implements integer printing into printf, and adds some testing logs

Makefile

@@ -2,7 +2,7 @@
 # or maybe add it to a bash script instead? im not sure
 
 CC = i686-elf-gcc
-CFLAGS = -m32 -ffreestanding -Wall -Wextra -Werror -Wpedantic --sysroot=$(PWD)/sysroot -isystem=/usr/include -Iinclude -MD
+CFLAGS = -m32 -ffreestanding -Wall -Wextra -Werror -Wpedantic --sysroot=$(PWD)/sysroot -isystem=/usr/include -Iinclude -MD -D__TESTING__
 
 AS = nasm
 ASFLAGS = -f elf

kernel/arch/gdt/gdt_entry.c

@@ -16,4 +16,3 @@ uint64_t create_descriptor(uint32_t base, uint32_t limit, uint16_t flag)
 
 	return descriptor;
 }
-

kernel/arch/idt/idt.c

@@ -1,5 +1,8 @@
 #include <stdbool.h>
 
+#ifdef __TESTING__
+#include <kernel/_kernel.h>
+#endif
 #include <kernel/x86/idt.h>
 
 __attribute__((aligned(0x10)))
@@ -29,6 +32,9 @@ void idt_set_descriptor(uint8_t vector, void *isr, uint8_t flags)
 extern void* isr_stub_table[];
 void idt_init(void)
 {
+#ifdef __TESTING__
+	kinfo("Initializing the IDT");	
+#endif
 	idtr.base = (uintptr_t)&idt[0];
 	idtr.limit = (uint16_t) sizeof(idt_entry_t) * IDT_MAX_DESCRIPTORS - 1;
 
@@ -40,5 +46,8 @@ void idt_init(void)
 	// The "m" indicates actual data, not a pointer
 	__asm__ volatile("lidt %0" : : "m"(idtr)); // load the new IDT
 	__asm__ volatile("sti"); // set the interrupt flag
+#ifdef __TESTING__
+	kinfo("Initialized the IDT");	
+#endif			 
 }
 

kernel/arch/pic/pic.c

@@ -1,3 +1,6 @@
+#ifdef __TESTING__
+#include <kernel/_kernel.h>
+#endif
 #include <kernel/x86/io.h>
 #include <kernel/x86/pic.h>
 
@@ -10,6 +13,9 @@ void PIC_sendEOI(uint8_t irq)
 
 void PIC_remap(int offset1, int offset2)
 {
+#ifdef __TESTING__
+	kinfo("Remapping the PIC...");
+#endif
 	// The io_wait calls are necessary for older machines, to give the PIC time to react
 	//
 	// After the init, the PIC requires 3 init words
@@ -38,12 +44,19 @@ void PIC_remap(int offset1, int offset2)
 	// Unmask the PICs
 	outb(PIC1_DATA, 0);
 	outb(PIC2_DATA, 0);
+
+#ifdef __TESTING__
+	kinfo("Remapped the PIC!");
+#endif
 }
 
 void pic_disable(void)
 { // Mask the PIC interrupts to disable them
 	outb(PIC1_DATA, 0xFF);
 	outb(PIC2_DATA, 0xFF);
+#ifdef __TESTING__
+	kinfo("Disabled the PIC");
+#endif
 }
 
 void IRQ_set_mask(uint8_t IRQline) // Masked IRQlines are ignored by the PIC, masked IRQ2 will fully ignore the slave

kernel/include/kernel/x86/gdt.h

@@ -47,13 +47,15 @@
                      SEG_PRIV(3)     | SEG_DATA_RDWR
 
 
+#define GDT_SIZE 5
+
 
 void setGdt(unsigned short limit, uint64_t* base);
 
 void reloadSegments();
 
 uint64_t create_descriptor(uint32_t base, uint32_t limit, uint16_t flag);
-
+void gdt_init(void);
 
 #endif
 

kernel/klog.c

@@ -2,6 +2,7 @@
 
 #include <kernel/_kernel.h>
 #include <kernel/serial.h>
+#include <kernel/tty.h>
 
 enum log_mode {
 	LOG_ERR,
@@ -14,16 +15,22 @@ void klog(const char* buf, enum log_mode mode)
 	switch(mode) {
 		case LOG_ERR:
 			serial_writestring("ERROR: ");
+			terminal_writestring("ERROR: ");
 			break;
 		case LOG_WARN:
 			serial_writestring("WARNING: ");
+			terminal_writestring("WARNING: ");
 			break;
 		case LOG_INFO:
 			serial_writestring("INFO: ");
+			terminal_writestring("INFO: ");
 			break;
 	}
 	serial_writestring(buf);
+	terminal_writestring(buf);
+
 	serial_writestring("\n");
+	terminal_writestring("\n");
 }
 
 void kerror(const char* buf)

kernel/kmain.c

@@ -1,19 +1,20 @@
 #include <stdio.h>
 #include <stdint.h>
 
+#include <kernel/_kernel.h>
 #include <kernel/tty.h>
 #include <kernel/serial.h>
 #include <kernel/x86/gdt.h>
 #include <kernel/x86/idt.h>
 #include <kernel/x86/pic.h>
 
-#define GDT_SIZE 5
-
 uint64_t gdt[GDT_SIZE];
 
-
-void gdt_init(void)
+void gdt_init()
 { 
+#ifdef __TESTING__
+	kinfo("Initializing the GDT");
+#endif
 	gdt[0] = create_descriptor(0, 0, 0); // null
 	gdt[1] = create_descriptor(0, 0x000FFFFF, (GDT_CODE_PL0)); // kernel code
 	gdt[2] = create_descriptor(0, 0x000FFFFF, (GDT_DATA_PL0)); // kernel data
@@ -22,25 +23,29 @@ void gdt_init(void)
 
 	setGdt((sizeof(uint64_t) * GDT_SIZE) - 1, &(gdt[0])); // limit, base
 	reloadSegments();
+#ifdef __TESTING__
+	kinfo("Initialized the GDT");
+#endif
 }
 
-#undef GDT_SIZE
-
 void kmain(void)
 {
-	gdt_init();		
-	idt_init();
-
-	PIC_remap(0x20, 0x28);
-	
-
+#ifdef __TESTING__ // important components should be declared first, but if we're testing we want to log all of that
 	terminal_initialize();
 	serial_initialize();
+#endif
 
 
-	terminal_writestring("test");
+	gdt_init();		
+	idt_init();
+	PIC_remap(0x20, 0x28);
 
-	serial_writestring("test!");
+#ifndef __TESTING__ 
+	terminal_initialize();
+	serial_initialize();
+#endif
 
-	printf("test..");
+
+	printf("Integer: %d\n", 10);
+	printf("Hex Int: %x\n", 2);
 }

libc/stdio/printf.c

@@ -4,11 +4,56 @@
 #include <stdio.h>
 #include <string.h>
 
+#include <kernel/_kernel.h>
+
+static void reverse(char* buf, int len)
+{
+	int start = 0;
+	int end = len - 1;
+	while (start < end) {
+		char tmp = buf[start];
+		buf[start] = buf[end];
+		buf[end] = tmp;
+		end--;
+		start++;
+	}
+}
+
+static char* itoa(int num, char* buf, int base)
+{
+	int i = 0;
+	bool neg = false;
+	
+	if (num == 0) { // Handle zero explicitly
+		buf[i++] = '0';
+		buf[i] = '\0';
+		return buf;
+	}
+
+	if (num < 0 && base == 10) { // only handle negative on base10
+		neg = true;
+		num = -num;
+	}
+
+	while (num != 0) {
+		int rem = num % base;
+		buf[i++] = (rem > 9) ? (rem - 10) + 'a' : rem + '0';
+		num = num / base;
+	}
+
+	if (neg) // lets reapply the negative sign
+		buf[i++] = '-'; 
+
+	buf[i] = '\0';
+
+	reverse(buf, i); // reverse, since we did it backwards!
+	return buf;
+}
+
 static bool print(const char* data, size_t length) {
 	const unsigned char* bytes = (const unsigned char*) data;
 	for (size_t i = 0; i < length; i++)
-		if (putchar(bytes[i]) == EOF)
-			return false;
+		if (putchar(bytes[i]) == EOF) return false;
 	return true;
 }
 
@@ -18,6 +63,8 @@ int printf(const char* restrict format, ...) {
 
 	int written = 0;
 
+	char buffer[512];
+
 	while (*format != '\0') {
 		size_t maxrem = INT_MAX - written;
 
@@ -61,6 +108,30 @@ int printf(const char* restrict format, ...) {
 			if (!print(str, len))
 				return -1;
 			written += len;
+		} else if (*format == 'd') {
+			format++;
+			int i = (int) va_arg(parameters, int);
+			itoa(i, buffer, 10);
+			size_t len = strlen(buffer);
+			if (maxrem < len) {
+				// TODO: Set errno to EOVERFLOW.
+				return -1;
+			}
+			if (!print(buffer, len))
+				return -1;
+			written += len;
+		} else if (*format == 'x') {
+			format++;
+			int i = (int) va_arg(parameters, int);
+			itoa(i, buffer, 16);
+			size_t len = strlen(buffer);
+			if (maxrem < len) {
+				// TODO: Set errno to EOVERFLOW.
+				return -1;
+			}
+			if (!print(buffer, len))
+				return -1;
+			written += len;
 		} else {
 			format = format_begun_at;
 			size_t len = strlen(format);