From d7c1781d2fd357f844e3159775a3dc64aa6237fc Mon Sep 17 00:00:00 2001
From: Nero <41307858+nero@users.noreply.github.com>
Date: Thu, 18 Feb 2021 20:20:40 +0000
Subject: [PATCH] mbr: set up first 7 bytes of kernel PSP

---
 boot/mbr.asm | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/boot/mbr.asm b/boot/mbr.asm
index 432f8ee..135763f 100644
--- a/boot/mbr.asm
+++ b/boot/mbr.asm
@@ -6,10 +6,12 @@
 
 init:	cli
 	mov ax, seg
-	mov ss, ax
 	mov ds, ax
 	mov es, ax
+	mov ss, ax
 	xor sp, sp
+	mov ax, sp
+	push ax
 
 .retry:	mov ax, 0x0208
 	mov cx, 2
@@ -19,6 +21,18 @@ init:	cli
 	int 0x13
 	jc .retry
 
+	xor di, di
+	mov ax, 0x18CD
+	stosw
+	int 0x12
+	mov cl, 6
+	shl ax, cl
+	stosw
+	mov al, 2
+	stosb
+	mov ax, 0x18CD
+	stosw
+
 	jmp seg:0x100
 
 	times (0x1BE - ($-$$)) db 0