Panic and interrupts

Added a basic kernel panic function and interrupt support for x86_64 (mostly for exception handling)

src/arch/x86_64/Makefile

@@ -1,4 +1,4 @@
-objects := $(patsubst %.c,%.o,$(wildcard *.c))
+objects := $(patsubst %.c,%.o,$(wildcard *.c)) israsm.o
 subdirs=boot
 OBJPATH=$(OBJDIR)/arch/${TARGET}/
 export
@@ -11,3 +11,7 @@ all: $(objects) $(subdirs)
 	mkdir -p $(OBJPATH) 
 	cp $@ $(OBJPATH)/$@
 
+israsm.o: isr.asm
+	nasm -f elf64 -o $@ $<
+	mkdir -p $(OBJPATH)
+	cp $@ $(OBJPATH)/$@

src/arch/x86_64/idt.c

@@ -0,0 +1,41 @@
+#include <arch/idt.h>
+#include <arch/isr.h>
+#include <stdint.h>
+#include <stddef.h>
+
+idtentry_t idt[256];
+
+void idt_setentry(idtentry_t *e, uint64_t offset, uint16_t segment, uint16_t flags, uint8_t ist){
+	e->offset1 = offset & 0xFFFF;
+	e->offset2 = (offset >> 16) & 0xFFFF;
+	e->offset3 = (offset >> 32) & 0xFFFFFFFF;
+	e->segment = segment;
+	e->flags   = flags | ist;
+	e->reserved = 0;
+}
+
+static void idt_reload(){
+	
+	idtr_t idtr;
+	idtr.offset = (uint64_t)&idt;
+	idtr.size = sizeof(idt)-1;
+
+	asm("lidt (%%rax)": : "a"(&idtr) : "memory");
+
+}
+
+void idt_bspinit(){
+
+	for(size_t i = 0; i < 256; ++i){
+		idt_setentry(&idt[i], asmisr_general, 0x28, FLAGS_PRESENT | FLAGS_TYPE_INTERRUPT, 0);
+	}
+	
+	for(size_t i = 0; i < 32; ++i){
+		idt_setentry(&idt[i], asmisr_except, 0x28, FLAGS_PRESENT | FLAGS_TYPE_TRAP, 0);
+	}
+	
+	idt_reload();
+
+	asm("int $0x0");
+
+}

src/arch/x86_64/include/arch/idt.h

@@ -0,0 +1,30 @@
+#ifndef _IDT_H_INCLUDE
+#define _IDT_H_INCLUDE
+
+#include <stdint.h>
+
+#define FLAGS_PRESENT (1 << 15)
+#define FLAGS_DPL3    (1 << 13)
+#define FLAGS_TYPE_INTERRUPT (0xE << 8)
+#define FLAGS_TYPE_TRAP (0xF << 8)
+
+
+
+typedef struct{
+	uint16_t size;
+	uint64_t offset;
+} __attribute__((packed)) idtr_t;
+
+typedef struct{
+	uint16_t offset1;
+	uint16_t segment;
+	uint16_t  flags;
+	uint16_t  offset2;
+	uint32_t  offset3;
+	uint32_t  reserved;
+
+} __attribute__((packed)) idtentry_t;
+
+void idt_bspinit();
+
+#endif

src/arch/x86_64/include/arch/isr.h

@@ -0,0 +1,9 @@
+#ifndef _ISR_H_INCLUDE
+#define _ISR_H_INCLUDE
+
+extern void asmisr_general(void*);
+extern void asmisr_except(void*);
+
+
+
+#endif

src/arch/x86_64/include/arch/panic.h

@@ -0,0 +1,6 @@
+#ifndef _PANIC_H_INCLUDE
+#define _PANIC_H_INCLUDE
+
+__attribute__((noreturn)) void _panic(char *reason);
+
+#endif

src/arch/x86_64/isr.asm

@@ -0,0 +1,113 @@
+section .text
+
+%macro pushregs 0
+
+	push rbp
+	push rsi
+	push rdi
+	push r15
+	push r14
+	push r13
+	push r12
+	push r11
+	push r10
+	push r9
+	push r8
+	push rdx
+	push rcx
+	push rbx
+	push rax
+	
+	mov rax, ds
+	push rax
+	mov rax, es
+	push rax
+	mov rax, fs
+	push rax
+	mov rax, gs
+	push rax
+
+	mov rdi,cr2
+	push rdi
+
+
+%endmacro
+
+%macro popregs 0 
+	
+	add rsp, 8 ; cr2
+
+	pop rax
+	mov gs,rax
+	pop rax
+	mov fs,rax
+	pop rax
+	mov es,rax
+	pop rax
+	mov ds,rax
+
+	pop rax
+	pop rbx
+	pop rcx
+	pop rdx
+	pop r8
+	pop r9
+	pop r10
+	pop r11
+	pop r12
+	pop r13
+	pop r14
+	pop r15
+	pop rdi
+	pop rsi
+	pop rbp
+
+
+%endmacro
+
+%macro isr 2
+	
+	global %1
+	%1:
+
+	pushregs
+
+	mov rdi,rsp
+
+	cld
+	extern %2
+	call %2
+	
+	popregs
+
+	iretq
+	
+	
+%endmacro
+
+
+
+
+%macro except 2
+	
+	global %1
+	%1:
+
+	pushregs
+	
+	mov rdi,rsp
+	
+	cld
+	extern %2
+	call %2
+	
+	popregs
+
+	add rsp,8 ; remove error code
+
+	iretq
+%endmacro
+
+except asmisr_pagefault, isr_pagefault
+isr    asmisr_general, isr_general
+except asmisr_except, isr_except

src/arch/x86_64/isr.c

@@ -0,0 +1,16 @@
+#include <arch/isr.h>
+#include <arch/panic.h>
+
+void isr_general(void*){
+	_panic("Unhandled interrupt");
+	asm("hlt");
+}
+
+void isr_except(void*){
+	_panic("CPU Exception");
+	asm("hlt;");
+}
+
+void isr_pagefault(void*){
+
+}

src/arch/x86_64/main.c

@@ -25,7 +25,8 @@ void kmain(){
 	console_setwritehook(liminewrite);
 	
 	bsp_setcls();
-
+	gdt_bspinit();
+	idt_bspinit();
 
 
 }

src/arch/x86_64/panic.c

@@ -0,0 +1,14 @@
+#include <arch/panic.h>
+#include <stdio.h>
+
+__attribute((noreturn)) void _panic(char* reason){
+	
+	// TODO stack trace and register print
+	
+	printf("Kernel panic.\nWhy: %s\nWhere: TODO\nWho: TODO\n", reason);
+
+	while(1){
+		asm("cli;hlt;");
+	}
+
+}