[isrs] Interrupt Service Routines

Makefile

@@ -7,7 +7,7 @@ install: kernel
 	cp kernel /mnt/kernel
 	umount /mnt
 
-kernel: start.o link.ld main.o vga.o gdt.o idt.o
+kernel: start.o link.ld main.o vga.o gdt.o idt.o isrs.o
 	ld -m elf_i386 -T link.ld -o kernel *.o
 
 %.o: %.c

idt.c

@@ -26,7 +26,7 @@ extern void idt_load();
  * Set an IDT gate
  */
 void
-set_idt_gate(
+idt_set_gate(
 		unsigned char num,
 		unsigned long base,
 		unsigned short sel,

include/system.h

@@ -20,4 +20,16 @@ extern void init_video();
 extern void gdt_install();
 extern void gdt_set_gate(int num, unsigned long base, unsigned long limit, unsigned char access, unsigned char gran);
 
+/* IDT */
+extern void idt_install();
+extern void idt_set_gate(unsigned char num, unsigned long base, unsigned short sel, unsigned char flags);
+
+/* Registers */
+struct regs {
+    unsigned int gs, fs, es, ds;
+    unsigned int edi, esi, ebp, esp, ebx, edx, ecx, eax;
+    unsigned int int_no, err_code;
+    unsigned int eip, cs, eflags, useresp, ss;
+};
+
 #endif

isrs.c

@@ -0,0 +1,117 @@
+#include <system.h>
+
+/*
+ * Exception Handlers
+ */
+extern void _isr0();
+extern void _isr1();
+extern void _isr2();
+extern void _isr3();
+extern void _isr4();
+extern void _isr5();
+extern void _isr6();
+extern void _isr7();
+extern void _isr8();
+extern void _isr9();
+extern void _isr10();
+extern void _isr11();
+extern void _isr12();
+extern void _isr13();
+extern void _isr14();
+extern void _isr15();
+extern void _isr16();
+extern void _isr17();
+extern void _isr18();
+extern void _isr19();
+extern void _isr20();
+extern void _isr21();
+extern void _isr22();
+extern void _isr23();
+extern void _isr24();
+extern void _isr25();
+extern void _isr26();
+extern void _isr27();
+extern void _isr28();
+extern void _isr29();
+extern void _isr30();
+extern void _isr31();
+
+void
+isrs_install() {
+	/* Exception Handlers */
+	idt_set_gate(0, (unsigned)_isr0, 0x08, 0x8E);
+	idt_set_gate(1, (unsigned)_isr1, 0x08, 0x8E);
+	idt_set_gate(2, (unsigned)_isr2, 0x08, 0x8E);
+	idt_set_gate(3, (unsigned)_isr3, 0x08, 0x8E);
+	idt_set_gate(4, (unsigned)_isr4, 0x08, 0x8E);
+	idt_set_gate(5, (unsigned)_isr5, 0x08, 0x8E);
+	idt_set_gate(6, (unsigned)_isr6, 0x08, 0x8E);
+	idt_set_gate(7, (unsigned)_isr7, 0x08, 0x8E);
+	idt_set_gate(8, (unsigned)_isr8, 0x08, 0x8E);
+	idt_set_gate(9, (unsigned)_isr9, 0x08, 0x8E);
+	idt_set_gate(10, (unsigned)_isr10, 0x08, 0x8E);
+	idt_set_gate(11, (unsigned)_isr11, 0x08, 0x8E);
+	idt_set_gate(12, (unsigned)_isr12, 0x08, 0x8E);
+	idt_set_gate(13, (unsigned)_isr13, 0x08, 0x8E);
+	idt_set_gate(14, (unsigned)_isr14, 0x08, 0x8E);
+	idt_set_gate(15, (unsigned)_isr15, 0x08, 0x8E);
+	idt_set_gate(16, (unsigned)_isr16, 0x08, 0x8E);
+	idt_set_gate(17, (unsigned)_isr17, 0x08, 0x8E);
+	idt_set_gate(18, (unsigned)_isr18, 0x08, 0x8E);
+	idt_set_gate(19, (unsigned)_isr19, 0x08, 0x8E);
+	idt_set_gate(20, (unsigned)_isr20, 0x08, 0x8E);
+	idt_set_gate(21, (unsigned)_isr21, 0x08, 0x8E);
+	idt_set_gate(22, (unsigned)_isr22, 0x08, 0x8E);
+	idt_set_gate(23, (unsigned)_isr23, 0x08, 0x8E);
+	idt_set_gate(24, (unsigned)_isr24, 0x08, 0x8E);
+	idt_set_gate(25, (unsigned)_isr25, 0x08, 0x8E);
+	idt_set_gate(26, (unsigned)_isr26, 0x08, 0x8E);
+	idt_set_gate(27, (unsigned)_isr27, 0x08, 0x8E);
+	idt_set_gate(28, (unsigned)_isr28, 0x08, 0x8E);
+	idt_set_gate(29, (unsigned)_isr29, 0x08, 0x8E);
+	idt_set_gate(30, (unsigned)_isr30, 0x08, 0x8E);
+	idt_set_gate(31, (unsigned)_isr31, 0x08, 0x8E);
+}
+
+unsigned char *exception_messages[] = {
+	"division by zero",
+	"debug",
+	"non-maskable interrupt",
+	"breakpoint",
+	"detected overflow",
+	"out-of-bounds",
+	"invalid opcode",
+	"no coprocessor",
+	"double fault",
+	"coprocessor segment overrun",
+	"bad TSS",
+	"segment not present",
+	"stack fault",
+	"general protection fault",
+	"page fault",
+	"unknown interrupt",
+	"coprocessor fault",
+	"alignment check",
+	"machine check",
+	"reserved",
+	"reserved",
+	"reserved",
+	"reserved",
+	"reserved",
+	"reserved",
+	"reserved",
+	"reserved",
+	"reserved",
+	"reserved",
+	"reserved",
+	"reserved",
+	"reserved"
+};
+
+void fault_handler(struct regs *r) {
+	if (r->int_no < 32) {
+		puts(exception_messages[r->int_no]);
+		puts(" exception. System halted.\n");
+		for (;;);
+	}
+}

main.c

@@ -103,6 +103,7 @@ int
 main() {
 	gdt_install();
 	idt_install();
+	isrs_install();
 	init_video();
 	puts("Good Morning!\n");
 	for (;;);

start.asm

@@ -54,7 +54,282 @@ idt_load:
 	ret
 
 ; Interrupt Service Routines
+global _isr0
+global _isr1
+global _isr2
+global _isr3
+global _isr4
+global _isr5
+global _isr6
+global _isr7
+global _isr8
+global _isr9
+global _isr10
+global _isr11
+global _isr12
+global _isr13
+global _isr14
+global _isr15
+global _isr16
+global _isr17
+global _isr18
+global _isr19
+global _isr20
+global _isr21
+global _isr22
+global _isr23
+global _isr24
+global _isr25
+global _isr26
+global _isr27
+global _isr28
+global _isr29
+global _isr30
+global _isr31
 
+;  0: Divide By Zero Exception
+_isr0:
+	cli
+	push byte 0
+	push byte 0
+	jmp isr_common_stub
+
+;  1: Debug Exception
+_isr1:
+	cli
+	push byte 0
+	push byte 1
+	jmp isr_common_stub
+
+;  2: Non Maskable Interrupt Exception
+_isr2:
+	cli
+	push byte 0
+	push byte 2
+	jmp isr_common_stub
+
+;  3: Int 3 Exception
+_isr3:
+	cli
+	push byte 0
+	push byte 3
+	jmp isr_common_stub
+
+;  4: INTO Exception
+_isr4:
+	cli
+	push byte 0
+	push byte 4
+	jmp isr_common_stub
+
+;  5: Out of Bounds Exception
+_isr5:
+	cli
+	push byte 0
+	push byte 5
+	jmp isr_common_stub
+
+;  6: Invalid Opcode Exception
+_isr6:
+	cli
+	push byte 0
+	push byte 6
+	jmp isr_common_stub
+
+;  7: Coprocessor Not Available Exception
+_isr7:
+	cli
+	push byte 0
+	push byte 7
+	jmp isr_common_stub
+
+;  8: Double Fault Exception (With Error Code!)
+_isr8:
+	cli
+	push byte 8
+	jmp isr_common_stub
+
+;  9: Coprocessor Segment Overrun Exception
+_isr9:
+	cli
+	push byte 0
+	push byte 9
+	jmp isr_common_stub
+
+; 10: Bad TSS Exception (With Error Code!)
+_isr10:
+	cli
+	push byte 10
+	jmp isr_common_stub
+
+; 11: Segment Not Present Exception (With Error Code!)
+_isr11:
+	cli
+	push byte 11
+	jmp isr_common_stub
+
+; 12: Stack Fault Exception (With Error Code!)
+_isr12:
+	cli
+	push byte 12
+	jmp isr_common_stub
+
+; 13: General Protection Fault Exception (With Error Code!)
+_isr13:
+	cli
+	push byte 13
+	jmp isr_common_stub
+
+; 14: Page Fault Exception (With Error Code!)
+_isr14:
+	cli
+	push byte 14
+	jmp isr_common_stub
+
+; 15: Reserved Exception
+_isr15:
+	cli
+	push byte 0
+	push byte 15
+	jmp isr_common_stub
+
+; 16: Floating Point Exception
+_isr16:
+	cli
+	push byte 0
+	push byte 16
+	jmp isr_common_stub
+
+; 17: Alignment Check Exception
+_isr17:
+	cli
+	push byte 0
+	push byte 17
+	jmp isr_common_stub
+
+; 18: Machine Check Exception
+_isr18:
+	cli
+	push byte 0
+	push byte 18
+	jmp isr_common_stub
+
+; 19: Reserved
+_isr19:
+	cli
+	push byte 0
+	push byte 19
+	jmp isr_common_stub
+
+; 20: Reserved
+_isr20:
+	cli
+	push byte 0
+	push byte 20
+	jmp isr_common_stub
+
+; 21: Reserved
+_isr21:
+	cli
+	push byte 0
+	push byte 21
+	jmp isr_common_stub
+
+; 22: Reserved
+_isr22:
+	cli
+	push byte 0
+	push byte 22
+	jmp isr_common_stub
+
+; 23: Reserved
+_isr23:
+	cli
+	push byte 0
+	push byte 23
+	jmp isr_common_stub
+
+; 24: Reserved
+_isr24:
+	cli
+	push byte 0
+	push byte 24
+	jmp isr_common_stub
+
+; 25: Reserved
+_isr25:
+	cli
+	push byte 0
+	push byte 25
+	jmp isr_common_stub
+
+; 26: Reserved
+_isr26:
+	cli
+	push byte 0
+	push byte 26
+	jmp isr_common_stub
+
+; 27: Reserved
+_isr27:
+	cli
+	push byte 0
+	push byte 27
+	jmp isr_common_stub
+
+; 28: Reserved
+_isr28:
+	cli
+	push byte 0
+	push byte 28
+	jmp isr_common_stub
+
+; 29: Reserved
+_isr29:
+	cli
+	push byte 0
+	push byte 29
+	jmp isr_common_stub
+
+; 30: Reserved
+_isr30:
+	cli
+	push byte 0
+	push byte 30
+	jmp isr_common_stub
+
+; 31: Reserved
+_isr31:
+	cli
+	push byte 0
+	push byte 31
+	jmp isr_common_stub
+
+extern fault_handler
+
+isr_common_stub:
+	pusha
+	push ds
+	push es
+	push fs
+	push gs
+	mov ax, 0x10
+	mov ds, ax
+	mov es, ax
+	mov fs, ax
+	mov gs, ax
+	mov eax, esp
+	push eax
+	mov eax, fault_handler
+	call eax
+	pop eax
+	pop gs
+	pop fs
+	pop es
+	pop ds
+	popa
+	add esp, 8
+	iret
 
 ; BSS Section
 SECTION .bss