[src/trunk]: src/sys/arch/arm32/stand/ofwboot Couple of changes:

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/16ae6c63ae48
branches:  trunk
changeset: 516947:16ae6c63ae48
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Fri Nov 02 20:24:37 2001 +0000

description:
Couple of changes:
- Set MARK_START to where we expect to be loading the kernel (0xf0100000).
- The ARM OpenFirmare bindings document describes how the client
  program is loaded: OFW allocates and maps 6MB of memory at load-base
  (0xf0000000), loads the client program, and then unmaps the memory from
  the end of the client program to the end of the allocated region.  Then
  transfers control to the client program.  We must emulate this behavior
  to load the kernel: allocate 5MB at 0xf0100000 (where we expect to load
  the kernel), load the kernel, then unmap the area after the kernel.

We can now load DHCP and load the kernel via NFS before getting the
dreaded Data Abort.

diffstat:

 sys/arch/arm32/stand/ofwboot/boot.c |  32 ++++++++++++++++++++++++++++----
 1 files changed, 28 insertions(+), 4 deletions(-)

diffs (67 lines):

diff -r e8e7cab7fc5e -r 16ae6c63ae48 sys/arch/arm32/stand/ofwboot/boot.c
--- a/sys/arch/arm32/stand/ofwboot/boot.c       Fri Nov 02 19:58:52 2001 +0000
+++ b/sys/arch/arm32/stand/ofwboot/boot.c       Fri Nov 02 20:24:37 2001 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: boot.c,v 1.2 2001/11/01 22:55:25 thorpej Exp $ */
+/*     $NetBSD: boot.c,v 1.3 2001/11/02 20:24:37 thorpej Exp $ */
 
 /*-
  * Copyright (c) 1997 The NetBSD Foundation, Inc.
@@ -196,8 +196,8 @@
                    bootprog_maker[], bootprog_date[];
        int chosen, options;
        char bootline[512];             /* Should check size? */
-       char *cp;
-       u_long marks[MARK_MAX];
+       char *cp, *startbuf, *endbuf;
+       u_long marks[MARK_MAX], size;
        u_int32_t entry;
        void *ssym, *esym;
 
@@ -219,6 +219,22 @@
        parseargs(bootline, &boothowto);
        DPRINTF("bootline=%s\n", bootline);
 
+       /*
+        * Per the ARM OpenFirmware bindings, the firmware must
+        * allocate and map at least 6MB of physical memory starting
+        * at VA 0xf0000000.  We have been loaded at 0xf0000000,
+        * and the memory after us has been unmapped and freed.
+        * We expect to load the kernel at 0xf0100000, so we will
+        * allocate 5MB of virtual memory starting there, and
+        * unmap/free what we don't use.
+        */
+       startbuf = OF_claim((void *) 0xf0100000, (5 * 1024 * 1024), 0);
+       if (startbuf != (void *) 0xf0100000) {
+               printf("Unable to claim buffer for kernel\n");
+               OF_exit();
+       }
+       endbuf = startbuf + (5 * 1024 * 1024);
+
        for (;;) {
                int i;
 
@@ -236,7 +252,7 @@
                for (i = 0; kernels[i]; i++) {
                        DPRINTF("Trying %s\n", kernels[i]);
 
-                       marks[MARK_START] = 0;
+                       marks[MARK_START] = 0xf0100000;
                        if (loadfile(kernels[i], marks, LOAD_KERNEL) >= 0)
                                goto loaded;
                }
@@ -244,6 +260,14 @@
                boothowto |= RB_ASKNAME;
        }
  loaded:
+       /*
+        * Okay, kernel is loaded, free the extra memory at the end.
+        * Round to the ARM OpenFirmare page size (4k).
+        */
+       cp = (char *) ((marks[MARK_END] + 0xfff) & ~0xfff);
+       size = (u_long) (endbuf - cp);
+       if (size)
+               OF_release(cp, size);
 
 #ifdef __notyet__
        OF_setprop(chosen, "bootpath", opened_name, strlen(opened_name) + 1);