UDF file system server

1 Current status

FS type	Reading	Writing
UDF Plain	±	-
DVD Video	+	N/A
Blu-Ray Video	-	N/A

2 TODO plan

• Complete reading UDF plain disks
• Complete and test reading Blu-ray disks
• Complete support big-endian archs
• Implement initial writing support for UDF plain disks

3 How to test

3.1 Download sources from my branch

bzr branch lp:~medvedeva-julia/helenos/udf helenos

3.2 Compile sources

cd helenos
make PROFILE=ia32

3.3 Create UDF disk image under Linux

To create UDF image under Linux you need to install package with ​UDF utilities. For example in Arch it's ​udftools. The package should contain the mkudffs tool.

mkudffs --media-type=hd --blocksize=512 --utf8 ./udf.img

You can also select media type: "hd" or "dvd" and blocksize: 512 or 2048 or something else.

Unless you are overwriting already existing image, you need to create an empty file first (otherwise you would get the trying to change type of multiple extents error). Following creates a 32M file:

dd if=/dev/zero of=./udf.img bs=4096 count=8192

3.4 Mount udf disk image under Linux

You can mount the UDF image (from step 3.3) under your Linux host and copy several files into it.

mount -o loop -t udf ./udf.img /mnt/udf-mount-point

where udf.img is the image from step 3.3

3.5 Boot HelenOS with user disk image

To boot HelenOS run QEMU:

qemu-system-i386 -m 512 -boot d -hda udf.img -cdrom image.iso

udf.img is the UDF disk image

3.6 Mount user disk image under HelenOS

In HelenOS run a batch script to run UDF server, ATA server and mount the first ATA disk as UDF.

batch u

Then, go to the /mnt directory:

cd /mnt

and here you are

4 Read functions dashboard

VFS method	Task	Implementation	File	Progress	TODO and comments
mounted	check volume recognition sequence	udf_volume_recongnition	udf_volume	done
	search for anchor volume descriptor	udf_get_anchor_volume_descriptor	udf_volume	done
	read volume descriptor sequence	udf_read_volume_descriptor_sequence	udf_volume	done
	data structure for saving information about item (file or dir)	udf_node_t	udf.h	done
	hash table for udf_node saving	udf_idx_	udf_idx	done	udf_idx_hash too simple
	ckecksum functions	entire file	udf_cksum	done
	osta unicode compression	entire file	udf_osta	done
	mount udf disk	udf_mounted	udf_ops	done
node_get	get, put and reading udf_node	udf_node_get	udf_ops	done
read	read icb sequence by index	udf_node_get_core	udf_file	done
	read file entry descriptor from icb	udf_read_icb	udf_file	done
	read allocation sequence from file entry descriptor	udf_read_allocation_sequence	udf_file	done	read allocator for next sequence
	sorting of allocators	udf_allocator_sort	udf_file	done	too simple
	read file by position	udf_read_file	udf_ops	done	read file saved in allocator
	read directory	udf_get_fid	udf_ops	in progress	rewrite for fragmented fid
root_get	get root directory	udf_root_get	udf_ops	done
match	search fid in directory by name	udf_match	udf_ops	done
node_put	delete node	udf_node_put	udf_ops	in progress
index_get	get index of node	udf_index_get	udf_ops	done
has_children	return true if a directory contains elements	udf_has_children	udf_ops	in progress
size_get	size of element (file or directory)	udf_size_get	udf_ops	done
lnkcnt_get	count links on node	udf_lnkcnt_get	udf_ops	done
is_directory	identify directory	udf_is_directory	udf_ops	done
is_file	identify file	udf_is_file	udf_ops	done
service_get	get service id	udf_service_get	udf_ops	done