view Documentation/cdrom/sonycd535 @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
line source
2 ========================================
4 This is the Sony CDU-535 (and 531) driver version 0.7 for Linux.
5 I do not think I have the documentation to add features like DMA support
6 so if anyone else wants to pursue it or help me with it, please do.
7 (I need to see what was done for the CDU-31A driver -- perhaps I can
8 steal some of that code.)
10 This is a Linux device driver for the Sony CDU-535 CDROM drive. This is
11 one of the older Sony drives with its own interface card (Sony bus).
12 The DOS driver for this drive is named SONY_CDU.SYS - when you boot DOS
13 your drive should be identified as a SONY CDU-535. The driver works
14 with a CDU-531 also. One user reported that the driver worked on drives
15 OEM'ed by Procomm, drive and interface board were labelled Procomm.
17 The Linux driver is based on Corey Minyard's sonycd 0.3 driver for
18 the CDU-31A. Ron Jeppesen just changed the commands that were sent
19 to the drive to correspond to the CDU-535 commands and registers.
20 There were enough changes to let bugs creep in but it seems to be stable.
21 Ron was able to tar an entire CDROM (should read all blocks) and built
22 ghostview and xfig off Walnut Creek's X11R5/GNU CDROM. xcdplayer and
23 workman work with the driver. Others have used the driver without
24 problems except those dealing with wait loops (fixed in third release).
25 Like Minyard's original driver this one uses a polled interface (this
26 is also the default setup for the DOS driver). It has not been tried
27 with interrupts or DMA enabled on the board.
30 ============
32 - Sony CDU-535 drive, preferably without interrupts and DMA
33 enabled on the card.
35 - Drive must be set up as unit 1. Only the first unit will be
36 recognized
38 - You must enter your interface address into
39 /usr/src/linux/drivers/cdrom/sonycd535.h and build the
40 appropriate kernel or use the "kernel command line" parameter
41 sonycd535=0x320
42 with the correct interface address.
45 ======
47 1) The drive MUST be turned on when booting or it will not be recognized!
48 (but see comments on modularized version below)
50 2) when the cdrom device is opened the eject button is disabled to keep the
51 user from ejecting a mounted disk and replacing it with another.
52 Unfortunately xcdplayer and workman also open the cdrom device so you
53 have to use the eject button in the software. Keep this in mind if your
54 cdrom player refuses to give up its disk -- exit workman or xcdplayer, or
55 umount the drive if it has been mounted.
58 ======
60 Many thanks to Ron Jeppesen (ronj.an@site007.saic.com) for getting
61 this project off the ground. He wrote the initial release
62 and the first two patches to this driver (0.1, 0.2, and 0.3).
63 Thanks also to Eberhard Moenkeberg (emoenke@gwdg.de) for prodding
64 me to place this code into the mainstream Linux source tree
65 (as of Linux version 1.1.91), as well as some patches to make
66 it a better device citizen. Further thanks to Joel Katz
67 <joelkatz@webchat.org> for his MODULE patches (see details below),
68 Porfiri Claudio <C.Porfiri@nisms.tei.ericsson.se> for patches
69 to make the driver work with the older CDU-510/515 series, and
70 Heiko Eissfeldt <heiko@colossus.escape.de> for pointing out that
71 the verify_area() checks were ignoring the results of said checks
72 (note: verify_area() has since been replaced by access_ok()).
74 (Acknowledgments from Ron Jeppesen in the 0.3 release:)
75 Thanks to Corey Minyard who wrote the original CDU-31A driver on which
76 this driver is based. Thanks to Ken Pizzini and Bob Blair who provided
77 patches and feedback on the first release of this driver.
79 Ken Pizzini
80 ken@halcyon.com
82 ------------------------------------------------------------------------------
83 (The following is from Joel Katz <joelkatz@webchat.org>.)
85 To build a version of sony535.o that can be installed as a module,
86 use the following command:
88 gcc -c -D__KERNEL__ -DMODULE -O2 sonycd535.c -o sonycd535.o
90 To install the module, simply type:
92 insmod sony535.o
93 or
94 insmod sony535.o sonycd535=<address>
96 And to remove it:
98 rmmod sony535
100 The code checks to see if MODULE is defined and behaves as it used
101 to if MODULE is not defined. That means your patched file should behave
102 exactly as it used to if compiled into the kernel.
104 I have an external drive, and I usually leave it powered off. I used
105 to have to reboot if I needed to use the CDROM drive. Now I don't.
107 Even if you have an internal drive, why waste the 96K of memory
108 (unswappable) that the driver uses if you use your CD-ROM drive infrequently?
110 This driver will not install (whether compiled in or loaded as a
111 module) if the CDROM drive is not available during its initialization. This
112 means that you can have the driver compiled into the kernel and still load
113 the module later (assuming the driver doesn't install itself during
114 power-on). This only wastes 12K when you boot with the CDROM drive off.
116 This is what I usually do; I leave the driver compiled into the
117 kernel, but load it as a module if I powered the system up with the drive
118 off and then later decided to use the CDROM drive.
120 Since the driver only uses a single page to point to the chunks,
121 attempting to set the buffer cache to more than 2 Megabytes would be very
122 bad; don't do that.