floppy.txt 8.3 KB

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