diff --git a/kernel/arch/i386/boot.S b/kernel/arch/i386/boot.S index 057b527..b97ef4b 100644 --- a/kernel/arch/i386/boot.S +++ b/kernel/arch/i386/boot.S @@ -43,16 +43,98 @@ _start: .global gdt_flush gdt_flush: - cli mov 0x4(%esp),%eax - sgdtl (%eax) + lgdt (%eax) + mov $0x10,%ax + mov %ax,%ds + mov %ax,%es + mov %ax,%fs + mov %ax,%gs + mov %ax,%ss + jmp $0x8,$.flush +.flush: + ret + +// IDT + +.global idt_flush +idt_flush: + mov 0x4(%esp),%eax + lidt (%eax) + ret + +// Interrupt Service Routine + +.macro ISR_NOERRCODE num +.global isr\num +isr\num: + cli + push $0x0 + push $0x\num + jmp isr_common_stub +.endm + +.macro ISR_ERRCODE num +.global isr\num +isr\num: + cli + push $0x\num + jmp isr_common_stub +.endm + +ISR_NOERRCODE 0 // Divide by sero +ISR_NOERRCODE 1 // Debug +ISR_NOERRCODE 2 // Non-maskable Interrupt +ISR_NOERRCODE 3 // Breakpoint +ISR_NOERRCODE 4 // Overflow +ISR_NOERRCODE 5 // Bound Range Exceeded +ISR_NOERRCODE 6 // Invalid Opcode +ISR_NOERRCODE 7 // Device Not Avalible +ISR_ERRCODE 8 // Double Fault +ISR_NOERRCODE 9 // Coprocessor Segment Overrun +ISR_ERRCODE 10 // Invalid TSS +ISR_ERRCODE 11 +ISR_ERRCODE 12 +ISR_ERRCODE 13 +ISR_ERRCODE 14 +ISR_NOERRCODE 15 +ISR_NOERRCODE 16 +ISR_ERRCODE 17 +ISR_NOERRCODE 18 +ISR_NOERRCODE 19 +ISR_NOERRCODE 20 +ISR_NOERRCODE 21 +ISR_NOERRCODE 22 +ISR_NOERRCODE 23 +ISR_NOERRCODE 24 +ISR_NOERRCODE 25 +ISR_NOERRCODE 26 +ISR_NOERRCODE 27 +ISR_NOERRCODE 28 +ISR_NOERRCODE 29 +ISR_ERRCODE 30 +ISR_NOERRCODE 31 + +isr_common_stub: + pusha + mov %ds,%ax + push %eax mov $0x10,%ax mov %eax,%ds mov %eax,%es mov %eax,%fs mov %eax,%gs - mov %eax,%ss - ljmp $0x8,$.flush -.flush: - ret + call isr_handler + + pop %eax + mov %eax,%ds + mov %eax,%es + mov %eax,%fs + mov %eax,%gs + popa + add $0x8,%esp + sti + iret + + diff --git a/kernel/kernel/early_kernel.c b/kernel/kernel/early_kernel.c index 5777188..c81301f 100644 --- a/kernel/kernel/early_kernel.c +++ b/kernel/kernel/early_kernel.c @@ -3,10 +3,15 @@ #include #include "serial.h" #include "gdt.c" +#include "interrupts.c" void kernel_early_main(void) { gdt_init(); - terminal_initialize(); init_serial(); serial_printf("gdt initialized!\n"); + idt_init(); + serial_printf("idt initialized!\n"); + //asm volatile("int $0x3"); + //asm volatile("int $0x4"); + terminal_initialize(); } diff --git a/kernel/kernel/gdt.c b/kernel/kernel/gdt.c index 01e5b4b..f19a7c2 100644 --- a/kernel/kernel/gdt.c +++ b/kernel/kernel/gdt.c @@ -1,54 +1,7 @@ - -// Used for creating GDT segment descriptors in 64-bit integer form. - #include #include -// Each define here is for a specific flag in the descriptor. -// Refer to the intel documentation for a description of what each one does. -#define SEG_DESCTYPE(x) ((x) << 0x04) // Descriptor type (0 for system, 1 for code/data) -#define SEG_PRES(x) ((x) << 0x07) // Present -#define SEG_SAVL(x) ((x) << 0x0C) // Available for system use -#define SEG_LONG(x) ((x) << 0x0D) // Long mode -#define SEG_SIZE(x) ((x) << 0x0E) // Size (0 for 16-bit, 1 for 32) -#define SEG_GRAN(x) ((x) << 0x0F) // Granularity (0 for 1B - 1MB, 1 for 4KB - 4GB) -#define SEG_PRIV(x) (((x) & 0x03) << 0x05) // Set privilege level (0 - 3) - -#define SEG_DATA_RD 0x00 // Read-Only -#define SEG_DATA_RDA 0x01 // Read-Only, accessed -#define SEG_DATA_RDWR 0x02 // Read/Write -#define SEG_DATA_RDWRA 0x03 // Read/Write, accessed -#define SEG_DATA_RDEXPD 0x04 // Read-Only, expand-down -#define SEG_DATA_RDEXPDA 0x05 // Read-Only, expand-down, accessed -#define SEG_DATA_RDWREXPD 0x06 // Read/Write, expand-down -#define SEG_DATA_RDWREXPDA 0x07 // Read/Write, expand-down, accessed -#define SEG_CODE_EX 0x08 // Execute-Only -#define SEG_CODE_EXA 0x09 // Execute-Only, accessed -#define SEG_CODE_EXRD 0x0A // Execute/Read -#define SEG_CODE_EXRDA 0x0B // Execute/Read, accessed -#define SEG_CODE_EXC 0x0C // Execute-Only, conforming -#define SEG_CODE_EXCA 0x0D // Execute-Only, conforming, accessed -#define SEG_CODE_EXRDC 0x0E // Execute/Read, conforming -#define SEG_CODE_EXRDCA 0x0F // Execute/Read, conforming, accessed - -#define GDT_CODE_PL0 SEG_DESCTYPE(1) | SEG_PRES(1) | SEG_SAVL(0) | \ - SEG_LONG(0) | SEG_SIZE(1) | SEG_GRAN(1) | \ - SEG_PRIV(0) | SEG_CODE_EXRD - -#define GDT_DATA_PL0 SEG_DESCTYPE(1) | SEG_PRES(1) | SEG_SAVL(0) | \ - SEG_LONG(0) | SEG_SIZE(1) | SEG_GRAN(1) | \ - SEG_PRIV(0) | SEG_DATA_RDWR - -#define GDT_CODE_PL3 SEG_DESCTYPE(1) | SEG_PRES(1) | SEG_SAVL(0) | \ - SEG_LONG(0) | SEG_SIZE(1) | SEG_GRAN(1) | \ - SEG_PRIV(3) | SEG_CODE_EXRD - -#define GDT_DATA_PL3 SEG_DESCTYPE(1) | SEG_PRES(1) | SEG_SAVL(0) | \ - SEG_LONG(0) | SEG_SIZE(1) | SEG_GRAN(1) | \ - SEG_PRIV(3) | SEG_DATA_RDWR -#define GDT_MAX_DESCRIPTORS 3 - -struct gdt_entry { +struct gdt_entry_struct { uint16_t limit_low; uint16_t base_low; uint8_t base_middle; @@ -56,53 +9,40 @@ struct gdt_entry { uint8_t granularity; uint8_t base_high; }__attribute__((packed)); +typedef struct gdt_entry_struct gdt_entry_t; -struct gdt_ptr { +struct gdt_ptr_struct { uint16_t limit; uint32_t base; }__attribute__((packed)); +typedef struct gdt_ptr_struct gdt_ptr_t; -struct gdt_entry gdt[GDT_MAX_DESCRIPTORS]; -struct gdt_ptr gp; +gdt_entry_t gdt_entries[5]; +gdt_ptr_t gdt_ptr; extern void gdt_flush(struct gdt_ptr* gdt_ptr_addr); -void -create_descriptor(uint32_t base, uint32_t limit, uint16_t flag) +static void gdt_set_gate(int32_t num, uint32_t base, uint32_t limit, uint8_t access, uint8_t gran) { - uint64_t descriptor; + gdt_entries[num].base_low = (base & 0xFFFF); + gdt_entries[num].base_middle = (base >> 16) & 0xFF; + gdt_entries[num].base_high = (base >> 24) & 0xFF; + + gdt_entries[num].limit_low = (limit & 0xFFFF); + gdt_entries[num].granularity = (limit >> 16) & 0x0F; - // Create the high 32 bit segment - descriptor = limit & 0x000F0000; // set limit bits 19:16 - descriptor |= (flag << 8) & 0x00F0FF00; // set type, p, dpl, s, g, d/b, l and avl fields - descriptor |= (base >> 16) & 0x000000FF; // set base bits 23:16 - descriptor |= base & 0xFF000000; // set base bits 31:24 - - // Shift by 32 to allow for low part of segment - descriptor <<= 32; - - // Create the low 32 bit segment - descriptor |= base << 16; // set base bits 15:0 - descriptor |= limit & 0x0000FFFF; // set limit bits 15:0 - - printf("0x%.16llX\n", descriptor); + gdt_entries[num].granularity |= gran & 0xF0; + gdt_entries[num].access = access; } void gdt_init() { - gp.limit = (sizeof(struct gdt_entry) * GDT_MAX_DESCRIPTORS) - 1; - gp.base = (uint32_t) &gdt; - - create_descriptor(0, 0, 0); - create_descriptor(0, 0x000FFFFF, (GDT_CODE_PL0)); - create_descriptor(0, 0x000FFFFF, (GDT_DATA_PL0)); - create_descriptor(0, 0x000FFFFF, (GDT_CODE_PL3)); - create_descriptor(0, 0x000FFFFF, (GDT_DATA_PL3)); - - /* + gdt_ptr.limit = (sizeof(gdt_entry_t) * 5) - 1; + gdt_ptr.base = (uint32_t)&gdt_entries; + gdt_set_gate(0, 0, 0, 0, 0); gdt_set_gate(1, 0, 0xFFFFFFFF, 0x9A, 0xCF); gdt_set_gate(2, 0, 0xFFFFFFFF, 0x92, 0xCF); - */ - gdt_flush(&gp); + + gdt_flush((uint32_t)&gdt_ptr); } diff --git a/kernel/kernel/interrupts.c b/kernel/kernel/interrupts.c new file mode 100644 index 0000000..5265ebd --- /dev/null +++ b/kernel/kernel/interrupts.c @@ -0,0 +1,116 @@ +struct idt_entry_struct +{ + uint16_t base_lo; // The lower 16 bits of the ISR's address + uint16_t sel; // The GDT segment selector that the CPU will load into CS before calling the ISR + uint8_t always0; // Always set to zero + uint8_t flags; // Type and attributes + uint16_t base_hi; // The higher 16 bits of the ISR's address +} __attribute__((packed)); +typedef struct idt_entry_struct idt_entry_t; + +struct idt_ptr_struct { + uint16_t limit; + uint32_t base; +} __attribute__((packed)); +typedef struct idt_ptr_struct idt_ptr_t; + +idt_entry_t idt_entries[256]; +idt_ptr_t idt_ptr; + +void idt_set_gate(uint8_t num, uint32_t base, uint16_t sel, uint8_t 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; +} + +void idt_init(void); +void idt_init() { + idt_ptr.base = (uintptr_t)&idt_entries; + idt_ptr.limit = (uint16_t)sizeof(idt_entry_t) * 256 - 1; + + memset(&idt_entries, 0, sizeof(idt_entry_t)*256); + + extern isr0; + extern isr1; + extern isr2; + extern isr3; + extern isr4; + extern isr5; + extern isr6; + extern isr7; + extern isr8; + extern isr9; + extern isr10; + extern isr11; + extern isr12; + extern isr13; + extern isr14; + extern isr15; + extern isr16; + extern isr17; + extern isr18; + extern isr19; + extern isr20; + extern isr21; + extern isr22; + extern isr23; + extern isr24; + extern isr25; + extern isr26; + extern isr27; + extern isr28; + extern isr29; + extern isr30; + extern isr31; + + idt_set_gate(0, (uint32_t)isr0, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr1, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr2, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr3, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr4, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr5, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr6, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr7, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr8, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr9, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr10, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr11, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr12, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr13, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr14, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr15, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr16, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr17, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr18, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr19, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr20, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr21, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr22, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr23, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr24, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr25, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr26, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr27, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr28, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr29, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr30, 0x08, 0x8E); + idt_set_gate(0, (uint32_t)isr31, 0x08, 0x8E); + + + //__asm__ volatile ("lidt %0" : : "memory"(idt_ptr)); // load the new IDT + //__asm__ volatile ("sti"); // set the interrupt flag + + extern void idt_flush(uint32); + idt_flush((uint32_t)&idt_ptr); + +} + +void isr_handler() +{ + serial_printf("Received interrupt\n"); +} + diff --git a/kernel/kernel/kernel.c b/kernel/kernel/kernel.c index 711670d..5846724 100644 --- a/kernel/kernel/kernel.c +++ b/kernel/kernel/kernel.c @@ -6,6 +6,6 @@ void kernel_main(void) { serial_printf("Test is success!\n"); serial_printf("Newline test\n"); char * test_string = "test"; - serial_printf("This is string from variable: %s", test_string); + serial_printf("This is string from variable: %s\n", test_string); printf("Test finished success!\n"); }