Index: libsmbios-2.2.28/src/bin/dellMediaDirectCtl.cpp
===================================================================
--- libsmbios-2.2.28.orig/src/bin/dellMediaDirectCtl.cpp
+++ libsmbios-2.2.28/src/bin/dellMediaDirectCtl.cpp
@@ -196,17 +196,21 @@ void _callSmi(smiRegs *r, u8 port)
 
     __asm__ __volatile__ (
            //   magic    port
+        "push %%ebx\n\t"
+        "mov %0, %%ebx\n\t"
         "outb   %%al,    %%dx     \n\t"
+        "mov %%ebx,%1\n\t"
+        "pop %%ebx\n\t"
 
         : /* output args */
           "=a" (r->eax),
-          "=b" (r->ebx),
+          "=g" (r->ebx),
           "=c" (r->ecx),
           "=S" (r->esi),
           "=D" (r->edi)
         : /* input args */
           "0" (r->eax),
-          "1" (r->ebx),
+          "g" (r->ebx),
           "2" (r->ecx),
           "3" (r->esi),
           "4" (r->edi),