From af6da0fbea09746b2408a17cf5dadef1acda62a1 Mon Sep 17 00:00:00 2001
From: Richard Burgess <>
Date: Wed, 21 Dec 1994 22:06:26 +0000
Subject: [PATCH] autocommit for file dated 1994-12-21 22:06:26

---
 ossource/mospdr.asm | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 ossource/mospdr.asm

diff --git a/ossource/mospdr.asm b/ossource/mospdr.asm
new file mode 100644
index 0000000..31bac99
--- /dev/null
+++ b/ossource/mospdr.asm
@@ -0,0 +1,44 @@
+;   MMURTL Operating System Source Code
+;   Copyright 1991,1992,1993,1994 Richard A. Burgess
+;   ALL RIGHTS RESERVED
+;   Version 1.0
+
+;This is MMURTL's page directory and initial page table.
+;The page directory has one entry in it which is the linear address
+;of it's only page table.  The page table has just enough entries
+;in it to cover the OS Data, Stack and Code.
+;Note that the page directory actual becomes assigned to the Monitor program
+;because the OS code isn't actually a task.  Remember, OS code runs in OTHER
+;job's tasks.  The monitor is the first true job launched, which can
+;install services, launch programs, report errors on termination, etc.
+
+;The page directory is 4K and is ALWAYS PAGE ALIGNED
+;We fill in the first page directory entry statically, then the
+;InitMem routine fills in the page table for us.
+;
+;A page directory or table entry with all zeros means "not used yet."
+;
+;The AVL bits are for OS use and are defined as follows:
+;	A - 1 = Alias of someone elses physical memory
+;	V - 1 = Undefined (use later for virtual memory mgmt)
+;	L - 1 = Undefined (use later for virtual memory mgmt)
+;The other bits are Hardware defined and set as follows:
+;	D - 1 = Dirty (written to) since created.  CPU sets this.
+;	A - 1 = Accessed since created. CPU sets this.
+;	U - 1 = User,  0 = Supervisor. OS sets this.
+;	W - 1 = Writable for user (super pages are always writable to the OS)
+;	P - 1 = Present. CPU will not read or mod entry if this is Zero
+;
+;
+;					20 Bit Address		AVL00DA00UWP
+;					|					|  | ||  |||
+PUBLIC PDir1	DD	00000000000000000011000000000101b	;PT physical address
+				DD  511 DUP (0)							;511 BLANK entries
+
+				DD	00000000000000000011000000000000b	;Shadow for PT Linear address
+				DD  511 DUP (0)							;511 BLANK entries
+
+PUBLIC PTbl1	DD  1024 DUP (0)						;1024 blank entries
+
+
+;-------------------- END OF MODULE ----------------------
-- 
2.40.0