mirror of https://github.com/tailix/kernel.git
244 lines
9.0 KiB
C
244 lines
9.0 KiB
C
#include "protected.h"
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#include "config.h"
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#include "info.h"
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#include "interrupts/main.h"
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#include <kernaux/arch/i386.h>
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#include <kernaux/asm/i386.h>
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#include <kernaux/drivers/console.h>
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#include <kernaux/drivers/intel_8259_pic.h>
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#include <stdint.h>
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#include <string.h>
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static struct KernAux_Arch_I386_DTR gdt_pointer;
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static struct KernAux_Arch_I386_DTR idt_pointer;
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static struct KernAux_Arch_I386_DTE gdt_entries[GDT_SIZE];
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static struct KernAux_Arch_I386_IDTE idt_entries[IDT_SIZE];
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static struct KernAux_Arch_I386_TSS tss;
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static void gdt_set_gates();
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static void idt_set_gates();
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static void idt_set_gate(uint8_t num, uint32_t base, uint16_t sel, uint8_t flags);
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void protected_initialize(const struct Kernel_Info *const kinfo)
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{
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kernaux_drivers_intel_8259_pic_remap(32, 40);
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kernaux_drivers_intel_8259_pic_disable_all();
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kernaux_drivers_console_puts("[INFO] protected: Setup GDT.");
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gdt_set_gates();
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kernaux_drivers_console_puts("[INFO] protected: Setup IDT.");
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idt_set_gates();
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kernaux_drivers_console_puts("[INFO] protected: Setup TSS.");
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memset(&tss, 0, sizeof(tss));
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tss.ss0 = GDT_KERNEL_DS_SELECTOR;
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tss.esp0 = kinfo->kernel_stack_start + kinfo->kernel_stack_size;
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kernaux_drivers_console_puts("[INFO] protected: Load GDT.");
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gdt_pointer.size = sizeof(struct KernAux_Arch_I386_DTE) * GDT_SIZE - 1;
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gdt_pointer.offset = (uint32_t)&gdt_entries;
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kernaux_asm_i386_flush_gdt(
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(uint32_t)&gdt_pointer,
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GDT_KERNEL_DS_SELECTOR,
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GDT_KERNEL_CS_SELECTOR
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);
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kernaux_drivers_console_puts("[INFO] protected: Load IDT.");
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idt_pointer.size = sizeof(struct KernAux_Arch_I386_IDTE) * IDT_SIZE - 1;
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idt_pointer.offset = (uint32_t)&idt_entries;
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kernaux_asm_i386_flush_idt((uint32_t)&idt_pointer);
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// kernaux_drivers_console_puts("[INFO] protected: Load TSS.");
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// kernaux_asm_i386_flush_tss(GDT_TSS_SELECTOR);
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kernaux_drivers_console_puts("[INFO] protected: Enable interrupts.");
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asm volatile ("sti");
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kernaux_drivers_console_puts("[INFO] protected: Finished.");
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}
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void gdt_set_gates()
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{
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memset(gdt_entries, 0, sizeof(gdt_entries));
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gdt_entries[GDT_NULL_INDEX].always_1 = 1;
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gdt_entries[GDT_KERNEL_CS_INDEX] = (struct KernAux_Arch_I386_DTE){
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.base_low = 0,
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.base_high = 0,
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.limit_low = 0xFFFF,
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.limit_high = 0xF,
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.available = 0,
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.always_0 = 0,
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.big = 1,
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.gran = 1,
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.accessed = 0,
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.read_write = 1,
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.conforming_expand_down = 0,
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.code = 1,
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.always_1 = 1,
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.DPL = 0,
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.present = 1,
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};
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gdt_entries[GDT_KERNEL_DS_INDEX] = (struct KernAux_Arch_I386_DTE){
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.base_low = 0,
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.base_high = 0,
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.limit_low = 0xFFFF,
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.limit_high = 0xF,
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.available = 0,
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.always_0 = 0,
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.big = 1,
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.gran = 1,
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.accessed = 0,
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.read_write = 1,
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.conforming_expand_down = 0,
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.code = 0,
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.always_1 = 1,
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.DPL = 0,
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.present = 1,
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};
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gdt_entries[GDT_USER_CS_INDEX] = (struct KernAux_Arch_I386_DTE){
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.base_low = 0,
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.base_high = 0,
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.limit_low = 0xFFFF,
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.limit_high = 0xF,
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.available = 0,
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.always_0 = 0,
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.big = 1,
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.gran = 1,
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.accessed = 0,
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.read_write = 1,
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.conforming_expand_down = 0,
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.code = 1,
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.always_1 = 1,
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.DPL = 3,
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.present = 1,
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};
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gdt_entries[GDT_USER_DS_INDEX] = (struct KernAux_Arch_I386_DTE){
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.base_low = 0,
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.base_high = 0,
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.limit_low = 0xFFFF,
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.limit_high = 0xF,
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.available = 0,
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.always_0 = 0,
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.big = 1,
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.gran = 1,
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.accessed = 0,
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.read_write = 1,
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.conforming_expand_down = 0,
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.code = 0,
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.always_1 = 1,
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.DPL = 3,
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.present = 1,
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};
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uint32_t base = (uint32_t)&tss;
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uint32_t limit = sizeof(tss);
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gdt_entries[GDT_TSS_INDEX] = (struct KernAux_Arch_I386_DTE){
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.base_low = base & 0xFFFFFF,
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.base_high = (base & 0xFF000000) >> 24,
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.limit_low = limit & 0xFFFF,
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.limit_high = (limit & 0xF0000) >> 16,
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.available = 0,
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.always_0 = 0,
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.big = 0,
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.gran = 0,
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.accessed = 1,
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.read_write = 0,
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.conforming_expand_down = 0,
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.code = 1,
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.always_1 = 1, // was 0
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.DPL = 3,
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.present = 1,
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};
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}
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void idt_set_gates()
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{
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memset(idt_entries, 0, sizeof(idt_entries));
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const uint16_t flags_base = 0x8e;
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const uint16_t flags_priv_user = 0x60;
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// exception
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idt_set_gate(0, (uint32_t)interrupt_0, 0x08, flags_base);
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idt_set_gate(1, (uint32_t)interrupt_1, 0x08, flags_base);
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idt_set_gate(2, (uint32_t)interrupt_2, 0x08, flags_base);
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idt_set_gate(3, (uint32_t)interrupt_3, 0x08, flags_base);
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idt_set_gate(4, (uint32_t)interrupt_4, 0x08, flags_base);
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idt_set_gate(5, (uint32_t)interrupt_5, 0x08, flags_base);
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idt_set_gate(6, (uint32_t)interrupt_6, 0x08, flags_base);
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idt_set_gate(7, (uint32_t)interrupt_7, 0x08, flags_base);
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idt_set_gate(8, (uint32_t)interrupt_8, 0x08, flags_base);
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idt_set_gate(9, (uint32_t)interrupt_9, 0x08, flags_base);
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idt_set_gate(10, (uint32_t)interrupt_10, 0x08, flags_base);
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idt_set_gate(11, (uint32_t)interrupt_11, 0x08, flags_base);
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idt_set_gate(12, (uint32_t)interrupt_12, 0x08, flags_base);
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idt_set_gate(13, (uint32_t)interrupt_13, 0x08, flags_base);
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idt_set_gate(14, (uint32_t)interrupt_14, 0x08, flags_base);
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idt_set_gate(15, (uint32_t)interrupt_15, 0x08, flags_base);
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idt_set_gate(16, (uint32_t)interrupt_16, 0x08, flags_base);
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idt_set_gate(17, (uint32_t)interrupt_17, 0x08, flags_base);
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idt_set_gate(18, (uint32_t)interrupt_18, 0x08, flags_base);
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idt_set_gate(19, (uint32_t)interrupt_19, 0x08, flags_base);
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idt_set_gate(20, (uint32_t)interrupt_20, 0x08, flags_base);
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idt_set_gate(21, (uint32_t)interrupt_21, 0x08, flags_base);
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idt_set_gate(22, (uint32_t)interrupt_22, 0x08, flags_base);
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idt_set_gate(23, (uint32_t)interrupt_23, 0x08, flags_base);
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idt_set_gate(24, (uint32_t)interrupt_24, 0x08, flags_base);
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idt_set_gate(25, (uint32_t)interrupt_25, 0x08, flags_base);
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idt_set_gate(26, (uint32_t)interrupt_26, 0x08, flags_base);
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idt_set_gate(27, (uint32_t)interrupt_27, 0x08, flags_base);
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idt_set_gate(28, (uint32_t)interrupt_28, 0x08, flags_base);
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idt_set_gate(29, (uint32_t)interrupt_29, 0x08, flags_base);
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idt_set_gate(30, (uint32_t)interrupt_30, 0x08, flags_base);
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idt_set_gate(31, (uint32_t)interrupt_31, 0x08, flags_base);
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// hwint: master PIC
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idt_set_gate(32, (uint32_t)interrupt_32, 0x08, flags_base);
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idt_set_gate(33, (uint32_t)interrupt_33, 0x08, flags_base);
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idt_set_gate(34, (uint32_t)interrupt_34, 0x08, flags_base);
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idt_set_gate(35, (uint32_t)interrupt_35, 0x08, flags_base);
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idt_set_gate(36, (uint32_t)interrupt_36, 0x08, flags_base);
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idt_set_gate(37, (uint32_t)interrupt_37, 0x08, flags_base);
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idt_set_gate(38, (uint32_t)interrupt_38, 0x08, flags_base);
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idt_set_gate(39, (uint32_t)interrupt_39, 0x08, flags_base);
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// hwint: slave PIC
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idt_set_gate(40, (uint32_t)interrupt_40, 0x08, flags_base);
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idt_set_gate(41, (uint32_t)interrupt_41, 0x08, flags_base);
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idt_set_gate(42, (uint32_t)interrupt_42, 0x08, flags_base);
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idt_set_gate(43, (uint32_t)interrupt_43, 0x08, flags_base);
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idt_set_gate(44, (uint32_t)interrupt_44, 0x08, flags_base);
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idt_set_gate(45, (uint32_t)interrupt_45, 0x08, flags_base);
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idt_set_gate(46, (uint32_t)interrupt_46, 0x08, flags_base);
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idt_set_gate(47, (uint32_t)interrupt_47, 0x08, flags_base);
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// syscall
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idt_set_gate(
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INT_SYSCALL,
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(uint32_t)interrupt_0x80,
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0x08,
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flags_base | flags_priv_user
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);
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}
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void idt_set_gate(uint8_t num, uint32_t base, uint16_t sel, uint8_t flags)
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{
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KernAux_Arch_I386_IDTE_set_offset(&idt_entries[num], base);
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idt_entries[num].selector = sel;
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idt_entries[num]._zero0 = 0;
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idt_entries[num].flags = flags;
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}
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