I was getting this error message:
nsh> mount -t vfat /dev/sda /mnt fat_checkbootrecord: WARNING: Signature: aa55 FS sectorsize: 37008 HW sectorsize: 512 fat_checkbootrecord: WARNING: Signature: 0000 FS sectorsize: 23552 HW sectorsize: 512 fat_mount: ERROR: No valid boot record nx_mount: ERROR: Bind method failed: -22 nsh: mount: mount failed: 22 nsh>
At first I created the Thumb driver on Linux (usual way with fdisk setting partition to “b” (now fdisk is using decimal, so: 11) and formatting with mkfs.vfat), they I tried to use Win10 Disk Manager. But same error appeared.
Then I decided to investigate further and notice that MBR is zeroed:
NuttShell (NSH) NuttX-12.1.0 nsh> nsh> mkrd 64 nsh> mkfatfs /dev/ram0 nsh> mount -t vfat /dev/ram0 /mnt nsh> ls /dev /dev: console null ram0 sda ttyS0 nsh> dd if=/dev/sda of=/mnt/disk.bin bs=512 count=3 nsh> ls -l /mnt/ /mnt: -rw-rw-rw- 1536 disk.bin nsh> hexdump /mnt/disk.bin /mnt/disk.bin at 00000000: 0000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0110: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0120: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0130: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0140: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0150: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0160: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0170: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0190: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01c0: 02 00 ee fe ff 77 01 00 00 00 ff ff ff ff 00 00 .....w.......... 01d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa ..............U. /mnt/disk.bin at 00000200: 0000: 45 46 49 20 50 41 52 54 00 00 01 00 5c 00 00 00 EFI PART....\... 0010: 79 0f c2 72 00 00 00 00 01 00 00 00 00 00 00 00 y..r............ 0020: ff bf d4 01 00 00 00 00 22 00 00 00 00 00 00 00 ........"....... 0030: de bf d4 01 00 00 00 00 b8 b2 9d a0 f6 b5 ae 43 ...............C 0040: af b3 91 e0 a9 01 89 a1 02 00 00 00 00 00 00 00 ................ 0050: 80 00 00 00 80 00 00 00 37 f2 cf 02 00 00 00 00 ........7....... 0060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0110: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0120: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0130: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0140: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0150: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0160: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0170: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0190: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ /mnt/disk.bin at 00000400: 0000: a2 a0 d0 eb e5 b9 33 44 87 c0 68 b6 b7 26 99 c7 ......3D..h..&.. 0010: 2b a7 bf 77 0c ee 7a 4e a8 18 94 7e dc 87 e3 2f +..w..zN...~.../ 0020: 00 08 00 00 00 00 00 00 ff b7 d4 01 00 00 00 00 ................ 0030: 00 00 00 00 00 00 00 00 42 00 61 00 73 00 69 00 ........B.a.s.i. 0040: 63 00 20 00 64 00 61 00 74 00 61 00 20 00 70 00 c. .d.a.t.a. .p. 0050: 61 00 72 00 74 00 69 00 74 00 69 00 6f 00 6e 00 a.r.t.i.t.i.o.n. 0060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0110: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0120: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0130: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0140: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0150: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0160: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0170: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0190: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ nsh>
So I finally found the solution: use the Disks application on Linux (this official name is gnome-disks)
I followed this tutorial:
An important tip: after you had formatted the Disk then create a new partition, but initially don’t select Erase the partition because it will format it as Linux partition instead of FAT (even you selecting FAT there).