--- trunk/grubby/grubby.c	2012/02/18 00:47:17	1717
+++ trunk/grubby/grubby.c	2012/02/18 00:51:28	1720
@@ -51,6 +51,9 @@
 #define MAX_EXTRA_INITRDS	  16	/* code segment checked by --bootloader-probe */
 #define CODE_SEG_SIZE	  128	/* code segment checked by --bootloader-probe */
 
+#define NOOP_OPCODE 0x90
+#define JMP_SHORT_OPCODE 0xeb
+
 /* comments get lumped in with indention */
 struct lineElement {
     char * item;
@@ -2468,12 +2471,22 @@
     if (memcmp(boot, bootSect, 3))
 	return 0;
 
-    if (boot[1] == 0xeb) {
+    if (boot[1] == JMP_SHORT_OPCODE) {
 	offset = boot[2] + 2;
     } else if (boot[1] == 0xe8 || boot[1] == 0xe9) {
 	offset = (boot[3] << 8) + boot[2] + 2;
-    } else if (boot[0] == 0xeb) {
-	offset = boot[1] + 2;
+    } else if (boot[0] == JMP_SHORT_OPCODE) {
+      offset = boot[1] + 2;
+        /*
+	 * it looks like grub, when copying stage1 into the mbr, patches stage1
+	 * right after the JMP location, replacing other instructions such as
+	 * JMPs for NOOPs. So, relax the check a little bit by skipping those
+	 * different bytes.
+	 */
+      if ((bootSect[offset + 1] == NOOP_OPCODE)
+	  && (bootSect[offset + 2] == NOOP_OPCODE)) {
+	offset = offset + 3;
+      }
     } else if (boot[0] == 0xe8 || boot[0] == 0xe9) {
 	offset = (boot[2] << 8) + boot[1] + 2;
     } else {
@@ -3147,6 +3160,7 @@
     struct singleEntry * template = NULL;
     int copyDefault = 0, makeDefault = 0;
     int displayDefault = 0;
+    int displayDefaultIndex = 0;
     struct poptOption options[] = {
 	{ "add-kernel", 0, POPT_ARG_STRING, &newKernelPath, 0,
 	    _("add an entry for the specified kernel"), _("kernel-path") },
@@ -3179,6 +3193,8 @@
 	      "template"), NULL },
 	{ "default-kernel", 0, 0, &displayDefault, 0,
 	    _("display the path of the default kernel") },
+	{ "default-index", 0, 0, &displayDefaultIndex, 0,
+	    _("display the index of the default kernel") },
 	{ "elilo", 0, POPT_ARG_NONE, &configureELilo, 0,
 	    _("configure elilo bootloader") },
 	{ "extlinux", 0, POPT_ARG_NONE, &configureExtLinux, 0,
@@ -3322,7 +3338,7 @@
 
     if (bootloaderProbe && (displayDefault || kernelInfo || newKernelVersion ||
 			  newKernelPath || removeKernelPath || makeDefault ||
-			  defaultKernel)) {
+			  defaultKernel || displayDefaultIndex)) {
 	fprintf(stderr, _("grubby: --bootloader-probe may not be used with "
 			  "specified option"));
 	return 1;
@@ -3373,7 +3389,7 @@
 
     if (!removeKernelPath && !newKernelPath && !displayDefault && !defaultKernel
 	&& !kernelInfo && !bootloaderProbe && !updateKernelPath 
-        && !removeMBKernel) {
+        && !removeMBKernel && !displayDefaultIndex) {
 	fprintf(stderr, _("grubby: no action specified\n"));
 	return 1;
     }
@@ -3468,6 +3484,11 @@
                ((rootspec != NULL) ? strlen(rootspec) : 0));
 
 	return 0;
+
+    } else if (displayDefaultIndex) {
+        if (config->defaultImage == -1) return 0;
+        printf("%i\n", config->defaultImage);
+
     } else if (kernelInfo)
 	return displayInfo(config, kernelInfo, bootPrefix);