--- trunk/grubby/grubby.c	2012/02/18 00:32:14	1714
+++ trunk/grubby/grubby.c	2012/02/18 00:49:41	1718
@@ -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;
@@ -156,8 +159,30 @@
     { NULL,	    0, 0 },
 };
 
+const char *grubFindConfig(struct configFileInfo *cfi) {
+    static const char *configFiles[] = {
+	"/etc/grub.conf",
+	"/boot/grub/grub.conf",
+	"/boot/grub/menu.lst",
+	NULL
+    };
+    static int i = -1;
+
+    if (i == -1) {
+	for (i = 0; configFiles[i] != NULL; i++) {
+	    dbgPrintf("Checking \"%s\": ", configFiles[i]);
+	    if (!access(configFiles[i], R_OK)) {
+		dbgPrintf("found\n");
+		return configFiles[i];
+	    }
+	    dbgPrintf("not found\n");
+	}
+    }
+    return configFiles[i];
+}
+
 struct configFileInfo grubConfigType = {
-    .defaultConfig = "/boot/grub/grub.conf",
+    .findConfig = grubFindConfig,
     .keywords = grubKeywords,
     .defaultIsIndex = 1,
     .defaultSupportSaved = 1,
@@ -2446,12 +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 {
@@ -3343,7 +3378,7 @@
 	defaultKernel = NULL;
     }
 
-    if (!strcmp(grubConfig, "-") && !outputFile) {
+    if (grubConfig && !strcmp(grubConfig, "-") && !outputFile) {
 	fprintf(stderr, _("grubby: output file must be specified if stdin "
 			"is used\n"));
 	return 1;
@@ -3390,8 +3425,9 @@
 		gr2c = checkForGrub2(gconfig);
 	} 
 
-	if (!access(grubConfigType.defaultConfig, F_OK)) {
-	    gconfig = readConfig(grubConfigType.defaultConfig, &grubConfigType);
+	const char *grubconfig = grubFindConfig(&grubConfigType);
+	if (!access(grubconfig, F_OK)) {
+	    gconfig = readConfig(grubconfig, &grubConfigType);
 	    if (!gconfig)
 		grc = 1;
 	    else