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Diffstat (limited to 'arch')
-rw-r--r--arch/i386/boot/memory.c30
1 files changed, 23 insertions, 7 deletions
diff --git a/arch/i386/boot/memory.c b/arch/i386/boot/memory.c
index 1a2e62db8be..bccaa1cf664 100644
--- a/arch/i386/boot/memory.c
+++ b/arch/i386/boot/memory.c
@@ -20,6 +20,7 @@
static int detect_memory_e820(void)
{
+ int count = 0;
u32 next = 0;
u32 size, id;
u8 err;
@@ -33,14 +34,24 @@ static int detect_memory_e820(void)
"=m" (*desc)
: "D" (desc), "a" (0xe820));
- if (err || id != SMAP)
+ /* Some BIOSes stop returning SMAP in the middle of
+ the search loop. We don't know exactly how the BIOS
+ screwed up the map at that point, we might have a
+ partial map, the full map, or complete garbage, so
+ just return failure. */
+ if (id != SMAP) {
+ count = 0;
break;
+ }
- boot_params.e820_entries++;
+ if (err)
+ break;
+
+ count++;
desc++;
- } while (next && boot_params.e820_entries < E820MAX);
+ } while (next && count < E820MAX);
- return boot_params.e820_entries;
+ return boot_params.e820_entries = count;
}
static int detect_memory_e801(void)
@@ -89,11 +100,16 @@ static int detect_memory_88(void)
int detect_memory(void)
{
+ int err = -1;
+
if (detect_memory_e820() > 0)
- return 0;
+ err = 0;
if (!detect_memory_e801())
- return 0;
+ err = 0;
+
+ if (!detect_memory_88())
+ err = 0;
- return detect_memory_88();
+ return err;
}