Moved stuff around and added a makefile also got a custom bootloader

based on the JazzOS bootloader (modified a bit)

source/kernel/features/cli.asm

@@ -0,0 +1,90 @@
+os_start_cli:
+	pusha
+	
+	call os_print_newline
+
+	mov si, prompt
+	call os_print_string
+
+	mov ax, 20
+
+	mov di, user_input
+
+	call os_display_input
+
+
+; ------------------------------------------------
+
+os_read_cli:
+	pusha
+
+.output_the_user_input:
+	call os_print_newline
+
+.check_matches:			; Check if the user input matches any internal commands
+	mov si, user_input
+	mov di, help_string
+	call os_compare_strings
+	cmp cl, 1
+	je help
+
+	mov si, user_input
+	mov di, clear_string
+	call os_compare_strings
+	cmp cl, 1
+	je clear
+	
+	mov si, user_input
+	mov di, pong_string
+	call os_compare_strings
+	cmp cl, 1
+	je pong
+
+	mov si, user_input
+	mov di, snake_string
+	call os_compare_strings
+	cmp cl, 1
+	je snake
+
+	jmp .unkown
+
+.unkown:
+	mov si, unknown_command
+	call os_print_string
+	mov si, user_input
+	call os_print_string_nl
+	jmp .finish
+
+.finish:
+	popa
+	call os_start_cli
+
+clear:
+	call os_set_text_mode
+	call os_read_cli.finish
+
+help:
+	mov si, help_text
+	call os_print_string_nl
+	call os_read_cli.finish
+
+pong:
+	call game_pong
+	call os_read_cli.finish
+
+snake:
+   call game_snake
+   call os_read_cli.finish
+
+section .data
+    welcome_text db 'Welcome to CrawOS, the Cool, Real and AWsome Operating System', 0
+	user_input times 20 db 0
+	prompt_length db 20
+	prompt db 'CrawOS sh> ', 0
+	help_string db 'HELP', 0
+	clear_string db 'CLEAR', 0
+	pong_string db 'PONG', 0
+	snake_string db 'SNAKE', 0
+	help_text db 'This is for Cowards: "HELP" for this help text, "CLEAR" to clear the screen, esc to reboot', 0
+	command_result_text db 'You typed: ', 0
+	unknown_command db 'Error: Unkown Command.. ', 0

source/kernel/features/graphics.asm

@@ -0,0 +1,53 @@
+os_set_graphics_mode:
+	pusha
+
+	mov ah, 00h
+	mov al, 13h
+	int 10h
+
+	popa
+	ret
+
+; --------------------------------------
+
+; x_end
+; y_end
+; x_start
+; y_start
+; colour
+os_draw_graphical_rectangle:
+	; Tell BIOS we're changing 'da pixels!
+	mov ah, 0Ch
+
+	mov al, 1100b
+
+	mov cx, [x_start]
+	mov dx, [y_start]
+
+	jmp .x_loop
+
+.x_loop:
+   int 10h
+   cmp cx, [x_end]
+   je .next_row
+   inc cx
+   call .x_loop
+
+.next_row:
+   mov cx, [x_start]
+   cmp dx, [y_end]
+   je .finish
+   inc dx					; Increase Row
+   call .x_loop
+
+.finish:
+   ret
+
+
+section .data
+	x_start dw 0
+	y_start dw 0
+	x_end dw 0
+	y_end dw 0
+	colour db 1111b
+

source/kernel/features/keyboard.asm

@@ -0,0 +1,77 @@
+; AX = key pressed
+os_read_input:
+	mov ah, 11h			; BIOS call to check for key
+	int 16h				; Interrupt
+	jnz .key_pressed		; Jump if input isn't 0
+
+	hlt
+	jmp os_read_input
+
+.key_pressed:
+	mov ah, 10h
+	int 16h
+	ret
+
+; -------------------------------------------
+
+os_display_input:
+	pusha
+	mov cx, [prompt_length]
+
+.loop:
+	call .check_key_pressed
+
+	jmp .loop
+
+.check_key_pressed:
+	call os_read_input
+
+	cmp al, 08h
+	je .backspace
+
+	cmp al, 0Dh
+	je .enter_key
+
+	cmp al, 1Bh
+	je .esc_key
+
+	cmp cx, 0
+	jb .check_key_pressed
+
+	call .print_current_input
+	dec cx
+	jmp .check_key_pressed
+
+.esc_key:
+	call os_reboot
+
+.enter_key:
+	mov al, 0
+	stosb
+	popa
+	call os_read_cli
+
+.backspace:
+	call .move_cursor_back			; then .move_cursor_back
+	call .loop				; Else .loop
+
+.move_cursor_back:
+	mov ah, 0Eh
+
+	mov al, 08h
+	int 10h
+	mov al, 20h
+	int 10h
+	mov al, 08h
+	int 10h
+
+	dec di
+	jmp os_display_input
+
+.print_current_input:
+	stosb
+
+	mov ah, 0Eh
+	int 10h
+
+	ret

source/kernel/features/power.asm

@@ -0,0 +1,6 @@
+os_reboot:
+   	mov ax, 0x5307
+   	mov bx, 0x0001
+   	mov cx, 0x0003
+   	int 0x19
+

source/kernel/features/strings.asm

@@ -0,0 +1,26 @@
+; How string comparison works
+;                   DI => scasb compares value stored in DI which is 's' with 's' stored in AX register
+;                         and then increments DI if DF is 0
+;                    v
+; memory address 1: |s|n|a|t|0|       
+; memory address 2: |s|n|a|k|e|0|     
+;                    ^
+;                   SI => lodsb loads value stored at SI to AX and then increments SI if DF is 0
+os_compare_strings:	
+	cld
+
+.compare:
+	lodsb
+	scasb			; Compare di to si
+	jne .unequal		; If they are no equal, jump to .unequal
+	cmp al, 0		; Check if string is finished
+	je .equal		; If it has, return true
+	jmp .compare		; Finally, repeat
+
+.unequal:
+	mov cl, 0		; Change to 0 if unquality is proven
+	ret
+
+.equal:
+	mov cl, 1
+	ret

source/kernel/features/text.asm

@@ -0,0 +1,70 @@
+; SI = pointer to start of string to be printed
+os_print_string:
+	pusha
+
+	mov ah, 0Eh			; int 10h teletype function, we're telling the BIOS we will print something
+
+.repeat:
+	lodsb				; Get char from si into al
+	cmp al, 0			; Compare al to 0
+	je .done			; If char is zero, end of string
+
+	int 10h				; Otherwise, print it
+	jmp .repeat			; And move on to next char
+
+.done:
+	popa
+	ret
+
+; Exact same as the above procedure, but this adds a newline 
+; after priting, similar to the difference between Rust's print! and println!
+os_print_string_nl:				
+	pusha
+
+	mov ah, 0Eh			; int 10h teletype function, we're telling the BIOS we will print something
+
+.repeat:
+	lodsb				; Get char from si into al
+	cmp al, 0			; Compare al to 0
+	je .done			; If char is zero, end of string
+
+	int 10h				; Otherwise, print it
+	jmp .repeat			; And move on to next char
+
+.done:
+	call os_print_newline
+	popa
+	ret
+
+; --------------------------------------------
+
+os_print_newline:
+	pusha
+	
+	mov ah, 0Eh
+	mov al, 13
+	int 10h
+	mov al, 10
+	int 10h
+
+	popa
+	ret
+
+; -------------------------------------------
+
+os_set_text_mode:
+	pusha
+	; Set mode = 80x25 (text mode)
+	mov ah, 00h
+	mov al, 03h
+	int 10h
+
+	; Move cursor to the top left
+	mov ah, 02h
+	mov dh, 0
+	mov dl, 0
+	int 10h
+
+	popa
+	ret
+