diff --git a/commands/md.c b/commands/md.c
index 07a03d5..c88259a 100644
--- a/commands/md.c
+++ b/commands/md.c
@@ -49,7 +49,7 @@
 	if (argc < 2)
 		return COMMAND_ERROR_USAGE;
 
-	if (mem_parse_options(argc, argv, "bwls:x", &mode, &filename, NULL,
+	if (mem_parse_options(argc, argv, "bwlqs:x", &mode, &filename, NULL,
 			&swab) < 0)
 		return 1;
 
@@ -105,6 +105,7 @@
 BAREBOX_CMD_HELP_OPT ("-b",  "byte access")
 BAREBOX_CMD_HELP_OPT ("-w",  "word access (16 bit)")
 BAREBOX_CMD_HELP_OPT ("-l",  "long access (32 bit)")
+BAREBOX_CMD_HELP_OPT ("-q",  "quad access (64 bit)")
 BAREBOX_CMD_HELP_OPT ("-s FILE",  "display file (default /dev/mem)")
 BAREBOX_CMD_HELP_OPT ("-x",       "swap bytes at output")
 BAREBOX_CMD_HELP_TEXT("")
diff --git a/commands/mem.c b/commands/mem.c
index 568050d..23c703f 100644
--- a/commands/mem.c
+++ b/commands/mem.c
@@ -84,6 +84,9 @@
 		case 'l':
 			*mode = O_RWSIZE_4;
 			break;
+		case 'q':
+			*mode = O_RWSIZE_8;
+			break;
 		case 's':
 			*sourcefile = optarg;
 			break;
diff --git a/commands/memcmp.c b/commands/memcmp.c
index d048150..e079d5f 100644
--- a/commands/memcmp.c
+++ b/commands/memcmp.c
@@ -49,7 +49,7 @@
 	int     offset = 0;
 	struct  stat statbuf;
 
-	if (mem_parse_options(argc, argv, "bwls:d:", &mode, &sourcefile,
+	if (mem_parse_options(argc, argv, "bwlqs:d:", &mode, &sourcefile,
 			&destfile, NULL) < 0)
 		return 1;
 
@@ -138,6 +138,7 @@
 BAREBOX_CMD_HELP_OPT ("-b",  "byte access")
 BAREBOX_CMD_HELP_OPT ("-w",  "word access (16 bit)")
 BAREBOX_CMD_HELP_OPT ("-l",  "long access (32 bit)")
+BAREBOX_CMD_HELP_OPT ("-q",  "quad access (64 bit)")
 BAREBOX_CMD_HELP_OPT ("-s FILE", "source file (default /dev/mem)")
 BAREBOX_CMD_HELP_OPT ("-d FILE", "destination file (default /dev/mem)")
 BAREBOX_CMD_HELP_END
diff --git a/commands/memcpy.c b/commands/memcpy.c
index 78716b1..9c8b645 100644
--- a/commands/memcpy.c
+++ b/commands/memcpy.c
@@ -47,7 +47,7 @@
 	struct stat statbuf;
 	int ret = 0;
 
-	if (mem_parse_options(argc, argv, "bwls:d:", &mode, &sourcefile,
+	if (mem_parse_options(argc, argv, "bwlqs:d:", &mode, &sourcefile,
 			&destfile, NULL) < 0)
 		return 1;
 
@@ -135,6 +135,7 @@
 BAREBOX_CMD_HELP_OPT ("-b", "byte access")
 BAREBOX_CMD_HELP_OPT ("-w", "word access (16 bit)")
 BAREBOX_CMD_HELP_OPT ("-l", "long access (32 bit)")
+BAREBOX_CMD_HELP_OPT ("-q", "quad access (64 bit)")
 BAREBOX_CMD_HELP_OPT ("-s FILE", "source file (default /dev/mem)")
 BAREBOX_CMD_HELP_OPT ("-d FILE", "write file (default /dev/mem)")
 BAREBOX_CMD_HELP_END
diff --git a/commands/memset.c b/commands/memset.c
index bb5f46d..fc5b659 100644
--- a/commands/memset.c
+++ b/commands/memset.c
@@ -44,7 +44,7 @@
 	int     ret = 1;
 	char	*file = "/dev/mem";
 
-	if (mem_parse_options(argc, argv, "bwld:", &mode, NULL, &file,
+	if (mem_parse_options(argc, argv, "bwlqd:", &mode, NULL, &file,
 			NULL) < 0)
 		return 1;
 
@@ -92,6 +92,7 @@
 BAREBOX_CMD_HELP_OPT ("-b",  "byte access")
 BAREBOX_CMD_HELP_OPT ("-w",  "word access (16 bit)")
 BAREBOX_CMD_HELP_OPT ("-l",  "long access (32 bit)")
+BAREBOX_CMD_HELP_OPT ("-q",  "quad access (64 bit)")
 BAREBOX_CMD_HELP_OPT ("-d FILE",  "write file (default /dev/mem)")
 BAREBOX_CMD_HELP_END
 
diff --git a/commands/mm.c b/commands/mm.c
index ff2e746..7c890a6 100644
--- a/commands/mm.c
+++ b/commands/mm.c
@@ -38,9 +38,10 @@
 	u8 val8;
 	u16 val16;
 	u32 val32;
-	u32 value, mask;
+	u64 val64;
+	u64 value, mask;
 
-	if (mem_parse_options(argc, argv, "bwld:", &mode, NULL, &filename,
+	if (mem_parse_options(argc, argv, "bwlqd:", &mode, NULL, &filename,
 			&swab) < 0)
 		return 1;
 
@@ -48,8 +49,8 @@
 		return COMMAND_ERROR_USAGE;
 
 	adr = strtoull_suffix(argv[optind++], NULL, 0);
-	value = simple_strtoul(argv[optind++], NULL, 0);
-	mask = simple_strtoul(argv[optind++], NULL, 0);
+	value = simple_strtoull(argv[optind++], NULL, 0);
+	mask = simple_strtoull(argv[optind++], NULL, 0);
 
 	fd = open_and_lseek(filename, mode | O_RDWR, adr);
 	if (fd < 0)
@@ -86,6 +87,16 @@
 		if (ret < 0)
 			goto out_write;
 		break;
+	case O_RWSIZE_8:
+		if (ret < 0)
+			goto out_read;
+		ret = pread(fd, &val64, 8, adr);
+		val64 &= ~mask;
+		val64 |= (value & mask);
+		ret = pwrite(fd, &val64, 8, adr);
+		if (ret < 0)
+			goto out_write;
+		break;
 	}
 
 	close(fd);
@@ -110,6 +121,7 @@
 BAREBOX_CMD_HELP_OPT ("-b",  "byte access")
 BAREBOX_CMD_HELP_OPT ("-w",  "word access (16 bit)")
 BAREBOX_CMD_HELP_OPT ("-l",  "long access (32 bit)")
+BAREBOX_CMD_HELP_OPT ("-q",  "quad access (64 bit)")
 BAREBOX_CMD_HELP_OPT ("-d FILE",  "write file (default /dev/mem)")
 BAREBOX_CMD_HELP_END
 
diff --git a/commands/mw.c b/commands/mw.c
index f0384f6..8ca3c61 100644
--- a/commands/mw.c
+++ b/commands/mw.c
@@ -42,7 +42,7 @@
 	loff_t adr;
 	int swab = 0;
 
-	if (mem_parse_options(argc, argv, "bwld:x", &mode, NULL, &filename,
+	if (mem_parse_options(argc, argv, "bwlqd:x", &mode, NULL, &filename,
 			&swab) < 0)
 		return 1;
 
@@ -59,6 +59,7 @@
 		u8 val8;
 		u16 val16;
 		u32 val32;
+		u64 val64;
 		switch (mode) {
 		case O_RWSIZE_1:
 			val8 = simple_strtoul(argv[optind], NULL, 0);
@@ -76,6 +77,12 @@
 				val32 = __swab32(val32);
 			ret = write(fd, &val32, 4);
 			break;
+		case O_RWSIZE_8:
+			val64 = simple_strtoull(argv[optind], NULL, 0);
+			if (swab)
+				val64 = __swab64(val64);
+			ret = write(fd, &val64, 8);
+			break;
 		}
 		if (ret < 0) {
 			perror("write");
@@ -97,6 +104,7 @@
 BAREBOX_CMD_HELP_OPT ("-b",  "byte access")
 BAREBOX_CMD_HELP_OPT ("-w",  "word access (16 bit)")
 BAREBOX_CMD_HELP_OPT ("-l",  "long access (32 bit)")
+BAREBOX_CMD_HELP_OPT ("-q",  "quad access (64 bit)")
 BAREBOX_CMD_HELP_OPT ("-d FILE",  "write file (default /dev/mem)")
 BAREBOX_CMD_HELP_END
 
diff --git a/common/memory_display.c b/common/memory_display.c
index 7b1d35e..ea91985 100644
--- a/common/memory_display.c
+++ b/common/memory_display.c
@@ -6,8 +6,8 @@
 
 int memory_display(const void *addr, loff_t offs, unsigned nbytes, int size, int swab)
 {
-	ulong linebytes, i;
-	u_char	*cp;
+	unsigned long linebytes, i;
+	unsigned char *cp;
 
 	/* Print the lines.
 	 *
@@ -15,20 +15,34 @@
 	 * once, and all accesses are with the specified bus width.
 	 */
 	do {
-		char linebuf[DISP_LINE_LEN];
-		uint32_t *uip = (uint   *)linebuf;
-		uint16_t *usp = (ushort *)linebuf;
-		uint8_t *ucp = (u_char *)linebuf;
+		unsigned char linebuf[DISP_LINE_LEN];
+		uint64_t *ullp = (uint64_t *)linebuf;
+		uint32_t *uip = (uint32_t *)linebuf;
+		uint16_t *usp = (uint16_t *)linebuf;
+		uint8_t *ucp = (uint8_t *)linebuf;
 		unsigned count = 52;
 
 		printf("%08llx:", offs);
 		linebytes = (nbytes > DISP_LINE_LEN) ? DISP_LINE_LEN : nbytes;
 
 		for (i = 0; i < linebytes; i += size) {
-			if (size == 4) {
-				u32 res;
+			if (size == 8) {
+				uint64_t res;
 				data_abort_mask();
-				res = *((uint *)addr);
+				res = *((uint64_t *)addr);
+				if (swab)
+					res = __swab64(res);
+				if (data_abort_unmask()) {
+					res = 0xffffffffffffffffULL;
+					count -= printf(" xxxxxxxxxxxxxxxx");
+				} else {
+					count -= printf(" %016llx", res);
+				}
+				*ullp++ = res;
+			} else if (size == 4) {
+				uint32_t res;
+				data_abort_mask();
+				res = *((uint32_t *)addr);
 				if (swab)
 					res = __swab32(res);
 				if (data_abort_unmask()) {
@@ -39,9 +53,9 @@
 				}
 				*uip++ = res;
 			} else if (size == 2) {
-				u16 res;
+				uint16_t res;
 				data_abort_mask();
-				res = *((ushort *)addr);
+				res = *((uint16_t *)addr);
 				if (swab)
 					res = __swab16(res);
 				if (data_abort_unmask()) {
@@ -52,9 +66,9 @@
 				}
 				*usp++ = res;
 			} else {
-				u8 res;
+				uint8_t res;
 				data_abort_mask();
-				res = *((u_char *)addr);
+				res = *((uint8_t *)addr);
 				if (data_abort_unmask()) {
 					res = 0xff;
 					count -= printf(" xx");
@@ -70,7 +84,7 @@
 		while (count--)
 			putchar(' ');
 
-		cp = (uint8_t *)linebuf;
+		cp = linebuf;
 		for (i = 0; i < linebytes; i++) {
 			if ((*cp < 0x20) || (*cp > 0x7e))
 				putchar('.');
diff --git a/fs/fs.c b/fs/fs.c
index 779f264..9a79a03 100644
--- a/fs/fs.c
+++ b/fs/fs.c
@@ -1590,6 +1590,9 @@
 		case 4:
 			*((ulong  *)dst) = *((ulong  *)src);
 			break;
+		case 8:
+			*((u64  *)dst) = *((u64  *)src);
+			break;
 		}
 		dst += rwsize;
 		src += rwsize;
diff --git a/include/fcntl.h b/include/fcntl.h
index aed741e..501b415 100644
--- a/include/fcntl.h
+++ b/include/fcntl.h
@@ -17,11 +17,12 @@
 #define O_NOFOLLOW	00400000	/* don't follow links */
 
 /* barebox additional flags */
-#define O_RWSIZE_MASK	00000070
+#define O_RWSIZE_MASK	00000170
 #define O_RWSIZE_SHIFT	3
 #define O_RWSIZE_1      00000010
 #define O_RWSIZE_2      00000020
 #define O_RWSIZE_4      00000040
+#define O_RWSIZE_8      00000100
 
 #define F_DUPFD		0	/* dup */
 #define F_GETFD		1	/* get close_on_exec */