diff options
Diffstat (limited to 'kernel/drivers/int.c')
| -rw-r--r-- | kernel/drivers/int.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/kernel/drivers/int.c b/kernel/drivers/int.c new file mode 100644 index 0000000..47a2699 --- /dev/null +++ b/kernel/drivers/int.c @@ -0,0 +1,187 @@ +// MIT License, Copyright (c) 2021 Marvin Borner + +#include <assert.h> +#include <def.h> +#include <drivers/int.h> +#include <drivers/pic.h> +#include <drivers/serial.h> + +/** + * IDT + */ + +PROTECTED extern u32 int_table[]; +PROTECTED static struct idt_entry idt[256] = { 0 }; +PROTECTED static struct idt_ptr idt_ptr = { 0 }; + +CLEAR void idt_install(void) +{ + idt_ptr.size = sizeof(idt) - 1; + idt_ptr.base = &idt; + + for (u8 i = 0; i < 3; i++) + idt[i] = IDT_ENTRY(int_table[i], 0x08, INT_GATE); + + idt[3] = IDT_ENTRY(int_table[3], 0x08, INT_TRAP); + idt[4] = IDT_ENTRY(int_table[4], 0x08, INT_TRAP); + + for (u8 i = 5; i < 48; i++) + idt[i] = IDT_ENTRY(int_table[i], 0x08, INT_GATE); + + idt[128] = IDT_ENTRY(int_table[48], 0x08, INT_GATE | INT_USER); + idt[129] = IDT_ENTRY(int_table[49], 0x08, INT_GATE); + + __asm__ volatile("lidt %0" : : "m"(idt_ptr)); +} + +/** + * Exception (trap) handling + */ + +PROTECTED const char *int_trap_names[32] = { + "Division By Zero", + "Debug", + "Non Maskable Interrupt", + "Breakpoint", + "Into 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", +}; + +PROTECTED static void (*int_trap_handlers[16])(u32 esp) = { 0 }; + +CLEAR void int_trap_handler_add(u32 int_no, void (*handler)(u32 esp)) +{ + assert(int_no < COUNT(int_trap_handlers)); + int_trap_handlers[int_no] = handler; +} + +static void int_trap_handler(struct int_frame *frame) +{ + static u8 faulting = 0; + faulting++; + + if (faulting == 2) { + // Fall back to serial driver + serial_print("Double fault, halting immediatly\n"); + while (1) + __asm__ volatile("cli\nhlt"); + } + + assert(frame->int_no < COUNT(int_trap_handlers)); + void (*handler)(u32 esp) = int_trap_handlers[frame->int_no]; + if (handler) + handler((u32)frame); + + printf("%s Exception (code %x) at 0x%x (ring %d), exiting!\n", + int_trap_names[frame->int_no], frame->err_code, frame->eip, RING(frame)); + struct proc *proc = proc_current(); + if (proc) { + printf("\t-> Exception occurred in %s at addr 0x%x (offset 0x%x)\n", proc->name, + frame->eip, frame->eip - proc->entry); + printf("\t\t-> Process: [entry: %x, kstack: %x, esp %x, ustack: %x]\n", proc->entry, + proc->stack.kernel, frame->esp, proc->stack.user); + proc_exit(proc, 1); + faulting--; + } else { + while (1) + __asm__ volatile("cli\nhlt"); + } +} + +/** + * Event handling + */ + +PROTECTED static void (*int_event_handlers[16])(void) = { 0 }; + +CLEAR void int_event_handler_add(u32 int_no, void (*handler)(void)) +{ + assert(int_no < COUNT(int_event_handlers)); + int_event_handlers[int_no] = handler; +} + +#include <mm.h> +static u32 int_event_handler(struct int_frame *frame) +{ + u32 int_no = frame->int_no - 32; + assert(int_no < COUNT(int_event_handlers)); + void (*handler)(void) = int_event_handlers[int_no]; + if (handler) + handler(); + + if (!int_no) + return scheduler((u32)frame); + return (u32)frame; +} + +/** + * Special interrupts (e.g. syscall, yield) + */ + +PROTECTED static u32 (*int_special_handlers[16])(u32 esp) = { 0 }; + +CLEAR void int_special_handler_add(u32 int_no, u32 (*handler)(u32 esp)) +{ + assert(int_no < COUNT(int_event_handlers)); + int_special_handlers[int_no] = handler; +} + +static u32 int_special_handler(struct int_frame *frame) +{ + u32 int_no = frame->int_no - 128; + assert(int_no < COUNT(int_event_handlers)); + u32 (*handler)(u32 esp) = int_special_handlers[int_no]; + if (handler) + return handler((u32)frame); + return (u32)frame; +} + +/** + * Universal handler + */ + +u32 int_handler(u32 esp); +u32 int_handler(u32 esp) +{ + struct int_frame *frame = (struct int_frame *)esp; + if (frame->int_no < 32) + int_trap_handler(frame); + else if (frame->int_no < 48) + esp = int_event_handler(frame); + else if (frame->int_no >= 128 && frame->int_no < 144) + esp = int_special_handler(frame); + else + panic("Unknown interrupt: %d\n", frame->int_no); + + pic_ack(frame->int_no); + return esp; +} |