From 39166e7863e32e4ef763d2a1b6fdcd6f616c1312 Mon Sep 17 00:00:00 2001
From: "E. Almqvist" <elalmqvist@gmail.com>
Date: Fri, 6 Aug 2021 23:05:28 +0200
Subject: [PATCH] Switching to PM

---
 src/pm.asm | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/src/pm.asm b/src/pm.asm
index 4a0a2f0..b74f3a4 100644
--- a/src/pm.asm
+++ b/src/pm.asm
@@ -6,8 +6,29 @@
 %include "pm/gdt.asm" 	; GDT defined here
 
 ; Switching to PM
-lgdt [gdt_descriptor] 	; Tell the CPU about the GDT
+[bits 16]
+switch_to_pm:
+	cli			; Switch interupts
+
+	lgdt [gdt_descriptor] 	; Tell the CPU about the GDT
+
+	mov eax, cr0		; Set first bit of the CR0 register
+	or eax, 0x1		; to 1
+	mov cr0, eax		; Update the control register
+
+[bits 32]
+; Init registers & stack when in PM
+init_pm:
+	mov ax, GDT_DATA_SEG	; Point the segment registers to GDT_DATA_SEG
+	; Segment registers
+	mov ds, ax
+	mov ss, ax
+	mov es, ax
+	mov fs, ax
+	mov gs, ax
+
+	mov ebp, 0x900000	; Update the stack pointer
+	mov esp, ebp
+
+	call BEGIN_PM
 
-mov eax, cr0			; Set first bit of the CR0 register
-or eax, 0x1			; to 1
-mov cr0, eax			; Update the control register