From e29dc737adaf9ba9fb4b1a6e8b74ca1a9afb4a4c Mon Sep 17 00:00:00 2001
From: Joe Tretter <j.tretter@gmail.com>
Date: Fri, 29 Aug 2025 19:07:30 -0500
Subject: [PATCH] add simple boot loader example

---
 bootloader1/boot.asm   | 21 +++++++++++++++++++++
 bootloader1/compile.sh |  3 +++
 2 files changed, 24 insertions(+)
 create mode 100644 bootloader1/boot.asm
 create mode 100755 bootloader1/compile.sh

diff --git a/bootloader1/boot.asm b/bootloader1/boot.asm
new file mode 100644
index 0000000..57840c2
--- /dev/null
+++ b/bootloader1/boot.asm
@@ -0,0 +1,21 @@
+; boot.asm - prints 'A' and halts
+BITS 16                  ; 16-bit real mode
+ORG 0x7C00               ; boot sector load address
+
+start:
+    mov ah, 0x0E         ; teletype output BIOS function
+    mov al, 'A'          ; character to print
+    mov bh, 0x00         ; page number 0
+    mov bl, 0x07         ; text attribute (light grey on black)
+    int 0x10             ; BIOS video interrupt
+
+    cli                  ; disable interrupts
+hang:
+    hlt                  ; halt CPU
+    jmp hang             ; infinite loop
+
+; fill the rest of the sector with zeros
+times 510-($-$$) db 0     
+
+; boot signature (2 bytes)
+dw 0xAA55
diff --git a/bootloader1/compile.sh b/bootloader1/compile.sh
new file mode 100755
index 0000000..147f43c
--- /dev/null
+++ b/bootloader1/compile.sh
@@ -0,0 +1,3 @@
+nasm -f bin boot.asm -o boot.bin
+dd if=boot.bin of=floppy.img bs=512 count=1 conv=notrunc
+qemu-system-x86_64 -fda floppy.img