From c489f6804b5671f1e595bea3ad477048d42e9f76 Mon Sep 17 00:00:00 2001
From: bjh21 <bjh21@NetBSD.org>
Date: Mon, 27 May 2002 20:17:11 +0000
Subject: [PATCH] Add a function, get_page(), whose job is to find which
 logical page should be used to load a given physical page.  At the moment,
 this just returns the page's current logical mapping, but in future it might
 handle returning bounce pages for physical pages which are in use, and
 copying to the correct page just before loading the kernel.

---
 sys/arch/acorn26/stand/boot26/boot26.c | 43 ++++++++++++++++----------
 1 file changed, 27 insertions(+), 16 deletions(-)

diff --git a/sys/arch/acorn26/stand/boot26/boot26.c b/sys/arch/acorn26/stand/boot26/boot26.c
index 1aaec2b39bf3..eb17ebb5a772 100644
--- a/sys/arch/acorn26/stand/boot26/boot26.c
+++ b/sys/arch/acorn26/stand/boot26/boot26.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: boot26.c,v 1.1 2002/03/24 15:47:25 bjh21 Exp $	*/
+/*	$NetBSD: boot26.c,v 1.2 2002/05/27 20:17:11 bjh21 Exp $	*/
 
 /*-
  * Copyright (c) 1998, 1999, 2000, 2001 Ben Harris
@@ -208,20 +208,39 @@ get_mem_map(struct os_mem_map_request *pginfo, enum pgstatus *pgstatus,
 	}
 }
 
+/*
+ * Return the address of a page that will end up corresponding to the
+ * target address when the kernel boots.  "target" is expected to be
+ * in the MEMC physical RAM area (0x02000000--0x02ffffff).  It need
+ * not be page-aligned.  The return value is in the logical RAM area,
+ * and either points to a mapping of the requested page or to a
+ * mapping of another page which will be copied to the requested page
+ * after RISC OS is shut down.
+ *
+ * At present, there's no relocation mechanism, so we panic if its use
+ * is required.
+ */
+static caddr_t
+get_page(caddr_t target)
+{
+	int ppn;
+
+	ppn = ((caddr_t)target - MEMC_PHYS_BASE) / nbpp;
+	if (pgstatus[ppn] != FREE)
+		panic("Page %d not free", ppn);
+	return pginfo[ppn].map;
+}
+
 ssize_t
 boot26_read(int f, void *addr, size_t size)
 {
-	int ppn;
 	caddr_t fragaddr;
 	size_t fragsize;
 	ssize_t retval, total;
 
 	total = 0;
 	while (size > 0) {
-		ppn = ((caddr_t)addr - MEMC_PHYS_BASE) / nbpp;
-		if (pgstatus[ppn] != FREE)
-			panic("Page %d not free", ppn);
-		fragaddr = pginfo[ppn].map + ((u_int)addr % nbpp);
+		fragaddr = get_page(addr) + ((u_int)addr % nbpp);
 		fragsize = nbpp - ((u_int)addr % nbpp);
 		if (fragsize > size)
 			fragsize = size;
@@ -240,16 +259,12 @@ boot26_read(int f, void *addr, size_t size)
 void *
 boot26_memcpy(void *dst, const void *src, size_t size)
 {
-	int ppn;
 	caddr_t fragaddr;
 	size_t fragsize;
 	void *addr = dst;
 
 	while (size > 0) {
-		ppn = ((caddr_t)addr - MEMC_PHYS_BASE) / nbpp;
-		if (pgstatus[ppn] != FREE)
-			panic("Page %d not free", ppn);
-		fragaddr = pginfo[ppn].map + ((u_int)addr % nbpp);
+		fragaddr = get_page(addr) + ((u_int)addr % nbpp);
 		fragsize = nbpp - ((u_int)addr % nbpp);
 		if (fragsize > size)
 			fragsize = size;
@@ -264,16 +279,12 @@ boot26_memcpy(void *dst, const void *src, size_t size)
 void *
 boot26_memset(void *dst, int c, size_t size)
 {
-	int ppn;
 	caddr_t fragaddr;
 	size_t fragsize;
 	void *addr = dst;
 
 	while (size > 0) {
-		ppn = ((caddr_t)addr - MEMC_PHYS_BASE) / nbpp;
-		if (pgstatus[ppn] != FREE)
-			panic("Page %d not free", ppn);
-		fragaddr = pginfo[ppn].map + ((u_int)addr % nbpp);
+		fragaddr = get_page(addr) + ((u_int)addr % nbpp);
 		fragsize = nbpp - ((u_int)addr % nbpp);
 		if (fragsize > size)
 			fragsize = size;