--- logfsprogs/mkfs.c.ark	2010-05-20 13:31:56.507563507 +0000
+++ logfsprogs/mkfs.c	2010-05-20 13:33:20.727554305 +0000
@@ -97,6 +97,7 @@ error:
 
 static int mtd_erase(struct super_block *sb, u64 ofs, size_t size)
 {
+#ifdef MEMERASE64 // Not available on pre-stoneage kernels like the iRex one
 	if (ofs >= 0x100000000ull) {
 		struct erase_info_user64 ei;
 
@@ -105,13 +106,16 @@ static int mtd_erase(struct super_block 
 
 		return ioctl(sb->fd, MEMERASE64, &ei);
 	} else {
+#endif
 		struct erase_info_user ei;
 
 		ei.start = ofs;
 		ei.length = size;
 
 		return ioctl(sb->fd, MEMERASE, &ei);
+#ifdef MEMERASE64
 	}
+#endif
 }
 
 static int mtd_prepare_sb(struct super_block *sb)