MyCatShoegazer · February 2, 2018 08:05 · alimkoca · Jul 28, 2021 · MyCatShoegazer · Jul 28, 2021
diff --git a/build.bat b/build.bat
 @echo on
 echo Bulding bin file...
 nasm loader.asm -f bin -o loader.bin

 echo Writing bin file to ploppy
 partcopy loader.bin 0 200 -f0
diff --git a/build.sh b/build.sh
 # Build bin file
 nasm loader.asm -f bin -o loader.bin

 # Write bin file to floppy
 dd if=loader.bin bs=512 of=/dev/fd0
diff --git a/loader.asm b/loader.asm
 [BITS 16]	                        ;Tells the assembler that its a 16 bit code
 [ORG 0x7C00]	                    ;Origin, tell the assembler that where the code will
 				                    ;be in memory after it is been loaded

 MOV SI, HelloString                 ;Store string pointer to SI
 CALL PrintString	                ;Call print string procedure
 JMP $ 		                        ;Infinite loop, hang it here.


 PrintCharacter:	                    ;Procedure to print character on screen
 	                                ;Assume that ASCII value is in register AL
 MOV AH, 0x0E	                    ;Tell BIOS that we need to print one charater on screen.
 MOV BH, 0x00	                    ;Page no.
 MOV BL, 0x07	                    ;Text attribute 0x07 is lightgrey font on black background

 INT 0x10	                        ;Call video interrupt
 RET		                            ;Return to calling procedure



 PrintString:	                    ;Procedure to print string on screen
 	                                ;Assume that string starting pointer is in register SI

 next_character:	                    ;Lable to fetch next character from string
 MOV AL, [SI]	                    ;Get a byte from string and store in AL register
 INC SI		                        ;Increment SI pointer
 OR AL, AL	                        ;Check if value in AL is zero (end of string)
 JZ exit_function                    ;If end then return
 CALL PrintCharacter                 ;Else print the character which is in AL register
 JMP next_character	                ;Fetch next character from string
 exit_function:	                    ;End label
 RET		                            ;Return from procedure


 ;Data
 HelloString db 'Hello World', 0	    ;HelloWorld string ending with 0

 TIMES 510 - ($ - $$) db 0	        ;Fill the rest of sector with 0
 DW 0xAA55			                ;Add boot signature at the end of bootloader
	@echo on
	echo Bulding bin file...
	nasm loader.asm -f bin -o loader.bin

	echo Writing bin file to ploppy
	partcopy loader.bin 0 200 -f0
	# Build bin file
	nasm loader.asm -f bin -o loader.bin

	# Write bin file to floppy
	dd if=loader.bin bs=512 of=/dev/fd0
	[BITS 16] ;Tells the assembler that its a 16 bit code
	[ORG 0x7C00] ;Origin, tell the assembler that where the code will
	;be in memory after it is been loaded

	MOV SI, HelloString ;Store string pointer to SI
	CALL PrintString ;Call print string procedure
	JMP $ ;Infinite loop, hang it here.


	PrintCharacter: ;Procedure to print character on screen
	;Assume that ASCII value is in register AL
	MOV AH, 0x0E ;Tell BIOS that we need to print one charater on screen.
	MOV BH, 0x00 ;Page no.
	MOV BL, 0x07 ;Text attribute 0x07 is lightgrey font on black background

	INT 0x10 ;Call video interrupt
	RET ;Return to calling procedure



	PrintString: ;Procedure to print string on screen
	;Assume that string starting pointer is in register SI

	next_character: ;Lable to fetch next character from string
	MOV AL, [SI] ;Get a byte from string and store in AL register
	INC SI ;Increment SI pointer
	OR AL, AL ;Check if value in AL is zero (end of string)
	JZ exit_function ;If end then return
	CALL PrintCharacter ;Else print the character which is in AL register
	JMP next_character ;Fetch next character from string
	exit_function: ;End label
	RET ;Return from procedure


	;Data
	HelloString db 'Hello World', 0 ;HelloWorld string ending with 0

	TIMES 510 - ($ - $$) db 0 ;Fill the rest of sector with 0
	DW 0xAA55 ;Add boot signature at the end of bootloader