Refactor duplicated code across kernel subsystems

kernel/include/command.h

@@ -4,5 +4,6 @@ void cmd_handle(const char* command);
 void cmd_ping();
 void cmd_crash();
 void cmd_reboot();
+void cmd_halt();
 void cmd_clear();
 void cmd_stack();

kernel/src/command/halt.c

@@ -0,0 +1,6 @@
+#include "command.h"
+#include "io.h"
+
+void cmd_halt() {
+	outw(0x604, 0x2000); // QEMU specific
+}

kernel/src/command/handle.c

@@ -1,24 +1,27 @@
 #include "command.h"
-#include "io.h"
 #include "utils.h"
 #include <stdio.h>
 #include <string.h>
 
+typedef struct {
+	const char* name;
+	void (*handler)(void);
+} command_t;
+
+static const command_t commands[] = {
+	{"ping", &cmd_ping}, {"crash", &cmd_crash}, {"reboot", &cmd_reboot},
+	{"halt", &cmd_halt}, {"clear", &cmd_clear}, {"stack", &cmd_stack},
+	{NULL, NULL} // sentinel
+};
+
 void cmd_handle(const char* command) {
-	if (strcmp(command, "ping") == 0) {
-		cmd_ping();
-	} else if (strcmp(command, "crash") == 0) {
-		cmd_crash();
-	} else if (strcmp(command, "reboot") == 0) {
-		cmd_reboot();
-	} else if (strcmp(command, "halt") == 0) {
-		outw(0x604, 0x2000); // QEMU specific
-	} else if (strcmp(command, "clear") == 0) {
-		cmd_clear();
-	} else if (strcmp(command, "stack") == 0) {
-		cmd_stack();
-	} else {
-		if (strlen(command) > 0)
-			printf("%s: command not found\n", command);
+	for (size_t i = 0; commands[i].name != NULL; i++) {
+		if (strcmp(command, commands[i].name) == 0) {
+			commands[i].handler();
+			return;
+		}
 	}
+
+	if (strlen(command) > 0)
+		printf("%s: command not found\n", command);
 }

kernel/src/memory/paging.c

@@ -42,6 +42,14 @@ static uintptr_t get_page_table_phys(uintptr_t virt_addr, bool create) {
 	return pt_phys;
 }
 
+static inline pte_t* get_page_table(uint32_t pd_idx, uintptr_t pt_phys) {
+	if (recursive_active()) {
+		return pt_virt_for_index(pd_idx);
+	} else {
+		return (pte_t*)pt_phys;
+	}
+}
+
 void map_page(uintptr_t virt_addr, uintptr_t phys_addr, uint32_t flags) {
 	virt_addr = page_align_down(virt_addr);
 	phys_addr = page_align_down(phys_addr);
@@ -50,12 +58,7 @@ void map_page(uintptr_t virt_addr, uintptr_t phys_addr, uint32_t flags) {
 	uint32_t pd_idx = pd_index(virt_addr);
 	uint32_t pt_idx = pt_index(virt_addr);
 
-	pte_t* pt;
-	if (recursive_active()) {
-		pt = pt_virt_for_index(pd_idx);
-	} else {
-		pt = (pte_t*)pt_phys;
-	}
+	pte_t* pt = get_page_table(pd_idx, pt_phys);
 
 	pt[pt_idx] = phys_addr | flags;
 	invlpg(virt_addr);
@@ -70,13 +73,8 @@ void unmap_page(uintptr_t virt_addr) {
 	if (!(page_directory[pd_idx] & PAGE_PRESENT))
 		return;
 
-	pte_t* pt;
-	if (recursive_active()) {
-		pt = pt_virt_for_index(pd_idx);
-	} else {
-		uintptr_t pt_phys = page_align_down(page_directory[pd_idx]);
-		pt = (pte_t*)pt_phys;
-	}
+	uintptr_t pt_phys = page_align_down(page_directory[pd_idx]);
+	pte_t* pt = get_page_table(pd_idx, pt_phys);
 
 	pt[pt_idx] = 0;
 	invlpg(virt_addr);
@@ -104,13 +102,8 @@ uintptr_t get_phys_addr(uintptr_t virt_addr) {
 		return 0;
 	}
 
-	const pte_t* pt;
-	if (recursive_active()) {
-		pt = pt_virt_for_index(pd_idx);
-	} else {
-		uintptr_t pt_phys = page_align_down(page_directory[pd_idx]);
-		pt = (pte_t*)pt_phys;
-	}
+	uintptr_t pt_phys = page_align_down(page_directory[pd_idx]);
+	const pte_t* pt = get_page_table(pd_idx, pt_phys);
 
 	if (!(pt[pt_idx] & PAGE_PRESENT)) {
 		return 0;

kernel/src/pic.c

@@ -1,5 +1,6 @@
 #include "pic.h"
 #include "io.h"
+#include <stdbool.h>
 
 void outb_wait(uint16_t port, uint8_t val) {
 	outb(port, val);
@@ -12,7 +13,7 @@ void pic_eoi(uint8_t irq) {
 	outb(PIC_PARENT_COMMAND, PIC_EOI);
 }
 
-void pic_enable_irq(uint8_t irq) {
+static void pic_set_irq_mask(uint8_t irq, bool enable) {
 	uint16_t port;
 	uint8_t mask;
 
@@ -23,25 +24,19 @@ void pic_enable_irq(uint8_t irq) {
 		irq -= 8;
 	}
 
-	mask = inb(port) & ~(1 << irq);
-	outb(port, mask);
-}
-
-void pic_disable_irq(uint8_t irq) {
-	uint16_t port;
-	uint8_t mask;
-
-	if (irq < 8) {
-		port = PIC_PARENT_DATA;
+	mask = inb(port);
+	if (enable) {
+		mask &= ~(1 << irq);
 	} else {
-		port = PIC_CHILD_DATA;
-		irq -= 8;
+		mask |= (1 << irq);
 	}
-
-	mask = inb(port) | (1 << irq);
 	outb(port, mask);
 }
 
+void pic_enable_irq(uint8_t irq) { pic_set_irq_mask(irq, true); }
+
+void pic_disable_irq(uint8_t irq) { pic_set_irq_mask(irq, false); }
+
 void pic_remap(int parent_offset, int child_offset) {
 	outb_wait(PIC_PARENT_COMMAND, PIC_ICW1_INIT);
 	outb_wait(PIC_CHILD_COMMAND, PIC_ICW1_INIT);

kernel/src/tty/printk.c

@@ -8,7 +8,7 @@ char* level_name[] = {"EMERG",	"ALERT", "CRIT",  "ERR", "WARN",
 					  "NOTICE", "INFO",	 "DEBUG", "",	 "CONT"};
 
 static int get_level(char c) {
-	if (c >= '0' || c <= '7')
+	if (c >= '0' && c <= '7')
 		return c - '0';
 	else if (c == 'c')
 		return 9;

kernel/src/tty/vprintf.c

@@ -20,17 +20,13 @@ int putnbr_base_unsigned(unsigned int n, const char* base) {
 int putnbr_base(long n, const char* base) {
 	if (!base)
 		return 0;
-	int len = 1;
-	size_t base_size = strlen(base);
+	int len = 0;
 	if (n < 0) {
 		tty_putchar('-');
 		n = -n;
 		++len;
 	}
-	if (n / base_size)
-		len += putnbr_base(n / base_size, base);
-	tty_putchar(base[n % base_size]);
-	return len;
+	return len + putnbr_base_unsigned((unsigned int)n, base);
 }
 
 int putstr_count(char* str) {