Little content

BIOS_equ.asm

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+; EQUs (lazy variables) for BIOS stuff
+BIOS_INT equ 0x10

README.md

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 # eOS
-A simple and operating system
+A simple x86_64 operating system. (BIOS)
 
-This operating system is in no way original nor do I recommend even taking a look at it. I am going of [this](https://tuhdo.github.io/os01/) book. I highly recommend it! :) 
+This operating system is in no way original nor do I recommend even taking a look at it. I am going of  unfinished book. 
+
+## Books
+[Operating Systems: From 0 to 1](https://tuhdo.github.io/os01/) (Open-Source, unfinished)
+[Writing a Simple Operating System - from Scratch](https://www.cs.bham.ac.uk/~exr/lectures/opsys/10_11/lectures/os-dev.pdf)

bootloader.asm

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+%include "BIOS_equ.asm"
+mov ah, 0x0e ; enter teletype mode (BIOS)
+
+mov al, "e"
+int BIOS_INT 
+
+mov al, "O"
+int BIOS_INT
+
+mov al, "S"
+int BIOS_INT
+
+mov al, 10 ; linebreak
+int BIOS_INT
+
+; ALPHABET PRINT
+
+
+mov al, 64 ; one less than A since we are printing in a loop and it increments before sys interupt
+loop:
+	inc al ; move to next char
+	int BIOS_INT ; bios interupt to print it
+	push al ; push al onto stack
+
+	mov al, 10 ; ASCII linebreak
+	int BIOS_INT 
+
+	pop al ; return to char
+
+	cmp al, 91 ; 26 letters in english alphabet (65 + 26)
+	jl loop ; if al < 65+26: jmp loop
+
 jmp $ 
 
 times 510-($-$$) db 0

start.sh

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+#!/usr/bin/bash
+qemu-system-x86_64 bin/bootloader.bin