separating: there will be libk and libc

2025-01-07 15:23:14 +01:00
parent b3687d20ee
commit a8582ba343
32 changed files with 29 additions and 31 deletions
--- a/kernel/gdt.c
+++ b/kernel/gdt.c
@@ -0,0 +1,44 @@
+// Global descriptor table setup
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include "gdt.h"
+#include "../libk/stdio.h"
+
+struct gdt_entry gdt[3];
+struct gdt_ptr gp;
+
+extern void gdt_flush();
+
+void gdt_set_gate(int num, unsigned long base, unsigned long limit, unsigned char access, unsigned char gran)
+{
+	gdt[num].base_low = (base & 0xFFFF);
+	gdt[num].base_middle = (base >> 16) & 0xFF;
+	gdt[num].base_high = (base >> 24) & 0xFF;
+
+	gdt[num].limit_low = (limit & 0xFFFF);
+	gdt[num].granularity = ((limit >> 16) & 0x0F);
+
+	gdt[num].granularity |= (gran & 0xF0);
+	gdt[num].access = access;
+}
+
+void gdt_install()
+{
+	gp.limit = (sizeof(struct gdt_entry)*3) - 1;
+	gp.base = (unsigned int)&gdt;
+
+	gdt_set_gate(0, 0, 0, 0, 0);
+	
+	// Ring 0 code + data
+	gdt_set_gate(1, 0, 0xFFFFFFFF, 0x9A, 0xCF);
+	gdt_set_gate(2, 0, 0xFFFFFFFF, 0x92, 0xCF);
+
+	// Ring 3
+	//gdt_set_gate(3, 0, 0xFFFFFFFF, 0xFA, 0xCF);
+	//gdt_set_gate(4, 0, 0xFFFFFFFF, 0xF2, 0xCF);
+
+	gdt_flush();
+	printf("[kernel] GDT gates set (ring 0), gdt=0x%x\n", (unsigned int)&gdt);
+}
--- a/kernel/gdt.h
+++ b/kernel/gdt.h
@@ -0,0 +1,28 @@
+// Global descriptor table setup header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#ifndef GDT_H
+#define GDT_H
+
+struct gdt_entry
+{
+	unsigned short limit_low;
+	unsigned short base_low;
+	unsigned char base_middle;
+	unsigned char access;
+	unsigned char granularity;
+	unsigned char base_high;
+} __attribute__((packed));
+
+struct gdt_ptr
+{
+	unsigned short limit;
+	unsigned int base;
+} __attribute__((packed));
+
+void gdt_set_gate(int num, unsigned long base, unsigned long limit, unsigned char access, unsigned char gran);
+void gdt_install();
+
+#endif
--- a/kernel/idt.c
+++ b/kernel/idt.c
@@ -0,0 +1,34 @@
+// Interrupt descriptor table setup
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include "idt.h"
+#include "system.h"
+#include "../libk/stdio.h"
+
+struct idt_entry idt[256];
+struct idt_ptr idtp;
+
+extern void idt_load();
+
+void idt_set_gate(unsigned char num, unsigned long base, unsigned short sel, unsigned char flags)
+{
+	idt[num].base_lo = (base & 0xFFFF);
+	idt[num].base_hi = (base >> 16) & 0xFFFF;
+
+	idt[num].sel = sel;
+	idt[num].always0 = 0;
+	idt[num].flags = flags;
+}
+
+void idt_install()
+{
+	idtp.limit = (sizeof (struct idt_entry)*256) - 1;
+	idtp.base = (unsigned int)&idt;
+
+	memset(&idt, 0, sizeof(struct idt_entry)*256);
+
+	idt_load();
+	printf("[kernel] loaded IDT at idt=0x%x\n", (unsigned int)&idt);
+}
--- a/kernel/idt.h
+++ b/kernel/idt.h
@@ -0,0 +1,27 @@
+// Interrupt descriptor table setup header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#ifndef IDT_H
+#define IDT_H
+
+struct idt_entry
+{
+	unsigned short base_lo;
+	unsigned short sel;
+	unsigned char always0;
+	unsigned char flags;
+	unsigned short base_hi;
+} __attribute__((packed));
+
+struct idt_ptr
+{
+	unsigned short limit;
+	unsigned int base;
+} __attribute__((packed));
+
+void idt_set_gate(unsigned char num, unsigned long base, unsigned short sel, unsigned char flags);
+void idt_install();
+
+#endif
--- a/kernel/initrd.c
+++ b/kernel/initrd.c
@@ -0,0 +1,250 @@
+// Initial TAR ramdisk kernel module 
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include "../libk/stdio.h"
+#include <stdint.h>
+#include "../libk/string.h"
+#include "initrd.h"
+#include "system.h"
+#include "kheap.h"
+
+static unsigned int octal_to_int(const char* str, size_t size)
+{
+	unsigned int result = 0;
+	while (*str && size-- > 0)
+	{
+		result = (result << 3) | (*str - '0');
+		str++;
+	}
+	return result;
+}
+
+uint32_t tar_parse_size(const char* in)
+{
+	uint32_t size = 0;
+	while (*in >= '0' && *in <= '7')
+	{
+		size = (size*8) + (*in - '0');
+		in++;
+	}
+	return size;
+}
+
+uint32_t tar_get_size(tar_header_t* header)
+{
+	uint32_t size = 0;
+	char* size_str = header->size;
+
+	for (int i=0; i<11 && size_str[i] != '\0'; i++)
+	{
+		size = size*8 + (size_str[i]-'0');
+	}
+	return size;
+}
+
+void tar_find_file(uint8_t *tar_start, const char* filename)
+{
+	uint8_t *ptr = tar_start;
+
+	while (1)
+	{
+		tar_header_t *header = (tar_header_t*)ptr;
+
+		if (header->filename[0] == '\0')
+		{
+			puts("[tar] EOF\n");
+			break;
+		}
+
+		unsigned int filesize = octal_to_int(header->size, 11);
+
+		if (strcmp(header->filename, filename) == 0)
+		{
+			printf("[tar] found file '%s', size=%u bytes\n", header->filename, filesize);
+
+			uint8_t *file_data = ptr+TAR_BLOCK_SIZE;
+			printf("[tar] content of '%s':\n", filename);
+			for (unsigned int i=0; i<filesize; i++)
+			{
+				putc(file_data[i]);
+			}
+			puts("\n");
+			return;
+		}
+
+		ptr += TAR_BLOCK_SIZE + ((filesize + TAR_BLOCK_SIZE-1) / TAR_BLOCK_SIZE) * TAR_BLOCK_SIZE;
+	}
+
+	printf("[tar] file '%s' not found\n", filename);
+}
+
+void ls_initrd(uint8_t* initrd, int verbose)
+{
+	tar_header_t *header = (tar_header_t*)initrd;
+	
+	if (verbose)
+	{
+		puts("Size       Type  Filename\n");
+	}
+
+	while (header->filename[0] != '\0')
+	{
+		if (!verbose)
+		{
+			if (header->typeflag == '5')
+			{
+				colorprintf(cyan, black, "%s\n", header->filename);
+			} else {
+				printf("%s\n", header->filename);
+			}
+		} else {
+			if (header->typeflag == '5')
+			{
+				printf("%7d\t%c\t", (int)header->size, header->typeflag);
+				colorprintf(cyan, black, " %s\n", header->filename);
+			} else {
+
+				printf("%7d\t%c\t %s\n", (int)header->size, header->typeflag, header->filename);
+			}
+		}
+
+		uint32_t size = tar_parse_size(header->size);
+		uint32_t next_file_offset = ((size+TAR_BLOCK_SIZE-1)/TAR_BLOCK_SIZE)*TAR_BLOCK_SIZE;
+		header = (tar_header_t*)((uint8_t*)header + next_file_offset + TAR_BLOCK_SIZE);
+	}
+}
+
+void cat_initrd(uint8_t* initrd, const char* filename)
+{
+	tar_header_t *header = (tar_header_t*)initrd;
+
+	while (header->filename[0] != '\0')
+	{
+		if (strcmp(header->filename, filename) == 0)
+		{
+			uint32_t size = tar_parse_size(header->size);
+			uint8_t* file_content = (uint8_t*)header + 512;
+
+			for (uint32_t i=0; i<size; i++) putc(file_content[i]);
+			return;
+		}
+
+		uint32_t next_file_offset = ((tar_parse_size(header->size)+TAR_BLOCK_SIZE-1)/TAR_BLOCK_SIZE)*TAR_BLOCK_SIZE;
+		header = (tar_header_t*)((uint8_t*)header + next_file_offset + TAR_BLOCK_SIZE);
+	}
+
+	printf("File '%s' not found\n", filename);
+}
+
+int tar_file_to_buffer(uint8_t* initrd, const char* filename, char* buffer)
+{
+	uint8_t* current_block = initrd;
+
+	while (1)
+	{
+		if (current_block[0] == '\0')
+		{
+			//puts("[tar] EOF\n");
+			return -1;
+		}
+
+		const char* file_name = (const char*)current_block;
+		uint32_t file_size = tar_parse_size((const char*)(current_block+124));
+
+		if (strcmp(file_name, filename) == 0)
+		{
+			uint8_t* file_data = current_block + TAR_BLOCK_SIZE;
+			if (sizeof(buffer) >= sizeof(file_data))
+			{
+				memcpy(buffer, file_data, file_size);
+				buffer[file_size] = '\0';
+				return 0;
+			} else {
+				printf("Invalid destination buffer size %d bytes < %d bytes\n", sizeof(buffer), sizeof(file_data));
+				return -1;
+			}
+			return -1;
+		}
+
+		uint32_t total_size = ((file_size + TAR_BLOCK_SIZE - 1) / TAR_BLOCK_SIZE) * TAR_BLOCK_SIZE;
+		current_block += TAR_BLOCK_SIZE + total_size;
+	}
+	printf("[tar] file '%s' not found\n", filename);
+	return -1;
+}
+
+uint32_t tar_get_file_size(uint8_t* initrd, const char* filename)
+{
+	uint8_t* current_block = initrd;
+
+	while (1)
+	{
+		if (current_block[0] == '\0')
+		{
+			return -1;
+		}
+
+		const char* file_name = (const char*)current_block;
+		uint32_t file_size = tar_parse_size((const char*)(current_block+124));
+
+		if (strcmp(file_name, filename) == 0)
+		{
+			return file_size;
+		}
+
+		uint32_t total_size = ((file_size + TAR_BLOCK_SIZE - 1) / TAR_BLOCK_SIZE) * TAR_BLOCK_SIZE;
+		current_block += TAR_BLOCK_SIZE + total_size;
+	}
+	return -1;
+}
+
+tar_header_t* tar_find(uint8_t* initrd, const char* filename)
+{
+	tar_header_t* header = (tar_header_t*)initrd;
+	while (header->filename[0] != '\0')
+	{
+		if (strcmp(header->filename, filename) == 0)
+		{
+			return header;
+		}
+
+		uint32_t file_size = tar_get_size(header);
+		uint32_t file_blocks = (file_size + 511)/512;
+		header = (tar_header_t*) ((uintptr_t)header+(file_blocks+1)*512);
+	}
+
+	return NULL;
+}
+
+void* tar_get_file_content(tar_header_t* header)
+{
+	return (void*) ((uintptr_t)header+512);
+}
+
+void* load_file_from_initrd(uint8_t* initrd, const char* filename)
+{
+	tar_header_t* file = tar_find(initrd, filename);
+	if (file == NULL)
+	{
+		printf("'%s' not found\n", filename);
+		return NULL;
+	}
+
+	uint32_t file_size = tar_get_size(file);
+
+	void* file_data = malloc(file_size);
+	if (file_data == NULL)
+	{
+		printf("Malloc error for file '%s'\n", filename);
+		return NULL;
+	}
+
+	void* file_content = tar_get_file_content(file);
+	memcpy(file_data, file_content, file_size);
+
+	printf("[initrd] Loaded '%s' at 0x%x, size=%u\n", filename, (unsigned int)file_data, file_size);
+
+	return file_data;
+}
--- a/kernel/initrd.h
+++ b/kernel/initrd.h
@@ -0,0 +1,40 @@
+// Initial TAR ramdisk kernel module header 
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#ifndef INITRD_H
+#define INITRD_H
+
+#define TAR_BLOCK_SIZE 512
+
+#include "system.h"
+
+typedef struct
+{
+	char filename[100];
+	char mode[8];
+	char owner[8];
+	char group[8];
+	char size[12];
+	char mtime[12];
+	char checksum[8];
+	char typeflag;
+	char linkname[100];
+	char magic[6];
+	char version[2];
+	char uname[32];
+	char gname[32];
+	char devmajor[8];
+	char devminor[8];
+	char prefix[155];
+} tar_header_t;
+
+void tar_find_file(uint8_t *tar_start, const char* filename);
+void ls_initrd(uint8_t* initrd, int verbose);
+void cat_initrd(uint8_t* initrd, const char* filename);
+int tar_file_to_buffer(uint8_t* initrd, const char* filename, char* buffer);
+uint32_t tar_get_file_size(uint8_t* initrd, const char* filename);
+void* load_file_from_initrd(uint8_t* initrd, const char* filename);
+
+#endif
--- a/kernel/io.h
+++ b/kernel/io.h
@@ -0,0 +1,15 @@
+// Raw CPU port I/O kernel module header 
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#ifndef IO_H
+#define IO_H
+
+#include <stdint.h>
+
+void outb(unsigned short port, unsigned char data);
+unsigned char inb(unsigned short port);
+void x86_div64_32(uint64_t dividend, uint32_t divisor, uint64_t* quotientOut, uint32_t* remainderOut);
+
+#endif
--- a/kernel/io.s
+++ b/kernel/io.s
@@ -0,0 +1,49 @@
+; Raw CPU port I/O kernel module
+; Author: xamidev
+; Licensed under the Unlicense. See the repo below.
+; https://github.com/xamidev/blankos
+
+global outb
+
+outb:
+    mov al, [esp + 8]
+    mov dx, [esp + 4]
+    out dx, al
+    ret
+
+global inb
+
+inb:
+    mov dx, [esp + 4]
+    in al, dx
+    ret
+
+global x86_div64_32
+
+x86_div64_32:
+    push ebp
+    mov ebp, esp
+
+    ; Arguments:
+    ; [ebp + 8]  - lower 32 bits of dividend (uint32_t)
+    ; [ebp + 12] - upper 32 bits of dividend (uint32_t)
+    ; [ebp + 16] - divisor (uint32_t)
+    ; [ebp + 20] - pointer to quotient (uint64_t*)
+    ; [ebp + 24] - pointer to remainder (uint32_t*)
+
+    mov eax, [ebp + 8]
+    mov edx, [ebp + 12]
+
+    mov ecx, [ebp + 16]
+
+    div ecx
+    mov esi, [ebp + 20]
+    mov [esi], eax
+
+    mov dword [esi + 4], 0
+
+    mov esi, [ebp + 24]
+    mov [esi], edx
+
+    pop ebp
+    ret
--- a/kernel/irq.c
+++ b/kernel/irq.c
@@ -0,0 +1,97 @@
+// Interrupt Requests setup
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include "system.h"
+#include "io.h"
+#include "idt.h"
+#include "../libk/stdio.h"
+
+extern void irq0();
+extern void irq1();
+extern void irq2();
+extern void irq3();
+extern void irq4();
+extern void irq5();
+extern void irq6();
+extern void irq7();
+extern void irq8();
+extern void irq9();
+extern void irq10();
+extern void irq11();
+extern void irq12();
+extern void irq13();
+extern void irq14();
+extern void irq15();
+
+void *irq_routines[16] =
+{
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0
+};
+
+void irq_install_handler(int irq, void (*handler)(struct regs *r))
+{
+	irq_routines[irq] = handler;
+}
+
+void irq_uninstall_handler(int irq)
+{
+	irq_routines[irq] = 0;
+}
+
+void irq_remap(void)
+{
+	outb(0x20, 0x11);
+	outb(0xA0, 0x11);
+	outb(0x21, 0x20);
+	outb(0xA1, 0x28);
+	outb(0x21, 0x04);
+	outb(0xA1, 0x02);
+	outb(0x21, 0x01);
+	outb(0xA1, 0x01);
+	outb(0x21, 0x0);
+	outb(0xA1, 0x0);
+}
+
+void irq_install()
+{
+	irq_remap();
+
+	idt_set_gate(32, (unsigned)irq0, 0x08, 0x8E);
+	idt_set_gate(33, (unsigned)irq1, 0x08, 0x8E);
+	idt_set_gate(34, (unsigned)irq2, 0x08, 0x8E);
+	idt_set_gate(35, (unsigned)irq3, 0x08, 0x8E);
+	idt_set_gate(36, (unsigned)irq4, 0x08, 0x8E);
+	idt_set_gate(37, (unsigned)irq5, 0x08, 0x8E);
+	idt_set_gate(38, (unsigned)irq6, 0x08, 0x8E);
+	idt_set_gate(39, (unsigned)irq7, 0x08, 0x8E);
+	idt_set_gate(40, (unsigned)irq8, 0x08, 0x8E);
+	idt_set_gate(41, (unsigned)irq9, 0x08, 0x8E);
+	idt_set_gate(42, (unsigned)irq10, 0x08, 0x8E);
+	idt_set_gate(43, (unsigned)irq11, 0x08, 0x8E);
+	idt_set_gate(44, (unsigned)irq12, 0x08, 0x8E);
+	idt_set_gate(45, (unsigned)irq13, 0x08, 0x8E);
+	idt_set_gate(46, (unsigned)irq14, 0x08, 0x8E);
+	idt_set_gate(47, (unsigned)irq15, 0x08, 0x8E);
+	printf("[kernel] installed irq 0-15\n");
+}
+
+void irq_handler(struct regs *r)
+{
+	void (*handler)(struct regs *r);
+
+	handler = irq_routines[r->int_no-32];
+	if (handler)
+	{
+		handler(r);
+	}
+
+	if (r->int_no >= 40)
+	{
+		outb(0xA0, 0x20);
+	}
+
+	outb(0x20, 0x20);
+}
--- a/kernel/isr.c
+++ b/kernel/isr.c
@@ -0,0 +1,122 @@
+// Interrupt service routines setup 
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include "system.h"
+#include "../libk/stdio.h"
+#include "idt.h"
+
+extern void isr0();
+extern void isr1();
+extern void isr2();
+extern void isr3();
+extern void isr4();
+extern void isr5();
+extern void isr6();
+extern void isr7();
+extern void isr8();
+extern void isr9();
+extern void isr10();
+extern void isr11();
+extern void isr12();
+extern void isr13();
+extern void isr14();
+extern void isr15();
+extern void isr16();
+extern void isr17();
+extern void isr18();
+extern void isr19();
+extern void isr20();
+extern void isr21();
+extern void isr22();
+extern void isr23();
+extern void isr24();
+extern void isr25();
+extern void isr26();
+extern void isr27();
+extern void isr28();
+extern void isr29();
+extern void isr30();
+extern void isr31();
+
+void isr_install()
+{
+	idt_set_gate(0, (unsigned)isr0, 0x08, 0x8E);
+	idt_set_gate(1, (unsigned)isr1, 0x08, 0x8E);
+	idt_set_gate(2, (unsigned)isr2, 0x08, 0x8E);
+	idt_set_gate(3, (unsigned)isr3, 0x08, 0x8E);
+	idt_set_gate(4, (unsigned)isr4, 0x08, 0x8E);
+	idt_set_gate(5, (unsigned)isr5, 0x08, 0x8E);
+	idt_set_gate(6, (unsigned)isr6, 0x08, 0x8E);
+	idt_set_gate(7, (unsigned)isr7, 0x08, 0x8E);
+	idt_set_gate(8, (unsigned)isr8, 0x08, 0x8E);
+	idt_set_gate(9, (unsigned)isr9, 0x08, 0x8E);
+	idt_set_gate(10, (unsigned)isr10, 0x08, 0x8E);
+	idt_set_gate(11, (unsigned)isr11, 0x08, 0x8E);
+	idt_set_gate(12, (unsigned)isr12, 0x08, 0x8E);
+	idt_set_gate(13, (unsigned)isr13, 0x08, 0x8E);
+	idt_set_gate(14, (unsigned)isr14, 0x08, 0x8E);
+	idt_set_gate(15, (unsigned)isr15, 0x08, 0x8E);
+	idt_set_gate(16, (unsigned)isr16, 0x08, 0x8E);
+	idt_set_gate(17, (unsigned)isr17, 0x08, 0x8E);
+	idt_set_gate(18, (unsigned)isr18, 0x08, 0x8E);
+	idt_set_gate(19, (unsigned)isr19, 0x08, 0x8E);
+	idt_set_gate(20, (unsigned)isr20, 0x08, 0x8E);
+	idt_set_gate(21, (unsigned)isr21, 0x08, 0x8E);
+	idt_set_gate(22, (unsigned)isr22, 0x08, 0x8E);
+	idt_set_gate(23, (unsigned)isr23, 0x08, 0x8E);
+	idt_set_gate(24, (unsigned)isr24, 0x08, 0x8E);
+	idt_set_gate(25, (unsigned)isr25, 0x08, 0x8E);
+	idt_set_gate(26, (unsigned)isr26, 0x08, 0x8E);
+	idt_set_gate(27, (unsigned)isr27, 0x08, 0x8E);
+	idt_set_gate(28, (unsigned)isr28, 0x08, 0x8E);
+	idt_set_gate(29, (unsigned)isr29, 0x08, 0x8E);
+	idt_set_gate(30, (unsigned)isr30, 0x08, 0x8E);
+	idt_set_gate(31, (unsigned)isr31, 0x08, 0x8E);
+	printf("[kernel] set ISRs 0-31\n");
+}
+
+char *exception_messages[] =
+{
+	"Division by Zero",
+	"Debug",
+	"Non Maskable Interrupt",
+	"Breakpoint",
+	"Into Detected Overflow",
+	"Out of Bounds",
+	"Invalid Opcode",
+	"No Coprocessor",
+	"Double Fault",
+	"Coprocessor Segment Overrun",
+	"Bad TSS",
+	"Segment Not Present",
+	"Stack Fault",
+	"General Protection Fault",
+	"Page Fault",
+	"Unknown Interrupt",
+	"Coprocessor Fault",
+	"Alignment Check",
+	"Machine Check",
+	"Reserved",
+	"Reserved",
+	"Reserved",
+	"Reserved",
+	"Reserved",
+	"Reserved",
+	"Reserved",
+	"Reserved",
+	"Reserved",
+	"Reserved",
+	"Reserved",
+	"Reserved"
+};
+
+void fault_handler(struct regs *r)
+{
+	if (r->int_no < 32)
+	{
+		colorprintf(white, red, "\n\n*** [Kernel panic - %s Exception] ***\nInterrupt error code %u\nedi: 0x%x\nesi: 0x%x\nebp: 0x%x\nesp: 0x%x\neip: 0x%x\neax: 0x%x\nebx: 0x%x\necx: 0x%x\nedx: 0x%x\ncs: 0x%x\neflags: 0x%x\nss: 0x%x\ngs: 0x%x\nfs: 0x%x\nes: 0x%x\nds: 0x%x\nHalting!\n", exception_messages[r->int_no], r->err_code, r->edi, r->esi, r->ebp, r->esp, r->eip, r->eax, r->ebx, r->ecx, r->edx, r->cs, r->eflags, r->ss, r->gs, r->fs, r->es, r->ds);
+		for (;;);
+	}
+}
--- a/kernel/kheap.c
+++ b/kernel/kheap.c
@@ -0,0 +1,83 @@
+// Kernel heap management
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include "kheap.h"
+#include <stdint.h>
+#include "system.h"
+#include "../libk/stdio.h"
+
+// Free list allocator
+
+static uint8_t heap[HEAP_SIZE];
+static block_t* free_list = NULL;
+
+void init_alloc()
+{
+	free_list = (block_t*)heap;
+	free_list->size = HEAP_SIZE-sizeof(block_t);
+	free_list->next = NULL;
+	printf("[kernel] initialized heap and allocator, start=0x%x\n", heap);
+}
+
+void* malloc(size_t size)
+{
+	block_t* prev = NULL;
+	block_t* curr = free_list;
+
+	while (curr != NULL)
+	{
+		if (curr->size >= size)
+		{
+			if (curr->size > (size_t)(size + sizeof(block_t)))
+			{
+				block_t* new_block = (block_t*)((uint8_t*)curr + sizeof(block_t) + size);
+				new_block->size = curr->size - size - sizeof(block_t);
+				new_block->next = curr->next;
+				curr->size = size;
+				curr->next = new_block;
+			}
+
+			if (prev == NULL)
+			{
+				free_list = curr->next;
+			} else {
+				prev->next = curr->next;
+			}
+
+			return (void*)((uint8_t*)curr + sizeof(block_t));
+		}
+
+		prev = curr;
+		curr = curr->next;
+	}
+
+	return NULL;
+}
+
+void* calloc(size_t num, size_t size)
+{
+	size_t total_size = num*size;
+	void* ptr = malloc(total_size);
+
+	if (ptr != NULL)
+	{
+		uint8_t* byte_ptr = (uint8_t*)ptr;
+		for (size_t i=0; i<total_size; i++)
+		{
+			byte_ptr[i] = 0;
+		}
+	}
+
+	return ptr;
+}
+
+void free(void* ptr)
+{
+	if (ptr == NULL) return;
+
+	block_t* block_to_free = (block_t*)((uint8_t*)ptr - sizeof(block_t));
+	block_to_free->next = free_list;
+	free_list = block_to_free;
+}
--- a/kernel/kheap.h
+++ b/kernel/kheap.h
@@ -0,0 +1,25 @@
+// Kernel heap management header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#ifndef KHEAP_H
+#define KHEAP_H
+
+#include <stdint.h>
+#include "system.h"
+
+typedef struct block
+{
+	size_t size;
+	struct block* next;
+} block_t;
+
+#define HEAP_SIZE 1024*1024	// 1MB malloc-able
+
+void init_alloc();
+void* malloc(size_t size);
+void free(void* ptr);
+void* calloc(size_t num, size_t size);
+
+#endif
--- a/kernel/kmain.c
+++ b/kernel/kmain.c
@@ -0,0 +1,117 @@
+// Kernel entry point
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include "../libk/stdio.h"
+#include "../drivers/serial.h"
+#include "gdt.h"
+#include "idt.h"
+#include "system.h"
+#include <stdint.h>
+#include "../drivers/framebuffer.h"
+#include "kmain.h"
+#include "multiboot2.h"
+#include "kheap.h"
+#include "initrd.h"
+
+void kmain(multiboot2_info *mb_info)
+{
+	multiboot2_tag_framebuffer *fb_info = NULL;
+	struct multiboot_tag_mmap *mmap_tag = NULL;
+	struct multiboot_tag_module *initrd_module = NULL;
+
+    uint8_t *tags = mb_info->tags;
+    while (1) {
+        uint32_t tag_type = *((uint32_t*) tags);
+        uint32_t tag_size = *((uint32_t*) (tags + 4));
+
+        if (tag_type == 0) break;
+        if (tag_type == MULTIBOOT_TAG_TYPE_FRAMEBUFFER) {
+            fb_info = (multiboot2_tag_framebuffer*) tags;
+        }
+	if (tag_type == MULTIBOOT_TAG_TYPE_MMAP) {
+		mmap_tag = (struct multiboot_tag_mmap*) tags;
+	}
+	if (tag_type == MULTIBOOT_TAG_TYPE_MODULE) {
+		initrd_module = (struct multiboot_tag_module*) tags;
+	}
+
+        tags += ((tag_size + 7) & ~7);
+    }
+
+    if (fb_info) { // fb setup
+        framebuffer = (uint32_t *)(uintptr_t) fb_info->framebuffer_addr;
+
+        uint32_t width = fb_info->framebuffer_width;
+        uint32_t height = fb_info->framebuffer_height;
+        bpp = fb_info->framebuffer_bpp;
+	pitch = fb_info->framebuffer_pitch;
+
+        //8x16 font, not padded 
+        VGA_WIDTH = width/8;
+        VGA_HEIGHT = height/16;
+        serial_printf(3, "VGA_WIDTH=%d, VGA_HEIGHT=%d", VGA_WIDTH, VGA_HEIGHT);
+        scanline = width * (bpp/8);	
+
+    	serial_printf(3, "Framebuffer Address: 0x%x", fb_info->framebuffer_addr);
+	serial_printf(3, "Framebuffer Width: %u", fb_info->framebuffer_width);
+	serial_printf(3, "Framebuffer Height: %u", fb_info->framebuffer_height);
+	serial_printf(3, "Framebuffer Pitch: %u", fb_info->framebuffer_pitch);
+	serial_printf(3, "Framebuffer BPP: %u", fb_info->framebuffer_bpp);
+    }
+    psf_init();
+    printf("[kernel] multiboot2 info at 0x%x, size=%u\n", mb_info, mb_info->total_size);
+    printf("[kernel] framebuffer discovered at 0x%x\n", (unsigned int)fb_info->framebuffer_addr);
+    printf("[kernel] fb0: width=%u, height=%u, pitch=%u, bpp=%u\n", fb_info->framebuffer_width, fb_info->framebuffer_height, fb_info->framebuffer_pitch, fb_info->framebuffer_bpp);
+
+    if (mmap_tag) // memmap debug print
+    {
+	puts("[kernel] found memory map tag by multiboot2\n");
+	struct multiboot_mmap_entry *mmap = mmap_tag->entries;
+
+	while ((uint8_t*) mmap < tags + mmap_tag->size)
+	{
+		
+		if (mmap->addr != 0)
+		{
+			/*
+			serial_printf(3, "base addr=0x%x%x, length=0x%x%x, type=%u",
+				(uint32_t) (mmap->addr >> 32),
+				(uint32_t) (mmap->addr & 0xFFFFFFFF),
+				(uint32_t) (mmap->len >> 32),
+				(uint32_t) (mmap->len & 0xFFFFFFFF),
+				mmap->type);
+			*/
+		}
+
+		mmap = (struct multiboot_mmap_entry*) ((uint8_t*)mmap + mmap_tag->entry_size);
+	}
+    }
+
+    if (initrd_module) {
+	initrd_addr = initrd_module->mod_start;
+
+	uint32_t initrd_start = initrd_module->mod_start;
+	uint32_t initrd_end = initrd_module->mod_end;
+	uint32_t initrd_size = initrd_end - initrd_start;
+
+	printf("[kernel] TAR initrd module found at 0x%x, size=%u bytes\n", initrd_start, initrd_size);
+
+    } else {
+	puts("[kernel] TAR initrd module not found\n");
+    }
+
+    init_serial();
+    gdt_install();
+    idt_install();
+    isr_install();
+    irq_install();
+    __asm__ __volatile__("sti");
+
+    init_alloc();
+
+    timer_install();
+    printf("Nothing to do, halting...");
+    asm("hlt");
+}
--- a/kernel/kmain.h
+++ b/kernel/kmain.h
@@ -0,0 +1,44 @@
+// Kernel entry point header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#ifndef KMAIN_H
+#define KMAIN_H
+
+#define BLANK_VERSION "0.3.123-alpha"
+
+#include <stdint.h>
+
+typedef struct {
+    uint32_t type;
+    uint32_t size;
+    uint64_t framebuffer_addr;
+    uint32_t framebuffer_pitch;
+    uint32_t framebuffer_width;
+    uint32_t framebuffer_height;
+    uint8_t framebuffer_bpp;
+    uint8_t framebuffer_type;
+    uint16_t reserved;
+} multiboot2_tag_framebuffer;
+
+typedef struct {
+    uint32_t total_size;
+    uint32_t reserved;
+    uint8_t tags[0];
+} multiboot2_info;
+
+unsigned int g_multiboot_info_address;
+
+uint32_t* framebuffer;
+int scanline;
+uint32_t initrd_addr;
+
+// in characters, not pixels
+uint32_t VGA_WIDTH;
+uint32_t VGA_HEIGHT;
+
+uint32_t bpp;
+uint32_t pitch;
+
+#endif
--- a/kernel/loader.s
+++ b/kernel/loader.s
@@ -0,0 +1,217 @@
+; Kernel loader assembly stub and multiboot2 header
+; Author: xamidev
+; Licensed under the Unlicense. See the repo below.
+; https://github.com/xamidev/blankos
+
+global loader
+
+section .multiboot_header
+
+mb_start:
+align 8
+
+; ASM macros
+
+MAGIC_NUMBER      equ 0xe85250d6  	; multiboot2 magic 
+FLAGS             equ 0x0	  		; 32-bit protected mode for i386
+HEADER_LEN	  equ mb_end-mb_start
+CHECKSUM          equ -(MAGIC_NUMBER + FLAGS + HEADER_LEN)
+
+; Multiboot 2 header, according to specification (16bytes)
+
+  dd MAGIC_NUMBER		; dd = 4 bytes = 32bits = u32
+  dd FLAGS			
+  dd HEADER_LEN
+  dd CHECKSUM
+
+; Tags? (28bytes)
+
+; Tag 1 : set graphics mode (only recommended, can be overriden by GRUB)
+  align 8
+  dw 5			; 2
+  dw 0			; 2
+  dd 20			; 4
+  dd 1920		; 4
+  dd 1080		; 4
+  dd 32			; 4
+
+; End of tags
+
+  align 8
+  dw 0			; 2
+  dw 0			; 2
+  dd 8			; 4
+
+; End of Multiboot 2 header
+mb_end:
+
+section .text:
+
+KERNEL_STACK_SIZE equ 4096
+extern kmain
+
+loader:
+	mov esp, kernel_stack + KERNEL_STACK_SIZE
+  	cli
+  	push ebx
+  	call kmain
+
+.loop:
+  	jmp .loop
+
+global gdt_flush
+extern gp
+
+gdt_flush:
+	lgdt [gp]
+	mov ax, 0x10
+	mov ds, ax
+	mov es, ax
+	mov fs, ax
+	mov gs, ax
+	mov ss, ax
+	jmp 0x08:flush2
+
+flush2:
+	ret
+
+global idt_load
+extern idtp
+
+idt_load:
+	lidt [idtp]
+	ret
+
+%macro ISR_NOERRCODE 1
+	global isr%1
+	isr%1:
+		cli
+		push byte 0
+		push byte %1
+		jmp isr_common_stub
+%endmacro
+
+%macro ISR_ERRCODE 1
+	global isr%1
+	isr%1:
+		cli
+		push byte %1
+		jmp isr_common_stub
+%endmacro
+
+ISR_NOERRCODE 0
+ISR_NOERRCODE 1
+ISR_NOERRCODE 2
+ISR_NOERRCODE 3
+ISR_NOERRCODE 4
+ISR_NOERRCODE 5
+ISR_NOERRCODE 6
+ISR_NOERRCODE 7
+ISR_ERRCODE 8
+ISR_NOERRCODE 9
+ISR_ERRCODE 10
+ISR_ERRCODE 11
+ISR_ERRCODE 12
+ISR_ERRCODE 13
+ISR_ERRCODE 14
+ISR_NOERRCODE 15
+ISR_NOERRCODE 16
+ISR_NOERRCODE 17
+ISR_NOERRCODE 18
+ISR_NOERRCODE 19
+ISR_NOERRCODE 20
+ISR_NOERRCODE 21
+ISR_NOERRCODE 22
+ISR_NOERRCODE 23
+ISR_NOERRCODE 24
+ISR_NOERRCODE 25
+ISR_NOERRCODE 26
+ISR_NOERRCODE 27
+ISR_NOERRCODE 28
+ISR_NOERRCODE 29
+ISR_NOERRCODE 30
+ISR_NOERRCODE 31
+
+extern fault_handler
+
+isr_common_stub:
+	pusha
+	push ds
+	push es
+	push fs
+	push gs
+	mov ax, 0x10
+	mov ds, ax
+	mov es, ax
+	mov fs, ax
+	mov gs, ax
+	mov eax, esp
+	push eax
+	mov eax, fault_handler
+	call eax
+	pop eax
+	pop gs
+	pop fs
+	pop es
+	pop ds
+	popa
+	add esp, 8
+	iret
+
+%macro IRQ 2
+	global irq%1
+	irq%1:
+		cli
+		push byte 0
+		push byte %2
+		jmp irq_common_stub
+%endmacro
+
+IRQ	0,	32
+IRQ	1,	33
+IRQ	2,	34
+IRQ	3,	35
+IRQ	4,	36
+IRQ	5,	37
+IRQ	6,	38
+IRQ	7,	39
+IRQ	8,	40
+IRQ	9,	41
+IRQ	10,	42
+IRQ	11,	43
+IRQ	12,	44
+IRQ	13,	45
+IRQ	14,	46
+IRQ	15,	47
+
+extern irq_handler
+
+irq_common_stub:
+	pusha
+	push ds
+	push es
+	push fs
+	push gs
+	mov ax, 0x10
+	mov ds, ax
+	mov es, ax
+	mov fs, ax
+	mov gs, ax
+	mov eax, esp
+	push eax
+	mov eax, irq_handler
+	call eax
+	pop eax
+	pop gs
+	pop fs
+	pop es
+	pop ds
+	popa
+	add esp, 8
+	iret
+
+section .bss
+align 4 
+
+kernel_stack:
+	resb KERNEL_STACK_SIZE
--- a/kernel/multiboot2.h
+++ b/kernel/multiboot2.h
@@ -0,0 +1,417 @@
+/*   multiboot2.h - Multiboot 2 header file. */
+/*   Copyright (C) 1999,2003,2007,2008,2009,2010  Free Software Foundation, Inc.
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to
+ *  deal in the Software without restriction, including without limitation the
+ *  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ *  sell copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in
+ *  all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL ANY
+ *  DEVELOPER OR DISTRIBUTOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ *  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+ *  IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef MULTIBOOT_HEADER
+#define MULTIBOOT_HEADER 1
+
+/*  How many bytes from the start of the file we search for the header. */
+#define MULTIBOOT_SEARCH                        32768
+#define MULTIBOOT_HEADER_ALIGN                  8
+
+/*  The magic field should contain this. */
+#define MULTIBOOT2_HEADER_MAGIC                 0xe85250d6
+
+/*  This should be in %eax. */
+#define MULTIBOOT2_BOOTLOADER_MAGIC             0x36d76289
+
+/*  Alignment of multiboot modules. */
+#define MULTIBOOT_MOD_ALIGN                     0x00001000
+
+/*  Alignment of the multiboot info structure. */
+#define MULTIBOOT_INFO_ALIGN                    0x00000008
+
+/*  Flags set in the ’flags’ member of the multiboot header. */
+
+#define MULTIBOOT_TAG_ALIGN                  8
+#define MULTIBOOT_TAG_TYPE_END               0
+#define MULTIBOOT_TAG_TYPE_CMDLINE           1
+#define MULTIBOOT_TAG_TYPE_BOOT_LOADER_NAME  2
+#define MULTIBOOT_TAG_TYPE_MODULE            3
+#define MULTIBOOT_TAG_TYPE_BASIC_MEMINFO     4
+#define MULTIBOOT_TAG_TYPE_BOOTDEV           5
+#define MULTIBOOT_TAG_TYPE_MMAP              6
+#define MULTIBOOT_TAG_TYPE_VBE               7
+#define MULTIBOOT_TAG_TYPE_FRAMEBUFFER       8
+#define MULTIBOOT_TAG_TYPE_ELF_SECTIONS      9
+#define MULTIBOOT_TAG_TYPE_APM               10
+#define MULTIBOOT_TAG_TYPE_EFI32             11
+#define MULTIBOOT_TAG_TYPE_EFI64             12
+#define MULTIBOOT_TAG_TYPE_SMBIOS            13
+#define MULTIBOOT_TAG_TYPE_ACPI_OLD          14
+#define MULTIBOOT_TAG_TYPE_ACPI_NEW          15
+#define MULTIBOOT_TAG_TYPE_NETWORK           16
+#define MULTIBOOT_TAG_TYPE_EFI_MMAP          17
+#define MULTIBOOT_TAG_TYPE_EFI_BS            18
+#define MULTIBOOT_TAG_TYPE_EFI32_IH          19
+#define MULTIBOOT_TAG_TYPE_EFI64_IH          20
+#define MULTIBOOT_TAG_TYPE_LOAD_BASE_ADDR    21
+
+#define MULTIBOOT_HEADER_TAG_END  0
+#define MULTIBOOT_HEADER_TAG_INFORMATION_REQUEST  1
+#define MULTIBOOT_HEADER_TAG_ADDRESS  2
+#define MULTIBOOT_HEADER_TAG_ENTRY_ADDRESS  3
+#define MULTIBOOT_HEADER_TAG_CONSOLE_FLAGS  4
+#define MULTIBOOT_HEADER_TAG_FRAMEBUFFER  5
+#define MULTIBOOT_HEADER_TAG_MODULE_ALIGN  6
+#define MULTIBOOT_HEADER_TAG_EFI_BS        7
+#define MULTIBOOT_HEADER_TAG_ENTRY_ADDRESS_EFI32  8
+#define MULTIBOOT_HEADER_TAG_ENTRY_ADDRESS_EFI64  9
+#define MULTIBOOT_HEADER_TAG_RELOCATABLE  10
+
+#define MULTIBOOT_ARCHITECTURE_I386  0
+#define MULTIBOOT_ARCHITECTURE_MIPS32  4
+#define MULTIBOOT_HEADER_TAG_OPTIONAL 1
+
+#define MULTIBOOT_LOAD_PREFERENCE_NONE 0
+#define MULTIBOOT_LOAD_PREFERENCE_LOW 1
+#define MULTIBOOT_LOAD_PREFERENCE_HIGH 2
+
+#define MULTIBOOT_CONSOLE_FLAGS_CONSOLE_REQUIRED 1
+#define MULTIBOOT_CONSOLE_FLAGS_EGA_TEXT_SUPPORTED 2
+
+#ifndef ASM_FILE
+
+typedef unsigned char           multiboot_uint8_t;
+typedef unsigned short          multiboot_uint16_t;
+typedef unsigned int            multiboot_uint32_t;
+typedef unsigned long long      multiboot_uint64_t;
+
+struct multiboot_header
+{
+  /*  Must be MULTIBOOT_MAGIC - see above. */
+  multiboot_uint32_t magic;
+
+  /*  ISA */
+  multiboot_uint32_t architecture;
+
+  /*  Total header length. */
+  multiboot_uint32_t header_length;
+
+  /*  The above fields plus this one must equal 0 mod 2^32. */
+  multiboot_uint32_t checksum;
+};
+
+struct multiboot_header_tag
+{
+  multiboot_uint16_t type;
+  multiboot_uint16_t flags;
+  multiboot_uint32_t size;
+};
+
+struct multiboot_header_tag_information_request
+{
+  multiboot_uint16_t type;
+  multiboot_uint16_t flags;
+  multiboot_uint32_t size;
+  multiboot_uint32_t requests[0];
+};
+
+struct multiboot_header_tag_address
+{
+  multiboot_uint16_t type;
+  multiboot_uint16_t flags;
+  multiboot_uint32_t size;
+  multiboot_uint32_t header_addr;
+  multiboot_uint32_t load_addr;
+  multiboot_uint32_t load_end_addr;
+  multiboot_uint32_t bss_end_addr;
+};
+
+struct multiboot_header_tag_entry_address
+{
+  multiboot_uint16_t type;
+  multiboot_uint16_t flags;
+  multiboot_uint32_t size;
+  multiboot_uint32_t entry_addr;
+};
+
+struct multiboot_header_tag_console_flags
+{
+  multiboot_uint16_t type;
+  multiboot_uint16_t flags;
+  multiboot_uint32_t size;
+  multiboot_uint32_t console_flags;
+};
+
+struct multiboot_header_tag_framebuffer
+{
+  multiboot_uint16_t type;
+  multiboot_uint16_t flags;
+  multiboot_uint32_t size;
+  multiboot_uint32_t width;
+  multiboot_uint32_t height;
+  multiboot_uint32_t depth;
+};
+
+struct multiboot_header_tag_module_align
+{
+  multiboot_uint16_t type;
+  multiboot_uint16_t flags;
+  multiboot_uint32_t size;
+};
+
+struct multiboot_header_tag_relocatable
+{
+  multiboot_uint16_t type;
+  multiboot_uint16_t flags;
+  multiboot_uint32_t size;
+  multiboot_uint32_t min_addr;
+  multiboot_uint32_t max_addr;
+  multiboot_uint32_t align;
+  multiboot_uint32_t preference;
+};
+
+struct multiboot_color
+{
+  multiboot_uint8_t red;
+  multiboot_uint8_t green;
+  multiboot_uint8_t blue;
+};
+
+struct multiboot_mmap_entry
+{
+  multiboot_uint64_t addr;
+  multiboot_uint64_t len;
+#define MULTIBOOT_MEMORY_AVAILABLE              1
+#define MULTIBOOT_MEMORY_RESERVED               2
+#define MULTIBOOT_MEMORY_ACPI_RECLAIMABLE       3
+#define MULTIBOOT_MEMORY_NVS                    4
+#define MULTIBOOT_MEMORY_BADRAM                 5
+  multiboot_uint32_t type;
+  multiboot_uint32_t zero;
+};
+typedef struct multiboot_mmap_entry multiboot_memory_map_t;
+
+struct multiboot_tag
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+};
+
+struct multiboot_tag_string
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  char string[0];
+};
+
+struct multiboot_tag_module
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  multiboot_uint32_t mod_start;
+  multiboot_uint32_t mod_end;
+  char cmdline[0];
+};
+
+struct multiboot_tag_basic_meminfo
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  multiboot_uint32_t mem_lower;
+  multiboot_uint32_t mem_upper;
+};
+
+struct multiboot_tag_bootdev
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  multiboot_uint32_t biosdev;
+  multiboot_uint32_t slice;
+  multiboot_uint32_t part;
+};
+
+struct multiboot_tag_mmap
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  multiboot_uint32_t entry_size;
+  multiboot_uint32_t entry_version;
+  struct multiboot_mmap_entry entries[0];  
+};
+
+struct multiboot_vbe_info_block
+{
+  multiboot_uint8_t external_specification[512];
+};
+
+struct multiboot_vbe_mode_info_block
+{
+  multiboot_uint8_t external_specification[256];
+};
+
+struct multiboot_tag_vbe
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+
+  multiboot_uint16_t vbe_mode;
+  multiboot_uint16_t vbe_interface_seg;
+  multiboot_uint16_t vbe_interface_off;
+  multiboot_uint16_t vbe_interface_len;
+
+  struct multiboot_vbe_info_block vbe_control_info;
+  struct multiboot_vbe_mode_info_block vbe_mode_info;
+};
+
+struct multiboot_tag_framebuffer_common
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+
+  multiboot_uint64_t framebuffer_addr;
+  multiboot_uint32_t framebuffer_pitch;
+  multiboot_uint32_t framebuffer_width;
+  multiboot_uint32_t framebuffer_height;
+  multiboot_uint8_t framebuffer_bpp;
+#define MULTIBOOT_FRAMEBUFFER_TYPE_INDEXED 0
+#define MULTIBOOT_FRAMEBUFFER_TYPE_RGB     1
+#define MULTIBOOT_FRAMEBUFFER_TYPE_EGA_TEXT     2
+  multiboot_uint8_t framebuffer_type;
+  multiboot_uint16_t reserved;
+};
+
+struct multiboot_tag_framebuffer
+{
+  struct multiboot_tag_framebuffer_common common;
+
+  union
+  {
+    struct
+    {
+      multiboot_uint16_t framebuffer_palette_num_colors;
+      struct multiboot_color framebuffer_palette[0];
+    };
+    struct
+    {
+      multiboot_uint8_t framebuffer_red_field_position;
+      multiboot_uint8_t framebuffer_red_mask_size;
+      multiboot_uint8_t framebuffer_green_field_position;
+      multiboot_uint8_t framebuffer_green_mask_size;
+      multiboot_uint8_t framebuffer_blue_field_position;
+      multiboot_uint8_t framebuffer_blue_mask_size;
+    };
+  };
+};
+
+struct multiboot_tag_elf_sections
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  multiboot_uint32_t num;
+  multiboot_uint32_t entsize;
+  multiboot_uint32_t shndx;
+  char sections[0];
+};
+
+struct multiboot_tag_apm
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  multiboot_uint16_t version;
+  multiboot_uint16_t cseg;
+  multiboot_uint32_t offset;
+  multiboot_uint16_t cseg_16;
+  multiboot_uint16_t dseg;
+  multiboot_uint16_t flags;
+  multiboot_uint16_t cseg_len;
+  multiboot_uint16_t cseg_16_len;
+  multiboot_uint16_t dseg_len;
+};
+
+struct multiboot_tag_efi32
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  multiboot_uint32_t pointer;
+};
+
+struct multiboot_tag_efi64
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  multiboot_uint64_t pointer;
+};
+
+struct multiboot_tag_smbios
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  multiboot_uint8_t major;
+  multiboot_uint8_t minor;
+  multiboot_uint8_t reserved[6];
+  multiboot_uint8_t tables[0];
+};
+
+struct multiboot_tag_old_acpi
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  multiboot_uint8_t rsdp[0];
+};
+
+struct multiboot_tag_new_acpi
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  multiboot_uint8_t rsdp[0];
+};
+
+struct multiboot_tag_network
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  multiboot_uint8_t dhcpack[0];
+};
+
+struct multiboot_tag_efi_mmap
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  multiboot_uint32_t descr_size;
+  multiboot_uint32_t descr_vers;
+  multiboot_uint8_t efi_mmap[0];
+}; 
+
+struct multiboot_tag_efi32_ih
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  multiboot_uint32_t pointer;
+};
+
+struct multiboot_tag_efi64_ih
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  multiboot_uint64_t pointer;
+};
+
+struct multiboot_tag_load_base_addr
+{
+  multiboot_uint32_t type;
+  multiboot_uint32_t size;
+  multiboot_uint32_t load_base_addr;
+};
+
+#endif /*  ! ASM_FILE */
+
+#endif /*  ! MULTIBOOT_HEADER */
--- a/kernel/system.c
+++ b/kernel/system.c
@@ -0,0 +1,53 @@
+// System utilities and routines kernel module
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include "system.h"
+#include <stdint.h>
+
+void *memset(void *dest, char val, size_t count)
+{
+	char *temp = (char *)dest;
+	for(; count != 0; count--) *temp++ = val;
+	return dest;
+}
+
+void *memmove(void* dest, const void* src, size_t n)
+{
+	unsigned char* d = (unsigned char*)dest;
+	const unsigned char* s = (const unsigned char*)src;
+
+	if (d < s)
+	{
+		for (size_t i=0; i<n; i++)
+		{
+			d[i] = s[i];
+		}
+	} else {
+		for (size_t i=n; i>0; i--)
+		{
+			d[i-1] = s[i-1];
+		}
+	}
+
+	return dest;
+}
+
+void *memcpy(void* dest, const void* src, uint32_t n)
+{
+	uint8_t* d = (uint8_t*)dest;
+	const uint8_t* s = (const uint8_t*)src;
+
+	for (uint32_t i=0; i<n; i++)
+	{
+		d[i] = s[i];
+	}
+	return dest;
+}
+
+void panic()
+{
+	for (;;);	
+}
+
--- a/kernel/system.h
+++ b/kernel/system.h
@@ -0,0 +1,45 @@
+// System utilities and routines kernel module header
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#ifndef SYSTEM_H
+#define SYSTEM_H
+
+#include <stdint.h>
+
+typedef int size_t;
+#define NULL ((void*)0)
+
+void *memset(void *dest, char val, size_t count);
+void *memmove(void* dest, const void* src, size_t n);
+void *memcpy(void* dest, const void* src, uint32_t n);
+
+struct regs
+{
+	unsigned int gs, fs, es, ds;
+	unsigned int edi, esi, ebp, esp, ebx, edx, ecx, eax;
+	unsigned int int_no, err_code;
+	unsigned int eip, cs, eflags, useresp, ss;
+};
+
+void panic();
+void isr_install();
+void irq_install();
+void irq_install_handler(int irq, void (*handler)(struct regs *r));
+void irq_uninstall_handler(int irq);
+void timer_install();
+void delay(int ticks);
+void keyboard_install();
+char keyboard_getchar();
+void shell_install();
+int uptime();
+
+extern volatile unsigned long global_ticks;
+
+extern unsigned int g_multiboot_info_address;
+
+void syscall_handler();
+
+#endif
+