]>
Commit | Line | Data |
---|---|---|
1 | This file describes the floppy driver. | |
2 | ||
3 | FAQ list: | |
4 | ========= | |
5 | ||
6 | A FAQ list may be found in the fdutils package (see below), and also | |
7 | at <http://fdutils.linux.lu/faq.html>. | |
8 | ||
9 | ||
10 | LILO configuration options (Thinkpad users, read this) | |
11 | ====================================================== | |
12 | ||
13 | The floppy driver is configured using the 'floppy=' option in | |
14 | lilo. This option can be typed at the boot prompt, or entered in the | |
15 | lilo configuration file. | |
16 | ||
17 | Example: If your kernel is called linux-2.6.9, type the following line | |
18 | at the lilo boot prompt (if you have a thinkpad): | |
19 | ||
20 | linux-2.6.9 floppy=thinkpad | |
21 | ||
22 | You may also enter the following line in /etc/lilo.conf, in the description | |
23 | of linux-2.6.9: | |
24 | ||
25 | append = "floppy=thinkpad" | |
26 | ||
27 | Several floppy related options may be given, example: | |
28 | ||
29 | linux-2.6.9 floppy=daring floppy=two_fdc | |
30 | append = "floppy=daring floppy=two_fdc" | |
31 | ||
32 | If you give options both in the lilo config file and on the boot | |
33 | prompt, the option strings of both places are concatenated, the boot | |
34 | prompt options coming last. That's why there are also options to | |
35 | restore the default behavior. | |
36 | ||
37 | ||
38 | Module configuration options | |
39 | ============================ | |
40 | ||
41 | If you use the floppy driver as a module, use the following syntax: | |
42 | modprobe floppy <options> | |
43 | ||
44 | Example: | |
45 | modprobe floppy omnibook messages | |
46 | ||
47 | If you need certain options enabled every time you load the floppy driver, | |
48 | you can put: | |
49 | ||
50 | options floppy omnibook messages | |
51 | ||
52 | in /etc/modprobe.conf. | |
53 | ||
54 | ||
55 | The floppy driver related options are: | |
56 | ||
57 | floppy=asus_pci | |
58 | Sets the bit mask to allow only units 0 and 1. (default) | |
59 | ||
60 | floppy=daring | |
61 | Tells the floppy driver that you have a well behaved floppy controller. | |
62 | This allows more efficient and smoother operation, but may fail on | |
63 | certain controllers. This may speed up certain operations. | |
64 | ||
65 | floppy=0,daring | |
66 | Tells the floppy driver that your floppy controller should be used | |
67 | with caution. | |
68 | ||
69 | floppy=one_fdc | |
70 | Tells the floppy driver that you have only one floppy controller. | |
71 | (default) | |
72 | ||
73 | floppy=two_fdc | |
74 | floppy=<address>,two_fdc | |
75 | Tells the floppy driver that you have two floppy controllers. | |
76 | The second floppy controller is assumed to be at <address>. | |
77 | This option is not needed if the second controller is at address | |
78 | 0x370, and if you use the 'cmos' option. | |
79 | ||
80 | floppy=thinkpad | |
81 | Tells the floppy driver that you have a Thinkpad. Thinkpads use an | |
82 | inverted convention for the disk change line. | |
83 | ||
84 | floppy=0,thinkpad | |
85 | Tells the floppy driver that you don't have a Thinkpad. | |
86 | ||
87 | floppy=omnibook | |
88 | floppy=nodma | |
89 | Tells the floppy driver not to use Dma for data transfers. | |
90 | This is needed on HP Omnibooks, which don't have a workable | |
91 | DMA channel for the floppy driver. This option is also useful | |
92 | if you frequently get "Unable to allocate DMA memory" messages. | |
93 | Indeed, dma memory needs to be continuous in physical memory, | |
94 | and is thus harder to find, whereas non-dma buffers may be | |
95 | allocated in virtual memory. However, I advise against this if | |
96 | you have an FDC without a FIFO (8272A or 82072). 82072A and | |
97 | later are OK. You also need at least a 486 to use nodma. | |
98 | If you use nodma mode, I suggest you also set the FIFO | |
99 | threshold to 10 or lower, in order to limit the number of data | |
100 | transfer interrupts. | |
101 | ||
102 | If you have a FIFO-able FDC, the floppy driver automatically | |
103 | falls back on non DMA mode if no DMA-able memory can be found. | |
104 | If you want to avoid this, explicitly ask for 'yesdma'. | |
105 | ||
106 | floppy=yesdma | |
107 | Tells the floppy driver that a workable DMA channel is available. | |
108 | (default) | |
109 | ||
110 | floppy=nofifo | |
111 | Disables the FIFO entirely. This is needed if you get "Bus | |
112 | master arbitration error" messages from your Ethernet card (or | |
113 | from other devices) while accessing the floppy. | |
114 | ||
115 | floppy=usefifo | |
116 | Enables the FIFO. (default) | |
117 | ||
118 | floppy=<threshold>,fifo_depth | |
119 | Sets the FIFO threshold. This is mostly relevant in DMA | |
120 | mode. If this is higher, the floppy driver tolerates more | |
121 | interrupt latency, but it triggers more interrupts (i.e. it | |
122 | imposes more load on the rest of the system). If this is | |
123 | lower, the interrupt latency should be lower too (faster | |
124 | processor). The benefit of a lower threshold is less | |
125 | interrupts. | |
126 | ||
127 | To tune the fifo threshold, switch on over/underrun messages | |
128 | using 'floppycontrol --messages'. Then access a floppy | |
129 | disk. If you get a huge amount of "Over/Underrun - retrying" | |
130 | messages, then the fifo threshold is too low. Try with a | |
131 | higher value, until you only get an occasional Over/Underrun. | |
132 | It is a good idea to compile the floppy driver as a module | |
133 | when doing this tuning. Indeed, it allows to try different | |
134 | fifo values without rebooting the machine for each test. Note | |
135 | that you need to do 'floppycontrol --messages' every time you | |
136 | re-insert the module. | |
137 | ||
138 | Usually, tuning the fifo threshold should not be needed, as | |
139 | the default (0xa) is reasonable. | |
140 | ||
141 | floppy=<drive>,<type>,cmos | |
142 | Sets the CMOS type of <drive> to <type>. This is mandatory if | |
143 | you have more than two floppy drives (only two can be | |
144 | described in the physical CMOS), or if your BIOS uses | |
145 | non-standard CMOS types. The CMOS types are: | |
146 | ||
147 | 0 - Use the value of the physical CMOS | |
148 | 1 - 5 1/4 DD | |
149 | 2 - 5 1/4 HD | |
150 | 3 - 3 1/2 DD | |
151 | 4 - 3 1/2 HD | |
152 | 5 - 3 1/2 ED | |
153 | 6 - 3 1/2 ED | |
154 | 16 - unknown or not installed | |
155 | ||
156 | (Note: there are two valid types for ED drives. This is because 5 was | |
157 | initially chosen to represent floppy *tapes*, and 6 for ED drives. | |
158 | AMI ignored this, and used 5 for ED drives. That's why the floppy | |
159 | driver handles both.) | |
160 | ||
161 | floppy=unexpected_interrupts | |
162 | Print a warning message when an unexpected interrupt is received. | |
163 | (default) | |
164 | ||
165 | floppy=no_unexpected_interrupts | |
166 | floppy=L40SX | |
167 | Don't print a message when an unexpected interrupt is received. This | |
168 | is needed on IBM L40SX laptops in certain video modes. (There seems | |
169 | to be an interaction between video and floppy. The unexpected | |
170 | interrupts affect only performance, and can be safely ignored.) | |
171 | ||
172 | floppy=broken_dcl | |
173 | Don't use the disk change line, but assume that the disk was | |
174 | changed whenever the device node is reopened. Needed on some | |
175 | boxes where the disk change line is broken or unsupported. | |
176 | This should be regarded as a stopgap measure, indeed it makes | |
177 | floppy operation less efficient due to unneeded cache | |
178 | flushings, and slightly more unreliable. Please verify your | |
179 | cable, connection and jumper settings if you have any DCL | |
180 | problems. However, some older drives, and also some laptops | |
181 | are known not to have a DCL. | |
182 | ||
183 | floppy=debug | |
184 | Print debugging messages. | |
185 | ||
186 | floppy=messages | |
187 | Print informational messages for some operations (disk change | |
188 | notifications, warnings about over and underruns, and about | |
189 | autodetection). | |
190 | ||
191 | floppy=silent_dcl_clear | |
192 | Uses a less noisy way to clear the disk change line (which | |
193 | doesn't involve seeks). Implied by 'daring' option. | |
194 | ||
195 | floppy=<nr>,irq | |
196 | Sets the floppy IRQ to <nr> instead of 6. | |
197 | ||
198 | floppy=<nr>,dma | |
199 | Sets the floppy DMA channel to <nr> instead of 2. | |
200 | ||
201 | floppy=slow | |
202 | Use PS/2 stepping rate: | |
203 | " PS/2 floppies have much slower step rates than regular floppies. | |
204 | It's been recommended that take about 1/4 of the default speed | |
205 | in some more extreme cases." | |
206 | ||
207 | ||
208 | Supporting utilities and additional documentation: | |
209 | ================================================== | |
210 | ||
211 | Additional parameters of the floppy driver can be configured at | |
212 | runtime. Utilities which do this can be found in the fdutils package. | |
213 | This package also contains a new version of mtools which allows to | |
214 | access high capacity disks (up to 1992K on a high density 3 1/2 disk!). | |
215 | It also contains additional documentation about the floppy driver. | |
216 | ||
217 | The latest version can be found at fdutils homepage: | |
218 | http://fdutils.linux.lu | |
219 | ||
220 | The fdutils releases can be found at: | |
221 | http://fdutils.linux.lu/download.html | |
222 | http://www.tux.org/pub/knaff/fdutils/ | |
223 | ftp://metalab.unc.edu/pub/Linux/utils/disk-management/ | |
224 | ||
225 | Reporting problems about the floppy driver | |
226 | ========================================== | |
227 | ||
228 | If you have a question or a bug report about the floppy driver, mail | |
229 | me at Alain.Knaff@poboxes.com . If you post to Usenet, preferably use | |
230 | comp.os.linux.hardware. As the volume in these groups is rather high, | |
231 | be sure to include the word "floppy" (or "FLOPPY") in the subject | |
232 | line. If the reported problem happens when mounting floppy disks, be | |
233 | sure to mention also the type of the filesystem in the subject line. | |
234 | ||
235 | Be sure to read the FAQ before mailing/posting any bug reports! | |
236 | ||
237 | Alain | |
238 | ||
239 | Changelog | |
240 | ========= | |
241 | ||
242 | 10-30-2004 : Cleanup, updating, add reference to module configuration. | |
243 | James Nelson <james4765@gmail.com> | |
244 | ||
245 | 6-3-2000 : Original Document |