debugger

arch/amd64/sym_lookup.py

@@ -14,8 +14,8 @@ class Symbol:
 	name: str
 
 readelf = subprocess.run(
-	["readelf", "-s", "build/kernel.bin"], 
-	capture_output=True, 
+	["readelf", "-s", "build/kernel.bin"],
+	capture_output=True,
 	encoding="UTF-8"
 )
 

include/backtrace.h

@@ -7,7 +7,7 @@
 size_t backtrace(void **dst, size_t len);
 
 // same as backtrace but with specified instruction and base pointer
-size_t backtrace_ex(void **dst, size_t len, void* ip, void *bp);
+size_t backtrace_ex(void **dst, size_t len, void *ip, void *bp);
 
 // Log a backtrace
 void log_backtrace();

include/lib.h

@@ -92,25 +92,25 @@ int ctoi(char c);
  * @param s - the string to convert
  * @returns the number inside s or 0 on error
  */
-int atoi(const char* s);
+int atoi(const char *s);
 
 /**
  * Converts the initial portiion of the string pointed to by s to long.
  * @param s - the string to convert
  * @returns the number inside s or 0 on error
  */
-long int atol(const char* s);
+long int atol(const char *s);
 
 /**
  * Converts the initial portiion of the string pointed to by s to long long.
  * @param s - the string to convert
  * @returns the number inside s or 0 on error
  */
-long long int atoll(const char* s);
+long long int atoll(const char *s);
 
 /**
  * Converts a integer to asci inside a string with a given radix (base).
- * @param n - the number to conver
+ * @param n - the number to convert
  * @param buffer - the string buffer
  * @param radix - the base to convert
  */
@@ -118,7 +118,7 @@ char *itoa(int n, char *buffer, int radix);
 
 /**
  * Converts a long to asci inside a string with a given radix (base).
- * @param n - the number to conver
+ * @param n - the number to convert
  * @param buffer - the string buffer
  * @param radix - the base to convert
  */
@@ -134,7 +134,7 @@ char *lltoa(long long int n, char *buffer, int radix);
 
 /**
  * Converts a unsigned integer to asci inside a string with a given radix (base).
- * @param n - the number to conver
+ * @param n - the number to convert
  * @param buffer - the string buffer
  * @param radix - the base to convert
  */
@@ -142,7 +142,7 @@ char *utoa(unsigned int n, char *buffer, int radix);
 
 /**
  * Converts a unsigned long to asci inside a string with a given radix (base).
- * @param n - the number to conver
+ * @param n - the number to convert
  * @param buffer - the string buffer
  * @param radix - the base to convert
  */

include/memory.h

@@ -7,46 +7,46 @@
 /**
  * Initalize system memory allocator
  */
-extern void memory_init(struct memory_map *map);
+void memory_init(struct memory_map *map);
 
 /**
  * Disabled cpu interupts to not interfere with
  * current memory allocations.
  */
-extern void memory_lock(void);
+void memory_lock(void);
 
 /**
  * Reenabled cpu interupts
  */
-extern void memory_unlock(void);
+void memory_unlock(void);
 
 /**
  * @returns how much memory the system has
  */
-extern uint64_t memory_total(void);
+uint64_t memory_total(void);
 
 /**
  * @returns how much memory is free
  */
-extern uint64_t memory_free(void);
+uint64_t memory_free(void);
 
 /**
  * @returns how much memory is used
  */
-extern uint64_t memory_used(void);
+uint64_t memory_used(void);
 
 /**
  * Allocates a single page in memory.
  * @returns the page if allocated or NULL on failure
  */
-extern void *alloc_page(void);
+void *alloc_page(void);
 
 /**
  * Allocats count pages in memory
  * @param count - the number of continious pages to allocate
  * @returns the pages if allocated or NULL on failure
  */
-extern void *alloc_pages(int count);
+void *alloc_pages(int count);
 
 /**
  * Frees a signle page in memory.
@@ -54,7 +54,7 @@ extern void *alloc_pages(int count);
  * Freeing in the middle of a block is allowed.
  * @param page - the pointer to the page
  */
-extern void free_page(void *page);
+void free_page(void *page);
 // TODO: implement free_page
 
 /**
@@ -64,7 +64,7 @@ extern void free_page(void *page);
  * free_pages will from *page to end of block allocated.
  * @param page - the pointer to the page
  */
-extern void free_pages(void *page);
+void free_pages(void *page);
 // TODO: implement freeing in middle of block
 
 /**
@@ -76,21 +76,21 @@ extern void free_pages(void *page);
  * @param writable - if this memory should be writable
  * @param user - if this memory should be user writable
  */
-extern void *mmap(void *addr, size_t len);
+void *mmap(void *addr, size_t len);
 
 /**
  * Unmaps mapped address from the mmap function
  * @param addr - the address returned from mmap
  * @param len - the length allocated
  */
-extern void unmap(void *addr);
+void unmap(void *addr);
 
 /**
  * Allocates size_t bytes in memory
  * @param size - the amount of bytes to allocate
  * @retruns the address allocated or NULL on failure
  */
-extern void *kalloc(size_t size);
+void *kalloc(size_t size);
 
 /**
  * Reallocates a given allocated ptr to a new size of bytes in memory.
@@ -99,10 +99,10 @@ extern void *kalloc(size_t size);
  * @param size - the amount of bytes to set the pointer to
  * @returns the address allocated or NULL on failure
  */
-extern void *krealloc(void *ptr, size_t size);
+void *krealloc(void *ptr, size_t size);
 
 /**
  * Frees a allocated pointer in memory
  * @param ptr - the pointer to free
  */
-extern void kfree(void *ptr);
+void kfree(void *ptr);

include/memory/physalloc.h

@@ -8,23 +8,23 @@
  * Allocates a single physical page in memory
  * @preturns the physical address of the page
  */
-extern void *alloc_phys_page(void);
+void *alloc_phys_page(void);
 
 /**
  * Allocates count physical pages in memory
  * @returns the physical address of the first page
  */
-extern void *alloc_phys_pages(int count);
+void *alloc_phys_pages(int count);
 
 /**
 * Frees a single physical page in memory
  * @param ptr - the physical address of the page
  */
-extern void free_phys_page(void *ptr);
+void free_phys_page(void *ptr);
 
 /**
  * Frees count physical pages in memory
  * @param ptr - the physical address of the first page
  * @param count - the number of pages in the list
  */
-extern void free_phys_pages(void *ptr, int count);
+void free_phys_pages(void *ptr, int count);

include/panic.h

@@ -4,6 +4,7 @@
 #define _PANIC_STR2(x) #x
 
 #define panic(msg) _panic_impl(_PANIC_STR(__LINE__), __FILE__, msg)
+#define kassert(val, msg) do { if (!(val)) { panic(msg); } } while(0)
 
 _Noreturn void _panic_impl(char *line, char *file, char *msg);
 

src/arch/amd64/acpi.c

@@ -162,13 +162,13 @@ static bool checksum(uint8_t *data, size_t len) {
 
 static int read_s5_addr(struct acpi_state *state) {
 	uintptr_t ptr = state->fadt.dsdt;
-	char *s5_addr = (void*) (ptr + 36);
+	char *s5_addr = (void *) (ptr + 36);
 
-	int dsdt_len = *((int*) (ptr+1)) - 36;
+	int dsdt_len = *((int *) (ptr+1)) - 36;
 	while (0 < dsdt_len--) {
-	   if ( memcmp(s5_addr, "_S5_", 4) == 0)
-		  break;
-	   s5_addr++;
+		if (memcmp(s5_addr, "_S5_", 4) == 0)
+			break;
+		s5_addr++;
 	}
 
 	if (dsdt_len > 0) {
@@ -178,12 +178,12 @@ static int read_s5_addr(struct acpi_state *state) {
 			s5_addr += ((*s5_addr &0xC0)>>6) +2;   // calculate PkgLength size
 
 			if (*s5_addr == 0x0A)
-			   s5_addr++;   // skip byteprefix
+				s5_addr++;   // skip byteprefix
 			state->SLP_TYPa = *(s5_addr)<<10;
 			s5_addr++;
 
 			if (*s5_addr == 0x0A)
-			   s5_addr++;   // skip byteprefix
+				s5_addr++;   // skip byteprefix
 			state->SLP_TYPb = *(s5_addr)<<10;
 
 			state->SLP_EN = 1<<13;

src/arch/amd64/backtrace.c

@@ -16,11 +16,11 @@ size_t backtrace(void **dst, size_t len) {
 size_t backtrace_ex(void **dst, size_t len, void *ip, void *bp) {
 	struct stackframe *frame = bp;
 	__asm__ volatile ("mov %%rbp, %0" : "=r"(frame));
-	if(len > 0) {
+	if (len > 0) {
 		dst[0] = ip;
 	}
 	size_t i;
-	for(i = 1; frame && i < len; i++) {
+	for (i = 1; frame && i < len; i++) {
 		dst[i] = frame->rip;
 		frame = frame->rbp;
 	}
@@ -42,7 +42,7 @@ void log_backtrace_ex(void *ip, void *bp) {
 	serial_out_str("  0x");
 	serial_out_str(buf);
 	serial_out_str("\n");
-	while(frame) {
+	while (frame) {
 		ultoa((size_t)frame->rip, buf, 16);
 		serial_out_str("  0x");
 		serial_out_str(buf);

src/arch/amd64/boot.S

@@ -61,25 +61,25 @@ LONG_MODE     equ 1 << 5
 
 GDT:
 	.Null: equ $ - GDT
-	    dq 0
+		dq 0
 	.Code: equ $ - GDT
-	    dd 0xFFFF                                   ; Limit & Base (low, bits 0-15)
-	    db 0                                        ; Base (mid, bits 16-23)
-	    db PRESENT | NOT_SYS | EXEC | RW            ; Access
-	    db GRAN_4K | LONG_MODE | 0xF                ; Flags & Limit (high, bits 16-19)
-	    db 0                                        ; Base (high, bits 24-31)
+		dd 0xFFFF                                   ; Limit & Base (low, bits 0-15)
+		db 0                                        ; Base (mid, bits 16-23)
+		db PRESENT | NOT_SYS | EXEC | RW            ; Access
+		db GRAN_4K | LONG_MODE | 0xF                ; Flags & Limit (high, bits 16-19)
+		db 0                                        ; Base (high, bits 24-31)
 	.Data: equ $ - GDT
-	    dd 0xFFFF                                   ; Limit & Base (low, bits 0-15)
-	    db 0                                        ; Base (mid, bits 16-23)
-	    db PRESENT | NOT_SYS | RW                   ; Access
-	    db GRAN_4K | SZ_32 | 0xF                    ; Flags & Limit (high, bits 16-19)
-	    db 0                                        ; Base (high, bits 24-31)
+		dd 0xFFFF                                   ; Limit & Base (low, bits 0-15)
+		db 0                                        ; Base (mid, bits 16-23)
+		db PRESENT | NOT_SYS | RW                   ; Access
+		db GRAN_4K | SZ_32 | 0xF                    ; Flags & Limit (high, bits 16-19)
+		db 0                                        ; Base (high, bits 24-31)
 	.TSS: equ $ - GDT
-	    dd 0x00000068
-	    dd 0x00CF8900
+		dd 0x00000068
+		dd 0x00CF8900
 	.Pointer:
-	    dw $ - GDT - 1
-	    dq GDT
+		dw $ - GDT - 1
+		dq GDT
 
 section .text
 align 8

src/arch/amd64/debugger.c

@@ -0,0 +1,343 @@
+#include <lib.h>
+#include <stddef.h>
+#include <serial.h>
+#include <backtrace.h>
+#include "debugger.h"
+
+struct dr6 {
+	uint64_t b0 : 1,
+	         b1 : 1,
+			 b2 : 1,
+			 b3 : 1,
+			 : 7,
+			 bld : 1,
+			 : 1,
+			 bd : 1,
+			 bs : 1,
+			 bt : 1,
+			 rtm : 1,
+			 : 47;
+};
+
+struct dr7 {
+	uint64_t l0 : 1,
+	         g0 : 1,
+			 l1 : 1,
+			 g1 : 1,
+			 l2 : 1,
+			 g2 : 1,
+			 l3 : 1,
+			 g3 : 1,
+			 : 8,
+			 rw0 : 2,
+			 len0 : 2,
+			 rw1 : 2,
+			 len1 : 2,
+			 rw2 : 2,
+			 len2 : 2,
+			 rw3 : 2,
+			 len3 : 2,
+			 : 32;
+};
+
+struct rflags {
+	uint64_t cf : 1,
+			 : 1,
+			 pf : 1,
+			 : 1,
+			 af : 1,
+			 : 1,
+			 zf : 1,
+			 sf : 1,
+
+			 tf : 1,
+			 if_ : 1,
+             df : 1,
+			 of : 1,
+			 iopl : 2,
+             nt : 1,
+			 md : 1,
+
+			 rf : 1,
+			 vm : 1,
+			 ac : 1,
+			 vif : 1,
+			 vip : 1,
+			 id : 1,
+			 : 42;
+};
+
+struct breakpoint {
+	uint64_t addr;
+	uint8_t len;
+	uint8_t rw;
+	uint8_t used;
+	uint8_t enable;
+};
+
+static size_t dbg_steps = 0;
+static int dbg_continue = 0;
+static struct breakpoint bkps[4] = {{0}, {0}, {0}, {0}};
+
+static void dbg_putc(char c) {
+	serial_out(c);
+}
+
+static void dbg_puts(char *msg) {
+	serial_out_str(msg);
+}
+
+static char dbg_getc() {
+	return serial_in();
+}
+
+static void debugger_msg(int cause, struct dr6 dr6) {
+	char buf[24];
+	switch (cause) {
+	case DEBUG_INT3:
+		dbg_puts("dbg: reached int3");
+		break;
+	case DEBUG_FAULT:
+		dbg_puts("dbg: a fault occured");
+		break;
+	case DEBUG_DBG:
+		if (dr6.bs)
+			dbg_puts("dbg: finished steps");
+		else if (dr6.b0)
+			dbg_puts("dbg: reached breakpoint 0");
+		else if (dr6.b1)
+			dbg_puts("dbg: reached breakpoint 1");
+		else if (dr6.b2)
+			dbg_puts("dbg: reached breakpoint 2");
+		else if (dr6.b3)
+			dbg_puts("dbg: reached breakpoint 3");
+	}
+	if (dbg_steps > 0) {
+		ultoa(dbg_steps, buf, 10);
+		dbg_puts(" (");
+		dbg_puts(buf);
+		dbg_puts(" steps left)");
+	}
+	if (dbg_continue > 0) {
+		dbg_puts(" (paused continue)");
+	}
+	dbg_puts("\n");
+}
+
+static void debugger_print_reg(char *name, uint64_t val) {
+	char buf[24];
+	char *end;
+	dbg_puts(name);
+	dbg_puts(": 0x");
+
+	end = ultoa(val, buf, 16);
+	for (int i = 0; i < 16 - (end - buf); i++) {
+		dbg_putc('0');
+	}
+	dbg_puts(buf);
+
+	dbg_puts(" (");
+	end = ultoa(val, buf, 10);
+	dbg_puts(buf);
+	dbg_puts(")\n");
+}
+
+static void debugger_print_regs(struct isr_regs *state) {
+	debugger_print_reg("rax", state->rax);
+	debugger_print_reg("rbx", state->rbx);
+	debugger_print_reg("rcx", state->rcx);
+	debugger_print_reg("rdx", state->rdx);
+	debugger_print_reg("rsi", state->rsi);
+	debugger_print_reg("rdi", state->rdi);
+	debugger_print_reg("rsp", state->rsp);
+	debugger_print_reg("rbp", state->rbp);
+	debugger_print_reg("r8 ", state->r8 );
+	debugger_print_reg("r9 ", state->r9 );
+	debugger_print_reg("r10", state->r10);
+	debugger_print_reg("r11", state->r11);
+	debugger_print_reg("r12", state->r12);
+	debugger_print_reg("r13", state->r13);
+	debugger_print_reg("r14", state->r14);
+	debugger_print_reg("r15", state->r15);
+	dbg_puts("---\n");
+	debugger_print_reg("rip", state->rip);
+	dbg_puts("---\n");
+	debugger_print_reg("rflags", state->rflags);
+	struct rflags *rflags = (struct rflags *)state->rflags;
+	dbg_puts("rflags: ");
+	if(rflags->cf)   dbg_puts("CF ");
+	if(rflags->pf)   dbg_puts("PF ");
+	if(rflags->af)   dbg_puts("AF ");
+	if(rflags->zf)   dbg_puts("ZF ");
+	if(rflags->sf)   dbg_puts("SF ");
+	if(rflags->tf)   dbg_puts("TF ");
+	if(rflags->if_)  dbg_puts("IF ");
+	if(rflags->df)   dbg_puts("DF ");
+	if(rflags->of)   dbg_puts("OF ");
+	if(rflags->iopl) dbg_puts("IOPL ");
+	if(rflags->nt)   dbg_puts("NT ");
+	if(rflags->md)   dbg_puts("MD ");
+	if(rflags->rf)   dbg_puts("RF ");
+	if(rflags->vm)   dbg_puts("VM ");
+	if(rflags->ac)   dbg_puts("AC ");
+	if(rflags->vif)  dbg_puts("VIF ");
+	if(rflags->vip)  dbg_puts("VIP ");
+	if(rflags->id)   dbg_puts("ID ");
+	dbg_putc('\n');
+}
+
+#define PROMPT_LEN 60
+
+static int debugger_handle_bkp_cmd(char *buf) {
+	if (buf[0] == 'l') {
+		// list breakpoints
+		char buf[20];
+		for (int i = 0; i < 4; i++) {
+			dbg_puts("breakpoint ");
+			dbg_putc('0' + i);
+			dbg_puts(": ");
+			struct breakpoint bkp = bkps[i];
+			if(!bkp.used) {
+				dbg_puts("unset\n");
+				continue;
+			}
+			dbg_puts(" 0x");
+			ultoa(bkp.addr, buf, 16);
+			dbg_puts(buf);
+			dbg_puts(" len=");
+			switch (bkp.len) {
+				case 0x0: dbg_putc('1'); break;
+				case 0x1: dbg_putc('2'); break;
+				case 0x2: dbg_putc('8'); break;
+				case 0x3: dbg_putc('4'); break;
+			}
+			dbg_puts(" trigger=");
+			switch (bkp.rw) {
+				case 0x0: dbg_puts("x "); break;
+				case 0x1: dbg_puts("w "); break;
+				case 0x2: dbg_puts("io"); break;
+				case 0x3: dbg_puts("rw"); break;
+			}
+			dbg_puts(bkp.enable ? " enabled" : " disabled");
+		}
+		return 1;
+	} else if (buf[0] == 'd') {
+		// disable breakpoints
+		bkps[0].enable = 0;
+		bkps[1].enable = 0;
+		bkps[2].enable = 0;
+		bkps[3].enable = 0;
+		return 1;
+	} else if (buf[0] == 'c') {
+		// clear breakpoints
+		bkps[0].used = 0;
+		bkps[1].used = 0;
+		bkps[2].used = 0;
+		bkps[3].used = 0;
+		return 1;
+	} else if (buf[0] <= '0' && buf[0] >= '3') {
+		dbg_puts("invalid breakpoint command\n");
+		return 1;
+	}
+	// TODO set breakpoints
+	return 1;
+}
+
+static void debugger_load_bkps() {
+	struct dr7 dr7;
+	__asm__ volatile ("mov %%dr7, %0" : "=r"(dr7));
+	dr7.g0 = bkps[0].enable & bkps[0].used;
+	dr7.g1 = bkps[1].enable & bkps[0].used;
+	dr7.g2 = bkps[2].enable & bkps[0].used;
+	dr7.g3 = bkps[3].enable & bkps[0].used;
+	dr7.l0 = 0;
+	dr7.l1 = 0;
+	dr7.l2 = 0;
+	dr7.l3 = 0;
+	dr7.rw0 = bkps[0].rw;
+	dr7.rw1 = bkps[1].rw;
+	dr7.rw2 = bkps[2].rw;
+	dr7.rw3 = bkps[3].rw;
+	dr7.len0 = bkps[0].len;
+	dr7.len1 = bkps[1].len;
+	dr7.len2 = bkps[2].len;
+	dr7.len3 = bkps[3].len;
+	__asm__ volatile ("mov %0, %%dr7" : : "r"(dr7));
+}
+
+static int debugger_prompt(struct isr_regs *state) {
+	char buf[PROMPT_LEN];
+	char *p = buf;
+	dbg_puts("dbg> ");
+	while ((*p = dbg_getc()) != '\r' && p < buf + PROMPT_LEN - 1) {
+		dbg_putc(*p++);
+	}
+	dbg_putc('\n');
+	for(; p < buf + PROMPT_LEN; p++) {
+		*p = 0;
+	}
+
+	struct rflags *rflags = (struct rflags *)&state->rflags;
+
+	switch (buf[0]) {
+	case '\0': // nothing entered
+		return 1;
+	case 'h': // help
+		dbg_puts("see debugger.c for help information\n");
+		return 1;
+	case 'q': // quit
+		return 0;
+	case 'c': // continue
+		rflags->tf = 1;
+		dbg_continue = 1;
+		return 0;
+	case 'r': // print registers
+		debugger_print_regs(state);
+		return 1;
+	case 'k': // backtrace
+		log_backtrace_ex((void *)state->rip, (void *)state->rbp);
+		return 1;
+	case 's': // step (n)
+		rflags->tf = 1;
+		dbg_steps = atol(buf + 1) - 1;
+		if (dbg_steps < 0) dbg_steps = 0;
+		return 0;
+	case 'b': // breakpoints
+		{
+			int res = debugger_handle_bkp_cmd(buf+1);
+			debugger_load_bkps();
+			return res;
+		}
+	default:
+		dbg_puts("unknown command\n");
+		return 1;
+	}
+}
+
+void debugger(struct isr_regs *state, int cause) {
+	struct dr6 dr6;
+	__asm__ volatile ("mov %%dr6, %0" : "=r"(dr6));
+
+	if (dr6.b0 || dr6.b1 || dr6.b2 || dr6.b3) {
+
+	} else {
+		if (dr6.bs && dbg_steps > 0) {
+			dbg_steps--;
+			return;
+		}
+
+		if (dr6.bs && dbg_continue) {
+			return;
+		}
+	}
+
+	debugger_msg(cause, dr6);
+
+	dbg_steps = 0;
+	dbg_continue = 0;
+
+	struct rflags *rflags = (struct rflags *)&state->rflags;
+	rflags->tf = 0;
+
+	while (debugger_prompt(state));
+}

src/arch/amd64/debugger.h

@@ -0,0 +1,9 @@
+#pragma once
+
+#include "idt.h"
+
+#define DEBUG_INT3  0x00
+#define DEBUG_DBG   0x01 
+#define DEBUG_FAULT 0x02
+
+void debugger(struct isr_regs *state, int cause);

src/arch/amd64/fb.c

@@ -9,8 +9,8 @@
 #define INDEX           0x1CE
 #define DATA            0x1CF
 #define FB_ADDR         0xE0000000
-#define FB_MAX		    0xFF000000
-#define FB_LEN			(FB_MAX - FB_ADDR)
+#define FB_MAX          0xFF000000
+#define FB_LEN          (FB_MAX - FB_ADDR)
 
 #define PREFERRED_VY    4096
 #define PREFERRED_B     32

src/arch/amd64/idt.S

@@ -11,9 +11,9 @@ extern idt_pic_eoi
 	push rbx
 	push rcx
 	push rdx
-	push rbp
-	push rdi
 	push rsi
+	push rdi
+	push rbp
 	push r8
 	push r9
 	push r10
@@ -33,9 +33,9 @@ extern idt_pic_eoi
 	pop r10
 	pop r9
 	pop r8
-	pop rsi
-	pop rdi
 	pop rbp
+	pop rdi
+	pop rsi
 	pop rdx
 	pop rcx
 	pop rbx
@@ -51,8 +51,7 @@ isr_stub_%+%1:
 	cld
 	mov rdi, %1                  ; exception number
 	mov rsi, 0                   ; placeholder error code
-	mov rdx, [rsp + 15 * 8]      ; instruction pointer
-	mov rcx, rbp                 ; base pointer for stack trace
+	mov rdx, rsp                 ; top of stack
 	call idt_exception_handler
 	POPALL
 	iretq
@@ -64,15 +63,18 @@ isr_stub_%+%1:
 %macro ISRExceptionCode 1
 align 8
 isr_stub_%+%1:
+	; retrieve the error code without corrupting registers
+	mov [isr_tmp], rax
+	pop rax
+	mov [isr_err_code], rax
+	mov rax, [isr_tmp]
 	PUSHALL
 	cld
 	mov rdi, %1                  ; exception number
-	mov rsi, [rsp + 15 * 8]      ; error code
-	mov rdx, [rsp + 16 * 8]      ; instruction pointer
-	mov rcx, rbp                 ; base pointer for stack trace
+	mov rsi, [isr_err_code]      ; error code
+	mov rdx, rsp                 ; top of stack
 	call idt_exception_handler
 	POPALL
-	sub rsp, 8                   ; discard error code
 	iretq
 %endmacro
 
@@ -188,6 +190,10 @@ PICGeneric  47 ; 15
 	%assign i i+1
 %endrep
 
+section .data
+isr_tmp: dq 0
+isr_err_code: dq 0
+
 ; isr stub table
 section .rodata
 bits 64

src/arch/amd64/idt.c

@@ -1,10 +1,10 @@
 #include <stdint.h>
 #include <stddef.h>
-#include <panic.h>
 #include <lib.h>
 #include <serial.h>
+#include <panic.h>
 
-#include "backtrace.h"
+#include "debugger.h"
 #include "idt.h"
 #include "pic.h"
 
@@ -53,8 +53,8 @@ void idt_init(void) {
 	idtr.size = (uint16_t)sizeof(struct idt_entry) * IDT_SIZE - 1;
 
 	// initialize idt
-	for(size_t vector = 0; vector < IDT_SIZE; vector++) {
-		struct idt_entry* entry = &idt[vector];
+	for (size_t vector = 0; vector < IDT_SIZE; vector++) {
+		struct idt_entry *entry = &idt[vector];
 
 		uint64_t isr = (uint64_t)isr_stub_table[vector];
 		// interrupts before 0x20 are for cpu exceptions
@@ -108,7 +108,16 @@ char *EXCEPTIONS[] = {
 	"0x1F Reserved",
 };
 
-void idt_exception_handler(uint64_t exception, uint64_t code, void *rip, void *rbp) {
+void idt_exception_handler(uint64_t exception, uint64_t code, struct isr_regs *state) {
+	// breakpoint interrupt
+	if (exception == 0x03) {
+		debugger(state, DEBUG_INT3);
+		return;
+	} else if (exception == 0x01) {
+		debugger(state, DEBUG_DBG);
+		return;
+	}
+
 	// TODO don't just panic
 	char buf[24];
 	char msg[256] = "Exception ";
@@ -120,7 +129,7 @@ void idt_exception_handler(uint64_t exception, uint64_t code, void *rip, void *r
 	strcat(msg, buf);
 
 	// page faults store the offending address in cr2
-	if(exception == 0x0E) {
+	if (exception == 0x0E) {
 		strcat(msg, "\nPage fault address: 0x");
 		void *addr;
 		__asm__ volatile ("mov %%cr2, %0" : "=r"(addr));
@@ -128,7 +137,7 @@ void idt_exception_handler(uint64_t exception, uint64_t code, void *rip, void *r
 		strcat(msg, buf);
 	}
 
-	panic_interrupt(rip, rbp, msg);
+	panic_interrupt((void *)state->rip, (void *)state->rbp, msg);
 }
 
 void idt_pic_eoi(uint8_t exception) {

src/arch/amd64/idt.h

@@ -1,3 +1,29 @@
 #pragma once
 
+#include <stdint.h>
+
+struct isr_regs {
+	uint64_t r15;
+	uint64_t r14;
+	uint64_t r13;
+	uint64_t r12;
+	uint64_t r11;
+	uint64_t r10;
+	uint64_t r9;
+	uint64_t r8;
+	uint64_t rbp;
+	uint64_t rdi;
+	uint64_t rsi;
+	uint64_t rdx;
+	uint64_t rcx;
+	uint64_t rbx;
+	uint64_t rax;
+
+	uint64_t rip;
+	uint64_t cs;
+	uint64_t rflags;
+	uint64_t rsp;
+	uint64_t ss;
+};
+
 void idt_init();

src/arch/amd64/mboot.c

@@ -13,81 +13,73 @@
 #define MBOOT_OLD_RSDP     14
 #define MBOOT_NEW_RSDP     15
 
-extern char symtab;
-#define kaddr(addr) ((uintptr_t)(&addr))
-
-typedef uint8_t   mboot_uint8_t;
-typedef uint16_t  mboot_uint16_t;
-typedef uint32_t  mboot_uint32_t;
-typedef uint64_t  mboot_uint64_t;
-
 struct mboot_info {
-	mboot_uint32_t total_size;
-	mboot_uint32_t reserved;
+	uint32_t total_size;
+	uint32_t reserved;
 	char tags[];
 };
 
 struct mboot_tag {
-	mboot_uint32_t type;
-	mboot_uint32_t size;
+	uint32_t type;
+	uint32_t size;
 	char data[];
 };
 
 struct mboot_tag_elf_sections {
-	mboot_uint32_t type;
-	mboot_uint32_t size;
-	mboot_uint16_t num;
-	mboot_uint16_t entsize;
-	mboot_uint16_t shndx;
-	mboot_uint16_t reserved;
+	uint32_t type;
+	uint32_t size;
+	uint16_t num;
+	uint16_t entsize;
+	uint16_t shndx;
+	uint16_t reserved;
 	char sections[];
 };
 
 struct mboot_tag_elf_sections_entry {
-	mboot_uint32_t sh_name;
-	mboot_uint32_t sh_type;
-	mboot_uint64_t sh_flags;
-	mboot_uint64_t sh_addr;
-	mboot_uint64_t sh_offset;
-	mboot_uint64_t sh_size;
-	mboot_uint32_t sh_link;
-	mboot_uint32_t sh_info;
-	mboot_uint64_t sh_addralign;
-	mboot_uint64_t sh_entsize;
+	uint32_t sh_name;
+	uint32_t sh_type;
+	uint64_t sh_flags;
+	uint64_t sh_addr;
+	uint64_t sh_offset;
+	uint64_t sh_size;
+	uint32_t sh_link;
+	uint32_t sh_info;
+	uint64_t sh_addralign;
+	uint64_t sh_entsize;
 };
 
 struct mboot_mmap_entry {
-	mboot_uint64_t addr;
-	mboot_uint64_t len;
-	mboot_uint32_t type;
-	mboot_uint32_t zero;
+	uint64_t addr;
+	uint64_t len;
+	uint32_t type;
+	uint32_t zero;
 };
 
 struct mboot_tag_mmap {
-	mboot_uint32_t type;
-	mboot_uint32_t size;
-	mboot_uint32_t entry_size;
-	mboot_uint32_t entry_version;
+	uint32_t type;
+	uint32_t size;
+	uint32_t entry_size;
+	uint32_t entry_version;
 	struct mboot_mmap_entry entries[];
 };
 
 
 struct mboot_tag_old_rsdp {
-	mboot_uint32_t type;
-	mboot_uint32_t size;
-	mboot_uint8_t rsdp[];
+	uint32_t type;
+	uint32_t size;
+	uint8_t rsdp[];
 };
 
 struct mboot_tag_new_rsdp {
-	mboot_uint32_t type;
-	mboot_uint32_t size;
-	mboot_uint8_t rsdp[];
+	uint32_t type;
+	uint32_t size;
+	uint8_t rsdp[];
 };
 
 struct mboot_tag_cmdline {
-	mboot_uint32_t type;
-	mboot_uint32_t size;
-	mboot_uint8_t cmdline[];
+	uint32_t type;
+	uint32_t size;
+	uint8_t cmdline[];
 };
 
 static void read_symbols(
@@ -100,33 +92,33 @@ static void read_symbols(
 //	struct mboot_elf_section_header *section =
 //		(struct mboot_elf_section_header *) (layout->elf_section_headers);
 //
-//	for (mboot_uint32_t i = 0; i < layout->num; i++) {
+//	for (uint32_t i = 0; i < layout->num; i++) {
 //		char buf[20];
 //
 //		ultoa(i, buf, 10);
 //		serial_out_str("[");
-//        serial_out_str(buf);
-//        serial_out_str("]\t");
+//		serial_out_str(buf);
+//		serial_out_str("]\t");
 //
 //		serial_out_str((char *)(kaddr(symtab) + section->sh_name));
 //		serial_out('\t');
 //
 //		ultoa(section->sh_type, buf, 16);
 //		serial_out_str("type: 0x");
-//        serial_out_str(buf);
-//        serial_out('\t');
+//		serial_out_str(buf);
+//		serial_out('\t');
 //
-//        ultoa(section->sh_addr, buf, 16);
-//        serial_out_str("addr: 0x");
-//        serial_out_str(buf);
-//        serial_out('\t');
+//		ultoa(section->sh_addr, buf, 16);
+//		serial_out_str("addr: 0x");
+//		serial_out_str(buf);
+//		serial_out('\t');
 //
-//        ultoa(section->sh_offset, buf, 16);
-//        serial_out_str("offset: 0x");
-//        serial_out_str(buf);
-//        serial_out('\n');
+//		ultoa(section->sh_offset, buf, 16);
+//		serial_out_str("offset: 0x");
+//		serial_out_str(buf);
+//		serial_out('\n');
 //
-//        section++;
+//		section++;
 //	}
 }
 
@@ -134,7 +126,7 @@ static void read_cmdline(
 		struct boot_info *shim_info,
 		struct mboot_tag_cmdline *cmdline
 ) {
-	mboot_uint32_t size = cmdline->size - 8;
+	uint32_t size = cmdline->size - 8;
 	if (size >= CMDLINE_MAX)
 		size = CMDLINE_MAX; // truncate :(
 	memcpy(shim_info->cmdline, cmdline->cmdline, size);

src/arch/amd64/paging.c

@@ -68,25 +68,18 @@ static struct pdpte *pdpt_mapped = (void *) (uintptr_t) 0x201000;
 static struct pde   *pd_mapped   = (void *) (uintptr_t) 0x202000;
 static struct pte   *pt_mapped   = (void *) (uintptr_t) 0x203000;
 
-static inline void
-invlpg(void *addr)
-{
+static inline void invlpg(void *addr) {
 	__asm volatile("invlpg (%0)" ::"r" (addr) : "memory");
 }
 
-static void
-load_addr(void *phys_addr)
-{
+static void load_addr(void *phys_addr) {
 	static struct pte *pt = &paging_pt[4];
 	pt->address = (uint64_t)phys_addr >> 12;
 	pt->flags = F_PRESENT | F_WRITEABLE;
 	invlpg(addr_mapped);
 }
 
-static void
-load_pml4(
-		void *phys
-) {
+static void load_pml4(void *phys) {
 	static struct pte *pt = &paging_pt[0];
 	if ((uint64_t)phys >> 12 == pt->address)
 		return;
@@ -95,10 +88,7 @@ load_pml4(
 	invlpg(pml4_mapped);
 }
 
-static void
-load_pdpt(
-		void *phys
-) {
+static void load_pdpt(void *phys) {
 	static struct pte *pt = &paging_pt[1];
 	if ((uint64_t)phys >> 12 == pt->address)
 		return;
@@ -107,10 +97,7 @@ load_pdpt(
 	invlpg(pdpt_mapped);
 }
 
-static void
-load_pd(
-		void *phys
-) {
+static void load_pd(void *phys) {
 	static struct pte *pt = &paging_pt[2];
 	if ((uint64_t)phys >> 12 == pt->address)
 		return;
@@ -119,10 +106,7 @@ load_pd(
 	invlpg(pdpt_mapped);
 }
 
-static void
-load_pt(
-		void *phys
-) {
+static void load_pt(void *phys) {
 	static struct pte *pt = &paging_pt[3];
 	if ((uint64_t)phys >> 12 == pt->address)
 		return;
@@ -135,8 +119,7 @@ load_pt(
 #define PAG_CANNOT_ALLOC 1
 #define PAG_NOT_PRESENT  2
 
-static int
-select_pdpt(
+static int select_pdpt(
 		void *virt,
 		unsigned int flags,
 		struct pml4e *root,
@@ -165,8 +148,7 @@ select_pdpt(
 	return PAG_SUCCESS;
 }
 
-static int
-select_pd(
+static int select_pd(
 		void *virt,
 		unsigned int flags,
 		struct pdpte *pdpt,
@@ -195,8 +177,7 @@ select_pd(
 	return PAG_SUCCESS;
 }
 
-static int
-select_pt(
+static int select_pt(
 		void *virt,
 		unsigned int flags,
 		struct pde *pd,
@@ -225,8 +206,7 @@ select_pt(
 	return PAG_SUCCESS;
 }
 
-static void
-select_page(
+static void select_page(
 		void *virt,
 		struct pte *pt,
 		struct pte **res
@@ -238,8 +218,7 @@ select_page(
 	return;
 }
 
-static inline void
-try_unmap_pml4(void) {
+static inline void try_unmap_pml4(void) {
 	for (int i = 0; i < 512; i++) {
 		if (pml4_mapped[i].flags & F_PRESENT)
 			return;
@@ -252,8 +231,7 @@ try_unmap_pml4(void) {
 	}
 }
 
-static inline void
-try_unmap_pdpt(void) {
+static inline void try_unmap_pdpt(void) {
 	for (int i = 0; i < 512; i++) {
 		if (pdpt_mapped[i].flags & F_PRESENT)
 			return;
@@ -267,8 +245,7 @@ try_unmap_pdpt(void) {
 	try_unmap_pml4();
 }
 
-static inline void
-try_unmap_pd(void) {
+static inline void try_unmap_pd(void) {
 	for (int i = 0; i < 512; i++) {
 		if (pd_mapped[i].flags & F_PRESENT)
 			return;
@@ -282,8 +259,7 @@ try_unmap_pd(void) {
 	try_unmap_pdpt();
 }
 
-static inline void
-try_unmap_pt(void) {
+static inline void try_unmap_pt(void) {
 	for (int i = 0; i < 512; i++) {
 		if (pt_mapped[i].flags & F_PRESENT)
 			return;
@@ -297,12 +273,10 @@ try_unmap_pt(void) {
 	try_unmap_pd();
 }
 
-static void
-unmap_page(
+static void unmap_page(
 		struct pml4e *root,
 		void *virt
 ) {
-
 	struct pdpte *pdpt;
 	struct pde   *pd;
 	struct pte   *pt;
@@ -331,13 +305,11 @@ unmap_page(
 	return;
 }
 
-static void
-unmap_pages(
+static void unmap_pages(
 		struct pml4e *root,
 		void *virt_start,
 		long page_count
 ) {
-
 	uint64_t pml4_o = -1,
 			 pdpt_o = -1,
 			 pd_o   = -1;
@@ -397,14 +369,12 @@ unmap_pages(
 	return;
 }
 
-static int
-map_page(
+static int map_page(
 		struct pml4e *root,
 		void *virt,
 		void *phys,
 		unsigned int flags
 ) {
-
 	struct pdpte *pdpt;
 	struct pde   *pd;
 	struct pte   *pt;
@@ -430,15 +400,13 @@ map_page(
 	return 0;
 }
 
-static int
-map_pages(
+static int map_pages(
 		struct pml4e *root,
 		void *virt_start,
 		void *phys_start,
 		unsigned int flags,
 		long page_count
 ) {
-
 	uint64_t pml4_o = -1,
 			 pdpt_o = -1,
 			 pd_o   = -1;
@@ -502,7 +470,6 @@ failed:
 }
 
 void paging_init(void) {
-
 	kernel_pml4[0].flags = F_PRESENT | F_WRITEABLE;
 	kernel_pml4[0].address = (uint64_t)(&kernel_pdpt_0) >> 12;
 

src/arch/amd64/paging.h

@@ -4,7 +4,7 @@
 #define F_WRITEABLE    0x002
 #define F_UNPRIVILEGED 0x004
 #define F_WRITETHROUGH 0x008
-#define F_CACHEDISABLE 0x010 
+#define F_CACHEDISABLE 0x010
 #define F_ACCESSED     0x020
 #define F_DIRTY        0x040
 #define F_MEGABYTE     0x080

src/arch/amd64/pic.c

@@ -53,7 +53,7 @@ void pic_remap(void) {
 void pic_mask(int irq) {
 	uint16_t port;
 	uint8_t mask;
-	if(irq < 8) {
+	if (irq < 8) {
 		port = PIC1_DATA;
 	} else {
 		port = PIC2_DATA;
@@ -66,7 +66,7 @@ void pic_mask(int irq) {
 void pic_unmask(int irq) {
 	uint16_t port;
 	uint8_t mask;
-	if(irq < 8) {
+	if (irq < 8) {
 		port = PIC1_DATA;
 	} else {
 		irq -= 8;
@@ -82,7 +82,7 @@ void pic_disable(void) {
 }
 
 void pic_eoi(int irq) {
-	if(irq >= 8) {
+	if (irq >= 8) {
 		outb(PIC2_COMMAND, PIC_EOI);
 	}
 	outb(PIC1_COMMAND, PIC_EOI);

src/arch/amd64/serial.c

@@ -18,7 +18,7 @@ int serial_init(void) {
 	outb(PORT + 0, 0xAE); // test by sending 0xAE
 
 	uint8_t response = inb(PORT + 0);
-	if(response != 0xAE) {
+	if (response != 0xAE) {
 		// TODO panic here?
 		return -1;
 	}
@@ -30,18 +30,18 @@ int serial_init(void) {
 
 uint8_t serial_in(void) {
 	// wait for data to be available
-	while((inb(PORT + 5) & 0x01) == 0);
+	while ((inb(PORT + 5) & 0x01) == 0);
 	return inb(PORT);
 }
 
 void serial_out(uint8_t ch) {
 	// wait for output to be free
-	while((inb(PORT + 5) & 0x20) == 0);
+	while ((inb(PORT + 5) & 0x20) == 0);
 	outb(PORT, ch);
 }
 
 void serial_out_str(const char *str) {
-	for(; *str != '\0'; str++) {
+	for (; *str != '\0'; str++) {
 		serial_out(*str);
 	}
 }

src/arch/amd64/shim.c

@@ -11,7 +11,7 @@
 
 static struct boot_info boot_info;
 
-void* amd64_shim(long mboot_magic, void *mboot_data_ptr) {
+void *amd64_shim(long mboot_magic, void *mboot_data_ptr) {
 	serial_init();
 	paging_init();
 	pic_remap();

src/kmain.c

@@ -4,6 +4,7 @@
 #include <serial.h>
 #include <fb.h>
 #include <shim.h>
+#include <panic.h>
 
 void kmain(struct boot_info *info) {
 	memory_init(&info->map);
@@ -12,8 +13,8 @@ void kmain(struct boot_info *info) {
 
 	kprintf("enterd kmain\n");
 
-	*(char*)(0xB8000 + 0x144) = 'h';
-	*(char*)(0xB8000 + 0x146) = 'i';
+	*(char *)(0xB8000 + 0x144) = 'h';
+	*(char *)(0xB8000 + 0x146) = 'i';
 
 	while (1) {
 		//kprintf("ret: 0x%p\n", kalloc(1024));

src/lib.c

@@ -45,19 +45,21 @@ int strncmp(const char *restrict lhs, const char *restrict rhs, unsigned long n)
 }
 
 char *strcpy(char *restrict dest, const char *restrict src) {
-	for(; (*dest = *src); dest++, src++);
+	char *d = dest;
+	for (; (*d = *src); d++, src++);
 	return dest;
 }
 
 char *strncpy(char *restrict dest, const char *restrict src, unsigned long n) {
-	for(; (*dest = *src) && n; dest++, src++, n--);
-	memset(dest, 0, n);
+	char *d = dest;
+	for (; (*d = *src) && n; d++, src++, n--);
+	memset(d, 0, n);
 	return dest;
 }
 
 size_t strlen(const char *str) {
 	const char *p;
-	for(p = str; *p != 0; p++) {}
+	for (p = str; *p != 0; p++) {}
 	return p - str;
 }
 
@@ -86,8 +88,8 @@ int isdigit(int c) {
 
 
 #define ATOX(name, type) \
-	type name(const char* s) { \
-		for(; isspace(*s); s++); \
+	type name(const char *s) { \
+		for (; isspace(*s); s++); \
 		int neg = 0; \
 		switch (*s) { \
 			case '-': \
@@ -111,7 +113,7 @@ ATOX(atol, long int)
 ATOX(atoll, long long int)
 
 char itoc(int i) {
-	if(i < 10) {
+	if (i < 10) {
 		return '0' + i;
 	} else {
 		return 'a' + (i - 10);
@@ -119,9 +121,9 @@ char itoc(int i) {
 }
 
 int ctoi(char c) {
-	if(c < 'A') {
+	if (c < 'A') {
 		return c - '0';
-	} else if(c < 'a') {
+	} else if (c < 'a') {
 		return c - 'A' + 10;
 	} else {
 		return c - 'a' + 10;
@@ -210,19 +212,20 @@ end:
 		if (n == 0) { \
 			buffer[0] = '0'; \
 			buffer[1] = '\0'; \
-			return buffer; \
+			return buffer + 1; \
 		} \
 		char *start = buffer; \
 		for (; n; n /= radix) { \
 			*buffer++ = itoc(n % radix); \
 		} \
+		char *buf_end = buffer; \
 		*buffer-- = '\0'; \
-		while(buffer > start) { \
+		while (buffer > start) { \
 			char tmp = *start; \
 			*start++ = *buffer; \
 			*buffer-- = tmp; \
 		} \
-		return buffer; \
+		return buf_end; \
 	}
 
 UXTOA(int, utoa)
@@ -230,11 +233,11 @@ UXTOA(long int, ultoa)
 UXTOA(long long int, ulltoa)
 
 #define XTOA(type, name) \
-	char *name(type n, char* buffer, int radix) { \
+	char *name(type n, char *buffer, int radix) { \
 		if (n == 0) { \
 			buffer[0] = '0'; \
 			buffer[1] = '\0'; \
-			return buffer; \
+			return buffer + 1; \
 		} \
 		if (n < 0) { \
 			*buffer++ = '-'; \
@@ -244,13 +247,14 @@ UXTOA(long long int, ulltoa)
 		for (; n; n /= radix) { \
 			*buffer++ = itoc(n % radix); \
 		} \
+		char *buf_end = buffer; \
 		*buffer-- = '\0'; \
-		while(buffer > start) { \
+		while (buffer > start) { \
 			char tmp = *start; \
 			*start++ = *buffer; \
 			*buffer-- = tmp; \
 		} \
-		return buffer; \
+		return buf_end; \
 	}
 
 XTOA(int, itoa)
@@ -260,7 +264,7 @@ XTOA(long long int, lltoa)
 #define STRTOX(name, type) \
 	type name(const char *s, char **endptr, int radix) { \
 		*endptr = NULL; \
-		for(; isspace(*s); s++); \
+		for (; isspace(*s); s++); \
 		int neg = 0; \
 		switch (*s) { \
 			case '-': \
@@ -283,9 +287,9 @@ XTOA(long long int, lltoa)
 				radix = 10; \
 			} \
 		} \
-		for (; *s == '0'; s++, *endptr = (void*) s); \
+		for (; *s == '0'; s++, *endptr = (void *) s); \
 		type num = 0; \
-		for (; isdigit(*s); s++, *endptr = (void*) s) { \
+		for (; isdigit(*s); s++, *endptr = (void *) s) { \
 			num *= radix; \
 			num += *s - '0'; \
 		} \

src/memory/memory.c

@@ -19,7 +19,7 @@ static const size_t header_len = sizeof(struct page_header);
 static struct page_header *start_header = NULL;
 static struct page_header *end_header = NULL;
 
-struct page_header* get_header(void *ptr) {
+struct page_header *get_header(void *ptr) {
 	struct page_header *header =
 		(struct page_header *) ((uintptr_t) ptr - header_len);
 

src/memory/physalloc.c

@@ -170,7 +170,7 @@ void memory_init(struct memory_map *map) {
 
 	segment_count = 0;
 
-	for(uint32_t i = 0; i < map->entry_count; i++) {
+	for (uint32_t i = 0; i < map->entry_count; i++) {
 		struct memory_segment *segment = &map->entries[i];
 
 		if (segment_invalid(segment))
@@ -201,7 +201,7 @@ void memory_init(struct memory_map *map) {
 	struct memory_area *area = page_start;
 
 	kprintf("MEMORY MAP\n");
-	for(uint32_t i = 0; i < map->entry_count; i++) {
+	for (uint32_t i = 0; i < map->entry_count; i++) {
 		struct memory_segment *segment = &map->entries[i];
 
 		if (segment_invalid(segment))

src/memory/virtalloc.c

@@ -118,7 +118,7 @@ void *virtaddr_alloc(int n_pages) {
 }
 
 static void merge_back(struct addr_node *node) {
-	while(node->prev && !node->is_alloc) {
+	while (node->prev && !node->is_alloc) {
 		struct addr_node *temp = node->prev;
 		node->start = node->prev->start;
 		node->prev = node->prev->prev;
@@ -130,7 +130,7 @@ static void merge_back(struct addr_node *node) {
 }
 
 static void merge_forward(struct addr_node *node) {
-	while(node->next && !node->is_alloc) {
+	while (node->next && !node->is_alloc) {
 		struct addr_node *temp = node->next;
 		node->end = node->next->end;
 		node->next = node->next->next;