1 files changed, 6 insertions, 3 deletions

diff --git a/arch/i386/boot/memory.c b/arch/i386/boot/memory.c
index bccaa1cf6645..378353956b5d 100644
--- a/arch/i386/boot/memory.c
+++ b/arch/i386/boot/memory.c
@@ -28,11 +28,14 @@ static int detect_memory_e820(void)
 
         do {
                 size = sizeof(struct e820entry);
-                id = SMAP;
+
+                /* Important: %edx is clobbered by some BIOSes,
+                   so it must be either used for the error output
+                   or explicitly marked clobbered. */
                 asm("int $0x15; setc %0"
-                    : "=am" (err), "+b" (next), "+d" (id), "+c" (size),
+                    : "=d" (err), "+b" (next), "=a" (id), "+c" (size),
                       "=m" (*desc)
-                    : "D" (desc), "a" (0xe820));
+                    : "D" (desc), "d" (SMAP), "a" (0xe820));
 
                 /* Some BIOSes stop returning SMAP in the middle of
                    the search loop.  We don't know exactly how the BIOS