From b5d9cf5c89cb89dc49a2ff0af7ad9b334b4d8953 Mon Sep 17 00:00:00 2001
From: "E. Almqvist" <elalmqvist@gmail.com>
Date: Tue, 23 Feb 2021 11:35:43 +0100
Subject: [PATCH] Disk read stuff

---
 src/bootloader_bios_disk.asm | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/bootloader_bios_disk.asm b/src/bootloader_bios_disk.asm
index 21e3204..211051f 100644
--- a/src/bootloader_bios_disk.asm
+++ b/src/bootloader_bios_disk.asm
@@ -1,5 +1,24 @@
 disk_read:
 	pusha
 
+	push dx
 	mov ah, BIOS_DISK_READ 
-	mov al, dh ; number of sectors to read
+	mov al, dh ; sector count 
+	mov cl, 0x02
+
+	mov ch, 0x00 ; read from first cylinder
+	mov dh, 0x00 ; head
+
+	; data pointer: es:bx (standard)
+	int BIOS_DISK_INT ; do the interrupt
+	jc disk_error ; if flag is set then jump to error
+
+disk_error:
+	mov bx, DISK_ERROR
+	call println
+
+	mov dh, ah
+
+
+DISK_ERROR: db "Disk read error", ASCII_END
+SECTORS_ERROR: db "Invalid number of sectors read", ASCII_END