diff -up kexec-tools-testing-20070330/makedumpfile/makedumpfile.8.orig kexec-tools-testing-20070330/makedumpfile/makedumpfile.8
--- kexec-tools-testing-20070330/makedumpfile/makedumpfile.8.orig	2009-05-19 06:59:47.000000000 -0400
+++ kexec-tools-testing-20070330/makedumpfile/makedumpfile.8	2009-05-19 06:59:23.000000000 -0400
@@ -134,6 +134,13 @@ Note that dump_level for Xen dump filter
     30 |      |  X   |  X    |  X   |  X
     31 |  X   |  X   |  X    |  X   |  X
 
+.TP
+\fB\-\-dump-dmesg
+This option overrides the normal behavior of makedumpfile.  Instead of
+compressing and filtering a vmcore to make it smaller, it simply extracts the
+dmesg log from the core and writes it to the specified output file.  This option
+assumes that a vmcoreinfo section is present in the vmcore file and contains the
+symbols for the location of the dmesg log
 
 .TP
 \fB\-E\fR
diff -up kexec-tools-testing-20070330/makedumpfile/makedumpfile.c.orig kexec-tools-testing-20070330/makedumpfile/makedumpfile.c
--- kexec-tools-testing-20070330/makedumpfile/makedumpfile.c.orig	2009-05-19 06:59:47.000000000 -0400
+++ kexec-tools-testing-20070330/makedumpfile/makedumpfile.c	2009-05-19 06:59:41.000000000 -0400
@@ -31,6 +31,9 @@ int message_level;
 
 int retcd = FAILED;	/* return code */
 
+int
+close_files_for_creating_dumpfile();
+
 void
 show_version()
 {
@@ -1813,6 +1816,10 @@ get_symbol_info()
 	SYMBOL_INIT(node_data, "node_data");
 	SYMBOL_INIT(pgdat_list, "pgdat_list");
 	SYMBOL_INIT(contig_page_data, "contig_page_data");
+	SYMBOL_INIT(log_buf, "log_buf");
+	SYMBOL_INIT(log_buf_len, "log_buf_len");
+	SYMBOL_INIT(log_end, "log_end");
+	SYMBOL_INIT(logged_chars, "logged_chars");
 
 	if (SYMBOL(node_data) != NOT_FOUND_SYMBOL)
 		SYMBOL_ARRAY_TYPE_INIT(node_data, "node_data");
@@ -2085,6 +2092,10 @@ generate_vmcoreinfo()
 	WRITE_SYMBOL("node_data", node_data);
 	WRITE_SYMBOL("pgdat_list", pgdat_list);
 	WRITE_SYMBOL("contig_page_data", contig_page_data);
+	WRITE_SYMBOL("log_buf", log_buf);
+	WRITE_SYMBOL("log_buf_len", log_buf_len);
+	WRITE_SYMBOL("log_end", log_end);
+	WRITE_SYMBOL("logged_chars", logged_chars);
 
 	/*
 	 * write the structure size of 1st kernel
@@ -2319,6 +2330,10 @@ read_vmcoreinfo()
 	READ_SYMBOL("node_data", node_data);
 	READ_SYMBOL("pgdat_list", pgdat_list);
 	READ_SYMBOL("contig_page_data", contig_page_data);
+	READ_SYMBOL("log_buf", log_buf);
+	READ_SYMBOL("log_buf_len", log_buf_len);
+	READ_SYMBOL("log_end", log_end);
+	READ_SYMBOL("logged_chars", logged_chars);
 
 	READ_STRUCTURE_SIZE("page", page);
 	READ_STRUCTURE_SIZE("mem_section", mem_section);
@@ -3890,6 +3905,99 @@ exclude_free_page(struct cache_data *bm2
 }
 
 int
+dump_dmesg()
+{
+	int log_buf_len, length_log, length_oldlog, ret = FALSE;
+	unsigned long log_addr, logged_chars, index;
+	char *log_buffer = NULL;
+
+	if (!open_files_for_creating_dumpfile())
+		 return FALSE;
+
+	if (!get_elf_info())
+		 return FALSE;
+
+	if (!initial())
+		 return FALSE;
+
+	if ((SYMBOL(log_buf) == NOT_FOUND_SYMBOL)
+	    || (SYMBOL(log_buf_len)  == NOT_FOUND_SYMBOL)
+	    || (SYMBOL(logged_chars) == NOT_FOUND_SYMBOL)
+	    || (SYMBOL(log_end) == NOT_FOUND_SYMBOL)) {
+		 printf("Cannot find some symbols for log_buf.\n");
+		 return FALSE;
+	}
+	if (!readmem(VADDR, SYMBOL(log_buf), &log_addr, sizeof(log_addr))) {
+		 printf("Failed to get log addr.\n");
+		 return FALSE;
+	}
+	if (!readmem(VADDR, SYMBOL(log_buf_len), &log_buf_len,
+	    sizeof(log_buf_len))) {
+		 printf("Failed to get log_buf_len.\n");
+		 return FALSE;
+	 }
+	if (!readmem(VADDR, SYMBOL(logged_chars), &logged_chars,
+	    sizeof(logged_chars))) {
+		 printf("Failed to get logged_chars.\n");
+		 return FALSE;
+	}
+	DEBUG_MSG("\n");
+	DEBUG_MSG("log_addr     : %lx\n", log_addr);
+	DEBUG_MSG("log_buf_len  : %d\n", log_buf_len);
+	DEBUG_MSG("logged_chars : %ld\n", logged_chars);
+
+	if ((log_buffer = malloc(log_buf_len)) == NULL) {
+		 ERRMSG("Can't allocate memory for log_buf. %s\n",
+		     strerror(errno));
+		 return FALSE;
+	 }
+
+	if (logged_chars < log_buf_len) {
+		 index = 0;
+		 length_log = logged_chars;
+
+		 if(!readmem(VADDR, log_addr, log_buffer, length_log)) {
+			  printf("Failed to read dmesg log.\n");
+			  goto out;
+		 }
+	} else {
+		 if (!readmem(VADDR, SYMBOL(log_end), &index, sizeof(index))) {
+			  printf("Failed to get log_end.\n");
+			  goto out;
+		 }
+		 DEBUG_MSG("log_end      : %lx\n", index);
+		 index &= log_buf_len - 1;
+		 length_log = log_buf_len;
+		 length_oldlog = log_buf_len - index;
+
+		 if(!readmem(VADDR, log_addr + index, log_buffer, length_oldlog)) {
+			  printf("Failed to read dmesg log.\n");
+			  goto out;
+		 }
+		 DEBUG_MSG("log_addr     : %lx\n", log_addr);
+		 DEBUG_MSG("length_oldlog: %d\n", length_oldlog);
+
+		 if(!readmem(VADDR, log_addr, log_buffer + length_oldlog, index)) {
+			  printf("Failed to read dmesg log.\n");
+			  goto out;
+		 }
+	}
+
+	if (write(info->fd_dumpfile, log_buffer, length_log) < 0)
+		 goto out;
+
+	if (!close_files_for_creating_dumpfile())
+		 goto out;
+
+	ret = TRUE;
+ out:
+	if (log_buffer)
+		 free(log_buffer);
+
+	return ret;
+}
+
+int
 create_dump_bitmap()
 {
 	int val, not_found_mem_map;
@@ -5995,6 +6103,7 @@ static struct option longopts[] = {
 	{"xen-vmcoreinfo", required_argument, NULL, 'z'},
  	{"xen_phys_start", required_argument, NULL, 'P'},
 	{"message-level", required_argument, NULL, 'm'},
+	{"dump-dmesg", no_argument, NULL, 'M'},
 	{"help", no_argument, NULL, 'h'},
 	{0, 0, 0, 0}
 };
@@ -6018,7 +6127,7 @@ main(int argc, char *argv[])
 
 	info->block_order = DEFAULT_ORDER;
 	message_level = DEFAULT_MSG_LEVEL;
-	while ((opt = getopt_long(argc, argv, "b:cDd:EFfg:hi:RvXx:y:", longopts,
+	while ((opt = getopt_long(argc, argv, "b:cDd:EFfg:hi:MRvXx:y:", longopts,
 	    NULL)) != -1) {
 		switch (opt) {
 		case 'b':
@@ -6058,6 +6167,9 @@ main(int argc, char *argv[])
 		case 'm':
 			message_level = atoi(optarg);
 			break;
+		case 'M':
+			info->flag_dmesg = 1;
+			break;
 		case 'P':
 			info->xen_phys_start = strtoul(optarg, NULL, 0);
 			break;
@@ -6166,9 +6278,11 @@ main(int argc, char *argv[])
 			info->name_dumpfile = argv[optind];
 
 		} else {
-			MSG("Commandline parameter is invalid.\n");
-			print_usage();
-			goto out;
+			if (!info->flag_dmesg) {
+				MSG("Commandline parameter is invalid.\n");
+				print_usage();
+				goto out;
+			}
 		}
 	}
 
@@ -6223,6 +6337,12 @@ main(int argc, char *argv[])
 		MSG("\n");
 		MSG("The dumpfile is saved to %s.\n", info->name_dumpfile);
 	} else {
+		if (info->flag_dmesg) {
+			dump_dmesg();
+			retcd = COMPLETED;
+			goto out;
+		}
+
 		if (!open_files_for_creating_dumpfile())
 			goto out;
 
diff -up kexec-tools-testing-20070330/makedumpfile/makedumpfile.h.orig kexec-tools-testing-20070330/makedumpfile/makedumpfile.h
--- kexec-tools-testing-20070330/makedumpfile/makedumpfile.h.orig	2009-05-19 06:59:47.000000000 -0400
+++ kexec-tools-testing-20070330/makedumpfile/makedumpfile.h	2009-05-19 06:59:23.000000000 -0400
@@ -653,6 +653,7 @@ struct DumpInfo {
 						flattened format */
 	int		flag_force;	     /* overwrite existing stuff */
 	int		flag_exclude_xen_dom;/* exclude Domain-U from xen-kdump */
+	int		flag_dmesg;	     /* dump the dmesg log out of the vmcore file */
 	long		page_size;           /* size of page */
 	long		page_shift;
 	unsigned long long	max_mapnr;   /* number of page descriptor */
@@ -769,6 +770,10 @@ struct symbol_table {
 	unsigned long	node_data;
 	unsigned long	pgdat_list;
 	unsigned long	contig_page_data;
+	unsigned long	log_buf;
+	unsigned long	log_end;
+	unsigned long 	log_buf_len;
+	unsigned long	logged_chars;
 
 	/*
 	 * for Xen extraction