From owner-p4-projects@FreeBSD.ORG  Sun May 11 15:21:45 2003
Return-Path: <owner-p4-projects@FreeBSD.ORG>
Delivered-To: p4-projects@freebsd.org
Received: by hub.freebsd.org (Postfix, from userid 32767)
	id 1263337B404; Sun, 11 May 2003 15:21:45 -0700 (PDT)
Delivered-To: perforce@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id A39FB37B401
	for <perforce@freebsd.org>; Sun, 11 May 2003 15:21:44 -0700 (PDT)
Received: from repoman.freebsd.org (repoman.freebsd.org [216.136.204.115])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 49C6743F93
	for <perforce@freebsd.org>; Sun, 11 May 2003 15:21:44 -0700 (PDT)
	(envelope-from peter@freebsd.org)
Received: from repoman.freebsd.org (localhost [127.0.0.1])
	by repoman.freebsd.org (8.12.6/8.12.6) with ESMTP id h4BMLi0U020133
	for <perforce@freebsd.org>; Sun, 11 May 2003 15:21:44 -0700 (PDT)
	(envelope-from peter@freebsd.org)
Received: (from perforce@localhost)
	by repoman.freebsd.org (8.12.6/8.12.6/Submit) id h4BMLhUg020130
	for perforce@freebsd.org; Sun, 11 May 2003 15:21:43 -0700 (PDT)
Date: Sun, 11 May 2003 15:21:43 -0700 (PDT)
Message-Id: <200305112221.h4BMLhUg020130@repoman.freebsd.org>
X-Authentication-Warning: repoman.freebsd.org: perforce set sender to
	peter@freebsd.org using -f
From: Peter Wemm <peter@FreeBSD.org>
To: Perforce Change Reviews <perforce@freebsd.org>
Subject: PERFORCE change 30967 for review
X-BeenThere: p4-projects@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: p4 projects tree changes <p4-projects.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/p4-projects>,
	<mailto:p4-projects-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/p4-projects>
List-Post: <mailto:p4-projects@freebsd.org>
List-Help: <mailto:p4-projects-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/p4-projects>,
	<mailto:p4-projects-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 11 May 2003 22:21:46 -0000

http://perforce.freebsd.org/chv.cgi?CH=30967

Change 30967 by peter@peter_overcee on 2003/05/11 15:21:05

	I dont know why I didn't think of this before.  Duplicate the
	same 1GB window over the entire address space for ease of
	KERNBASE selection.  Very easy.

Affected files ...

.. //depot/projects/hammer/sys/boot/i386/libi386/elf64_freebsd.c#15 edit

Differences ...

==== //depot/projects/hammer/sys/boot/i386/libi386/elf64_freebsd.c#15 (text+ko) ====

@@ -86,20 +86,20 @@
     bzero(PT3, PAGE_SIZE);
     bzero(PT2, PAGE_SIZE);
 
-    /* single PML4 entry */
-    PT4[0] = (p4_entry_t)VTOP((uintptr_t)&PT3[0]);
-    PT4[0] |= PG_V | PG_RW | PG_U;
+    /*
+     * This is kinda brutal, but every single 1GB VM memory segment points to
+     * the same first 1GB of physical memory.  But it is more than adequate.
+     */
+    for (i = 0; i < 512; i++) {
+	/* Each slot of the level 4 pages points to the same level 3 page */
+	PT4[i] = (p4_entry_t)VTOP((uintptr_t)&PT3[0]);
+	PT4[i] |= PG_V | PG_RW | PG_U;
 
-    /* Direct map 1GB at address zero */
-    PT3[0] = (p3_entry_t)VTOP((uintptr_t)&PT2[0]);
-    PT3[0] |= PG_V | PG_RW | PG_U;
+	/* Each slot of the level 3 pages points to the same level 2 page */
+	PT3[i] = (p3_entry_t)VTOP((uintptr_t)&PT2[0]);
+	PT3[i] |= PG_V | PG_RW | PG_U;
 
-    /* Direct map 1GB at KERNBASE (hardcoded for now) */
-    PT3[1] = (p3_entry_t)VTOP((uintptr_t)&PT2[0]);
-    PT3[1] |= PG_V | PG_RW | PG_U;
-
-    /* 512 PG_PS (2MB) page mappings for 1GB of direct mapping */
-    for (i = 0; i < 512; i++) {
+	/* The level 2 page slots are mapped with 2MB pages for 1GB. */
 	PT2[i] = i * (2 * 1024 * 1024);
 	PT2[i] |= PG_V | PG_RW | PG_PS | PG_U;
     }