[Xen-changelog] Slight fix to BIOS e820 bug workaround. Remove the check

[Xen patchbot -3.0-testing <patchbot-3.0-testing@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID 5baa96bedc13924e9ff4c04ebedcac4e8a0e4da4
# Parent  69b30657132e5fd89cbe19765ad3e01a7ed8222c
Slight fix to BIOS e820 bug workaround. Remove the check
for whether e820 list is below 1MB: all bootloaders place
it below 1MB so teh check is ineffective and, in any case,
SYSLINUX has the same issue as GRUB (does not pre-initialize
the memory area that e820 function writes to).

Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>

xen-unstable cset: 3dc1c23dd5085ec0fc7dbfa5e4f052ddfa4e4260
committer: Robert Read <robert@xxxxxxxxxxxxx>

diff -r 69b30657132e -r 5baa96bedc13 xen/arch/x86/setup.c
--- a/xen/arch/x86/setup.c      Thu Dec 15 19:11:41 2005
+++ b/xen/arch/x86/setup.c      Thu Dec 15 19:57:27 2005
@@ -315,19 +315,15 @@
             memory_map_t *map = __va(mbi->mmap_addr + bytes);
 
             /*
-             * This is a gross workaround for a BIOS/GRUB bug. GRUB does
+             * This is a gross workaround for a BIOS bug. Some bootloaders do
              * not write e820 map entries into pre-zeroed memory. This is
              * okay if the BIOS fills in all fields of the map entry, but
              * some broken BIOSes do not bother to write the high word of
              * the length field if the length is smaller than 4GB. We
              * detect and fix this by flagging sections below 4GB that
-             * appear to be larger than 4GB in size. We disable this check
-             * for mbootpack and syslinux (which we can detect because they
-             * place the mmap_addr list above 1MB in memory).
+             * appear to be larger than 4GB in size.
              */
-            if ( (mbi->mmap_addr < 0x100000) &&
-                 (map->base_addr_high == 0) &&
-                 (map->length_high != 0) )
+            if ( (map->base_addr_high == 0) && (map->length_high != 0) )
             {
                 e820_warn = 1;
                 map->length_high = 0;

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