I have an SD card without obvious file system. I'm seeing if the data on there (largely) follows a particular file system's convention. In linux, I ran
sudo dd if=/dev/mmcblk0 of=SDcard.bin
fdisk SDcard.bin gives
Disk SDcard.bin: 3.7GiB, 3965190144 bytes, 7744512 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 / 512 bytes
I/O size (minimum/optimal):512 / 512 bytes
sudo mount -o ro,loop SDcard.bin /mnt/SD
results in a error:
mount: wrong fs type, bad option bad superblock on /dev/loop0, missing codepage or helper program, or other error
sudo losetup --partscan --find --show SDcard.bin
responds with "/dev/loop0"
but I can't
fsck /dev/loop0 or
mount /dev/loop0 /mnt/SD, even trying several options for
I did an
xxd SDcard.bin SDcard.hex and I see, in the middle of the file (e.g. around address 00400040)
a2b2NO NAME FAT32 . (spacing sic,  = no data) and some readable text earlier than that in several places.
Should I try to mount as Fat32 with offsets, e.g.
losetup --offset 00400040 /dev/loop0 SDCard.bin*
*where I translate 00400040 from hex to dec first