[src/trunk]: src/sys/arch/i386/i386 As said in the comment (lines 327-336), w...

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

details:   https://anonhg.NetBSD.org/src/rev/0b26d205d84b
branches:  trunk
changeset: 760708:0b26d205d84b
user:      gsutre <gsutre%NetBSD.org@localhost>
date:      Tue Jan 11 12:24:37 2011 +0000

description:
As said in the comment (lines 327-336), we must make sure that
we don't overwrite valid data when moving the symbol and string
tables.

Assume for instance that the boot-loader left us with:

  +--------------+   +--------+     +--------------+
  | string table |   | kernel |     | symbol table |
  +--------------+   +--------+     +--------------+

The new addresses computed by lines 338-359 (here, it's really
lines 344-345) will move the tables so that they end up as:

                     +--------+--------------+--------------+
                     | kernel | symbol table | string table |
                     +--------+--------------+--------------+

The current version (rev. 1.20) will, however, first copy the
string table and then the symbol table.  But the copy of the
string table will overwrite the symbol table (see the pictures).

The old code (rev. 1.19) uses the right order of table copy to
make sure that we don't overwrite one table when moving the
other.  Here, we simply restore this behavior.  This makes
multibooting from GRUB2 work again (for MONOLITHIC).

ok jmcneill@

diffstat:

 sys/arch/i386/i386/multiboot.c |  17 ++++++++++++-----
 1 files changed, 12 insertions(+), 5 deletions(-)

diffs (57 lines):

diff -r 830df89816aa -r 0b26d205d84b sys/arch/i386/i386/multiboot.c
--- a/sys/arch/i386/i386/multiboot.c    Tue Jan 11 11:26:28 2011 +0000
+++ b/sys/arch/i386/i386/multiboot.c    Tue Jan 11 12:24:37 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: multiboot.c,v 1.20 2010/07/24 00:45:55 jym Exp $       */
+/*     $NetBSD: multiboot.c,v 1.21 2011/01/11 12:24:37 gsutre Exp $    */
 
 /*-
  * Copyright (c) 2005, 2006 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: multiboot.c,v 1.20 2010/07/24 00:45:55 jym Exp $");
+__KERNEL_RCSID(0, "$NetBSD: multiboot.c,v 1.21 2011/01/11 12:24:37 gsutre Exp $");
 
 #include "opt_multiboot.h"
 
@@ -339,28 +339,35 @@
            (void *)strtabp < RELOC(void *, &end)) {
                symstart = RELOC(Elf32_Addr, &end);
                strstart = symstart + symsize;
+               memcpy((void *)symstart, (void *)symaddr, symsize);
+               memcpy((void *)strstart, (void *)straddr, strsize);
         } else if ((void *)symtabp > RELOC(void *, &end) &&
                   (void *)strtabp < RELOC(void *, &end)) {
                symstart = RELOC(Elf32_Addr, &end);
                strstart = symstart + symsize;
+               memcpy((void *)symstart, (void *)symaddr, symsize);
+               memcpy((void *)strstart, (void *)straddr, strsize);
         } else if ((void *)symtabp < RELOC(void *, &end) &&
                   (void *)strtabp > RELOC(void *, &end)) {
                strstart = RELOC(Elf32_Addr, &end);
                symstart = strstart + strsize;
+               memcpy((void *)strstart, (void *)straddr, strsize);
+               memcpy((void *)symstart, (void *)symaddr, symsize);
        } else {
                /* symtabp and strtabp are both over end */
                if (symtabp < strtabp) {
                        symstart = RELOC(Elf32_Addr, &end);
                        strstart = symstart + symsize;
+                       memcpy((void *)symstart, (void *)symaddr, symsize);
+                       memcpy((void *)strstart, (void *)straddr, strsize);
                } else {
                        strstart = RELOC(Elf32_Addr, &end);
                        symstart = strstart + strsize;
+                       memcpy((void *)strstart, (void *)straddr, strsize);
+                       memcpy((void *)symstart, (void *)symaddr, symsize);
                }
        }
 
-       memcpy((void *)strstart, (void *)straddr, strsize);
-       memcpy((void *)symstart, (void *)symaddr, symsize);
-
        *RELOC(int *, &esym) =
            (int)(symstart + symsize + strsize + KERNBASE);