Added warning flags and fixed them :)

45 files changed, 234 insertions, 252 deletions

diff --git a/Makefile b/Makefile
index 91abfaf..a1a54db 100644
--- a/Makefile
+++ b/Makefile
@@ -1,12 +1,13 @@
 # MIT License, Copyright (c) 2020 Marvin Borner
 
 # Kernel optimization
-OPTIMIZATION = -Ofast
+OPTIMIZATION = -Os
 
-# Remove tree optimizations for kernel - TODO: Why?!
-CFLAGS_EXTRA = -fno-tree-bit-ccp -fno-tree-builtin-call-dce -fno-tree-ccp -fno-tree-ch -fno-tree-coalesce-vars -fno-tree-copy-prop -fno-tree-dce -fno-tree-dominator-opts -fno-tree-dse -fno-tree-fre -fno-tree-pta -fno-tree-sink -fno-tree-slsr -fno-tree-sra -fno-tree-ter -fno-tree-loop-vectorize -fno-inline-functions -fno-inline-functions-called-once
-# Remove ipa optimizations for kernel - TODO: Why?!?!
-CFLAGS_EXTRA += -fno-inline-functions -fno-inline-functions-called-once -fno-reorder-functions -fno-reorder-blocks -fno-reorder-blocks-and-partition -fno-ipa-profile -fno-ipa-pure-const -fno-ipa-reference -fno-ipa-reference-addressable -fno-merge-constants -fno-ipa-bit-cp -fno-ipa-cp -fno-ipa-icf -fno-ipa-ra -fno-ipa-sra -fno-ipa-vrp -fno-ipa-cp-clone
+# Remove tree optimizations for kernel
+#CFLAGS_EXTRA = -fno-tree-bit-ccp -fno-tree-builtin-call-dce -fno-tree-ccp -fno-tree-ch -fno-tree-coalesce-vars -fno-tree-copy-prop -fno-tree-dce -fno-tree-dominator-opts -fno-tree-dse -fno-tree-fre -fno-tree-pta -fno-tree-sink -fno-tree-slsr -fno-tree-sra -fno-tree-ter -fno-tree-loop-vectorize -fno-inline-functions -fno-inline-functions-called-once
+# Remove ipa optimizations for kernel
+#CFLAGS_EXTRA += -fno-inline-functions -fno-inline-functions-called-once -fno-reorder-functions -fno-reorder-blocks -fno-reorder-blocks-and-partition -fno-ipa-profile -fno-ipa-pure-const -fno-ipa-reference -fno-ipa-reference-addressable -fno-merge-constants -fno-ipa-bit-cp -fno-ipa-cp -fno-ipa-icf -fno-ipa-ra -fno-ipa-sra -fno-ipa-vrp -fno-ipa-cp-clone
+CFLAGS_EXTRA = -pie -fPIE -mno-80387 -mno-mmx -mno-sse -mno-sse2 -fno-asynchronous-unwind-tables
 
 export
 
diff --git a/apps/Makefile b/apps/Makefile
index 2f6f430..322b7b6 100644
--- a/apps/Makefile
+++ b/apps/Makefile
@@ -5,7 +5,8 @@ CC = ccache ../cross/opt/bin/i686-elf-gcc
 LD = ccache ../cross/opt/bin/i686-elf-ld
 OC = ccache ../cross/opt/bin/i686-elf-objcopy
 
-CFLAGS = -Wall -Wextra -nostdlib -nostdinc -fno-builtin -std=c99 -m32 -pedantic-errors -I../libc/inc/ -I../libgui/inc/ -I../libtxt/inc/ -fPIE -Duserspace -Os
+WARNINGS = -Wall -Wextra -pedantic-errors -Wshadow -Wpointer-arith -Wwrite-strings -Wredundant-decls -Wnested-externs -Wno-long-long
+CFLAGS = $(WARNINGS) -nostdlib -nostdinc -fno-builtin -std=c99 -m32 -I../libc/inc/ -I../libgui/inc/ -I../libtxt/inc/ -fPIE -Duserspace -Ofast
 
 all: $(COBJS)
 
diff --git a/apps/cc.c b/apps/cc.c
index 6e989f9..6b571b1 100644
--- a/apps/cc.c
+++ b/apps/cc.c
@@ -5,6 +5,7 @@
 #include <def.h>
 #include <mem.h>
 #include <print.h>
+#include <str.h>
 #include <sys.h>
 
 char *p, *lp, // current position in source code
@@ -744,7 +745,7 @@ void stmt()
 
 int main(int argc, char **argv)
 {
-	int bt, ty, poolsz, *idmain;
+	int bt, poolsz, *idmain;
 	int *pc, *sp, *bp, a, cycle; // vm registers
 	int i, *t; // temps
 
@@ -777,8 +778,8 @@ int main(int argc, char **argv)
 	memset(e, 0, poolsz);
 	memset(data, 0, poolsz);
 
-	p = "char else enum if int return sizeof while "
-	    "open read close printf malloc free memset memcmp exit void main";
+	p = strdup("char else enum if int return sizeof while "
+		   "open read close printf malloc free memset memcmp exit void main");
 	i = Char;
 	while (i <= While) {
 		next();
diff --git a/apps/files.c b/apps/files.c
index 2176a99..c27e39c 100644
--- a/apps/files.c
+++ b/apps/files.c
@@ -17,7 +17,7 @@ struct dirent {
 	char name[];
 };
 
-void render_list(char *path);
+void render_list(const char *path);
 void on_click(struct event_mouse *event, struct element *elem)
 {
 	(void)event;
@@ -31,7 +31,7 @@ void on_click(struct event_mouse *event, struct element *elem)
 }
 
 // TODO: Dir iterator as kernel syscall?
-void render_list(char *path)
+void render_list(const char *path)
 {
 	static struct element *list = NULL;
 	if (list)
@@ -49,7 +49,7 @@ void render_list(char *path)
 		d->name[d->name_len] = '\0';
 		struct element *label = gui_add_label(list, 5, cnt * (gfx_font_height(FONT_16) + 5),
 						      FONT_16, d->name, COLOR_BLACK, COLOR_WHITE);
-		label->attributes = path;
+		label->attributes = (char *)path;
 
 		if (d->type_indicator == 2) // Dir
 			label->event.on_click = on_click;
diff --git a/apps/test.c b/apps/test.c
index 874136e..c47e060 100644
--- a/apps/test.c
+++ b/apps/test.c
@@ -63,11 +63,11 @@ void test_conv()
 
 void test_mem()
 {
-	char *str0 = "";
-	char *str1 = "";
-	char *str2 = "12345";
-	char *str3 = "12345";
-	char *str4 = "12354";
+	const char *str0 = "";
+	const char *str1 = "";
+	const char *str2 = "12345";
+	const char *str3 = "12345";
+	const char *str4 = "12354";
 	equals(memcmp(str4, str2, strlen(str2)), 1);
 	equals(memcmp(str2, str4, strlen(str2)), -1);
 	equals(memcmp(str2, str3, strlen(str2)), 0);
diff --git a/apps/window.c b/apps/window.c
index 4f2aec7..7e1b4be 100644
--- a/apps/window.c
+++ b/apps/window.c
@@ -20,8 +20,8 @@ int main()
 	struct element *root = gui_init("test", 600, 400, COLOR_BG);
 	struct element *container =
 		gui_add_container(root, 0, 0, root->ctx->width / 2, root->ctx->height, COLOR_RED);
-	struct element *button =
-		gui_add_button(container, 10, 10, FONT_24, "Button", COLOR_WHITE, COLOR_BLACK);
+	struct element *button = gui_add_button(container, 10, 10, FONT_24, strdup("Button"),
+						COLOR_WHITE, COLOR_BLACK);
 	struct element *text_input =
 		gui_add_text_input(container, 10, 50, 200, FONT_24, COLOR_WHITE, COLOR_BLACK);
 	(void)text_input;
diff --git a/kernel/Makefile b/kernel/Makefile
index c449cd9..cca186c 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -23,7 +23,8 @@ LD = ccache ../cross/opt/bin/i686-elf-ld
 OC = ccache ../cross/opt/bin/i686-elf-objcopy
 AS = ccache nasm
 
-CFLAGS = -Wall -Wextra -Wno-address-of-packed-member -nostdlib -nostdinc -ffreestanding -fno-builtin -mno-red-zone -mgeneral-regs-only -std=c99 -m32 -pedantic-errors -Wl,-ekernel_main -I../libc/inc/ -Iinc/ -Dkernel $(CFLAGS_EXTRA) $(OPTIMIZATION)
+WARNINGS = -Wall -Wextra -pedantic-errors -Wshadow -Wpointer-arith -Wwrite-strings -Wredundant-decls -Wnested-externs -Wno-long-long
+CFLAGS = $(WARNINGS) -Wno-address-of-packed-member -nostdlib -nostdinc -ffreestanding -fno-builtin -mno-red-zone -mgeneral-regs-only -std=c99 -m32 -Wl,-ekernel_main -I../libc/inc/ -Iinc/ -Dkernel $(CFLAGS_EXTRA) $(OPTIMIZATION)
 ASFLAGS = -f elf32
 
 all: compile
@@ -36,5 +37,5 @@ all: compile
 
 compile: $(COBJS)
 	@mkdir -p ../build/
-	@$(LD) -N -ekernel_main -Ttext 0x00050000 -o ../build/kernel.bin -L../build/ $+ -lk --oformat binary
-	@$(CC) $(CFLAGS) -o ../build/debug.o -L../build/ $+ -lk
+	@$(LD) -N -ekernel_main -Ttext 0x00050000 -o ../build/kernel.elf -L../build/ $+ -lk
+	@$(OC) -O binary ../build/kernel.elf ../build/kernel.bin
diff --git a/kernel/drivers/acpi.c b/kernel/drivers/acpi.c
index 0db4522..5ab0ac6 100644
--- a/kernel/drivers/acpi.c
+++ b/kernel/drivers/acpi.c
@@ -12,7 +12,7 @@ int check_sdt(struct sdt_header *header)
 	u8 sum = 0;
 
 	for (u32 i = 0; i < header->length; i++)
-		sum += ((char *)header)[i];
+		sum += (u8)(((u8 *)header)[i]);
 
 	return sum == 0;
 }
@@ -22,12 +22,12 @@ int check_sdp(struct sdp_header *header)
 	u8 sum = 0;
 
 	for (u32 i = 0; i < sizeof(struct rsdp); i++)
-		sum += ((char *)header)[i];
+		sum += (u8)(((u8 *)header)[i]);
 
 	return sum == 0;
 }
 
-struct rsdp *find_rsdp()
+struct rsdp *find_rsdp(void)
 {
 	// Main BIOS area
 	for (int i = 0xe0000; i < 0xfffff; i++) {
@@ -47,9 +47,9 @@ struct rsdp *find_rsdp()
 
 void *find_sdt(struct rsdt *rsdt, const char *signature)
 {
-	int entries = (rsdt->header.length - sizeof(rsdt->header)) / 4;
+	u32 entries = (rsdt->header.length - sizeof(rsdt->header)) / 4;
 
-	for (int i = 0; i < entries; i++) {
+	for (u32 i = 0; i < entries; i++) {
 		struct sdt_header *header = (struct sdt_header *)rsdt->sdt_pointer[i];
 		if (memcmp(header->signature, signature, 4) == 0) {
 			if (check_sdt(header))
@@ -62,7 +62,7 @@ void *find_sdt(struct rsdt *rsdt, const char *signature)
 	return NULL;
 }
 
-void acpi_install()
+void acpi_install(void)
 {
 	struct rsdp *rsdp = find_rsdp();
 	assert(rsdp && rsdp->header.revision == 0 && check_sdp(&rsdp->header));
@@ -77,7 +77,7 @@ void acpi_install()
 	madt_install();
 }
 
-void hpet_install(int period)
+void hpet_install(u32 period)
 {
 	if (hpet && hpet->legacy_replacement && hpet->comparator_count > 0) {
 		struct hpet_registers *r = (struct hpet_registers *)hpet->address.phys;
@@ -97,7 +97,7 @@ void hpet_install(int period)
 	}
 }
 
-void madt_install()
+void madt_install(void)
 {
 	if (!madt)
 		return;
diff --git a/kernel/drivers/fpu.c b/kernel/drivers/fpu.c
index f7eeceb..e61e267 100644
--- a/kernel/drivers/fpu.c
+++ b/kernel/drivers/fpu.c
@@ -7,12 +7,12 @@ void set_fpu_cw(const u16 cw)
 	__asm__ volatile("fldcw %0" ::"m"(cw));
 }
 
-void fpu_install()
+void fpu_install(void)
 {
 	__asm__ volatile("clts");
 	u32 t = 0;
 	__asm__ volatile("mov %%cr0, %0" : "=r"(t));
-	t &= ~(1 << 2);
+	t &= (u32) ~(1 << 2);
 	t |= (1 << 1);
 	__asm__ volatile("mov %0, %%cr0" ::"r"(t));
 
diff --git a/kernel/drivers/ide.c b/kernel/drivers/ide.c
index 1a94ae3..227dfe5 100644
--- a/kernel/drivers/ide.c
+++ b/kernel/drivers/ide.c
@@ -16,7 +16,7 @@ int ide_stat()
 
 void ide_wait()
 {
-	u8 stat = 0;
+	int stat = 0;
 	do
 		stat = ide_stat();
 	while ((stat & IDE_BUSY) != 0);
@@ -25,10 +25,10 @@ void ide_wait()
 // TODO: Fix strange ide_read bugs
 void *ide_read(void *b, u32 block)
 {
-	int sector_count = BLOCK_SIZE / SECTOR_SIZE; // 2
-	int sector = block * sector_count;
+	u8 sector_count = BLOCK_SIZE / SECTOR_SIZE; // 2
+	u32 sector = block * sector_count;
 
-	outb(IDE_IO + IDE_SECTOR_COUNT, sector_count); // Number of sectors
+	outb(IDE_IO + IDE_SECTOR_COUNT, (u8)sector_count); // Number of sectors
 
 	outb(IDE_IO + IDE_LOW, LBA_LOW(sector));
 	outb(IDE_IO + IDE_MID, LBA_MID(sector));
diff --git a/kernel/drivers/interrupts.c b/kernel/drivers/interrupts.c
index 57b0ab5..b0751d6 100644
--- a/kernel/drivers/interrupts.c
+++ b/kernel/drivers/interrupts.c
@@ -90,7 +90,7 @@ void irq_handler(struct regs *r)
 }
 
 // Map ISRs to the correct entries in the IDT
-void irq_install()
+void irq_install(void)
 {
 	irq_remap();
 
@@ -182,7 +182,7 @@ void isr_handler(struct regs *r)
 	}
 }
 
-void isr_install()
+void isr_install(void)
 {
 	idt_set_gate(0, (u32)isr0, 0x08, 0x8E);
 	idt_set_gate(1, (u32)isr1, 0x08, 0x8E);
@@ -224,7 +224,7 @@ void isr_install()
 /**
  * Combined
  */
-void interrupts_install()
+void interrupts_install(void)
 {
 	idt_install();
 	isr_install();
diff --git a/kernel/drivers/keyboard.c b/kernel/drivers/keyboard.c
index 2bd67ba..67e0a72 100644
--- a/kernel/drivers/keyboard.c
+++ b/kernel/drivers/keyboard.c
@@ -15,7 +15,7 @@ int state = 0;
 int merged = 0;
 void keyboard_handler()
 {
-	u32 scancode = (u32)inb(0x60);
+	int scancode = inb(0x60);
 
 	// TODO: Support more than two-byte scancodes
 	if (scancode == 0xe0) {
@@ -40,20 +40,20 @@ void keyboard_handler()
 	merged = 0;
 }
 
-void keyboard_acknowledge()
+void keyboard_acknowledge(void)
 {
 	while (inb(0x60) != 0xfa)
 		;
 }
 
-void keyboard_rate()
+void keyboard_rate(void)
 {
 	outb(0x60, 0xF3);
 	keyboard_acknowledge();
 	outb(0x60, 0x0); // Rate{00000} Delay{00} 0
 }
 
-void keyboard_install()
+void keyboard_install(void)
 {
 	//keyboard_rate(); TODO: Fix keyboard rate?
 	irq_install_handler(1, keyboard_handler);
@@ -67,7 +67,7 @@ char keymap[128] = {
 	0, // Alt key
 	' ', // Space bar
 	15, // Caps lock
-	0,    0,    0,   0,   0,   0,   0,   0,   0,   0, // F keys
+	0,    0,    0,	 0,   0,   0,	0,   0,	  0,   0, // F keys
 	0, // Num lock
 	0, // Scroll lock
 	0, // Home key
diff --git a/kernel/drivers/mouse.c b/kernel/drivers/mouse.c
index a5f5d0c..9b34b0a 100644
--- a/kernel/drivers/mouse.c
+++ b/kernel/drivers/mouse.c
@@ -17,18 +17,18 @@ void mouse_handler()
 {
 	switch (mouse_cycle) {
 	case 0:
-		mouse_byte[0] = inb(0x60);
+		mouse_byte[0] = (char)inb(0x60);
 		if (((mouse_byte[0] >> 3) & 1) == 1)
 			mouse_cycle++;
 		else
 			mouse_cycle = 0;
 		break;
 	case 1:
-		mouse_byte[1] = inb(0x60);
+		mouse_byte[1] = (char)inb(0x60);
 		mouse_cycle++;
 		break;
 	case 2:
-		mouse_byte[2] = inb(0x60);
+		mouse_byte[2] = (char)inb(0x60);
 
 		free(event);
 		event = malloc(sizeof(*event));
@@ -71,13 +71,13 @@ void mouse_write(u8 a_write)
 	outb(0x60, a_write);
 }
 
-char mouse_read()
+u8 mouse_read(void)
 {
 	mouse_wait(0);
 	return inb(0x60);
 }
 
-void mouse_install()
+void mouse_install(void)
 {
 	u8 status;
 
diff --git a/kernel/drivers/pci.c b/kernel/drivers/pci.c
index 6130cd0..72b9aa8 100644
--- a/kernel/drivers/pci.c
+++ b/kernel/drivers/pci.c
@@ -100,7 +100,7 @@ static u32 pci_isa = 0;
 static u8 pci_remaps[4] = { 0 };
 
 // Remap
-void pci_install()
+void pci_install(void)
 {
 	pci_scan(&find_isa_bridge, -1, &pci_isa);
 	if (pci_isa) {
@@ -122,7 +122,7 @@ int pci_get_interrupt(u32 device)
 		u32 irq_pin = pci_read_field(device, 0x3D, 1);
 		if (irq_pin == 0)
 			return (int)pci_read_field(device, PCI_INTERRUPT_LINE, 1);
-		int pirq = (int)(irq_pin + pci_extract_slot(device) - 2) % 4;
+		int pirq = ((int)irq_pin + pci_extract_slot(device) - 2) % 4;
 		int int_line = (int)pci_read_field(device, PCI_INTERRUPT_LINE, 1);
 
 		if (pci_remaps[pirq] >= 0x80) {
diff --git a/kernel/drivers/rtl8139.c b/kernel/drivers/rtl8139.c
index 14770c8..ec45bd7 100644
--- a/kernel/drivers/rtl8139.c
+++ b/kernel/drivers/rtl8139.c
@@ -13,12 +13,11 @@
 
 static u8 mac[6];
 static u8 *rx_buffer;
-static u32 current_packet_ptr;
 
 static u32 rtl_device_pci = 0;
 static u32 rtl_iobase = 0;
 
-u8 *rtl8139_get_mac()
+u8 *rtl8139_get_mac(void)
 {
 	if (!rtl_device_pci)
 		return NULL;
@@ -26,8 +25,10 @@ u8 *rtl8139_get_mac()
 	return mac;
 }
 
-void rtl8139_receive_packet()
+void rtl8139_receive_packet(void)
 {
+	static u32 current_packet_ptr;
+
 	if (!rtl_device_pci)
 		return;
 
@@ -39,12 +40,12 @@ void rtl8139_receive_packet()
 	memcpy(packet, t, length);
 	ethernet_handle_packet(packet, length);
 
-	current_packet_ptr = (current_packet_ptr + length + 4 + 3) & (~3);
+	current_packet_ptr = (current_packet_ptr + length + 4 + 3) & (u32)(~3);
 
 	if (current_packet_ptr >= RX_BUF_SIZE)
 		current_packet_ptr -= RX_BUF_SIZE;
 
-	outw(rtl_iobase + RTL_PORT_RXPTR, current_packet_ptr - 0x10);
+	outw((u16)(rtl_iobase + RTL_PORT_RXPTR), (u16)(current_packet_ptr - 0x10));
 }
 
 static u8 tsad_array[4] = { 0x20, 0x24, 0x28, 0x2C };
@@ -56,8 +57,8 @@ void rtl8139_send_packet(void *data, u32 len)
 		return;
 
 	/* printf("Sending packet %d\n\n", len); */
-	outl(rtl_iobase + tsad_array[tx_current], (u32)data);
-	outl(rtl_iobase + tsd_array[tx_current++], len);
+	outl((u16)(rtl_iobase + tsad_array[tx_current]), (u32)data);
+	outl((u16)(rtl_iobase + tsd_array[tx_current++]), len);
 	if (tx_current > 3)
 		tx_current = 0;
 }
@@ -69,16 +70,15 @@ void rtl8139_find(u32 device, u16 vendor_id, u16 device_id, void *extra)
 	}
 }
 
-// TODO: Fix late packet arrival
 void rtl8139_irq_handler()
 {
 	if (!rtl_device_pci)
 		return;
 
 	/* print("\nRTL INT!\n"); */
-	u16 status = inw(rtl_iobase + RTL_PORT_ISR);
+	u16 status = inw((u16)(rtl_iobase + RTL_PORT_ISR));
 
-	outw(rtl_iobase + RTL_PORT_ISR, 0x5);
+	outw((u16)(rtl_iobase + RTL_PORT_ISR), 0x5);
 
 	if (status & RTL_TOK) {
 		print("Got response!\n");
@@ -88,7 +88,7 @@ void rtl8139_irq_handler()
 	}
 }
 
-void rtl8139_init()
+void rtl8139_init(void)
 {
 	if (!rtl_device_pci)
 		return;
@@ -104,41 +104,41 @@ void rtl8139_init()
 	rtl_iobase = 0;
 
 	if (rtl_bar0 & 0x00000001)
-		rtl_iobase = rtl_bar0 & (~0x3);
+		rtl_iobase = rtl_bar0 & ((u32)~0x3);
 
 	// Get mac address
-	for (int i = 0; i < 6; ++i)
-		mac[i] = inb(rtl_iobase + RTL_PORT_MAC + i);
+	for (u32 i = 0; i < 6; ++i)
+		mac[i] = inb((u16)(rtl_iobase + RTL_PORT_MAC + i));
 	printf("Mac address: %x:%x:%x:%x:%x:%x\n", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
 
 	// Activate
-	outb(rtl_iobase + RTL_PORT_CONFIG, 0x0);
+	outb((u16)(rtl_iobase + RTL_PORT_CONFIG), 0x0);
 
 	// Reset
 	outb((u16)(rtl_iobase + RTL_PORT_CMD), 0x10);
-	while ((inb(rtl_iobase + RTL_PORT_CMD) & 0x10) != 0)
+	while ((inb((u16)(rtl_iobase + RTL_PORT_CMD)) & 0x10) != 0)
 		;
 
 	// Set receive buffer
 	rx_buffer = (u8 *)malloc(RX_BUF_SIZE + 1516);
 	memset(rx_buffer, 0, RX_BUF_SIZE + 1516);
-	outl(rtl_iobase + RTL_PORT_RBSTART, (u32)rx_buffer);
+	outl((u16)(rtl_iobase + RTL_PORT_RBSTART), (u32)rx_buffer);
 
 	// Set TOK and ROK
-	outw(rtl_iobase + RTL_PORT_IMR, 0x0005);
+	outw((u16)(rtl_iobase + RTL_PORT_IMR), 0x0005);
 
 	// AB+AM+APM+AAP except WRAP
-	outl(rtl_iobase + RTL_PORT_RCR, 0xf | (1 << 7));
+	outl((u16)(rtl_iobase + RTL_PORT_RCR), 0xf | (1 << 7));
 
 	// Enable receive and transmit
-	outb(rtl_iobase + RTL_PORT_CMD, 0x08 | 0x04);
+	outb((u16)(rtl_iobase + RTL_PORT_CMD), 0x08 | 0x04);
 
 	// Install interrupt handler
-	u32 rtl_irq = pci_get_interrupt(rtl_device_pci);
+	int rtl_irq = pci_get_interrupt(rtl_device_pci);
 	irq_install_handler(rtl_irq, rtl8139_irq_handler);
 }
 
-int rtl8139_install()
+int rtl8139_install(void)
 {
 	pci_scan(&rtl8139_find, -1, &rtl_device_pci);
 
@@ -146,5 +146,6 @@ int rtl8139_install()
 		print("Found rtl8139 card\n");
 		rtl8139_init();
 	}
-	return rtl_device_pci;
+
+	return (int)rtl_device_pci;
 }
diff --git a/kernel/drivers/timer.c b/kernel/drivers/timer.c
index 3bc1811..e9e90a0 100644
--- a/kernel/drivers/timer.c
+++ b/kernel/drivers/timer.c
@@ -11,11 +11,11 @@ void timer_phase(int hz)
 {
 	int divisor = 3579545 / 3 / hz;
 	outb(0x43, 0x36); // 01 10 11 0b // CTR, RW, MODE, BCD
-	outb(0x40, divisor & 0xFF);
-	outb(0x40, divisor >> 8);
+	outb(0x40, (u8)(divisor & 0xFF));
+	outb(0x40, (u8)(divisor >> 8));
 }
 
-u32 timer_get()
+u32 timer_get(void)
 {
 	return timer_ticks;
 }
@@ -38,7 +38,7 @@ void timer_wait(u32 ticks)
 }
 
 // Install timer handler into IRQ0
-void timer_install()
+void timer_install(void)
 {
 	/* hpet_install(10000); // TODO: Find optimal femtosecond period */
 	/* if (!hpet) */
diff --git a/kernel/features/fs.c b/kernel/features/fs.c
index ceb345d..941ba76 100644
--- a/kernel/features/fs.c
+++ b/kernel/features/fs.c
@@ -9,12 +9,12 @@
 #include <print.h>
 #include <str.h>
 
-void *buffer_read(int block)
+void *buffer_read(u32 block)
 {
 	return ide_read(malloc(BLOCK_SIZE), block);
 }
 
-struct superblock *get_superblock()
+struct superblock *get_superblock(void)
 {
 	struct superblock *sb = buffer_read(EXT2_SUPER);
 	if (sb->magic != EXT2_MAGIC)
@@ -22,21 +22,21 @@ struct superblock *get_superblock()
 	return sb;
 }
 
-struct bgd *get_bgd()
+struct bgd *get_bgd(void)
 {
 	return buffer_read(EXT2_SUPER + 1);
 }
 
-struct inode *get_inode(int i)
+struct inode *get_inode(u32 i)
 {
 	struct superblock *s = get_superblock();
 	assert(s);
 	struct bgd *b = get_bgd();
 	assert(b);
 
-	int block_group = (i - 1) / s->inodes_per_group;
-	int index = (i - 1) % s->inodes_per_group;
-	int block = (index * INODE_SIZE) / BLOCK_SIZE;
+	u32 block_group = (i - 1) / s->inodes_per_group;
+	u32 index = (i - 1) % s->inodes_per_group;
+	u32 block = (index * INODE_SIZE) / BLOCK_SIZE;
 	b += block_group;
 
 	u32 *data = buffer_read(b->inode_table + block);
@@ -57,7 +57,7 @@ void *read_inode(struct inode *in)
 	if (!in)
 		return NULL;
 
-	int num_blocks = in->blocks / (BLOCK_SIZE / SECTOR_SIZE);
+	u32 num_blocks = in->blocks / (BLOCK_SIZE / SECTOR_SIZE);
 
 	assert(num_blocks != 0);
 	if (!num_blocks)
@@ -68,13 +68,12 @@ void *read_inode(struct inode *in)
 	printf("Loading %dKiB\n", sz >> 10);
 	assert(buf != NULL);
 
-	int indirect = 0;
-
-	int blocknum = 0;
+	u32 indirect = 0;
+	u32 blocknum = 0;
 	char *data = 0;
 	// TODO: Support triply indirect pointers
 	// TODO: This can be heavily optimized by saving the indirect block lists
-	for (int i = 0; i < num_blocks; i++) {
+	for (u32 i = 0; i < num_blocks; i++) {
 		if (i < 12) {
 			blocknum = in->block[i];
 			data = buffer_read(blocknum);
@@ -130,10 +129,10 @@ void *read_file(char *path)
 	return read_inode(get_inode(inode));
 }
 
-int find_inode(const char *name, int dir_inode)
+u32 find_inode(const char *name, u32 dir_inode)
 {
 	if (!dir_inode)
-		return -1;
+		return (unsigned)-1;
 
 	struct inode *i = get_inode(dir_inode);
 
@@ -160,10 +159,10 @@ int find_inode(const char *name, int dir_inode)
 
 	} while (sum < (1024 * i->blocks / 2));
 	free(buf);
-	return -1;
+	return (unsigned)-1;
 }
 
-void ls_root()
+void ls_root(void)
 {
 	struct inode *i = get_inode(2);
 
@@ -176,11 +175,11 @@ void ls_root()
 
 	struct dirent *d = (struct dirent *)buf;
 
+	u16 calc = 0;
 	int sum = 0;
-	int calc = 0;
 	printf("\nRoot directory:\n");
 	do {
-		calc = (sizeof(struct dirent) + d->name_len + 4) & ~0x3;
+		calc = (sizeof(struct dirent) + d->name_len + 4) & (u32)~0x3;
 		sum += d->total_len;
 		d->name[d->name_len] = '\0';
 		printf("/%s\n", d->name);
diff --git a/kernel/features/net.c b/kernel/features/net.c
index f9b9d12..12d4162 100644
--- a/kernel/features/net.c
+++ b/kernel/features/net.c
@@ -9,7 +9,7 @@
 #include <rtl8139.h>
 #include <str.h>
 
-static u32 ip_addr = 0x0f02000a;
+static u32 current_ip_addr = 0x0f02000a;
 static u32 gateway_addr = 0x0202000a;
 static u8 gateway_mac[6] = { 0 };
 
@@ -23,12 +23,12 @@ u16 ip_calculate_checksum(struct ip_packet *packet)
 	u16 *array = (u16 *)packet;
 	u32 sum = 0;
 	for (int i = 0; i < array_size; i++) {
-		sum += htons(array[i]);
+		sum += (u32)htons(array[i]);
 	}
 	u32 carry = sum >> 16;
 	sum = sum & 0x0000ffff;
 	sum = sum + carry;
-	u16 ret = ~sum;
+	u16 ret = (u16)~sum;
 	return ret;
 }
 
@@ -39,26 +39,26 @@ u16 tcp_calculate_checksum(struct tcp_packet *packet, struct tcp_pseudo_header *
 	u16 *s = (u16 *)header;
 
 	// TODO: Checksums for options?
-	for (int i = 0; i < 6; ++i) {
-		sum += ntohs(s[i]);
+	for (int i = 0; i < 6; i++) {
+		sum += (u32)ntohs(s[i]);
 		if (sum > 0xffff) {
 			sum = (sum >> 16) + (sum & 0xffff);
 		}
 	}
 
 	s = (u16 *)packet;
-	for (int i = 0; i < 10; ++i) {
-		sum += ntohs(s[i]);
+	for (int i = 0; i < 10; i++) {
+		sum += (u32)ntohs(s[i]);
 		if (sum > 0xffff) {
 			sum = (sum >> 16) + (sum & 0xffff);
 		}
 	}
 
-	u16 d_words = len / 2;
+	u16 d_words = (u16)(len / 2);
 
 	s = (u16 *)data;
-	for (unsigned int i = 0; i < d_words; ++i) {
-		sum += ntohs(s[i]);
+	for (u32 i = 0; i < d_words; ++i) {
+		sum += (u32)ntohs(s[i]);
 		if (sum > 0xffff) {
 			sum = (sum >> 16) + (sum & 0xffff);
 		}
@@ -72,7 +72,7 @@ u16 tcp_calculate_checksum(struct tcp_packet *packet, struct tcp_pseudo_header *
 
 		u16 *f = (u16 *)tmp;
 
-		sum += ntohs(f[0]);
+		sum += (u32)ntohs(f[0]);
 		if (sum > 0xffff) {
 			sum = (sum >> 16) + (sum & 0xffff);
 		}
@@ -92,7 +92,7 @@ u16 icmp_calculate_checksum(struct icmp_packet *packet)
 	if (sum > 0xffff)
 		sum = (sum >> 16) + (sum & 0xffff);
 
-	return ~sum;
+	return (u16)~sum;
 }
 
 void *dhcp_get_options(struct dhcp_packet *packet, u8 type)
@@ -118,12 +118,12 @@ void *dhcp_get_options(struct dhcp_packet *packet, u8 type)
 void ethernet_send_packet(u8 *dst, u8 *data, int len, int prot)
 {
 	print("Ethernet send packet\n");
-	struct ethernet_packet *packet = malloc(sizeof(*packet) + len);
+	struct ethernet_packet *packet = malloc(sizeof(*packet) + (u32)len);
 	memcpy(packet->src, rtl8139_get_mac(), 6);
 	memcpy(packet->dst, dst, 6);
-	memcpy(packet->data, data, len);
-	packet->type = htons(prot);
-	rtl8139_send_packet(packet, sizeof(*packet) + len);
+	memcpy(packet->data, data, (u32)len);
+	packet->type = (u16)htons(prot);
+	rtl8139_send_packet(packet, sizeof(*packet) + (u32)len);
 	free(packet);
 }
 
@@ -134,10 +134,10 @@ void arp_send_packet(u8 *dst_mac, u32 dst_protocol_addr, u8 opcode)
 	struct arp_packet *packet = malloc(sizeof(*packet));
 
 	memcpy(packet->src_mac, rtl8139_get_mac(), 6);
-	packet->src_protocol_addr = ip_addr;
+	packet->src_protocol_addr = current_ip_addr;
 	memcpy(packet->dst_mac, dst_mac, 6);
 	packet->dst_protocol_addr = dst_protocol_addr;
-	packet->opcode = htons(opcode);
+	packet->opcode = (u16)htons(opcode);
 	packet->hardware_addr_len = 6;
 	packet->protocol_addr_len = 4;
 	packet->hardware_type = htons(HARDWARE_TYPE_ETHERNET);
@@ -148,23 +148,23 @@ void arp_send_packet(u8 *dst_mac, u32 dst_protocol_addr, u8 opcode)
 }
 
 int arp_lookup(u8 *ret_hardware_addr, u32 ip_addr);
-void ip_send_packet(u32 dst, void *data, int len, int prot)
+void ip_send_packet(u32 dst, void *data, int len, u8 prot)
 {
 	print("IP send packet\n");
-	struct ip_packet *packet = malloc(sizeof(*packet) + len);
+	struct ip_packet *packet = malloc(sizeof(*packet) + (u32)len);
 	memset(packet, 0, sizeof(*packet));
 	packet->version_ihl = ((0x4 << 4) | (0x5 << 0));
-	packet->length = sizeof(*packet) + len;
+	packet->length = (u16)sizeof(*packet) + (u16)len;
 	packet->id = htons(1); // TODO: IP fragmentation
 	packet->ttl = 64;
 	packet->protocol = prot;
-	packet->src = ip_addr;
+	packet->src = current_ip_addr;
 	packet->dst = dst;
-	packet->length = htons(sizeof(*packet) + len);
-	packet->checksum = htons(ip_calculate_checksum(packet));
+	packet->length = (u16)htons(sizeof(*packet) + (u32)len);
+	packet->checksum = (u16)htons(ip_calculate_checksum(packet));
 
 	if (data)
-		memcpy(packet->data, data, len);
+		memcpy(packet->data, data, (u32)len);
 
 	u8 dst_mac[6];
 
@@ -190,18 +190,18 @@ void ip_send_packet(u32 dst, void *data, int len, int prot)
 void udp_send_packet(u32 dst, u16 src_port, u16 dst_port, void *data, int len)
 {
 	print("UDP send packet\n");
-	int length = sizeof(struct udp_packet) + len;
+	u32 length = sizeof(struct udp_packet) + (u32)len;
 	struct udp_packet *packet = malloc(length);
 	memset(packet, 0, sizeof(*packet));
-	packet->src_port = htons(src_port);
-	packet->dst_port = htons(dst_port);
-	packet->length = htons(length);
+	packet->src_port = (u16)htons(src_port);
+	packet->dst_port = (u16)htons(dst_port);
+	packet->length = (u16)htons(length);
 	packet->checksum = 0; // Optional
 
 	if (data)
-		memcpy(packet->data, data, len);
+		memcpy(packet->data, data, (u32)len);
 
-	ip_send_packet(dst, packet, length, IP_PROT_UDP);
+	ip_send_packet(dst, packet, (int)length, IP_PROT_UDP);
 	free(packet);
 }
 
@@ -209,14 +209,14 @@ u32 seq_no, ack_no = 0; // TODO: Per socket
 void tcp_send_packet(u32 dst, u16 src_port, u16 dst_port, u16 flags, void *data, int len)
 {
 	print("TCP send packet\n");
-	int length = sizeof(struct tcp_packet) + len;
+	u32 length = sizeof(struct tcp_packet) + (u32)len;
 	struct tcp_packet *packet = malloc(length);
 	memset(packet, 0, sizeof(*packet));
-	packet->src_port = htons(src_port);
-	packet->dst_port = htons(dst_port);
+	packet->src_port = (u16)htons(src_port);
+	packet->dst_port = (u16)htons(dst_port);
 	packet->seq_number = htonl(seq_no);
 	packet->ack_number = flags & TCP_FLAG_ACK ? htonl(ack_no) : 0;
-	packet->flags = htons(0x5000 ^ (flags & 0xff));
+	packet->flags = (u16)htons(0x5000 ^ (flags & 0xff));
 	packet->window_size = htons(1548 - 54);
 	packet->urgent = 0;
 	packet->checksum = 0; // Later
@@ -224,28 +224,28 @@ void tcp_send_packet(u32 dst, u16 src_port, u16 dst_port, u16 flags, void *data,
 	if ((flags & 0xff) == TCP_FLAG_SYN)
 		seq_no++;
 	else
-		seq_no += len;
+		seq_no += (u32)len;
 
 	if (data)
-		memcpy(packet->data, data, len);
+		memcpy(packet->data, data, (u32)len);
 
 	struct tcp_pseudo_header checksum_hd = {
-		.src = ip_addr,
+		.src = current_ip_addr,
 		.dst = dst,
 		.zeros = 0,
 		.protocol = 6,
-		.tcp_len = htons(length),
+		.tcp_len = (u16)htons(length),
 	};
 	u16 checksum = tcp_calculate_checksum(packet, &checksum_hd, data,
-					      length - (htons(packet->flags) >> 12) * 4);
-	packet->checksum = htons(checksum);
+					      length - ((u32)htons(packet->flags) >> 12) * 4);
+	packet->checksum = (u16)htons(checksum);
 
-	ip_send_packet(dst, packet, length, IP_PROT_TCP);
+	ip_send_packet(dst, packet, (int)length, IP_PROT_TCP);
 	free(packet);
 }
 
 void dhcp_make_packet(struct dhcp_packet *packet, u8 msg_type);
-void dhcp_request()
+void dhcp_request(void)
 {
 	u32 dst = 0xffffffff;
 	struct dhcp_packet *packet = malloc(sizeof(*packet));
@@ -282,8 +282,8 @@ void dhcp_handle_packet(struct dhcp_packet *packet)
 			print("DHCP offer\n");
 			dhcp_request();
 		} else if (*type == 5) { // ACK
-			ip_addr = packet->your_ip;
-			printf("ACK! New IP: %x\n", ip_addr);
+			current_ip_addr = packet->your_ip;
+			printf("ACK! New IP: %x\n", current_ip_addr);
 		}
 		free(type);
 	}
@@ -292,8 +292,8 @@ void dhcp_handle_packet(struct dhcp_packet *packet)
 void tcp_handle_packet(struct tcp_packet *packet, u32 dst, int len)
 {
 	printf("TCP Port: %d\n", ntohs(packet->dst_port));
-	int data_length = len - (htons(packet->flags) >> 12) * 4;
-	u16 flags = ntohs(packet->flags);
+	u32 data_length = (u32)len - ((u32)htons(packet->flags) >> 12) * 4;
+	u16 flags = (u16)ntohs(packet->flags);
 	printf("%b\n", flags);
 
 	if (seq_no != ntohl(packet->ack_number)) {
@@ -345,7 +345,6 @@ void udp_handle_packet(struct udp_packet *packet)
 
 void ip_handle_packet(struct ip_packet *packet, int len)
 {
-	(void)len;
 	switch (packet->protocol) {
 	case IP_PROT_ICMP:
 		print("ICMP Packet!\n");
@@ -375,7 +374,7 @@ void arp_handle_packet(struct arp_packet *packet, int len)
 	u32 dst_protocol_addr = packet->src_protocol_addr;
 	if (ntohs(packet->opcode) == ARP_REQUEST) {
 		print("Got ARP request\n");
-		if (packet->dst_protocol_addr == ip_addr) {
+		if (packet->dst_protocol_addr == current_ip_addr) {
 			print("Returning ARP request\n");
 			arp_send_packet(dst_mac, dst_protocol_addr, ARP_REPLY);
 		}
@@ -397,7 +396,7 @@ void arp_handle_packet(struct arp_packet *packet, int len)
 void ethernet_handle_packet(struct ethernet_packet *packet, int len)
 {
 	void *data = packet->data;
-	int data_len = len - sizeof(*packet);
+	int data_len = len - (int)sizeof(*packet);
 	if (ntohs(packet->type) == ETHERNET_TYPE_ARP) {
 		print("ARP PACKET\n");
 		arp_handle_packet(data, data_len);
@@ -440,7 +439,7 @@ void dhcp_make_packet(struct dhcp_packet *packet, u8 msg_type)
 	*(options++) = 0xff;
 }
 
-void dhcp_discover()
+void dhcp_discover(void)
 {
 	print("DHCP discover\n");
 	u32 dst_ip = 0xffffffff;
@@ -480,7 +479,7 @@ int arp_lookup(u8 *ret_hardware_addr, u32 ip_addr)
  * Install
  */
 
-void net_install()
+void net_install(void)
 {
 	if (rtl8139_install()) {
 		sti();
diff --git a/kernel/features/proc.c b/kernel/features/proc.c
index 16931e3..76f552b 100644
--- a/kernel/features/proc.c
+++ b/kernel/features/proc.c
@@ -12,9 +12,8 @@
 #include <str.h>
 #include <timer.h>
 
-u32 pid = 0;
+u32 current_pid = 0;
 u32 quantum = 0;
-struct proc *kernel_proc;
 struct proc *priority_proc;
 struct list *proc_list;
 struct node *current;
@@ -62,17 +61,17 @@ void scheduler(struct regs *regs)
 	/* printf("{%d}", ((struct proc *)current->data)->pid); */
 }
 
-void scheduler_enable()
+void scheduler_enable(void)
 {
 	irq_install_handler(0, scheduler);
 }
 
-void scheduler_disable()
+void scheduler_disable(void)
 {
-	irq_install_handler(0, timer_handler);
+	irq_install_handler(0, scheduler);
 }
 
-void proc_print()
+void proc_print(void)
 {
 	struct node *node = proc_list->head;
 
@@ -85,7 +84,7 @@ void proc_print()
 	printf("\n");
 }
 
-struct proc *proc_current()
+struct proc *proc_current(void)
 {
 	return current && current->data ? current->data : NULL;
 }
@@ -99,8 +98,8 @@ void proc_send(struct proc *src, struct proc *dest, u32 type, void *data)
 	msg->src = src;
 	msg->dest = dest;
 	msg->msg = malloc(sizeof(struct message));
-	msg->msg->src = src->pid;
-	msg->msg->type = type;
+	msg->msg->src = (int)src->pid;
+	msg->msg->type = (int)type;
 	msg->msg->data = data;
 	list_add(dest->messages, msg);
 	priority_proc = dest;
@@ -158,10 +157,10 @@ void proc_yield(struct regs *r)
 	scheduler(r);
 }
 
-struct proc *proc_make()
+struct proc *proc_make(void)
 {
 	struct proc *proc = malloc(sizeof(*proc));
-	proc->pid = pid++;
+	proc->pid = current_pid++;
 	proc->messages = list_new();
 	proc->state = PROC_RUNNING;
 
@@ -171,10 +170,10 @@ struct proc *proc_make()
 	return proc;
 }
 
-extern void proc_jump_userspace();
+extern void proc_jump_userspace(void);
 
 u32 _esp, _eip;
-void proc_init()
+void proc_init(void)
 {
 	if (proc_list)
 		return;
@@ -186,15 +185,15 @@ void proc_init()
 	kernel_proc = proc_make();
 
 	struct node *new = list_add(proc_list, proc_make());
-	bin_load("/bin/init", new->data);
+	bin_load((char *)"/bin/init", new->data);
 	current = new;
 
 	_eip = ((struct proc *)new->data)->regs.eip;
 	_esp = ((struct proc *)new->data)->regs.useresp;
 
-	int argc = 2;
+	u32 argc = 2;
 	char **argv = malloc(sizeof(*argv) * (argc + 1));
-	argv[0] = "init";
+	argv[0] = strdup("init");
 	argv[1] = (char *)boot_passed->vbe;
 	argv[2] = NULL;
 
diff --git a/kernel/features/syscall.c b/kernel/features/syscall.c
index 798ca45..63badd9 100644
--- a/kernel/features/syscall.c
+++ b/kernel/features/syscall.c
@@ -43,8 +43,8 @@ void syscall_handler(struct regs *r)
 	case SYS_EXEC: {
 		char *path = (char *)r->ebx;
 		struct proc *proc = proc_make();
-		r->eax = bin_load(path, proc);
-		int argc = 3; // TODO: Add argc evaluator
+		r->eax = (u32)bin_load(path, proc);
+		u32 argc = 3; // TODO: Add argc evaluator
 		char **argv = malloc(sizeof(*argv) * (argc + 1));
 		argv[0] = (char *)r->ecx;
 		argv[1] = (char *)r->edx;
@@ -54,11 +54,11 @@ void syscall_handler(struct regs *r)
 		((u32 *)proc->regs.useresp)[0] = argc;
 		((u32 *)proc->regs.useresp)[1] = (u32)argv;
 		if (r->eax)
-			proc_exit(proc, r->eax);
+			proc_exit(proc, (int)r->eax);
 		break;
 	}
 	case SYS_EXIT: {
-		proc_exit(proc_current(), r->ebx);
+		proc_exit(proc_current(), (int)r->ebx);
 		break;
 	}
 	case SYS_YIELD: {
@@ -98,7 +98,7 @@ void syscall_handler(struct regs *r)
 	}
 }
 
-void syscall_init()
+void syscall_init(void)
 {
 	idt_set_gate(0x80, (u32)isr128, 0x08, 0x8E);
 	isr_install_handler(0x80, syscall_handler);
diff --git a/kernel/inc/acpi.h b/kernel/inc/acpi.h
index 4e04037..f2fd030 100644
--- a/kernel/inc/acpi.h
+++ b/kernel/inc/acpi.h
@@ -183,8 +183,8 @@ struct madt *madt;
 struct fadt *fadt;
 struct hpet *hpet;
 
-void acpi_install();
-void hpet_install(int frequency);
-void madt_install();
+void acpi_install(void);
+void hpet_install(u32 period);
+void madt_install(void);
 
 #endif
diff --git a/kernel/inc/fpu.h b/kernel/inc/fpu.h
index d747708..d3ec8d9 100644
--- a/kernel/inc/fpu.h
+++ b/kernel/inc/fpu.h
@@ -3,6 +3,6 @@
 #ifndef FPU_H
 #define FPU_H
 
-void fpu_install();
+void fpu_install(void);
 
 #endif
diff --git a/kernel/inc/fs.h b/kernel/inc/fs.h
index 775a1ce..d7e3544 100644
--- a/kernel/inc/fs.h
+++ b/kernel/inc/fs.h
@@ -93,10 +93,10 @@ struct file {
 	u32 curr_block_pos;
 };
 
-int find_inode(const char *name, int dir_inode);
-struct inode *get_inode(int i);
+u32 find_inode(const char *name, u32 dir_inode);
+struct inode *get_inode(u32 i);
 void *read_inode(struct inode *in);
 void *read_file(char *path);
-void ls_root(); // DEMO ;)
+void ls_root(void); // DEMO ;)
 
 #endif
diff --git a/kernel/inc/interrupts.h b/kernel/inc/interrupts.h
index e943e5a..61d31fc 100644
--- a/kernel/inc/interrupts.h
+++ b/kernel/inc/interrupts.h
@@ -36,7 +36,7 @@ void irq_uninstall_handler(int irq);
 void isr_install_handler(int isr, void (*handler)(struct regs *r));
 void isr_uninstall_handler(int isr);
 
-void interrupts_install();
+void interrupts_install(void);
 
 // External handlers (ASM)
 
diff --git a/kernel/inc/keyboard.h b/kernel/inc/keyboard.h
index f0effc7..32168f4 100644
--- a/kernel/inc/keyboard.h
+++ b/kernel/inc/keyboard.h
@@ -3,6 +3,6 @@
 #ifndef KEYBOARD_H
 #define KEYBOARD_H
 
-void keyboard_install();
+void keyboard_install(void);
 
 #endif
diff --git a/kernel/inc/mouse.h b/kernel/inc/mouse.h
index ccea383..e8072aa 100644
--- a/kernel/inc/mouse.h
+++ b/kernel/inc/mouse.h
@@ -3,6 +3,6 @@
 #ifndef MOUSE_H
 #define MOUSE_H
 
-void mouse_install();
+void mouse_install(void);
 
 #endif
diff --git a/kernel/inc/net.h b/kernel/inc/net.h
index 81754d8..26ee1ef 100644
--- a/kernel/inc/net.h
+++ b/kernel/inc/net.h
@@ -138,6 +138,6 @@ struct arp_table_entry {
 };
 
 void ethernet_handle_packet(struct ethernet_packet *packet, int len);
-void net_install();
+void net_install(void);
 
 #endif
diff --git a/kernel/inc/pci.h b/kernel/inc/pci.h
index 10aea56..11fad6f 100644
--- a/kernel/inc/pci.h
+++ b/kernel/inc/pci.h
@@ -61,25 +61,26 @@ struct pci_device_descriptor {
 	u8 revision;
 };
 
-static inline int pci_extract_bus(u32 device)
+static inline u8 pci_extract_bus(u32 device)
 {
 	return (u8)((device >> 16));
 }
 
-static inline int pci_extract_slot(u32 device)
+static inline u8 pci_extract_slot(u32 device)
 {
 	return (u8)((device >> 8));
 }
 
-static inline int pci_extract_func(u32 device)
+static inline u8 pci_extract_func(u32 device)
 {
 	return (u8)(device);
 }
 
 static inline u32 pci_get_addr(u32 device, int field)
 {
-	return 0x80000000 | (pci_extract_bus(device) << 16) | (pci_extract_slot(device) << 11) |
-	       (pci_extract_func(device) << 8) | ((field)&0xFC);
+	return 0x80000000 | (u32)(pci_extract_bus(device) << 16) |
+	       (u32)(pci_extract_slot(device) << 11) | (u32)(pci_extract_func(device) << 8) |
+	       ((field)&0xFC);
 }
 
 static inline u32 pci_box_device(int bus, int slot, int func)
@@ -96,6 +97,6 @@ void pci_scan_slot(pci_func_t f, int type, int bus, int slot, void *extra);
 void pci_scan_bus(pci_func_t f, int type, int bus, void *extra);
 void pci_scan(pci_func_t f, int type, void *extra);
 int pci_get_interrupt(u32 device);
-void pci_install();
+void pci_install(void);
 
 #endif
diff --git a/kernel/inc/proc.h b/kernel/inc/proc.h
index 97ee69a..ad95104 100644
--- a/kernel/inc/proc.h
+++ b/kernel/inc/proc.h
@@ -36,16 +36,16 @@ struct proc_message {
 
 struct proc *kernel_proc;
 
-void scheduler_enable();
-void scheduler_disable();
-void proc_init();
-void proc_print();
-struct proc *proc_current();
+void scheduler_enable(void);
+void scheduler_disable(void);
+void proc_init(void);
+void proc_print(void);
+struct proc *proc_current(void);
 void proc_send(struct proc *src, struct proc *dest, u32 type, void *data);
 struct proc_message *proc_receive(struct proc *proc);
 struct proc *proc_from_pid(u32 pid);
 void proc_exit(struct proc *proc, int status);
 void proc_yield(struct regs *r);
-struct proc *proc_make();
+struct proc *proc_make(void);
 
 #endif
diff --git a/kernel/inc/rtl8139.h b/kernel/inc/rtl8139.h
index d84d115..faeb3f6 100644
--- a/kernel/inc/rtl8139.h
+++ b/kernel/inc/rtl8139.h
@@ -28,8 +28,8 @@
 #define RTL_PORT_RXMISS 0x4C
 #define RTL_PORT_CONFIG 0x52
 
-int rtl8139_install();
+int rtl8139_install(void);
 void rtl8139_send_packet(void *data, u32 len);
-u8 *rtl8139_get_mac();
+u8 *rtl8139_get_mac(void);
 
 #endif
diff --git a/kernel/inc/syscall.h b/kernel/inc/syscall.h
index 3f89365..ff13d39 100644
--- a/kernel/inc/syscall.h
+++ b/kernel/inc/syscall.h
@@ -3,6 +3,6 @@
 #ifndef SYSCALL_H
 #define SYSCALL_H
 
-void syscall_init();
+void syscall_init(void);
 
 #endif
diff --git a/kernel/inc/test.h b/kernel/inc/test.h
deleted file mode 100644
index 8bd0d41..0000000
--- a/kernel/inc/test.h
+++ /dev/null
@@ -1,24 +0,0 @@
-// MIT License, Copyright (c) 2020 Marvin Borner
-
-#ifndef TEST_H
-#define TEST_H
-
-#include <boot.h>
-#include <print.h>
-#include <str.h>
-
-#define a_mag 0x55
-#define b_mag 0x42
-
-void pass_or_fail(const char *file_name, int line_num, const char *func, const char *first,
-		  const char *second, int success);
-
-#define check(exp) pass_or_fail(__FILE__, __LINE__, __func__, #exp, "1", exp);
-#define equals(first, second)                                                                      \
-	pass_or_fail(__FILE__, __LINE__, __func__, #first, #second, (first) == (second));
-#define equals_str(first, second)                                                                  \
-	pass_or_fail(__FILE__, __LINE__, __func__, #first, #second, strcmp((first), (second)) == 0);
-
-void test_all(struct vid_info *vid_info);
-
-#endif
diff --git a/kernel/inc/timer.h b/kernel/inc/timer.h
index fbd1500..21dd437 100644
--- a/kernel/inc/timer.h
+++ b/kernel/inc/timer.h
@@ -5,9 +5,9 @@
 
 #include <def.h>
 
-u32 timer_get();
+u32 timer_get(void);
 void timer_wait(u32 ticks);
-void timer_install();
-void timer_handler(); // For scheduler
+void timer_install(void);
+void timer_handler(void); // For scheduler
 
 #endif
diff --git a/libc/Makefile b/libc/Makefile
index a290445..0b7e279 100644
--- a/libc/Makefile
+++ b/libc/Makefile
@@ -16,7 +16,8 @@ LD = ccache ../cross/opt/bin/i686-elf-ld
 AR = ccache ../cross/opt/bin/i686-elf-ar
 AS = ccache nasm
 
-CFLAGS = -Wall -Wextra -nostdlib -nostdinc -fno-builtin -mgeneral-regs-only -std=c99 -m32 -pedantic-errors -Iinc/ -Ofast
+WARNINGS = -Wall -Wextra -pedantic-errors -Wshadow -Wpointer-arith -Wwrite-strings -Wredundant-decls -Wnested-externs -Wno-long-long
+CFLAGS = $(WARNINGS) -nostdlib -nostdinc -fno-builtin -mgeneral-regs-only -std=c99 -m32 -Iinc/ -Ofast
 
 ASFLAGS = -f elf32
 
@@ -29,7 +30,7 @@ libc: $(COBJS)
 	@mkdir -p ../build/
 	@$(AR) rcs ../build/libc.a crt0.o $+
 
-libk: CFLAGS += -Dkernel -ffreestanding
+libk: CFLAGS += -Dkernel -ffreestanding $(CFLAGS_EXTRA)
 libk: $(COBJS)
 	@mkdir -p ../build/
 	@$(AR) rcs ../build/libk.a $+
diff --git a/libc/conv.c b/libc/conv.c
index 3bde4ec..d0a9a59 100644
--- a/libc/conv.c
+++ b/libc/conv.c
@@ -8,7 +8,7 @@
 static const char HTOA_TABLE[] = "0123456789ABCDEF";
 static const char ITOA_TABLE[] = "0123456789";
 
-int atoi(char *str)
+int atoi(const char *str)
 {
 	u32 s_str = strlen(str);
 	if (!s_str)
@@ -58,7 +58,7 @@ char *htoa(u32 n)
 	return ret;
 }
 
-int htoi(char *str)
+int htoi(const char *str)
 {
 	u32 s_str = strlen(str);
 
diff --git a/libc/cpu.c b/libc/cpu.c
index 1f0b7e4..52c0280 100644
--- a/libc/cpu.c
+++ b/libc/cpu.c
@@ -76,35 +76,35 @@ char *cpu_string(char buf[13])
 	return buf;
 }
 
-void cpu_print()
+void cpu_print(void)
 {
 	char buf[13] = { 0 };
 	printf("%s\n", cpu_string(buf));
 }
 
 #ifdef kernel
-void cli()
+void cli(void)
 {
 	__asm__ volatile("cli");
 }
 
-void sti()
+void sti(void)
 {
 	__asm__ volatile("sti");
 }
 
-void hlt()
+void hlt(void)
 {
 	__asm__ volatile("hlt");
 }
 
-void idle()
+void idle(void)
 {
 	while (1)
 		hlt();
 }
 
-void loop()
+void loop(void)
 {
 	cli();
 	idle();
diff --git a/libc/inc/assert.h b/libc/inc/assert.h
index f4fa4b4..3e45f44 100644
--- a/libc/inc/assert.h
+++ b/libc/inc/assert.h
@@ -10,9 +10,9 @@
 #define assert(exp)                                                                                \
 	if (!(exp)) {                                                                              \
 		printf("%s:%d: %s: Assertion '%s' failed\n", __FILE__, __LINE__, __func__, #exp);  \
-		struct proc *proc = proc_current();                                                \
-		if (proc)                                                                          \
-			proc_exit(proc, 1);                                                        \
+		struct proc *assert_proc = proc_current();                                         \
+		if (assert_proc)                                                                   \
+			proc_exit(assert_proc, 1);                                                 \
 		else                                                                               \
 			__asm__ volatile("cli\nhlt");                                              \
 	}
diff --git a/libc/inc/conv.h b/libc/inc/conv.h
index d878deb..adf9003 100644
--- a/libc/inc/conv.h
+++ b/libc/inc/conv.h
@@ -5,9 +5,9 @@
 
 #include <def.h>
 
-int atoi(char *str);
+int atoi(const char *str);
 char *htoa(u32 n);
-int htoi(char *str);
+int htoi(const char *str);
 char *itoa(int n);
 
 char *conv_base(int value, char *result, int base, int is_signed);
diff --git a/libc/inc/cpu.h b/libc/inc/cpu.h
index e742390..033743d 100644
--- a/libc/inc/cpu.h
+++ b/libc/inc/cpu.h
@@ -18,14 +18,14 @@ void outl(u16 port, u32 data);
 
 void cpuid(int code, u32 *a, u32 *b, u32 *c, u32 *d);
 char *cpu_string(char buf[12]);
-void cpu_print();
+void cpu_print(void);
 
 #ifdef kernel
-void cli();
-void sti();
-void hlt();
-void idle();
-void loop();
+void cli(void);
+void sti(void);
+void hlt(void);
+void idle(void);
+void loop(void);
 #endif
 
 static inline void spinlock(int *ptr)
diff --git a/libgui/Makefile b/libgui/Makefile
index a29a393..6d2f087 100644
--- a/libgui/Makefile
+++ b/libgui/Makefile
@@ -8,7 +8,8 @@ CC = ccache ../cross/opt/bin/i686-elf-gcc
 LD = ccache ../cross/opt/bin/i686-elf-ld
 AR = ccache ../cross/opt/bin/i686-elf-ar
 
-CFLAGS = -Wall -Wextra -nostdlib -nostdinc -fno-builtin -mgeneral-regs-only -std=c99 -m32 -pedantic-errors -Iinc/ -I../libc/inc/ -fPIE -Duserspace -Ofast
+WARNINGS = -Wall -Wextra -pedantic-errors -Wshadow -Wpointer-arith -Wwrite-strings -Wredundant-decls -Wnested-externs -Wno-long-long
+CFLAGS = $(WARNINGS) -nostdlib -nostdinc -fno-builtin -mgeneral-regs-only -std=c99 -m32 -Iinc/ -I../libc/inc/ -fPIE -Duserspace -Ofast
 
 all: libgui
 
diff --git a/libgui/bmp.c b/libgui/bmp.c
index 0b08aeb..25745a7 100644
--- a/libgui/bmp.c
+++ b/libgui/bmp.c
@@ -6,7 +6,7 @@
 #include <print.h>
 #include <sys.h>
 
-struct bmp *bmp_load(char *path)
+struct bmp *bmp_load(const char *path)
 {
 	void *buf = read(path);
 	if (!buf)
diff --git a/libgui/gfx.c b/libgui/gfx.c
index 6e8b56a..304f935 100644
--- a/libgui/gfx.c
+++ b/libgui/gfx.c
@@ -28,7 +28,7 @@ static void load_font(enum font_type font_type)
 	if (fonts[font_type])
 		return;
 
-	char *path = NULL;
+	const char *path = NULL;
 
 	switch (font_type) {
 	case FONT_8:
@@ -111,7 +111,7 @@ void gfx_write(struct context *ctx, int x, int y, enum font_type font_type, u32
 	/* gfx_redraw(); */
 }
 
-void gfx_load_image(struct context *ctx, char *path, int x, int y)
+void gfx_load_image(struct context *ctx, const char *path, int x, int y)
 {
 	// TODO: Support x, y
 	struct bmp *bmp = bmp_load(path);
@@ -130,7 +130,7 @@ void gfx_load_image(struct context *ctx, char *path, int x, int y)
 	/* gfx_redraw(); */
 }
 
-void gfx_load_wallpaper(struct context *ctx, char *path)
+void gfx_load_wallpaper(struct context *ctx, const char *path)
 {
 	gfx_load_image(ctx, path, 0, 0);
 }
diff --git a/libgui/inc/bmp.h b/libgui/inc/bmp.h
index 909bc92..ea7a07f 100644
--- a/libgui/inc/bmp.h
+++ b/libgui/inc/bmp.h
@@ -34,6 +34,6 @@ struct bmp {
 	u32 pitch;
 };
 
-struct bmp *bmp_load(char *path);
+struct bmp *bmp_load(const char *path);
 
 #endif
diff --git a/libgui/inc/gfx.h b/libgui/inc/gfx.h
index 0b37d84..58a03cb 100644
--- a/libgui/inc/gfx.h
+++ b/libgui/inc/gfx.h
@@ -67,8 +67,8 @@ struct context {
 struct font *gfx_resolve_font(enum font_type font_type);
 void gfx_write_char(struct context *ctx, int x, int y, enum font_type font_type, u32 c, char ch);
 void gfx_write(struct context *ctx, int x, int y, enum font_type font_type, u32 c, char *text);
-void gfx_load_image(struct context *ctx, char *path, int x, int y);
-void gfx_load_wallpaper(struct context *ctx, char *path);
+void gfx_load_image(struct context *ctx, const char *path, int x, int y);
+void gfx_load_wallpaper(struct context *ctx, const char *path);
 void gfx_copy(struct context *dest, struct context *src, int x, int y, u32 width, u32 height);
 void gfx_ctx_on_ctx(struct context *dest, struct context *src, int x, int y);
 void gfx_draw_rectangle(struct context *ctx, int x1, int y1, int x2, int y2, u32 c);
diff --git a/libtxt/Makefile b/libtxt/Makefile
index 3731aa2..436cb3b 100644
--- a/libtxt/Makefile
+++ b/libtxt/Makefile
@@ -5,7 +5,8 @@ CC = ccache ../cross/opt/bin/i686-elf-gcc
 LD = ccache ../cross/opt/bin/i686-elf-ld
 AR = ccache ../cross/opt/bin/i686-elf-ar
 
-CFLAGS = -Wall -Wextra -nostdlib -nostdinc -fno-builtin -mgeneral-regs-only -std=c99 -m32 -pedantic-errors -Iinc/ -I../libc/inc/ -fPIE -Duserspace -Ofast
+WARNINGS = -Wall -Wextra -pedantic-errors -Wshadow -Wpointer-arith -Wwrite-strings -Wredundant-decls -Wnested-externs -Wno-long-long
+CFLAGS = $(WARNINGS) -nostdlib -nostdinc -fno-builtin -mgeneral-regs-only -std=c99 -m32 -Iinc/ -I../libc/inc/ -fPIE -Duserspace -Ofast
 
 all: libtxt