add files
add some rule
add printf_txt function
add handle video for text mode graphic
add string.h and string.c
fix include check
split kernel to string and graphic_txt
add include check include/asm_functions.h
fix Makefile
add asm files
fix itoa and printf for Negative number
change file and directory structures
fix makefiles
add Macro
fix printf
fix gitignore
add initialize pic
fix README.md
add initialization PIT
add interrupt handlers but buggy yet