From 79f2fa136f26a0b87917336e089485712ee49bd6 Mon Sep 17 00:00:00 2001
From: Marvin Borner
Date: Fri, 7 Aug 2020 21:14:20 +0200
Subject: Dual-tasking works.

I don't know why triple-tasking doesn't though...
---
 src/features/proc.asm | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 src/features/proc.asm

(limited to 'src/features/proc.asm')

diff --git a/src/features/proc.asm b/src/features/proc.asm
new file mode 100644
index 0000000..3d6bbc4
--- /dev/null
+++ b/src/features/proc.asm
@@ -0,0 +1,25 @@
+%define USER_CODE_SEGMENT 0x18
+%define USER_DATA_SEGMENT 0x20
+%define RING3_MASK 0b11
+
+global proc_jump_userspace
+extern _esp
+extern _eip
+proc_jump_userspace:
+	mov ax, USER_DATA_SEGMENT | RING3_MASK
+	mov ds, ax
+	mov es, ax
+	mov fs, ax
+	mov gs, ax
+
+	mov eax, dword [_esp]
+	push USER_DATA_SEGMENT | RING3_MASK
+	push eax
+	pushf
+
+	sti
+
+	push USER_CODE_SEGMENT | RING3_MASK
+	push dword [_eip]
+
+	iret
-- 
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