,
.L = 0,
.DB = 1,
.G = 1,
},
.BaseHigh = 0x0,
},
.UserCode = {
.Limit0 = 0xFFFF,
.BaseLow = 0x0,
.BaseMiddle = 0x0,
.Access = {
.A = 0,
.RW = 1,
.DC = 0,
.E = 1,
.S = 1,
.DPL = 3,
.P = 1,
},
// .Limit1 = 0xF,
.Flags = {
.Reserved = 0xF, /* Workaround for Limit1 */
.AVL = 0,
.L = 0,
.DB = 1,
.G = 1,
},
.BaseHigh = 0x0,
},
.TaskStateSegment = {},
};
GlobalDescriptorTableEntries GDTEntries[MAX_CPU] __aligned(16);
GlobalDescriptorTableDescriptor gdt[MAX_CPU] __aligned(16);
TaskStateSegment tss[MAX_CPU] = {
0,
{0, 0, 0},
0,
{0, 0, 0, 0, 0, 0, 0},
0,
0,
0,
};
void *CPUStackPointer[MAX_CPU];
nsa void Init(int Core)
{
memcpy(&GDTEntries[Core], &GDTEntriesTemplate, sizeof(GlobalDescriptorTableEntries));
gdt[Core] = {.Length = sizeof(GlobalDescriptorTableEntries) - 1, .Entries = &GDTEntries[Core]};
debug("GDT: %#lx", &gdt[Core]);
debug("GDT KERNEL: CODE %#lx: Limit0: 0x%X, BaseLow: 0x%X, BaseMiddle: 0x%X, Access: 0x%X, Limit1: 0x%X, Flags: 0x%X, BaseHigh: 0x%X",
GDT_KERNEL_CODE,
GDTEntries[Core].Code.Limit0,
GDTEntries[Core].Code.BaseLow,
GDTEntries[Core].Code.BaseMiddle,
GDTEntries[Core].Code.Access.Raw,
GDTEntries[Core].Code.Flags.Reserved,
GDTEntries[Core].Code.Flags.Raw & ~0xF,
GDTEntries[Core].Code.BaseHigh);
debug("GDT KERNEL: DATA %#lx: Limit0: 0x%X, BaseLow: 0x%X, BaseMiddle: 0x%X, Access: 0x%X, Limit1: 0x%X, Flags: 0x%X, BaseHigh: 0x%X",
GDT_KERNEL_DATA,
GDTEntries[Core].Data.Limit0,
GDTEntries[Core].Data.BaseLow,
GDTEntries[Core].Data.BaseMiddle,
GDTEntries[Core].Data.Access.Raw,
GDTEntries[Core].Data.Flags.Reserved,
GDTEntries[Core].Data.Flags.Raw & ~0xF,
GDTEntries[Core].Data.BaseHigh);
debug("GDT USER: CODE %#lx: Limit0: 0x%X, BaseLow: 0x%X, BaseMiddle: 0x%X, Access: 0x%X, Limit1: 0x%X, Flags: 0x%X, BaseHigh: 0x%X",
GDT_USER_CODE,
GDTEntries[Core].UserCode.Limit0,
GDTEntries[Core].UserCode.BaseLow,
GDTEntries[Core].UserCode.BaseMiddle,
GDTEntries[Core].UserCode.Access.Raw,
GDTEntries[Core].UserCode.Flags.Reserved,
GDTEntries[Core].UserCode.Flags.Raw & ~0xF,
GDTEntries[Core].UserCode.BaseHigh);
debug("GDT USER: DATA %#lx: Limit0: 0x%X, BaseLow: 0x%X, BaseMiddle: 0x%X, Access: 0x%X, Limit1: 0x%X, Flags: 0x%X, BaseHigh: 0x%X",
GDT_USER_DATA,
GDTEntries[Core].UserData.Limit0,
GDTEntries[Core].UserData.BaseLow,
GDTEntries[Core].UserData.BaseMiddle,
GDTEntries[Core].UserData.Access.Raw,
GDTEntries[Core].UserData.Flags.Reserved,
GDTEntries[Core].UserData.Flags.Raw & ~0xF,
GDTEntries[Core].UserData.BaseHigh);
CPU::x32::lgdt(&gdt[Core]);
asmv("mov %%esp, %%eax\n"
"push $16\n"
"push %%eax\n"
"pushf\n"
"push $8\n"
"push $1f\n"
"iret\n"
"1:\n"
"movw $16, %%ax\n"
"movw %%ax, %%ds\n"
"movw %%ax, %%es\n" ::
: "memory", "eax");
CPUStackPointer[Core] = StackManager.Allocate(STACK_SIZE);
memset(CPUStackPointer[Core], 0, STACK_SIZE);
debug("CPU %d Stack Pointer: %#lx-%#lx (%d pages)", Core,
CPUStackPointer[Core], (uintptr_t)CPUStackPointer[Core] + STACK_SIZE,
TO_PAGES(STACK_SIZE + 1));
uintptr_t Base = (uintptr_t)&tss[Core];
size_t Limit = Base + sizeof(TaskStateSegment);
gdt[Core].Entries->TaskStateSegment.Limit = Limit & 0xFFFF;
gdt[Core].Entries->TaskStateSegment.BaseLow = Base & 0xFFFF;
gdt[Core].Entries->TaskStateSegment.BaseMiddle = uint8_t((Base >> 16) & 0xFF);
gdt[Core].Entries->TaskStateSegment.BaseHigh = uint8_t((Base >> 24) & 0xFF);
#pragma GCC diagnostic ignored "-Wshift-count-overflow"
gdt[Core].Entries->TaskStateSegment.BaseUpper = s_cst(uint32_t, (Base >> 32) & 0xFFFFFFFF);
gdt[Core].Entries->TaskStateSegment.Access = {.A = 1, .RW = 0, .DC = 0, .E = 1, .S = 0, .DPL = 0, .P = 1};
gdt[Core].Entries->TaskStateSegment.Granularity = (0 << 4) | ((Limit >> 16) & 0xF);
tss[Core].IOMapBaseAddressOffset = sizeof(TaskStateSegment);
tss[Core].StackPointer[0] = (uint32_t)CPUStackPointer[Core] + STACK_SIZE;
tss[Core].StackPointer[1] = 0x0;
tss[Core].StackPointer[2] = 0x0;
for (size_t i = 0; i < sizeof(tss[Core].InterruptStackTable) / sizeof(tss[Core].InterruptStackTable[7]); i++)
{
void *NewStack = StackManager.Allocate(STACK_SIZE);
tss[Core].InterruptStackTable[i] = (uint32_t)NewStack + STACK_SIZE;
memset((void *)(tss[Core].InterruptStackTable[i] - STACK_SIZE), 0, STACK_SIZE);
debug("IST-%d: %#lx-%#lx", i, NewStack, (uintptr_t)NewStack + STACK_SIZE);
}
CPU::x32::ltr(GDT_TSS);
debug("Global Descriptor Table initialized");
}
nsa void SetKernelStack(void *Stack)
{
stub;
}
void *GetKernelStack() { return (void *)nullptr; }
}