initial

5 files changed, 339 insertions, 0 deletions

diff --git a/kernel/src/interrupt/idt.c b/kernel/src/interrupt/idt.c
new file mode 100644
index 0000000..6df3793
--- /dev/null
+++ b/kernel/src/interrupt/idt.c
@@ -0,0 +1,108 @@
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <sys.h>
+#include <print.h>
+#include <panic.h>
+
+#include "acpi/acpi.h"
+#include "drivers/ps2kb.h"
+#include "drivers/ps2mouse.h"
+#include "tty/color.h"
+#include "idt.h"
+#include "pic.h"
+#include "tty/term.h"
+
+static int timer = 0;
+
+void idt_pic_eoi(uint8_t exception) {
+	pic_eoi(exception - PIC_REMAP_OFFSET);
+}
+
+void idt_pic_timer(void) {
+	uint32_t state = term_save();
+	term_setfg(VGA_LIGHT_GREEN);
+	term_setpos(60, 0);
+	puts("        ");
+	term_setpos(60, 0);
+	printk("%d", timer);
+	timer += 1;
+	term_load(state);
+}
+
+void idt_pic_keyboard(void) {
+	ps2kb_recv();
+}
+
+void idt_pic_mouse(void) {
+	ps2mouse_recv();
+}
+
+void idt_exception_handler(uint8_t exception) {
+	char* msg;
+	switch(exception) {
+		case 0x00:
+			msg = "Division by zero";
+			break;
+		case 0x02:
+			msg = "NMI";
+			break;
+		case 0x04:
+			msg = "Overflow";
+			break;
+		case 0x06:
+			msg = "invalid opcode";
+			break;
+		case 0x08:
+			msg = "double fault";
+			break;
+		case 0x0A:
+			msg = "invalid task state segment";
+			break;
+		case 0x0C:
+			msg = "stack segment fault";
+			break;
+		case 0x0D:
+			msg = "general protection fault";
+			break;
+		case 0x0E:
+			msg = "page fault";
+			break;
+		default:
+			msg = "unknown exception";
+			break;
+	}
+	panic("E%u: %s", exception, msg);
+}
+
+__attribute__((aligned(0x10)))
+static struct IdtEntry idt[256];
+static struct Idtr idtr;
+extern void* isr_stub_table[];
+
+static void set_descriptor(uint8_t vector, void* isr, uint8_t flags) {
+	struct IdtEntry* entry = &idt[vector];
+	entry->isr_low = (size_t)isr & 0xffff;
+	entry->kernel_cs = 0x08;
+	entry->attributes = flags;
+	entry->isr_high = (size_t)isr >> 16;
+	entry->_reserved = 0;
+}
+
+void idt_init(void) {
+
+    debugk("Loading IDT");
+
+	idtr.base = (uintptr_t)&idt[0];
+	idtr.limit = (uint16_t)sizeof(struct IdtEntry) * IDT_SIZE - 1;
+
+	for(int i = 0; i < IDT_INTERRUPTS; i++) {
+		set_descriptor(i, isr_stub_table[i], 0x8e);
+	}
+
+	__asm__ volatile ("lidt %0" : : "m"(idtr));
+
+    succek("IDT has been loaded");
+}
+
diff --git a/kernel/src/interrupt/idt.h b/kernel/src/interrupt/idt.h
new file mode 100644
index 0000000..86a685f
--- /dev/null
+++ b/kernel/src/interrupt/idt.h
@@ -0,0 +1,36 @@
+#pragma once
+
+#include <stdint.h>
+
+#define IDT_SIZE 256
+#define IDT_INTERRUPTS 256
+
+struct IdtEntry {
+	uint16_t isr_low;
+	uint16_t kernel_cs;
+	uint8_t _reserved;
+	uint8_t attributes;
+	uint16_t isr_high;
+} __attribute__((packed));
+
+struct Idtr {
+	uint16_t	limit;
+	uint32_t	base;
+} __attribute__((packed));
+
+enum IDTFlags {
+	IDT_FLAG_GATE_TASK = 0x5,
+	IDT_FLAG_GATE_16BIT_INT = 0x6,
+	IDT_FLAG_GATE_16BIT_TRAP = 0x7,
+	IDT_FLAG_GATE_32BIT_INT = 0xE,
+	IDT_FLAG_GATE_32BIT_TRAP = 0xF,
+
+	IDT_FLAG_RING0 = (0 << 5),
+	IDT_FLAG_RING1 = (1 << 5),
+	IDT_FLAG_RING2 = (2 << 5),
+	IDT_FLAG_RING3 = (3 << 5),
+
+	IDT_FLAG_PRESENT = 0x80,
+};
+
+void idt_init(void);
diff --git a/kernel/src/interrupt/isr.asm b/kernel/src/interrupt/isr.asm
new file mode 100644
index 0000000..6cccdc6
--- /dev/null
+++ b/kernel/src/interrupt/isr.asm
@@ -0,0 +1,99 @@
+extern idt_exception_handler
+extern idt_pic_timer
+extern idt_pic_keyboard
+extern idt_pic_mouse
+extern idt_pic_eoi
+global isr_stub_table
+
+%macro ISRErrorStub 1
+isr_stub_%+%1:
+    push dword %1
+    call idt_exception_handler
+    pop eax
+    iret
+%endmacro
+
+%macro PICGeneric 1
+isr_stub_%+%1:
+    push dword %1
+    call idt_pic_eoi
+    pop eax
+    iret
+%endmacro
+
+%macro PICTimer 1
+isr_stub_%+%1:
+    call idt_pic_timer
+    push dword %1
+    call idt_pic_eoi
+    pop eax
+    iret
+%endmacro
+
+%macro PICKeyboard 1
+isr_stub_%+%1:
+    call idt_pic_keyboard
+    push dword %1
+    call idt_pic_eoi
+    pop eax
+    iret
+%endmacro
+
+%macro PICMouse 1
+isr_stub_%+%1:
+    call idt_pic_mouse
+    push dword %1
+    call idt_pic_eoi
+    pop eax
+    iret
+%endmacro
+
+%macro ISRSyscall 1
+isr_stub_%+%1:
+    push eax
+    push ebx
+    push ecx
+    push edx
+    call idt_syscall
+    add esp, 16
+    pop eax
+    iret
+%endmacro
+
+section .text
+align 8
+%assign i 0
+%rep    32
+    ISRErrorStub i
+%assign i i+1
+%endrep
+PICTimer    32 ; 0 
+PICKeyboard 33 ; 1
+PICGeneric  34 ; 2
+PICGeneric  35 ; 3
+PICGeneric  36 ; 4
+PICGeneric  37 ; 5
+PICGeneric  38 ; 6
+PICGeneric  39 ; 7
+PICGeneric  40 ; 8
+PICGeneric  41 ; 9
+PICGeneric  42 ; 10
+PICGeneric  43 ; 11
+PICMouse    44 ; 12
+PICGeneric  45 ; 13
+PICGeneric  46 ; 14
+PICGeneric  47 ; 15
+%assign i 48
+%rep    256 - 48
+    ISRErrorStub i
+%assign i i+1
+%endrep
+
+section .rodata
+align 8
+isr_stub_table:
+%assign i 0x00
+%rep    256
+    dd isr_stub_%+i
+%assign i i+0x01
+%endrep
diff --git a/kernel/src/interrupt/pic.c b/kernel/src/interrupt/pic.c
new file mode 100644
index 0000000..86056a1
--- /dev/null
+++ b/kernel/src/interrupt/pic.c
@@ -0,0 +1,85 @@
+#include <sys.h>
+#include <print.h>
+
+#include "pic.h"
+
+#define PIC1_COMMAND_PORT 0x20
+#define PIC1_DATA_PORT 0x21
+#define PIC2_COMMAND_PORT 0xA0
+#define PIC2_DATA_PORT 0xA1
+
+void pic_remap(uint8_t offset) {
+
+    debugk("Remapping PIC");
+
+	char a1 = inb(PIC1_DATA_PORT);
+	char a2 = inb(PIC2_DATA_PORT);
+	// control word 1
+	// 0x11: initialize, enable ICW4
+	outb(PIC1_COMMAND_PORT, 0x11);
+	io_wait();
+	outb(PIC2_COMMAND_PORT, 0x11);
+	io_wait();
+	// control word 2
+	// interrupt offset
+	outb(PIC1_DATA_PORT, offset);
+	io_wait();
+	outb(PIC2_DATA_PORT, offset + 8);
+	io_wait();
+	// control word 3
+	// primary pic: set which pin secondary is connected to
+	// (pin 2)
+	outb(PIC1_DATA_PORT, 0x04);
+	io_wait();
+	outb(PIC2_DATA_PORT, 2);
+	io_wait();
+	// control word 3
+	// 0x01: enable 8086 mode
+	outb(PIC1_DATA_PORT, 0x01);
+	io_wait();
+	outb(PIC2_DATA_PORT, 0x01);
+	io_wait();
+	// clear data registers
+	outb(PIC1_DATA_PORT, a1);
+	outb(PIC2_DATA_PORT, a2);
+
+    succek("PIC has been remapped to offset 0x%X", offset);
+}
+
+void pic_mask(int irq) {
+	uint8_t port;
+	if(irq < 8) {
+		port = PIC1_DATA_PORT;
+	} else {
+		irq -= 8;
+		port = PIC2_DATA_PORT;
+	}
+	uint8_t mask = inb(port);
+	outb(port, mask | (1 << irq));
+}
+
+void pic_unmask(int irq) {
+	uint8_t port;
+	if(irq < 8) {
+		port = PIC1_DATA_PORT;
+	} else {
+		irq -= 8;
+		port = PIC2_DATA_PORT;
+	}
+	uint8_t mask = inb(port);
+	outb(port, mask & ~(1 << irq));
+}
+
+void pic_disable(void) {
+	outb(PIC1_DATA_PORT, 0xff);
+	io_wait();
+	outb(PIC2_DATA_PORT, 0xff);
+	io_wait();
+}
+
+void pic_eoi(int irq) {
+	if(irq >= 8) {
+		outb(PIC2_COMMAND_PORT, 0x20);
+	}
+	outb(PIC1_COMMAND_PORT, 0x20);
+}
diff --git a/kernel/src/interrupt/pic.h b/kernel/src/interrupt/pic.h
new file mode 100644
index 0000000..a87420d
--- /dev/null
+++ b/kernel/src/interrupt/pic.h
@@ -0,0 +1,11 @@
+#pragma once
+
+#include <stdint.h>
+
+#define PIC_REMAP_OFFSET 0x20
+
+void pic_remap(uint8_t offset);
+void pic_mask(int irq);
+void pic_unmask(int irq);
+void pic_disable(void);
+void pic_eoi(int irq);