#include "protected.h" #include "config.h" #include "info.h" #include "interrupts/main.h" #include #include #include #include #include struct GdtPointer { unsigned short limit; unsigned int base; } __attribute__((packed)); struct IdtPointer { unsigned short limit; unsigned int base; } __attribute__((packed)); struct IdtEntry { unsigned short base_lo; unsigned short sel; unsigned char always0; unsigned char flags; unsigned short base_hi; }; static struct GdtPointer gdt_pointer; static struct IdtPointer idt_pointer; static struct KernAux_Arch_I386_DTE gdt_entries[GDT_SIZE]; static struct IdtEntry idt_entries[IDT_SIZE]; static struct KernAux_Arch_I386_TSS tss; static void gdt_set_gates(); static void idt_set_gates(); static void idt_set_gate(unsigned char num, unsigned int base, unsigned short sel, unsigned char flags); void protected_initialize(const struct Kernel_Info *const kinfo) { kernaux_drivers_intel_8259_pic_remap(32, 40); kernaux_drivers_intel_8259_pic_disable_all(); kernaux_drivers_console_print("[INFO] protected: Setup GDT.\n"); gdt_set_gates(); kernaux_drivers_console_print("[INFO] protected: Setup IDT.\n"); idt_set_gates(); kernaux_drivers_console_print("[INFO] protected: Setup TSS.\n"); memset(&tss, 0, sizeof(tss)); tss.ss0 = GDT_KERNEL_DS_SELECTOR; tss.esp0 = kinfo->kernel_stack_start + kinfo->kernel_stack_size; kernaux_drivers_console_print("[INFO] protected: Load GDT.\n"); gdt_pointer.limit = sizeof(struct KernAux_Arch_I386_DTE) * GDT_SIZE - 1; gdt_pointer.base = (unsigned int)&gdt_entries; kernaux_asm_i386_flush_gdt( (uint32_t)&gdt_pointer, GDT_KERNEL_DS_SELECTOR, GDT_KERNEL_CS_SELECTOR ); kernaux_drivers_console_print("[INFO] protected: Load IDT.\n"); idt_pointer.limit = sizeof(struct IdtEntry) * IDT_SIZE - 1; idt_pointer.base = (unsigned int)&idt_entries; kernaux_asm_i386_flush_idt((uint32_t)&idt_pointer); kernaux_drivers_console_print("[INFO] protected: Load TSS.\n"); kernaux_asm_i386_flush_tss(GDT_TSS_SELECTOR); kernaux_drivers_console_print("[INFO] protected: Enable interrupts.\n"); asm volatile ("sti"); kernaux_drivers_console_print("[INFO] protected: Finished.\n"); } void gdt_set_gates() { memset(gdt_entries, 0, sizeof(gdt_entries)); gdt_entries[GDT_NULL_INDEX].always_1 = 1; gdt_entries[GDT_KERNEL_CS_INDEX] = (struct KernAux_Arch_I386_DTE){ .base_low = 0, .base_high = 0, .limit_low = 0xFFFF, .limit_high = 0xF, .available = 0, .always_0 = 0, .big = 1, .gran = 1, .accessed = 0, .read_write = 1, .conforming_expand_down = 0, .code = 1, .always_1 = 1, .DPL = 0, .present = 1, }; gdt_entries[GDT_KERNEL_DS_INDEX] = (struct KernAux_Arch_I386_DTE){ .base_low = 0, .base_high = 0, .limit_low = 0xFFFF, .limit_high = 0xF, .available = 0, .always_0 = 0, .big = 1, .gran = 1, .accessed = 0, .read_write = 1, .conforming_expand_down = 0, .code = 0, .always_1 = 1, .DPL = 0, .present = 1, }; gdt_entries[GDT_USER_CS_INDEX] = (struct KernAux_Arch_I386_DTE){ .base_low = 0, .base_high = 0, .limit_low = 0xFFFF, .limit_high = 0xF, .available = 0, .always_0 = 0, .big = 1, .gran = 1, .accessed = 0, .read_write = 1, .conforming_expand_down = 0, .code = 1, .always_1 = 1, .DPL = 3, .present = 1, }; gdt_entries[GDT_USER_DS_INDEX] = (struct KernAux_Arch_I386_DTE){ .base_low = 0, .base_high = 0, .limit_low = 0xFFFF, .limit_high = 0xF, .available = 0, .always_0 = 0, .big = 1, .gran = 1, .accessed = 0, .read_write = 1, .conforming_expand_down = 0, .code = 0, .always_1 = 1, .DPL = 3, .present = 1, }; uint32_t base = (uint32_t)&tss; uint32_t limit = sizeof(tss); gdt_entries[GDT_TSS_INDEX] = (struct KernAux_Arch_I386_DTE){ .base_low = base & 0xFFFFFF, .base_high = (base & 0xFF000000) >> 24, .limit_low = limit & 0xFFFF, .limit_high = (limit & 0xF0000) >> 16, .available = 0, .always_0 = 0, .big = 0, .gran = 0, .accessed = 1, .read_write = 0, .conforming_expand_down = 0, .code = 1, .always_1 = 1, // was 0 .DPL = 3, .present = 1, }; } void idt_set_gates() { memset(idt_entries, 0, sizeof(idt_entries)); // exception idt_set_gate(0, (unsigned int)interrupt_0, 0x08, 0x8E); idt_set_gate(1, (unsigned int)interrupt_1, 0x08, 0x8E); idt_set_gate(2, (unsigned int)interrupt_2, 0x08, 0x8E); idt_set_gate(3, (unsigned int)interrupt_3, 0x08, 0x8E); idt_set_gate(4, (unsigned int)interrupt_4, 0x08, 0x8E); idt_set_gate(5, (unsigned int)interrupt_5, 0x08, 0x8E); idt_set_gate(6, (unsigned int)interrupt_6, 0x08, 0x8E); idt_set_gate(7, (unsigned int)interrupt_7, 0x08, 0x8E); idt_set_gate(8, (unsigned int)interrupt_8, 0x08, 0x8E); idt_set_gate(9, (unsigned int)interrupt_9, 0x08, 0x8E); idt_set_gate(10, (unsigned int)interrupt_10, 0x08, 0x8E); idt_set_gate(11, (unsigned int)interrupt_11, 0x08, 0x8E); idt_set_gate(12, (unsigned int)interrupt_12, 0x08, 0x8E); idt_set_gate(13, (unsigned int)interrupt_13, 0x08, 0x8E); idt_set_gate(14, (unsigned int)interrupt_14, 0x08, 0x8E); idt_set_gate(15, (unsigned int)interrupt_15, 0x08, 0x8E); idt_set_gate(16, (unsigned int)interrupt_16, 0x08, 0x8E); idt_set_gate(17, (unsigned int)interrupt_17, 0x08, 0x8E); idt_set_gate(18, (unsigned int)interrupt_18, 0x08, 0x8E); idt_set_gate(19, (unsigned int)interrupt_19, 0x08, 0x8E); idt_set_gate(20, (unsigned int)interrupt_20, 0x08, 0x8E); idt_set_gate(21, (unsigned int)interrupt_21, 0x08, 0x8E); idt_set_gate(22, (unsigned int)interrupt_22, 0x08, 0x8E); idt_set_gate(23, (unsigned int)interrupt_23, 0x08, 0x8E); idt_set_gate(24, (unsigned int)interrupt_24, 0x08, 0x8E); idt_set_gate(25, (unsigned int)interrupt_25, 0x08, 0x8E); idt_set_gate(26, (unsigned int)interrupt_26, 0x08, 0x8E); idt_set_gate(27, (unsigned int)interrupt_27, 0x08, 0x8E); idt_set_gate(28, (unsigned int)interrupt_28, 0x08, 0x8E); idt_set_gate(29, (unsigned int)interrupt_29, 0x08, 0x8E); idt_set_gate(30, (unsigned int)interrupt_30, 0x08, 0x8E); idt_set_gate(31, (unsigned int)interrupt_31, 0x08, 0x8E); // hwint: master PIC idt_set_gate(32, (unsigned int)interrupt_32, 0x08, 0x8E); idt_set_gate(33, (unsigned int)interrupt_33, 0x08, 0x8E); idt_set_gate(34, (unsigned int)interrupt_34, 0x08, 0x8E); idt_set_gate(35, (unsigned int)interrupt_35, 0x08, 0x8E); idt_set_gate(36, (unsigned int)interrupt_36, 0x08, 0x8E); idt_set_gate(37, (unsigned int)interrupt_37, 0x08, 0x8E); idt_set_gate(38, (unsigned int)interrupt_38, 0x08, 0x8E); idt_set_gate(39, (unsigned int)interrupt_39, 0x08, 0x8E); // hwint: slave PIC idt_set_gate(40, (unsigned int)interrupt_40, 0x08, 0x8E); idt_set_gate(41, (unsigned int)interrupt_41, 0x08, 0x8E); idt_set_gate(42, (unsigned int)interrupt_42, 0x08, 0x8E); idt_set_gate(43, (unsigned int)interrupt_43, 0x08, 0x8E); idt_set_gate(44, (unsigned int)interrupt_44, 0x08, 0x8E); idt_set_gate(45, (unsigned int)interrupt_45, 0x08, 0x8E); idt_set_gate(46, (unsigned int)interrupt_46, 0x08, 0x8E); idt_set_gate(47, (unsigned int)interrupt_47, 0x08, 0x8E); // syscall idt_set_gate(INT_SYSCALL, (unsigned int)interrupt_0x80, 0x08, 0x8E | 0x60); } void idt_set_gate(unsigned char num, unsigned int base, unsigned short sel, unsigned char flags) { idt_entries[num].base_lo = base & 0xFFFF; idt_entries[num].base_hi = (base >> 16) & 0xFFFF; idt_entries[num].sel = sel; idt_entries[num].always0 = 0; idt_entries[num].flags = flags; }