refactor, improve exception message

6 files changed, 130 insertions, 85 deletions

diff --git a/include/lib.h b/include/lib.h
index 43b95a6..1b6d1f4 100644
--- a/include/lib.h
+++ b/include/lib.h
@@ -1,92 +1,111 @@
 #pragma once
 
+#include <stddef.h>
+
 /**
  * The  memcmp() function compares the first n bytes (each interpreted as unsigned char) of the memory
  * areas s1 and s2.
  */
-extern int memcmp(const void *restrict s1, const void *restrict s2, unsigned long n);
+int memcmp(const void *restrict s1, const void *restrict s2, unsigned long n);
 
 /**
  * The  memcpy()  function  copies n bytes from memory area src to memory area dest.
  * The memory areas must not overlap.
  */
-extern void *memcpy(void *restrict dest, const void *restrict src, unsigned long n);
+void *memcpy(void *restrict dest, const void *restrict src, unsigned long n);
 
 /**
  * The  memmove()  function copies n bytes from memory area src to memory area dest.  The memory areas
  * may overlap: copying takes place as though the bytes in src are first copied into a temporary array
  * that does not overlap src or dest, and the bytes are then copied from the temporary array to dest.
  */
-extern void *memmove(void *dest, const void *src, unsigned long n);
+void *memmove(void *dest, const void *src, unsigned long n);
 
 /**
  * The  memset() function fills the first n bytes of the memory area pointed to by s with the constant
  * byte c.
  */
-extern void *memset(void *restrict dest, int c, unsigned long n);
+void *memset(void *restrict dest, int c, unsigned long n);
 
 /**
  * The  strcmp()  function  compares  the two strings s1 and s2.  The locale is not taken into account
  * (for a locale-aware comparison, see strcoll(3)).  The comparison is done using unsigned characters.
  */
-extern int strncmp(const char *restrict s1, const char *restrict s2, unsigned long n);
+int strncmp(const char *restrict s1, const char *restrict s2, unsigned long n);
 
 /**
  * Copys the string pointed to by src , into a string at the buffer pointer to by dest.
  * The dest buffer must be long enough to hold src.
  */
-extern char *strcpy(char *restrict dest, const char *restrict src);
+char *strcpy(char *restrict dest, const char *restrict src);
 
 /**
  * Copys the string pointed to by src , into a string at the buffer pointer to by dest.
  * The dest buffer must be long enough to hold src or size n.
  */
-extern char *strncpy(char *restrict dest, const char *restrict src, unsigned long n);
+char *strncpy(char *restrict dest, const char *restrict src, unsigned long n);
+
+/**
+ * Calculates the length of the string pointed to by str, excluding
+ * the terminating null byte
+ * @param str - the string pointer
+ * @returns the length of the string in bytes
+ */
+size_t strlen(const char *str);
+
+/**
+ * Concatenate the string pointed to by src after the string pointed
+ * to by dst.
+ * @param dst - the pointer to the destination string
+ * @param src - the pointer to the source string
+ * @returns dst
+ */
+char *strcat(char *restrict dst, const char *restrict src);
 
 /**
  * @returns 1 if c is a space
  */
-extern int isspace(int c);
+int isspace(int c);
 
 /**
  * @returns 1 if c is a digit (0 - 9)
  */
-extern int isdigit(int c);
+int isdigit(int c);
 
 /**
  * converts single digit int to base 36
  * @param i - int
  * @returns c - base 36 char
  */
-extern char itoc(int i);
+char itoc(int i);
 
 /**
  * converts single base 36 chat into int
  * @param c - base 36 char
  * @returns i - int
  */
-extern int ctoi(char c);
+int ctoi(char c);
 
 /**
  * Converts the initial portiion of the string pointed to by s to int.
  * @param s - the string to convert
  * @returns the number inside s or 0 on error
  */
-extern 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
  */
-extern 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
  */
-extern 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).
@@ -94,7 +113,7 @@ extern long long int atoll(const char* s);
  * @param buffer - the string buffer
  * @param radix - the base to convert
  */
-extern char *itoa(int n, char *buffer, int radix);
+char *itoa(int n, char *buffer, int radix);
 
 /**
  * Converts a long to asci inside a string with a given radix (base).
@@ -102,7 +121,7 @@ extern char *itoa(int n, char *buffer, int radix);
  * @param buffer - the string buffer
  * @param radix - the base to convert
  */
-extern char *ltoa(long int n, char *buffer, int radix);
+char *ltoa(long int n, char *buffer, int radix);
 
 /**
  * Converts a unsigned integer to asci inside a string with a given radix (base).
@@ -110,7 +129,7 @@ extern char *ltoa(long int n, char *buffer, int radix);
  * @param buffer - the string buffer
  * @param radix - the base to convert
  */
-extern char *utoa(unsigned int n, char *buffer, int radix);
+char *utoa(unsigned int n, char *buffer, int radix);
 
 /**
  * Converts a unsigned long to asci inside a string with a given radix (base).
@@ -118,7 +137,7 @@ extern char *utoa(unsigned int n, char *buffer, int radix);
  * @param buffer - the string buffer
  * @param radix - the base to convert
  */
-extern char *ultoa(unsigned long int n, char *buffer, int radix);
+char *ultoa(unsigned long int n, char *buffer, int radix);
 
 /**
  * Converts the string in str to an int value based on the given base.
@@ -128,7 +147,7 @@ extern char *ultoa(unsigned long int n, char *buffer, int radix);
  * @param base - the base to convert to
  * @returns 0 on error or success, error if endptr is still equal to str
  */
-extern int strtoi(const char *str, char **endptr, int base);
+int strtoi(const char *str, char **endptr, int base);
 
 /**
  * Converts the string in str to an long value based on the given base.
@@ -138,7 +157,7 @@ extern int strtoi(const char *str, char **endptr, int base);
  * @param base - the base to convert to
  * @returns 0 on error or success, error if endptr is still equal to str
  */
-extern long int strtol(const char *str, char **endptr, int base);
+long int strtol(const char *str, char **endptr, int base);
 
 /**
  * Converts the string in str to an long long value based on the given base.
@@ -148,4 +167,4 @@ extern long int strtol(const char *str, char **endptr, int base);
  * @param base - the base to convert to
  * @returns 0 on error or success, error if endptr is still equal to str
  */
-extern long long int strtoll(const char *str, char **endptr, int base);
+long long int strtoll(const char *str, char **endptr, int base);
diff --git a/src/arch/amd64/idt.S b/src/arch/amd64/idt.S
index 1098057..32670c8 100644
--- a/src/arch/amd64/idt.S
+++ b/src/arch/amd64/idt.S
@@ -7,11 +7,13 @@ extern idt_pic_mouse
 extern idt_pic_eoi
 
 %macro PUSHALL 0
+    push rax
     push rbx
     push rcx
     push rdx
-    push rsi
+    push rbp
     push rdi
+    push rsi
     push r8
     push r9
     push r10
@@ -31,11 +33,13 @@ extern idt_pic_eoi
     pop r10
     pop r9
     pop r8
-    pop rdi
     pop rsi
+    pop rdi
+    pop rbp
     pop rdx
     pop rcx
     pop rbx
+    pop rax
 %endmacro
 
 ; call the exception handler with the interrupt number
diff --git a/src/arch/amd64/idt.c b/src/arch/amd64/idt.c
index 5c6261c..83b792c 100644
--- a/src/arch/amd64/idt.c
+++ b/src/arch/amd64/idt.c
@@ -73,68 +73,81 @@ void idt_init(void) {
 
 // Intel manual vol 3 ch 6.3.1
 char *EXCEPTIONS[] = {
-	"Exception 0x00 Divide Error",
-	"Exception 0x01 Debug Exception",
-	"Exception 0x02 NMI Interrupt",
-	"Exception 0x03 Breakpoint",
-	"Exception 0x04 Overflow",
-	"Exception 0x05 BOUND Range Exceeded",
-	"Exception 0x06 Invalid Opcode",
-	"Exception 0x07 Device Not Available",
-	"Exception 0x08 Double Fault",
-	"Exception 0x09 Coprocessor Segment Overrun",
-	"Exception 0x0A Invalid TSS",
-	"Exception 0x0B Segment Not Present",
-	"Exception 0x0C Stack-Segment Fault",
-	"Exception 0x0D General Protection",
-	"Exception 0x0E Page Fault",
-	"Exception 0x0F Reserved",
-	"Exception 0x10 x87 FPU Floating-Point Error",
-	"Exception 0x11 Alignment Check",
-	"Exception 0x12 Machine Check",
-	"Exception 0x13 SIMD Floaing-Point Exception",
-	"Exception 0x14 Virtualization Exception",
-	"Exception 0x15 Control Protection Exception",
-	"Exception 0x16 Reserved",
-	"Exception 0x17 Reserved",
-	"Exception 0x18 Reserved",
-	"Exception 0x19 Reserved",
-	"Exception 0x1A Reserved",
-	"Exception 0x1B Reserved",
-	"Exception 0x1C Reserved",
-	"Exception 0x1D Reserved",
-	"Exception 0x1E Reserved",
-	"Exception 0x1F Reserved",
+	"0x00 Division Error",
+	"0x01 Debug",
+	"0x02 NMI",
+	"0x03 Breakpoint",
+	"0x04 Overflow",
+	"0x05 BOUND Range Exceeded",
+	"0x06 Invalid Opcode",
+	"0x07 Device Not Available",
+	"0x08 Double Fault",
+	"0x09 Coprocessor Segment Overrun",
+	"0x0A Invalid TSS",
+	"0x0B Segment Not Present",
+	"0x0C Stack-Segment Fault",
+	"0x0D General Protection Fault",
+	"0x0E Page Fault",
+	"0x0F Reserved",
+	"0x10 x87 Floating-Point Error",
+	"0x11 Alignment Check",
+	"0x12 Machine Check",
+	"0x13 SIMD Floaing-Point Exception",
+	"0x14 Virtualization Exception",
+	"0x15 Control Protection Exception",
+	"0x16 Reserved",
+	"0x17 Reserved",
+	"0x18 Reserved",
+	"0x19 Reserved",
+	"0x1A Reserved",
+	"0x1B Reserved",
+	"0x1C Hypervisor Injection Exception",
+	"0x1D VMM Communication Exception",
+	"0x1E Security Exception",
+	"0x1F Reserved",
 };
 
+void idt_exception_handler(uint64_t exception, uint64_t code) {
+	// TODO don't just panic
+	char buf[24];
+	char msg[256] = "Exception ";
+
+	strcat(msg, EXCEPTIONS[exception]);
+
+	strcat(msg, "\nError code 0x");
+	ultoa(code, buf, 16);
+	strcat(msg, buf);
+
+	// page faults store the offending address in cr2
+	if(exception == 0x0E) {
+		strcat(msg, "\nPage fault address: 0x");
+		void *addr;
+		__asm__ volatile ("mov %%cr2, %0" : "=r"(addr));
+		ultoa((size_t)addr, buf, 16);
+		strcat(msg, buf);
+	}
+
+	panic(msg);
+}
+
 void idt_pic_eoi(uint8_t exception) {
 	pic_eoi(exception - PIC_REMAP_OFFSET);
 }
 
-static size_t timer = 0;
+int counter = 0;
 
 void idt_pic_timer(void) {
-	timer += 1;
-	char buf[20];
-	ltoa(timer, buf, 10);
-	serial_out_str(buf);
-	serial_out_str("\n");
-}
-
-void idt_pic_keyboard(void) {
-	serial_out_str("ps2 kbd");
+	// print a message once we know the timer works
+	// but avoid spamming the logs
+	if (counter == 3) {
+		serial_out_str("pic timer!\n");
+	}
+	if (counter <= 3) {
+		counter++;
+	}
 }
 
-void idt_pic_mouse(void) {
-	serial_out_str("ps2 mouse");
-}
+void idt_pic_keyboard(void) {}
 
-void idt_exception_handler(uint64_t exception, uint64_t code) {
-	// TODO don't just panic
-	char buf[80];
-	char *end = strcpy(buf, EXCEPTIONS[exception]);
-	end = strcpy(end, "\nError code 0x");
-	ltoa(code, end, 16);
-	panic(buf);
-}
+void idt_pic_mouse(void) {}
 
diff --git a/src/arch/amd64/panic.c b/src/arch/amd64/panic.c
index 227ecce..c034b90 100644
--- a/src/arch/amd64/panic.c
+++ b/src/arch/amd64/panic.c
@@ -6,11 +6,12 @@
 _Noreturn void _panic_impl(char *line, char *file, char *msg) {
 	cli();
 	serial_out_str("\n\n!!! PANIC !!!\n");
-	serial_out_str(msg);
-	serial_out_str("\nin file ");
+	serial_out_str("In file ");
 	serial_out_str(file);
 	serial_out_str(" at line ");
 	serial_out_str(line);
+	serial_out_str(":\n");
+	serial_out_str(msg);
 	serial_out('\n');
 	while (1) {
 		halt();
diff --git a/src/kmain.c b/src/kmain.c
index 701c135..d5bee56 100644
--- a/src/kmain.c
+++ b/src/kmain.c
@@ -5,14 +5,11 @@
 #include <shim.h>
 
 void kmain(struct boot_info *info) {
-	char buf[20];
-	*(char*)0xB8000 = 'c';
 	memory_init(info->map);
-	//*(char*)(0xB8002 + 0x20'0000) = 'd';
-	itoa((long)info, buf, 16);
-	itoa(*(long*)info, buf, 16);
-	//fb_init(1024, 768);	
-	serial_out_str(buf);
+	serial_out_str("entered kmain\n");
+	*(char*)(0xB8000 + 0x144) = 'h';
+	*(char*)(0xB8000 + 0x146) = 'i';
+	//fb_init(1024, 768);
 	while (1) {
 		// loop so we dont halt
 		// this allows interrupts to fire
diff --git a/src/lib.c b/src/lib.c
index 1f57f83..d01252d 100644
--- a/src/lib.c
+++ b/src/lib.c
@@ -54,6 +54,17 @@ char *strncpy(char *restrict dest, const char *restrict src, unsigned long n) {
 	return dest;
 }
 
+size_t strlen(const char *str) {
+    const char *p;
+    for(p = str; *p != 0; p++) {}
+    return p - str;
+}
+
+char *strcat(char *restrict dst, const char *restrict src) {
+    strcpy(dst + strlen(dst), src);
+    return dst;
+}
+
 int isspace(int c) {
     switch (c) {
         case ' ':