Le 08/09/2020 à 23:25, Brad Boyer a écrit : > On Tue, Sep 08, 2020 at 05:07:50PM +0200, Dirk Heinrichs wrote: >> Am 08.09.20 um 11:02 schrieb Emmanuel Kasper: >> >>> Considering it is possible to mount such a partition as root with sudo >>> mount /dev/mmcblk0p1 /mnt what would need be in udev to recognize the >>> filesystem ? >> >> udev is about devices, not filesystems. Just use above mount command to >> mount it (given the kernel has support for it, either built in or as a >> module). If you want udev to create a more convenient name for >> /dev/mmcblk0, you need to write a rule for it. > > That almost sounds like libblkid isn't recognizing the FS. Can you try > running blkid on the device? If it can't detect the FS type, that might > be a place where there is an issue. The libblkid code is not based on > the drivers in the kernel, but is still essential for a portion of the > auto-detection of file systems in user-space.
Hi Brad Indeed blkid does not recognize the FS type, thanks for the hint ! sudo blkid -p /dev/mmcblk0p1 /dev/mmcblk0p1: PART_ENTRY_SCHEME="atari" PART_ENTRY_TYPE="BGM" PART_ENTRY_NUMBER="1" PART_ENTRY_OFFSET="2" PART_ENTRY_SIZE="131072" PART_ENTRY_DISK="179:256" I suppose this is because the Atari GEMDOS FAT16 partitions have a variable sector size wich is larger that 512 bytes for partitions > 16MB, whereas MSDOS FAT16 always uses a 512 bytes sectorsize . The disktype tool, provided in the archive, gave me the hint about the sector size difference: http://disktype.sourceforge.net/doc/ch03s03.html and this technical guide, which has all the FAT subtilities explained: http://info-coach.fr/atari/documents/_mydoc/Atari_HD_File_Sytem_Reference_Guide.pdf sudo disktype /dev/mmcblk0p1 --- /dev/mmcblk0p1 Block device, size 64 MiB (67108864 bytes) FAT16 file system (hints score 3 of 5, ATARI ST bootable) Unusual sector size 4096 bytes Volume size 63.95 MiB (67051520 bytes, 8185 clusters of 8 KiB) Now I had a quicklook at libblkid, and it should be able at first view to cope with sector size up to 4096 bytes, so I am a bit puzzled here. https://github.com/karelzak/util-linux/blob/master/libblkid/src/superblocks/vfat.c#L218 Something to dig in. Emmanuel
