FS#11332 - Loopback filesystem support

Attached to Project: Rockbox
Opened by Frank Gevaerts (fg) - Saturday, 29 May 2010, 23:01 GMT
Last edited by Frank Gevaerts (fg) - Tuesday, 24 January 2012, 20:42 GMT
Task Type Patches
Category Drivers
Status Closed
Assigned To No-one
Operating System All players
Severity Low
Priority Low
Reported Version Release 3.4
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 0
Private No


This patch adds preliminary support for loopback-mounting a disk image.
This isn't very useful as such, but with some more work this could be used to export arbitrary disk images as USB devices, possibly even (with some more USB work) CD-ROM devices. With this sort of feature, it would become possible to carry random bootable rescue images on a DAP.

What works now is mounting an image within rockbox on a non-hotswap target. The image is also exported over USB currently, but this is dangerous since the main disk (which has the image) is also exported. Also, this only works by accident because unmounting a filesystem doesn't forcibly close file handles.

What needs more work:
- HAVE_HOTSWAP currently that only one driver supports hotswappable disks on a given target. This needs to be cleaned up.
- the USB code needs a mechanism to only export selected disks. This might actually be useful for other usecases as well (e.g. it might be possible to export the SD card slot while playing audio from the internal storage), but that would need even more work
This task depends upon

Closed by  Frank Gevaerts (fg)
Tuesday, 24 January 2012, 20:42 GMT
Reason for closing:  Out of Date
Additional comments about closing:  This now tracked in gerrit, at