Initial commit

make.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+cd src/
+nasm boot.asm -f bin -o ../build/boot.bin
+nasm os.asm -f bin -o ../build/os.bin
+
+cd ../build/
+cat boot.bin os.bin > EttinOS.img
+rm boot.bin os.bin

src/boot.asm

@@ -0,0 +1,23 @@
+[ORG 0x7c00]
+mov ax, 0
+mov ds, ax
+jmp 0:start
+start:
+
+mov ax, 0x1000
+mov es, ax
+mov bx, 0
+
+mov al, 32
+mov dh, 0
+mov ch, 0
+mov cl, 2
+
+mov ah, 2
+int 0x13
+
+jmp 0x1000:0
+
+times 510-($-$$) db 0
+db 0x55
+db 0xaa

src/os.asm

@@ -0,0 +1,93 @@
+mov ax, 0x1000
+mov ds, ax
+
+mov si, welcome
+call print
+
+loop:
+mov si, prompt
+call print
+mov di, input
+call read
+cmp byte [input], 0
+je loop
+mov si, input
+call print
+mov si, newline
+call print
+mov cx, 0x4e
+mov di, input
+mov al, 0
+rep stosb
+jmp loop
+
+print:
+lodsb
+cmp al, 0
+je .done
+mov ah, 0xe
+int 0x10
+jmp print
+.done:
+ret
+
+read:
+mov cl, 0
+.loop:
+mov ah, 0
+int 0x16
+cmp al, 0xd
+je .return
+cmp al, 8
+je .backspace
+cmp cl, 0x4d
+je .loop
+cmp al, 0x20
+je .space
+cmp al, 0x9
+je .erase
+cmp al, 0
+je .loop
+.character:
+mov byte [di], 0
+mov ah, 0xe
+int 0x10
+stosb
+inc cl
+jmp .loop
+.erase:
+mov al, 0x20
+jmp .character
+.space:
+cmp byte [di], 0
+je .character
+mov al, byte [di]
+mov ah, 0xe
+int 0x10
+inc di
+inc cl
+jmp .loop
+.backspace:
+cmp cl, 0
+je .loop
+mov ah, 0xe
+int 0x10
+dec di
+dec cl
+jmp .loop
+.return:
+mov si, newline
+call print
+ret
+
+welcome:
+db 0xd, 0xa, "Welcome to EttinOS!", 0xd, 0xa, 0xd, 0xa, 0
+
+input:
+times 78 db 0
+
+prompt:
+db "> ", 0
+
+newline:
+db 0xd, 0xa, 0