genode

History

Norman Feske bbe3ee8dc5 block_session: server-defined payload alignment This patch replaces the formerly fixed 2 KiB data alignment within the packet-stream buffer by a server-defined alignment. This has two benefits. First, when using block servers that provide small block sizes like 512 bytes, we avoid fragmenting the packet-stream buffer, which occurs when aligning 512-byte requests at 2 KiB boundaries. This reduces meta data costs for the packet-stream allocator and also allows fitting more requests into the buffer. Second, block drivers with alignment constraints dictated by the hardware can now pass those constraints to the client, thereby easing the use of zero-copy DMA directly into the packet stream. The alignment is determined by the Block::Session_client at construction time and applied by the Block::Session_client::alloc_packet method. Block-session clients should always use this method, not the 'alloc_packet' method of the packet stream (tx source) directly. The latter merely applies a default alignment of 2 KiB. At the server side, the alignment is automatically checked by block/component.h (old API) and block/request_stream.h (new API). Issue #3274		2019-05-03 13:53:12 +02:00
..
iso9660.cc	block_session: server-defined payload alignment	2019-05-03 13:53:12 +02:00
iso9660.h	Adjust file headers to refer to the AGPLv3	2017-02-28 12:59:29 +01:00
main.cc	Add missing override annotations	2019-02-19 11:12:11 +01:00
README	Move repositories to 'repos/' subdirectory	2014-05-14 16:08:00 +02:00
target.mk	Move repositories to 'repos/' subdirectory	2014-05-14 16:08:00 +02:00

README

This directory contains an implementation of an ISO 9660 file system.

Limitations
-----------

At the moment, the only file-name format supported is the Rock Ridge extension.
The ISO specified 8.3 upper-case-file names are not supported, as well as Joliet.

Usage
-----

The server requires an ATAPI-block device as back-end. Please have a look at
'os/src/drivers/atapi'. The front-end of the server is implemented as a ROM
session server. In order to access this server from your application, you need
to route the ROM session to the ISO-ROM-session server in Genode's configuration
file:

!<start name="test-iso">
!  <resource name="RAM" quantum="10M" />
!    <route>
!      <service name="ROM"><child name="iso9660"/></service>
!    </route>
!</start>

Currently, the RAM quota necessary to obtain a file from the ISO file system
is allocated on behalf of the ISO server. Please make sure to provide
sufficient RAM quota to the ISO server.