About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Documentation / m68k / kernel-options.txt

Based on kernel version 2.6.26. Page generated on 2008-07-16 21:13 EST.

1	
2	
3					  Command Line Options for Linux/m68k
4					  ===================================
5	
6	Last Update: 2 May 1999
7	Linux/m68k version: 2.2.6
8	Author: Roman.Hodek[AT]informatik.uni-erlangen[DOT]de (Roman Hodek)
9	Update: jds[AT]kom.auc.dk (Jes Sorensen) and faq@linux-m68k[DOT]org (Chris Lawrence)
10	
11	0) Introduction
12	===============
13	
14	  Often I've been asked which command line options the Linux/m68k
15	kernel understands, or how the exact syntax for the ... option is, or
16	... about the option ... . I hope, this document supplies all the
17	answers...
18	
19	  Note that some options might be outdated, their descriptions being
20	incomplete or missing. Please update the information and send in the
21	patches.
22	
23	
24	1) Overview of the Kernel's Option Processing
25	=============================================
26	
27	The kernel knows three kinds of options on its command line:
28	
29	  1) kernel options
30	  2) environment settings
31	  3) arguments for init
32	
33	To which of these classes an argument belongs is determined as
34	follows: If the option is known to the kernel itself, i.e. if the name
35	(the part before the '=') or, in some cases, the whole argument string
36	is known to the kernel, it belongs to class 1. Otherwise, if the
37	argument contains an '=', it is of class 2, and the definition is put
38	into init's environment. All other arguments are passed to init as
39	command line options.
40	
41	  This document describes the valid kernel options for Linux/m68k in
42	the version mentioned at the start of this file. Later revisions may
43	add new such options, and some may be missing in older versions.
44	
45	  In general, the value (the part after the '=') of an option is a
46	list of values separated by commas. The interpretation of these values
47	is up to the driver that "owns" the option. This association of
48	options with drivers is also the reason that some are further
49	subdivided.
50	
51	
52	2) General Kernel Options
53	=========================
54	
55	2.1) root=
56	----------
57	
58	Syntax: root=/dev/<device>
59	    or: root=<hex_number>
60	
61	This tells the kernel which device it should mount as the root
62	filesystem. The device must be a block device with a valid filesystem
63	on it.
64	
65	  The first syntax gives the device by name. These names are converted
66	into a major/minor number internally in the kernel in an unusual way.
67	Normally, this "conversion" is done by the device files in /dev, but
68	this isn't possible here, because the root filesystem (with /dev)
69	isn't mounted yet... So the kernel parses the name itself, with some
70	hardcoded name to number mappings. The name must always be a
71	combination of two or three letters, followed by a decimal number.
72	Valid names are:
73	
74	  /dev/ram: -> 0x0100 (initial ramdisk)
75	  /dev/hda: -> 0x0300 (first IDE disk)
76	  /dev/hdb: -> 0x0340 (second IDE disk)
77	  /dev/sda: -> 0x0800 (first SCSI disk)
78	  /dev/sdb: -> 0x0810 (second SCSI disk)
79	  /dev/sdc: -> 0x0820 (third SCSI disk)
80	  /dev/sdd: -> 0x0830 (forth SCSI disk)
81	  /dev/sde: -> 0x0840 (fifth SCSI disk)
82	  /dev/fd : -> 0x0200 (floppy disk)
83	  /dev/xda: -> 0x0c00 (first XT disk, unused in Linux/m68k)
84	  /dev/xdb: -> 0x0c40 (second XT disk, unused in Linux/m68k)
85	
86	  The name must be followed by a decimal number, that stands for the
87	partition number. Internally, the value of the number is just
88	added to the device number mentioned in the table above. The
89	exceptions are /dev/ram and /dev/fd, where /dev/ram refers to an
90	initial ramdisk loaded by your bootstrap program (please consult the
91	instructions for your bootstrap program to find out how to load an
92	initial ramdisk). As of kernel version 2.0.18 you must specify
93	/dev/ram as the root device if you want to boot from an initial
94	ramdisk. For the floppy devices, /dev/fd, the number stands for the
95	floppy drive number (there are no partitions on floppy disks). I.e.,
96	/dev/fd0 stands for the first drive, /dev/fd1 for the second, and so
97	on. Since the number is just added, you can also force the disk format
98	by adding a number greater than 3. If you look into your /dev
99	directory, use can see the /dev/fd0D720 has major 2 and minor 16. You
100	can specify this device for the root FS by writing "root=/dev/fd16" on
101	the kernel command line.
102	
103	[Strange and maybe uninteresting stuff ON]
104	
105	  This unusual translation of device names has some strange
106	consequences: If, for example, you have a symbolic link from /dev/fd
107	to /dev/fd0D720 as an abbreviation for floppy driver #0 in DD format,
108	you cannot use this name for specifying the root device, because the
109	kernel cannot see this symlink before mounting the root FS and it
110	isn't in the table above. If you use it, the root device will not be 
111	set at all, without an error message. Another example: You cannot use a
112	partition on e.g. the sixth SCSI disk as the root filesystem, if you
113	want to specify it by name. This is, because only the devices up to
114	/dev/sde are in the table above, but not /dev/sdf. Although, you can
115	use the sixth SCSI disk for the root FS, but you have to specify the
116	device by number... (see below). Or, even more strange, you can use the
117	fact that there is no range checking of the partition number, and your
118	knowledge that each disk uses 16 minors, and write "root=/dev/sde17"
119	(for /dev/sdf1).
120	
121	[Strange and maybe uninteresting stuff OFF]
122	
123	  If the device containing your root partition isn't in the table
124	above, you can also specify it by major and minor numbers. These are
125	written in hex, with no prefix and no separator between. E.g., if you
126	have a CD with contents appropriate as a root filesystem in the first
127	SCSI CD-ROM drive, you boot from it by "root=0b00". Here, hex "0b" =
128	decimal 11 is the major of SCSI CD-ROMs, and the minor 0 stands for
129	the first of these. You can find out all valid major numbers by
130	looking into include/linux/major.h.
131	
132	
133	2.2) ro, rw
134	-----------
135	
136	Syntax: ro
137	    or: rw
138	
139	These two options tell the kernel whether it should mount the root
140	filesystem read-only or read-write. The default is read-only, except
141	for ramdisks, which default to read-write.
142	
143	
144	2.3) debug
145	----------
146	
147	Syntax: debug
148	
149	This raises the kernel log level to 10 (the default is 7). This is the
150	same level as set by the "dmesg" command, just that the maximum level
151	selectable by dmesg is 8.
152	
153	
154	2.4) debug=
155	-----------
156	
157	Syntax: debug=<device>
158	
159	This option causes certain kernel messages be printed to the selected
160	debugging device. This can aid debugging the kernel, since the
161	messages can be captured and analyzed on some other machine. Which
162	devices are possible depends on the machine type. There are no checks
163	for the validity of the device name. If the device isn't implemented,
164	nothing happens.
165	
166	  Messages logged this way are in general stack dumps after kernel
167	memory faults or bad kernel traps, and kernel panics. To be exact: all
168	messages of level 0 (panic messages) and all messages printed while
169	the log level is 8 or more (their level doesn't matter). Before stack
170	dumps, the kernel sets the log level to 10 automatically. A level of
171	at least 8 can also be set by the "debug" command line option (see
172	2.3) and at run time with "dmesg -n 8".
173	
174	Devices possible for Amiga:
175	
176	 - "ser": built-in serial port; parameters: 9600bps, 8N1
177	 - "mem": Save the messages to a reserved area in chip mem. After
178	          rebooting, they can be read under AmigaOS with the tool
179	          'dmesg'.
180	
181	Devices possible for Atari:
182	
183	 - "ser1": ST-MFP serial port ("Modem1"); parameters: 9600bps, 8N1
184	 - "ser2": SCC channel B serial port ("Modem2"); parameters: 9600bps, 8N1
185	 - "ser" : default serial port
186	           This is "ser2" for a Falcon, and "ser1" for any other machine
187	 - "midi": The MIDI port; parameters: 31250bps, 8N1
188	 - "par" : parallel port
189	           The printing routine for this implements a timeout for the
190	           case there's no printer connected (else the kernel would
191	           lock up). The timeout is not exact, but usually a few
192	           seconds.
193	
194	
195	2.6) ramdisk_size=
196	-------------
197	
198	Syntax: ramdisk_size=<size>
199	
200	  This option instructs the kernel to set up a ramdisk of the given
201	size in KBytes. Do not use this option if the ramdisk contents are
202	passed by bootstrap! In this case, the size is selected automatically
203	and should not be overwritten.
204	
205	  The only application is for root filesystems on floppy disks, that
206	should be loaded into memory. To do that, select the corresponding
207	size of the disk as ramdisk size, and set the root device to the disk
208	drive (with "root=").
209	
210	
211	2.7) swap=
212	2.8) buff=
213	-----------
214	
215	  I can't find any sign of these options in 2.2.6.
216	
217	
218	3) General Device Options (Amiga and Atari)
219	===========================================
220	
221	3.1) ether=
222	-----------
223	
224	Syntax: ether=[<irq>[,<base_addr>[,<mem_start>[,<mem_end>]]]],<dev-name>
225	
226	  <dev-name> is the name of a net driver, as specified in
227	drivers/net/Space.c in the Linux source. Most prominent are eth0, ...
228	eth3, sl0, ... sl3, ppp0, ..., ppp3, dummy, and lo.
229	
230	  The non-ethernet drivers (sl, ppp, dummy, lo) obviously ignore the
231	settings by this options. Also, the existing ethernet drivers for
232	Linux/m68k (ariadne, a2065, hydra) don't use them because Zorro boards
233	are really Plug-'n-Play, so the "ether=" option is useless altogether
234	for Linux/m68k.
235	
236	
237	3.2) hd=
238	--------
239	
240	Syntax: hd=<cylinders>,<heads>,<sectors>
241	
242	  This option sets the disk geometry of an IDE disk. The first hd=
243	option is for the first IDE disk, the second for the second one.
244	(I.e., you can give this option twice.) In most cases, you won't have
245	to use this option, since the kernel can obtain the geometry data
246	itself. It exists just for the case that this fails for one of your
247	disks.
248	
249	
250	3.3) max_scsi_luns=
251	-------------------
252	
253	Syntax: max_scsi_luns=<n>
254	
255	  Sets the maximum number of LUNs (logical units) of SCSI devices to
256	be scanned. Valid values for <n> are between 1 and 8. Default is 8 if
257	"Probe all LUNs on each SCSI device" was selected during the kernel
258	configuration, else 1.
259	
260	
261	3.4) st=
262	--------
263	
264	Syntax: st=<buffer_size>,[<write_thres>,[<max_buffers>]]
265	
266	  Sets several parameters of the SCSI tape driver. <buffer_size> is
267	the number of 512-byte buffers reserved for tape operations for each
268	device. <write_thres> sets the number of blocks which must be filled
269	to start an actual write operation to the tape. Maximum value is the
270	total number of buffers. <max_buffer> limits the total number of
271	buffers allocated for all tape devices.
272	
273	
274	3.5) dmasound=
275	--------------
276	
277	Syntax: dmasound=[<buffers>,<buffer-size>[,<catch-radius>]]
278	
279	  This option controls some configurations of the Linux/m68k DMA sound
280	driver (Amiga and Atari): <buffers> is the number of buffers you want
281	to use (minimum 4, default 4), <buffer-size> is the size of each
282	buffer in kilobytes (minimum 4, default 32) and <catch-radius> says
283	how much percent of error will be tolerated when setting a frequency
284	(maximum 10, default 0). For example with 3% you can play 8000Hz
285	AU-Files on the Falcon with its hardware frequency of 8195Hz and thus
286	don't need to expand the sound.
287	
288	
289	
290	4) Options for Atari Only
291	=========================
292	
293	4.1) video=
294	-----------
295	
296	Syntax: video=<fbname>:<sub-options...>
297	
298	The <fbname> parameter specifies the name of the frame buffer,
299	eg. most atari users will want to specify `atafb' here. The
300	<sub-options> is a comma-separated list of the sub-options listed
301	below.
302	
303	NB: Please notice that this option was renamed from `atavideo' to
304	    `video' during the development of the 1.3.x kernels, thus you
305	    might need to update your boot-scripts if upgrading to 2.x from
306	    an 1.2.x kernel.
307	
308	NBB: The behavior of video= was changed in 2.1.57 so the recommended
309	option is to specify the name of the frame buffer.
310	
311	4.1.1) Video Mode
312	-----------------
313	
314	This sub-option may be any of the predefined video modes, as listed
315	in atari/atafb.c in the Linux/m68k source tree. The kernel will
316	activate the given video mode at boot time and make it the default
317	mode, if the hardware allows. Currently defined names are:
318	
319	 - stlow           : 320x200x4
320	 - stmid, default5 : 640x200x2
321	 - sthigh, default4: 640x400x1
322	 - ttlow           : 320x480x8, TT only
323	 - ttmid, default1 : 640x480x4, TT only
324	 - tthigh, default2: 1280x960x1, TT only
325	 - vga2            : 640x480x1, Falcon only
326	 - vga4            : 640x480x2, Falcon only
327	 - vga16, default3 : 640x480x4, Falcon only
328	 - vga256          : 640x480x8, Falcon only
329	 - falh2           : 896x608x1, Falcon only
330	 - falh16          : 896x608x4, Falcon only
331	
332	  If no video mode is given on the command line, the kernel tries the
333	modes names "default<n>" in turn, until one is possible with the
334	hardware in use.
335	
336	  A video mode setting doesn't make sense, if the external driver is
337	activated by a "external:" sub-option.
338	
339	4.1.2) inverse
340	--------------
341	
342	Invert the display. This affects both, text (consoles) and graphics
343	(X) display. Usually, the background is chosen to be black. With this
344	option, you can make the background white.
345	
346	4.1.3) font
347	-----------
348	
349	Syntax: font:<fontname>
350	
351	Specify the font to use in text modes. Currently you can choose only
352	between `VGA8x8', `VGA8x16' and `PEARL8x8'. `VGA8x8' is default, if the
353	vertical size of the display is less than 400 pixel rows. Otherwise, the
354	`VGA8x16' font is the default.
355	
356	4.1.4) hwscroll_
357	----------------
358	
359	Syntax: hwscroll_<n>
360	
361	The number of additional lines of video memory to reserve for
362	speeding up the scrolling ("hardware scrolling"). Hardware scrolling
363	is possible only if the kernel can set the video base address in steps
364	fine enough. This is true for STE, MegaSTE, TT, and Falcon. It is not
365	possible with plain STs and graphics cards (The former because the
366	base address must be on a 256 byte boundary there, the latter because
367	the kernel doesn't know how to set the base address at all.)
368	
369	  By default, <n> is set to the number of visible text lines on the
370	display. Thus, the amount of video memory is doubled, compared to no
371	hardware scrolling. You can turn off the hardware scrolling altogether
372	by setting <n> to 0.
373	
374	4.1.5) internal:
375	----------------
376	
377	Syntax: internal:<xres>;<yres>[;<xres_max>;<yres_max>;<offset>]
378	
379	This option specifies the capabilities of some extended internal video
380	hardware, like e.g. OverScan. <xres> and <yres> give the (extended)
381	dimensions of the screen.
382	
383	  If your OverScan needs a black border, you have to write the last
384	three arguments of the "internal:". <xres_max> is the maximum line
385	length the hardware allows, <yres_max> the maximum number of lines.
386	<offset> is the offset of the visible part of the screen memory to its
387	physical start, in bytes.
388	
389	  Often, extended interval video hardware has to be activated somehow.
390	For this, see the "sw_*" options below.
391	
392	4.1.6) external:
393	----------------
394	
395	Syntax:
396	  external:<xres>;<yres>;<depth>;<org>;<scrmem>[;<scrlen>[;<vgabase>\
397	           [;<colw>[;<coltype>[;<xres_virtual>]]]]]
398	
399	[I had to break this line...]
400	
401	  This is probably the most complicated parameter... It specifies that
402	you have some external video hardware (a graphics board), and how to
403	use it under Linux/m68k. The kernel cannot know more about the hardware
404	than you tell it here! The kernel also is unable to set or change any
405	video modes, since it doesn't know about any board internal. So, you
406	have to switch to that video mode before you start Linux, and cannot
407	switch to another mode once Linux has started.
408	
409	  The first 3 parameters of this sub-option should be obvious: <xres>,
410	<yres> and <depth> give the dimensions of the screen and the number of
411	planes (depth). The depth is the logarithm to base 2 of the number
412	of colors possible. (Or, the other way round: The number of colors is
413	2^depth).
414	
415	  You have to tell the kernel furthermore how the video memory is
416	organized. This is done by a letter as <org> parameter:
417	
418	 'n': "normal planes", i.e. one whole plane after another
419	 'i': "interleaved planes", i.e. 16 bit of the first plane, than 16 bit
420	      of the next, and so on... This mode is used only with the
421		  built-in Atari video modes, I think there is no card that
422		  supports this mode.
423	 'p': "packed pixels", i.e. <depth> consecutive bits stand for all
424		  planes of one pixel; this is the most common mode for 8 planes
425		  (256 colors) on graphic cards
426	 't': "true color" (more or less packed pixels, but without a color
427		  lookup table); usually depth is 24
428	
429	For monochrome modes (i.e., <depth> is 1), the <org> letter has a
430	different meaning:
431	
432	 'n': normal colors, i.e. 0=white, 1=black
433	 'i': inverted colors, i.e. 0=black, 1=white
434	
435	  The next important information about the video hardware is the base
436	address of the video memory. That is given in the <scrmem> parameter,
437	as a hexadecimal number with a "0x" prefix. You have to find out this
438	address in the documentation of your hardware.
439	
440	  The next parameter, <scrlen>, tells the kernel about the size of the
441	video memory. If it's missing, the size is calculated from <xres>,
442	<yres>, and <depth>. For now, it is not useful to write a value here.
443	It would be used only for hardware scrolling (which isn't possible
444	with the external driver, because the kernel cannot set the video base
445	address), or for virtual resolutions under X (which the X server
446	doesn't support yet). So, it's currently best to leave this field
447	empty, either by ending the "external:" after the video address or by
448	writing two consecutive semicolons, if you want to give a <vgabase>
449	(it is allowed to leave this parameter empty).
450	
451	  The <vgabase> parameter is optional. If it is not given, the kernel
452	cannot read or write any color registers of the video hardware, and
453	thus you have to set appropriate colors before you start Linux. But if
454	your card is somehow VGA compatible, you can tell the kernel the base
455	address of the VGA register set, so it can change the color lookup
456	table. You have to look up this address in your board's documentation.
457	To avoid misunderstandings: <vgabase> is the _base_ address, i.e. a 4k
458	aligned address. For read/writing the color registers, the kernel
459	uses the addresses vgabase+0x3c7...vgabase+0x3c9. The <vgabase>
460	parameter is written in hexadecimal with a "0x" prefix, just as
461	<scrmem>.
462	
463	  <colw> is meaningful only if <vgabase> is specified. It tells the
464	kernel how wide each of the color register is, i.e. the number of bits
465	per single color (red/green/blue). Default is 6, another quite usual
466	value is 8.
467	
468	  Also <coltype> is used together with <vgabase>. It tells the kernel
469	about the color register model of your gfx board. Currently, the types
470	"vga" (which is also the default) and "mv300" (SANG MV300) are
471	implemented.
472	
473	  Parameter <xres_virtual> is required for ProMST or ET4000 cards where
474	the physical linelength differs from the visible length. With ProMST, 
475	xres_virtual must be set to 2048. For ET4000, xres_virtual depends on the
476	initialisation of the video-card.
477	If you're missing a corresponding yres_virtual: the external part is legacy,
478	therefore we don't support hardware-dependent functions like hardware-scroll,
479	panning or blanking.
480	
481	4.1.7) eclock:
482	--------------
483	
484	The external pixel clock attached to the Falcon VIDEL shifter. This
485	currently works only with the ScreenWonder!
486	
487	4.1.8) monitorcap:
488	-------------------
489	
490	Syntax: monitorcap:<vmin>;<vmax>;<hmin>;<hmax>
491	
492	This describes the capabilities of a multisync monitor. Don't use it
493	with a fixed-frequency monitor! For now, only the Falcon frame buffer
494	uses the settings of "monitorcap:".
495	
496	  <vmin> and <vmax> are the minimum and maximum, resp., vertical frequencies
497	your monitor can work with, in Hz. <hmin> and <hmax> are the same for
498	the horizontal frequency, in kHz.
499	
500	  The defaults are 58;62;31;32 (VGA compatible).
501	
502	  The defaults for TV/SC1224/SC1435 cover both PAL and NTSC standards.
503	
504	4.1.9) keep
505	------------
506	
507	If this option is given, the framebuffer device doesn't do any video
508	mode calculations and settings on its own. The only Atari fb device
509	that does this currently is the Falcon.
510	
511	  What you reach with this: Settings for unknown video extensions
512	aren't overridden by the driver, so you can still use the mode found
513	when booting, when the driver doesn't know to set this mode itself.
514	But this also means, that you can't switch video modes anymore...
515	
516	  An example where you may want to use "keep" is the ScreenBlaster for
517	the Falcon.
518	
519	
520	4.2) atamouse=
521	--------------
522	
523	Syntax: atamouse=<x-threshold>,[<y-threshold>]
524	
525	  With this option, you can set the mouse movement reporting threshold.
526	This is the number of pixels of mouse movement that have to accumulate
527	before the IKBD sends a new mouse packet to the kernel. Higher values
528	reduce the mouse interrupt load and thus reduce the chance of keyboard
529	overruns. Lower values give a slightly faster mouse responses and
530	slightly better mouse tracking.
531	
532	  You can set the threshold in x and y separately, but usually this is
533	of little practical use. If there's just one number in the option, it
534	is used for both dimensions. The default value is 2 for both
535	thresholds.
536	
537	
538	4.3) ataflop=
539	-------------
540	
541	Syntax: ataflop=<drive type>[,<trackbuffering>[,<steprateA>[,<steprateB>]]]
542	
543	   The drive type may be 0, 1, or 2, for DD, HD, and ED, resp. This
544	   setting affects how many buffers are reserved and which formats are
545	   probed (see also below). The default is 1 (HD). Only one drive type
546	   can be selected. If you have two disk drives, select the "better"
547	   type.
548	
549	   The second parameter <trackbuffer> tells the kernel whether to use
550	   track buffering (1) or not (0). The default is machine-dependent:
551	   no for the Medusa and yes for all others.
552	
553	   With the two following parameters, you can change the default
554	   steprate used for drive A and B, resp. 
555	
556	
557	4.4) atascsi=
558	-------------
559	
560	Syntax: atascsi=<can_queue>[,<cmd_per_lun>[,<scat-gat>[,<host-id>[,<tagged>]]]]
561	
562	  This option sets some parameters for the Atari native SCSI driver.
563	Generally, any number of arguments can be omitted from the end. And
564	for each of the numbers, a negative value means "use default". The
565	defaults depend on whether TT-style or Falcon-style SCSI is used.
566	Below, defaults are noted as n/m, where the first value refers to
567	TT-SCSI and the latter to Falcon-SCSI. If an illegal value is given
568	for one parameter, an error message is printed and that one setting is
569	ignored (others aren't affected).
570	
571	  <can_queue>:
572	    This is the maximum number of SCSI commands queued internally to the
573	    Atari SCSI driver. A value of 1 effectively turns off the driver
574	    internal multitasking (if it causes problems). Legal values are >=
575	    1. <can_queue> can be as high as you like, but values greater than
576	    <cmd_per_lun> times the number of SCSI targets (LUNs) you have
577	    don't make sense. Default: 16/8.
578	
579	  <cmd_per_lun>:
580	    Maximum number of SCSI commands issued to the driver for one
581	    logical unit (LUN, usually one SCSI target). Legal values start
582	    from 1. If tagged queuing (see below) is not used, values greater
583	    than 2 don't make sense, but waste memory. Otherwise, the maximum
584	    is the number of command tags available to the driver (currently
585	    32). Default: 8/1. (Note: Values > 1 seem to cause problems on a
586	    Falcon, cause not yet known.)
587	
588	      The <cmd_per_lun> value at a great part determines the amount of
589	    memory SCSI reserves for itself. The formula is rather
590	    complicated, but I can give you some hints:
591	      no scatter-gather  : cmd_per_lun * 232 bytes
592	      full scatter-gather: cmd_per_lun * approx. 17 Kbytes
593	
594	  <scat-gat>:
595	    Size of the scatter-gather table, i.e. the number of requests
596	    consecutive on the disk that can be merged into one SCSI command.
597	    Legal values are between 0 and 255. Default: 255/0. Note: This
598	    value is forced to 0 on a Falcon, since scatter-gather isn't
599	    possible with the ST-DMA. Not using scatter-gather hurts
600	    performance significantly.
601	
602	  <host-id>:
603	    The SCSI ID to be used by the initiator (your Atari). This is
604	    usually 7, the highest possible ID. Every ID on the SCSI bus must
605	    be unique. Default: determined at run time: If the NV-RAM checksum
606	    is valid, and bit 7 in byte 30 of the NV-RAM is set, the lower 3
607	    bits of this byte are used as the host ID. (This method is defined
608	    by Atari and also used by some TOS HD drivers.) If the above
609	    isn't given, the default ID is 7. (both, TT and Falcon).
610	
611	  <tagged>:
612	    0 means turn off tagged queuing support, all other values > 0 mean
613	    use tagged queuing for targets that support it. Default: currently
614	    off, but this may change when tagged queuing handling has been
615	    proved to be reliable.
616	
617	    Tagged queuing means that more than one command can be issued to
618	    one LUN, and the SCSI device itself orders the requests so they
619	    can be performed in optimal order. Not all SCSI devices support
620	    tagged queuing (:-().
621	
622	4.5 switches=
623	-------------
624	
625	Syntax: switches=<list of switches>
626	
627	  With this option you can switch some hardware lines that are often
628	used to enable/disable certain hardware extensions. Examples are
629	OverScan, overclocking, ...
630	
631	  The <list of switches> is a comma-separated list of the following
632	items:
633	
634	  ikbd: set RTS of the keyboard ACIA high
635	  midi: set RTS of the MIDI ACIA high
636	  snd6: set bit 6 of the PSG port A
637	  snd7: set bit 6 of the PSG port A
638	
639	It doesn't make sense to mention a switch more than once (no
640	difference to only once), but you can give as many switches as you
641	want to enable different features. The switch lines are set as early
642	as possible during kernel initialization (even before determining the
643	present hardware.)
644	
645	  All of the items can also be prefixed with "ov_", i.e. "ov_ikbd",
646	"ov_midi", ... These options are meant for switching on an OverScan
647	video extension. The difference to the bare option is that the
648	switch-on is done after video initialization, and somehow synchronized
649	to the HBLANK. A speciality is that ov_ikbd and ov_midi are switched
650	off before rebooting, so that OverScan is disabled and TOS boots
651	correctly.
652	
653	  If you give an option both, with and without the "ov_" prefix, the
654	earlier initialization ("ov_"-less) takes precedence. But the
655	switching-off on reset still happens in this case.
656	
657	5) Options for Amiga Only:
658	==========================
659	
660	5.1) video=
661	-----------
662	
663	Syntax: video=<fbname>:<sub-options...>
664	
665	The <fbname> parameter specifies the name of the frame buffer, valid
666	options are `amifb', `cyber', 'virge', `retz3' and `clgen', provided
667	that the respective frame buffer devices have been compiled into the
668	kernel (or compiled as loadable modules). The behavior of the <fbname>
669	option was changed in 2.1.57 so it is now recommended to specify this
670	option.
671	
672	The <sub-options> is a comma-separated list of the sub-options listed
673	below. This option is organized similar to the Atari version of the
674	"video"-option (4.1), but knows fewer sub-options.
675	
676	5.1.1) video mode
677	-----------------
678	
679	Again, similar to the video mode for the Atari (see 4.1.1). Predefined
680	modes depend on the used frame buffer device.
681	
682	OCS, ECS and AGA machines all use the color frame buffer. The following
683	predefined video modes are available:
684	
685	NTSC modes:
686	 - ntsc            : 640x200, 15 kHz, 60 Hz
687	 - ntsc-lace       : 640x400, 15 kHz, 60 Hz interlaced
688	PAL modes:
689	 - pal             : 640x256, 15 kHz, 50 Hz
690	 - pal-lace        : 640x512, 15 kHz, 50 Hz interlaced
691	ECS modes:
692	 - multiscan       : 640x480, 29 kHz, 57 Hz
693	 - multiscan-lace  : 640x960, 29 kHz, 57 Hz interlaced
694	 - euro36          : 640x200, 15 kHz, 72 Hz
695	 - euro36-lace     : 640x400, 15 kHz, 72 Hz interlaced
696	 - euro72          : 640x400, 29 kHz, 68 Hz
697	 - euro72-lace     : 640x800, 29 kHz, 68 Hz interlaced
698	 - super72         : 800x300, 23 kHz, 70 Hz
699	 - super72-lace    : 800x600, 23 kHz, 70 Hz interlaced
700	 - dblntsc-ff      : 640x400, 27 kHz, 57 Hz
701	 - dblntsc-lace    : 640x800, 27 kHz, 57 Hz interlaced
702	 - dblpal-ff       : 640x512, 27 kHz, 47 Hz
703	 - dblpal-lace     : 640x1024, 27 kHz, 47 Hz interlaced
704	 - dblntsc         : 640x200, 27 kHz, 57 Hz doublescan
705	 - dblpal          : 640x256, 27 kHz, 47 Hz doublescan
706	VGA modes:
707	 - vga             : 640x480, 31 kHz, 60 Hz
708	 - vga70           : 640x400, 31 kHz, 70 Hz
709	
710	Please notice that the ECS and VGA modes require either an ECS or AGA
711	chipset, and that these modes are limited to 2-bit color for the ECS
712	chipset and 8-bit color for the AGA chipset.
713	
714	5.1.2) depth
715	------------
716	
717	Syntax: depth:<nr. of bit-planes>
718	
719	Specify the number of bit-planes for the selected video-mode.
720	
721	5.1.3) inverse
722	--------------
723	
724	Use inverted display (black on white). Functionally the same as the
725	"inverse" sub-option for the Atari.
726	
727	5.1.4) font
728	-----------
729	
730	Syntax: font:<fontname>
731	
732	Specify the font to use in text modes. Functionally the same as the
733	"font" sub-option for the Atari, except that `PEARL8x8' is used instead
734	of `VGA8x8' if the vertical size of the display is less than 400 pixel
735	rows.
736	
737	5.1.5) monitorcap:
738	-------------------
739	
740	Syntax: monitorcap:<vmin>;<vmax>;<hmin>;<hmax>
741	
742	This describes the capabilities of a multisync monitor. For now, only
743	the color frame buffer uses the settings of "monitorcap:".
744	
745	  <vmin> and <vmax> are the minimum and maximum, resp., vertical frequencies
746	your monitor can work with, in Hz. <hmin> and <hmax> are the same for
747	the horizontal frequency, in kHz.
748	
749	  The defaults are 50;90;15;38 (Generic Amiga multisync monitor).
750	
751	
752	5.2) fd_def_df0=
753	----------------
754	
755	Syntax: fd_def_df0=<value>
756	
757	Sets the df0 value for "silent" floppy drives. The value should be in
758	hexadecimal with "0x" prefix.
759	
760	
761	5.3) wd33c93=
762	-------------
763	
764	Syntax: wd33c93=<sub-options...>
765	
766	These options affect the A590/A2091, A3000 and GVP Series II SCSI
767	controllers.
768	
769	The <sub-options> is a comma-separated list of the sub-options listed
770	below.
771	
772	5.3.1) nosync
773	-------------
774	
775	Syntax: nosync:bitmask
776	
777	  bitmask is a byte where the 1st 7 bits correspond with the 7
778	possible SCSI devices. Set a bit to prevent sync negotiation on that
779	device. To maintain backwards compatibility, a command-line such as
780	"wd33c93=255" will be automatically translated to
781	"wd33c93=nosync:0xff". The default is to disable sync negotiation for
782	all devices, eg. nosync:0xff.
783	
784	5.3.2) period
785	-------------
786	
787	Syntax: period:ns
788	
789	  `ns' is the minimum # of nanoseconds in a SCSI data transfer
790	period. Default is 500; acceptable values are 250 - 1000.
791	
792	5.3.3) disconnect
793	-----------------
794	
795	Syntax: disconnect:x
796	
797	  Specify x = 0 to never allow disconnects, 2 to always allow them.
798	x = 1 does 'adaptive' disconnects, which is the default and generally
799	the best choice.
800	
801	5.3.4) debug
802	------------
803	
804	Syntax: debug:x
805	
806	  If `DEBUGGING_ON' is defined, x is a bit mask that causes various
807	types of debug output to printed - see the DB_xxx defines in
808	wd33c93.h.
809	
810	5.3.5) clock
811	------------
812	
813	Syntax: clock:x
814	
815	  x = clock input in MHz for WD33c93 chip. Normal values would be from
816	8 through 20. The default value depends on your hostadapter(s),
817	default for the A3000 internal controller is 14, for the A2091 it's 8
818	and for the GVP hostadapters it's either 8 or 14, depending on the
819	hostadapter and the SCSI-clock jumper present on some GVP
820	hostadapters.
821	
822	5.3.6) next
823	-----------
824	
825	  No argument. Used to separate blocks of keywords when there's more
826	than one wd33c93-based host adapter in the system.
827	
828	5.3.7) nodma
829	------------
830	
831	Syntax: nodma:x
832	
833	  If x is 1 (or if the option is just written as "nodma"), the WD33c93
834	controller will not use DMA (= direct memory access) to access the
835	Amiga's memory.  This is useful for some systems (like A3000's and
836	A4000's with the A3640 accelerator, revision 3.0) that have problems
837	using DMA to chip memory.  The default is 0, i.e. to use DMA if
838	possible.
839	
840	
841	5.4) gvp11=
842	-----------
843	
844	Syntax: gvp11=<addr-mask>
845	
846	  The earlier versions of the GVP driver did not handle DMA
847	address-mask settings correctly which made it necessary for some
848	people to use this option, in order to get their GVP controller
849	running under Linux. These problems have hopefully been solved and the
850	use of this option is now highly unrecommended!
851	
852	  Incorrect use can lead to unpredictable behavior, so please only use
853	this option if you *know* what you are doing and have a reason to do
854	so. In any case if you experience problems and need to use this
855	option, please inform us about it by mailing to the Linux/68k kernel
856	mailing list.
857	
858	  The address mask set by this option specifies which addresses are
859	valid for DMA with the GVP Series II SCSI controller. An address is
860	valid, if no bits are set except the bits that are set in the mask,
861	too.
862	
863	  Some versions of the GVP can only DMA into a 24 bit address range,
864	some can address a 25 bit address range while others can use the whole
865	32 bit address range for DMA. The correct setting depends on your
866	controller and should be autodetected by the driver. An example is the
867	24 bit region which is specified by a mask of 0x00fffffe.
868	
869	
870	/* Local Variables: */
871	/* mode: text       */
872	/* End:             */
Hide Line Numbers
About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Information is copyright its respective author. All material is available from the Linux Kernel Source distributed under a GPL License. This page is provided as a free service by mjmwired.net.