912 lines · plain
1===================================2Command Line Options for Linux/m68k3===================================4 5Last Update: 2 May 19996 7Linux/m68k version: 2.2.68 9Author: Roman.Hodek@informatik.uni-erlangen.de (Roman Hodek)10 11Update: jds@kom.auc.dk (Jes Sorensen) and faq@linux-m68k.org (Chris Lawrence)12 130) Introduction14===============15 16Often I've been asked which command line options the Linux/m68k17kernel understands, or how the exact syntax for the ... option is, or18... about the option ... . I hope, this document supplies all the19answers...20 21Note that some options might be outdated, their descriptions being22incomplete or missing. Please update the information and send in the23patches.24 25 261) Overview of the Kernel's Option Processing27=============================================28 29The kernel knows three kinds of options on its command line:30 31 1) kernel options32 2) environment settings33 3) arguments for init34 35To which of these classes an argument belongs is determined as36follows: If the option is known to the kernel itself, i.e. if the name37(the part before the '=') or, in some cases, the whole argument string38is known to the kernel, it belongs to class 1. Otherwise, if the39argument contains an '=', it is of class 2, and the definition is put40into init's environment. All other arguments are passed to init as41command line options.42 43This document describes the valid kernel options for Linux/m68k in44the version mentioned at the start of this file. Later revisions may45add new such options, and some may be missing in older versions.46 47In general, the value (the part after the '=') of an option is a48list of values separated by commas. The interpretation of these values49is up to the driver that "owns" the option. This association of50options with drivers is also the reason that some are further51subdivided.52 53 542) General Kernel Options55=========================56 572.1) root=58----------59 60:Syntax: root=/dev/<device>61:or: root=<hex_number>62 63This tells the kernel which device it should mount as the root64filesystem. The device must be a block device with a valid filesystem65on it.66 67The first syntax gives the device by name. These names are converted68into a major/minor number internally in the kernel in an unusual way.69Normally, this "conversion" is done by the device files in /dev, but70this isn't possible here, because the root filesystem (with /dev)71isn't mounted yet... So the kernel parses the name itself, with some72hardcoded name to number mappings. The name must always be a73combination of two or three letters, followed by a decimal number.74Valid names are::75 76 /dev/ram: -> 0x0100 (initial ramdisk)77 /dev/hda: -> 0x0300 (first IDE disk)78 /dev/hdb: -> 0x0340 (second IDE disk)79 /dev/sda: -> 0x0800 (first SCSI disk)80 /dev/sdb: -> 0x0810 (second SCSI disk)81 /dev/sdc: -> 0x0820 (third SCSI disk)82 /dev/sdd: -> 0x0830 (forth SCSI disk)83 /dev/sde: -> 0x0840 (fifth SCSI disk)84 /dev/fd : -> 0x0200 (floppy disk)85 86The name must be followed by a decimal number, that stands for the87partition number. Internally, the value of the number is just88added to the device number mentioned in the table above. The89exceptions are /dev/ram and /dev/fd, where /dev/ram refers to an90initial ramdisk loaded by your bootstrap program (please consult the91instructions for your bootstrap program to find out how to load an92initial ramdisk). As of kernel version 2.0.18 you must specify93/dev/ram as the root device if you want to boot from an initial94ramdisk. For the floppy devices, /dev/fd, the number stands for the95floppy 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 so97on. Since the number is just added, you can also force the disk format98by adding a number greater than 3. If you look into your /dev99directory, use can see the /dev/fd0D720 has major 2 and minor 16. You100can specify this device for the root FS by writing "root=/dev/fd16" on101the kernel command line.102 103[Strange and maybe uninteresting stuff ON]104 105This unusual translation of device names has some strange106consequences: If, for example, you have a symbolic link from /dev/fd107to /dev/fd0D720 as an abbreviation for floppy driver #0 in DD format,108you cannot use this name for specifying the root device, because the109kernel cannot see this symlink before mounting the root FS and it110isn't in the table above. If you use it, the root device will not be111set at all, without an error message. Another example: You cannot use a112partition on e.g. the sixth SCSI disk as the root filesystem, if you113want to specify it by name. This is, because only the devices up to114/dev/sde are in the table above, but not /dev/sdf. Although, you can115use the sixth SCSI disk for the root FS, but you have to specify the116device by number... (see below). Or, even more strange, you can use the117fact that there is no range checking of the partition number, and your118knowledge that each disk uses 16 minors, and write "root=/dev/sde17"119(for /dev/sdf1).120 121[Strange and maybe uninteresting stuff OFF]122 123If the device containing your root partition isn't in the table124above, you can also specify it by major and minor numbers. These are125written in hex, with no prefix and no separator between. E.g., if you126have a CD with contents appropriate as a root filesystem in the first127SCSI CD-ROM drive, you boot from it by "root=0b00". Here, hex "0b" =128decimal 11 is the major of SCSI CD-ROMs, and the minor 0 stands for129the first of these. You can find out all valid major numbers by130looking into include/linux/major.h.131 132In addition to major and minor numbers, if the device containing your133root partition uses a partition table format with unique partition134identifiers, then you may use them. For instance,135"root=PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF". It is also136possible to reference another partition on the same device using a137known partition UUID as the starting point. For example,138if partition 5 of the device has the UUID of13900112233-4455-6677-8899-AABBCCDDEEFF then partition 3 may be found as140follows:141 142 PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF/PARTNROFF=-2143 144Authoritative information can be found in145"Documentation/admin-guide/kernel-parameters.rst".146 147 1482.2) ro, rw149-----------150 151:Syntax: ro152:or: rw153 154These two options tell the kernel whether it should mount the root155filesystem read-only or read-write. The default is read-only, except156for ramdisks, which default to read-write.157 158 1592.3) debug160----------161 162:Syntax: debug163 164This raises the kernel log level to 10 (the default is 7). This is the165same level as set by the "dmesg" command, just that the maximum level166selectable by dmesg is 8.167 168 1692.4) debug=170-----------171 172:Syntax: debug=<device>173 174This option causes certain kernel messages be printed to the selected175debugging device. This can aid debugging the kernel, since the176messages can be captured and analyzed on some other machine. Which177devices are possible depends on the machine type. There are no checks178for the validity of the device name. If the device isn't implemented,179nothing happens.180 181Messages logged this way are in general stack dumps after kernel182memory faults or bad kernel traps, and kernel panics. To be exact: all183messages of level 0 (panic messages) and all messages printed while184the log level is 8 or more (their level doesn't matter). Before stack185dumps, the kernel sets the log level to 10 automatically. A level of186at least 8 can also be set by the "debug" command line option (see1872.3) and at run time with "dmesg -n 8".188 189Devices possible for Amiga:190 191 - "ser":192 built-in serial port; parameters: 9600bps, 8N1193 - "mem":194 Save the messages to a reserved area in chip mem. After195 rebooting, they can be read under AmigaOS with the tool196 'dmesg'.197 198Devices possible for Atari:199 200 - "ser1":201 ST-MFP serial port ("Modem1"); parameters: 9600bps, 8N1202 - "ser2":203 SCC channel B serial port ("Modem2"); parameters: 9600bps, 8N1204 - "ser" :205 default serial port206 This is "ser2" for a Falcon, and "ser1" for any other machine207 - "midi":208 The MIDI port; parameters: 31250bps, 8N1209 - "par" :210 parallel port211 212 The printing routine for this implements a timeout for the213 case there's no printer connected (else the kernel would214 lock up). The timeout is not exact, but usually a few215 seconds.216 217 2182.6) ramdisk_size=219------------------220 221:Syntax: ramdisk_size=<size>222 223This option instructs the kernel to set up a ramdisk of the given224size in KBytes. Do not use this option if the ramdisk contents are225passed by bootstrap! In this case, the size is selected automatically226and should not be overwritten.227 228The only application is for root filesystems on floppy disks, that229should be loaded into memory. To do that, select the corresponding230size of the disk as ramdisk size, and set the root device to the disk231drive (with "root=").232 233 2342.7) swap=235 236 I can't find any sign of this option in 2.2.6.237 2382.8) buff=239-----------240 241 I can't find any sign of this option in 2.2.6.242 243 2443) General Device Options (Amiga and Atari)245===========================================246 2473.1) ether=248-----------249 250:Syntax: ether=[<irq>[,<base_addr>[,<mem_start>[,<mem_end>]]]],<dev-name>251 252<dev-name> is the name of a net driver, as specified in253drivers/net/Space.c in the Linux source. Most prominent are eth0, ...254eth3, sl0, ... sl3, ppp0, ..., ppp3, dummy, and lo.255 256The non-ethernet drivers (sl, ppp, dummy, lo) obviously ignore the257settings by this options. Also, the existing ethernet drivers for258Linux/m68k (ariadne, a2065, hydra) don't use them because Zorro boards259are really Plug-'n-Play, so the "ether=" option is useless altogether260for Linux/m68k.261 262 2633.2) hd=264--------265 266:Syntax: hd=<cylinders>,<heads>,<sectors>267 268This option sets the disk geometry of an IDE disk. The first hd=269option is for the first IDE disk, the second for the second one.270(I.e., you can give this option twice.) In most cases, you won't have271to use this option, since the kernel can obtain the geometry data272itself. It exists just for the case that this fails for one of your273disks.274 275 2763.3) max_scsi_luns=277-------------------278 279:Syntax: max_scsi_luns=<n>280 281Sets the maximum number of LUNs (logical units) of SCSI devices to282be scanned. Valid values for <n> are between 1 and 8. Default is 8 if283"Probe all LUNs on each SCSI device" was selected during the kernel284configuration, else 1.285 286 2873.4) st=288--------289 290:Syntax: st=<buffer_size>,[<write_thres>,[<max_buffers>]]291 292Sets several parameters of the SCSI tape driver. <buffer_size> is293the number of 512-byte buffers reserved for tape operations for each294device. <write_thres> sets the number of blocks which must be filled295to start an actual write operation to the tape. Maximum value is the296total number of buffers. <max_buffer> limits the total number of297buffers allocated for all tape devices.298 299 3003.5) dmasound=301--------------302 303:Syntax: dmasound=[<buffers>,<buffer-size>[,<catch-radius>]]304 305This option controls some configurations of the Linux/m68k DMA sound306driver (Amiga and Atari): <buffers> is the number of buffers you want307to use (minimum 4, default 4), <buffer-size> is the size of each308buffer in kilobytes (minimum 4, default 32) and <catch-radius> says309how much percent of error will be tolerated when setting a frequency310(maximum 10, default 0). For example with 3% you can play 8000Hz311AU-Files on the Falcon with its hardware frequency of 8195Hz and thus312don't need to expand the sound.313 314 315 3164) Options for Atari Only317=========================318 3194.1) video=320-----------321 322:Syntax: video=<fbname>:<sub-options...>323 324The <fbname> parameter specifies the name of the frame buffer,325eg. most atari users will want to specify `atafb` here. The326<sub-options> is a comma-separated list of the sub-options listed327below.328 329NB:330 Please notice that this option was renamed from `atavideo` to331 `video` during the development of the 1.3.x kernels, thus you332 might need to update your boot-scripts if upgrading to 2.x from333 an 1.2.x kernel.334 335NBB:336 The behavior of video= was changed in 2.1.57 so the recommended337 option is to specify the name of the frame buffer.338 3394.1.1) Video Mode340-----------------341 342This sub-option may be any of the predefined video modes, as listed343in atari/atafb.c in the Linux/m68k source tree. The kernel will344activate the given video mode at boot time and make it the default345mode, if the hardware allows. Currently defined names are:346 347 - stlow : 320x200x4348 - stmid, default5 : 640x200x2349 - sthigh, default4: 640x400x1350 - ttlow : 320x480x8, TT only351 - ttmid, default1 : 640x480x4, TT only352 - tthigh, default2: 1280x960x1, TT only353 - vga2 : 640x480x1, Falcon only354 - vga4 : 640x480x2, Falcon only355 - vga16, default3 : 640x480x4, Falcon only356 - vga256 : 640x480x8, Falcon only357 - falh2 : 896x608x1, Falcon only358 - falh16 : 896x608x4, Falcon only359 360If no video mode is given on the command line, the kernel tries the361modes names "default<n>" in turn, until one is possible with the362hardware in use.363 364A video mode setting doesn't make sense, if the external driver is365activated by a "external:" sub-option.366 3674.1.2) inverse368--------------369 370Invert the display. This affects only text consoles.371Usually, the background is chosen to be black. With this372option, you can make the background white.373 3744.1.3) font375-----------376 377:Syntax: font:<fontname>378 379Specify the font to use in text modes. Currently you can choose only380between `VGA8x8`, `VGA8x16` and `PEARL8x8`. `VGA8x8` is default, if the381vertical size of the display is less than 400 pixel rows. Otherwise, the382`VGA8x16` font is the default.383 3844.1.4) `hwscroll_`385------------------386 387:Syntax: `hwscroll_<n>`388 389The number of additional lines of video memory to reserve for390speeding up the scrolling ("hardware scrolling"). Hardware scrolling391is possible only if the kernel can set the video base address in steps392fine enough. This is true for STE, MegaSTE, TT, and Falcon. It is not393possible with plain STs and graphics cards (The former because the394base address must be on a 256 byte boundary there, the latter because395the kernel doesn't know how to set the base address at all.)396 397By default, <n> is set to the number of visible text lines on the398display. Thus, the amount of video memory is doubled, compared to no399hardware scrolling. You can turn off the hardware scrolling altogether400by setting <n> to 0.401 4024.1.5) internal:403----------------404 405:Syntax: internal:<xres>;<yres>[;<xres_max>;<yres_max>;<offset>]406 407This option specifies the capabilities of some extended internal video408hardware, like e.g. OverScan. <xres> and <yres> give the (extended)409dimensions of the screen.410 411If your OverScan needs a black border, you have to write the last412three arguments of the "internal:". <xres_max> is the maximum line413length the hardware allows, <yres_max> the maximum number of lines.414<offset> is the offset of the visible part of the screen memory to its415physical start, in bytes.416 417Often, extended interval video hardware has to be activated somehow.418For this, see the "sw_*" options below.419 4204.1.6) external:421----------------422 423:Syntax:424 external:<xres>;<yres>;<depth>;<org>;<scrmem>[;<scrlen>[;<vgabase>425 [;<colw>[;<coltype>[;<xres_virtual>]]]]]426 427.. I had to break this line...428 429This is probably the most complicated parameter... It specifies that430you have some external video hardware (a graphics board), and how to431use it under Linux/m68k. The kernel cannot know more about the hardware432than you tell it here! The kernel also is unable to set or change any433video modes, since it doesn't know about any board internal. So, you434have to switch to that video mode before you start Linux, and cannot435switch to another mode once Linux has started.436 437The first 3 parameters of this sub-option should be obvious: <xres>,438<yres> and <depth> give the dimensions of the screen and the number of439planes (depth). The depth is the logarithm to base 2 of the number440of colors possible. (Or, the other way round: The number of colors is4412^depth).442 443You have to tell the kernel furthermore how the video memory is444organized. This is done by a letter as <org> parameter:445 446 'n':447 "normal planes", i.e. one whole plane after another448 'i':449 "interleaved planes", i.e. 16 bit of the first plane, than 16 bit450 of the next, and so on... This mode is used only with the451 built-in Atari video modes, I think there is no card that452 supports this mode.453 'p':454 "packed pixels", i.e. <depth> consecutive bits stand for all455 planes of one pixel; this is the most common mode for 8 planes456 (256 colors) on graphic cards457 't':458 "true color" (more or less packed pixels, but without a color459 lookup table); usually depth is 24460 461For monochrome modes (i.e., <depth> is 1), the <org> letter has a462different meaning:463 464 'n':465 normal colors, i.e. 0=white, 1=black466 'i':467 inverted colors, i.e. 0=black, 1=white468 469The next important information about the video hardware is the base470address of the video memory. That is given in the <scrmem> parameter,471as a hexadecimal number with a "0x" prefix. You have to find out this472address in the documentation of your hardware.473 474The next parameter, <scrlen>, tells the kernel about the size of the475video memory. If it's missing, the size is calculated from <xres>,476<yres>, and <depth>. For now, it is not useful to write a value here.477It would be used only for hardware scrolling (which isn't possible478with the external driver, because the kernel cannot set the video base479address), or for virtual resolutions under X (which the X server480doesn't support yet). So, it's currently best to leave this field481empty, either by ending the "external:" after the video address or by482writing two consecutive semicolons, if you want to give a <vgabase>483(it is allowed to leave this parameter empty).484 485The <vgabase> parameter is optional. If it is not given, the kernel486cannot read or write any color registers of the video hardware, and487thus you have to set appropriate colors before you start Linux. But if488your card is somehow VGA compatible, you can tell the kernel the base489address of the VGA register set, so it can change the color lookup490table. You have to look up this address in your board's documentation.491To avoid misunderstandings: <vgabase> is the _base_ address, i.e. a 4k492aligned address. For read/writing the color registers, the kernel493uses the addresses vgabase+0x3c7...vgabase+0x3c9. The <vgabase>494parameter is written in hexadecimal with a "0x" prefix, just as495<scrmem>.496 497<colw> is meaningful only if <vgabase> is specified. It tells the498kernel how wide each of the color register is, i.e. the number of bits499per single color (red/green/blue). Default is 6, another quite usual500value is 8.501 502Also <coltype> is used together with <vgabase>. It tells the kernel503about the color register model of your gfx board. Currently, the types504"vga" (which is also the default) and "mv300" (SANG MV300) are505implemented.506 507Parameter <xres_virtual> is required for ProMST or ET4000 cards where508the physical linelength differs from the visible length. With ProMST,509xres_virtual must be set to 2048. For ET4000, xres_virtual depends on the510initialisation of the video-card.511If you're missing a corresponding yres_virtual: the external part is legacy,512therefore we don't support hardware-dependent functions like hardware-scroll,513panning or blanking.514 5154.1.7) eclock:516--------------517 518The external pixel clock attached to the Falcon VIDEL shifter. This519currently works only with the ScreenWonder!520 5214.1.8) monitorcap:522-------------------523 524:Syntax: monitorcap:<vmin>;<vmax>;<hmin>;<hmax>525 526This describes the capabilities of a multisync monitor. Don't use it527with a fixed-frequency monitor! For now, only the Falcon frame buffer528uses the settings of "monitorcap:".529 530<vmin> and <vmax> are the minimum and maximum, resp., vertical frequencies531your monitor can work with, in Hz. <hmin> and <hmax> are the same for532the horizontal frequency, in kHz.533 534 The defaults are 58;62;31;32 (VGA compatible).535 536 The defaults for TV/SC1224/SC1435 cover both PAL and NTSC standards.537 5384.1.9) keep539------------540 541If this option is given, the framebuffer device doesn't do any video542mode calculations and settings on its own. The only Atari fb device543that does this currently is the Falcon.544 545What you reach with this: Settings for unknown video extensions546aren't overridden by the driver, so you can still use the mode found547when booting, when the driver doesn't know to set this mode itself.548But this also means, that you can't switch video modes anymore...549 550An example where you may want to use "keep" is the ScreenBlaster for551the Falcon.552 553 5544.2) atamouse=555--------------556 557:Syntax: atamouse=<x-threshold>,[<y-threshold>]558 559With this option, you can set the mouse movement reporting threshold.560This is the number of pixels of mouse movement that have to accumulate561before the IKBD sends a new mouse packet to the kernel. Higher values562reduce the mouse interrupt load and thus reduce the chance of keyboard563overruns. Lower values give a slightly faster mouse responses and564slightly better mouse tracking.565 566You can set the threshold in x and y separately, but usually this is567of little practical use. If there's just one number in the option, it568is used for both dimensions. The default value is 2 for both569thresholds.570 571 5724.3) ataflop=573-------------574 575:Syntax: ataflop=<drive type>[,<trackbuffering>[,<steprateA>[,<steprateB>]]]576 577 The drive type may be 0, 1, or 2, for DD, HD, and ED, resp. This578 setting affects how many buffers are reserved and which formats are579 probed (see also below). The default is 1 (HD). Only one drive type580 can be selected. If you have two disk drives, select the "better"581 type.582 583 The second parameter <trackbuffer> tells the kernel whether to use584 track buffering (1) or not (0). The default is machine-dependent:585 no for the Medusa and yes for all others.586 587 With the two following parameters, you can change the default588 steprate used for drive A and B, resp.589 590 5914.4) atascsi=592-------------593 594:Syntax: atascsi=<can_queue>[,<cmd_per_lun>[,<scat-gat>[,<host-id>[,<tagged>]]]]595 596This option sets some parameters for the Atari native SCSI driver.597Generally, any number of arguments can be omitted from the end. And598for each of the numbers, a negative value means "use default". The599defaults depend on whether TT-style or Falcon-style SCSI is used.600Below, defaults are noted as n/m, where the first value refers to601TT-SCSI and the latter to Falcon-SCSI. If an illegal value is given602for one parameter, an error message is printed and that one setting is603ignored (others aren't affected).604 605 <can_queue>:606 This is the maximum number of SCSI commands queued internally to the607 Atari SCSI driver. A value of 1 effectively turns off the driver608 internal multitasking (if it causes problems). Legal values are >=609 1. <can_queue> can be as high as you like, but values greater than610 <cmd_per_lun> times the number of SCSI targets (LUNs) you have611 don't make sense. Default: 16/8.612 613 <cmd_per_lun>:614 Maximum number of SCSI commands issued to the driver for one615 logical unit (LUN, usually one SCSI target). Legal values start616 from 1. If tagged queuing (see below) is not used, values greater617 than 2 don't make sense, but waste memory. Otherwise, the maximum618 is the number of command tags available to the driver (currently619 32). Default: 8/1. (Note: Values > 1 seem to cause problems on a620 Falcon, cause not yet known.)621 622 The <cmd_per_lun> value at a great part determines the amount of623 memory SCSI reserves for itself. The formula is rather624 complicated, but I can give you some hints:625 626 no scatter-gather:627 cmd_per_lun * 232 bytes628 full scatter-gather:629 cmd_per_lun * approx. 17 Kbytes630 631 <scat-gat>:632 Size of the scatter-gather table, i.e. the number of requests633 consecutive on the disk that can be merged into one SCSI command.634 Legal values are between 0 and 255. Default: 255/0. Note: This635 value is forced to 0 on a Falcon, since scatter-gather isn't636 possible with the ST-DMA. Not using scatter-gather hurts637 performance significantly.638 639 <host-id>:640 The SCSI ID to be used by the initiator (your Atari). This is641 usually 7, the highest possible ID. Every ID on the SCSI bus must642 be unique. Default: determined at run time: If the NV-RAM checksum643 is valid, and bit 7 in byte 30 of the NV-RAM is set, the lower 3644 bits of this byte are used as the host ID. (This method is defined645 by Atari and also used by some TOS HD drivers.) If the above646 isn't given, the default ID is 7. (both, TT and Falcon).647 648 <tagged>:649 0 means turn off tagged queuing support, all other values > 0 mean650 use tagged queuing for targets that support it. Default: currently651 off, but this may change when tagged queuing handling has been652 proved to be reliable.653 654 Tagged queuing means that more than one command can be issued to655 one LUN, and the SCSI device itself orders the requests so they656 can be performed in optimal order. Not all SCSI devices support657 tagged queuing (:-().658 6594.5 switches=660-------------661 662:Syntax: switches=<list of switches>663 664With this option you can switch some hardware lines that are often665used to enable/disable certain hardware extensions. Examples are666OverScan, overclocking, ...667 668The <list of switches> is a comma-separated list of the following669items:670 671 ikbd:672 set RTS of the keyboard ACIA high673 midi:674 set RTS of the MIDI ACIA high675 snd6:676 set bit 6 of the PSG port A677 snd7:678 set bit 6 of the PSG port A679 680It doesn't make sense to mention a switch more than once (no681difference to only once), but you can give as many switches as you682want to enable different features. The switch lines are set as early683as possible during kernel initialization (even before determining the684present hardware.)685 686All of the items can also be prefixed with `ov_`, i.e. `ov_ikbd`,687`ov_midi`, ... These options are meant for switching on an OverScan688video extension. The difference to the bare option is that the689switch-on is done after video initialization, and somehow synchronized690to the HBLANK. A speciality is that ov_ikbd and ov_midi are switched691off before rebooting, so that OverScan is disabled and TOS boots692correctly.693 694If you give an option both, with and without the `ov_` prefix, the695earlier initialization (`ov_`-less) takes precedence. But the696switching-off on reset still happens in this case.697 6985) Options for Amiga Only:699==========================700 7015.1) video=702-----------703 704:Syntax: video=<fbname>:<sub-options...>705 706The <fbname> parameter specifies the name of the frame buffer, valid707options are `amifb`, `cyber`, 'virge', `retz3` and `clgen`, provided708that the respective frame buffer devices have been compiled into the709kernel (or compiled as loadable modules). The behavior of the <fbname>710option was changed in 2.1.57 so it is now recommended to specify this711option.712 713The <sub-options> is a comma-separated list of the sub-options listed714below. This option is organized similar to the Atari version of the715"video"-option (4.1), but knows fewer sub-options.716 7175.1.1) video mode718-----------------719 720Again, similar to the video mode for the Atari (see 4.1.1). Predefined721modes depend on the used frame buffer device.722 723OCS, ECS and AGA machines all use the color frame buffer. The following724predefined video modes are available:725 726NTSC modes:727 - ntsc : 640x200, 15 kHz, 60 Hz728 - ntsc-lace : 640x400, 15 kHz, 60 Hz interlaced729 730PAL modes:731 - pal : 640x256, 15 kHz, 50 Hz732 - pal-lace : 640x512, 15 kHz, 50 Hz interlaced733 734ECS modes:735 - multiscan : 640x480, 29 kHz, 57 Hz736 - multiscan-lace : 640x960, 29 kHz, 57 Hz interlaced737 - euro36 : 640x200, 15 kHz, 72 Hz738 - euro36-lace : 640x400, 15 kHz, 72 Hz interlaced739 - euro72 : 640x400, 29 kHz, 68 Hz740 - euro72-lace : 640x800, 29 kHz, 68 Hz interlaced741 - super72 : 800x300, 23 kHz, 70 Hz742 - super72-lace : 800x600, 23 kHz, 70 Hz interlaced743 - dblntsc-ff : 640x400, 27 kHz, 57 Hz744 - dblntsc-lace : 640x800, 27 kHz, 57 Hz interlaced745 - dblpal-ff : 640x512, 27 kHz, 47 Hz746 - dblpal-lace : 640x1024, 27 kHz, 47 Hz interlaced747 - dblntsc : 640x200, 27 kHz, 57 Hz doublescan748 - dblpal : 640x256, 27 kHz, 47 Hz doublescan749 750VGA modes:751 - vga : 640x480, 31 kHz, 60 Hz752 - vga70 : 640x400, 31 kHz, 70 Hz753 754Please notice that the ECS and VGA modes require either an ECS or AGA755chipset, and that these modes are limited to 2-bit color for the ECS756chipset and 8-bit color for the AGA chipset.757 7585.1.2) depth759------------760 761:Syntax: depth:<nr. of bit-planes>762 763Specify the number of bit-planes for the selected video-mode.764 7655.1.3) inverse766--------------767 768Use inverted display (black on white). Functionally the same as the769"inverse" sub-option for the Atari.770 7715.1.4) font772-----------773 774:Syntax: font:<fontname>775 776Specify the font to use in text modes. Functionally the same as the777"font" sub-option for the Atari, except that `PEARL8x8` is used instead778of `VGA8x8` if the vertical size of the display is less than 400 pixel779rows.780 7815.1.5) monitorcap:782-------------------783 784:Syntax: monitorcap:<vmin>;<vmax>;<hmin>;<hmax>785 786This describes the capabilities of a multisync monitor. For now, only787the color frame buffer uses the settings of "monitorcap:".788 789<vmin> and <vmax> are the minimum and maximum, resp., vertical frequencies790your monitor can work with, in Hz. <hmin> and <hmax> are the same for791the horizontal frequency, in kHz.792 793The defaults are 50;90;15;38 (Generic Amiga multisync monitor).794 795 7965.2) fd_def_df0=797----------------798 799:Syntax: fd_def_df0=<value>800 801Sets the df0 value for "silent" floppy drives. The value should be in802hexadecimal with "0x" prefix.803 804 8055.3) wd33c93=806-------------807 808:Syntax: wd33c93=<sub-options...>809 810These options affect the A590/A2091, A3000 and GVP Series II SCSI811controllers.812 813The <sub-options> is a comma-separated list of the sub-options listed814below.815 8165.3.1) nosync817-------------818 819:Syntax: nosync:bitmask820 821bitmask is a byte where the 1st 7 bits correspond with the 7822possible SCSI devices. Set a bit to prevent sync negotiation on that823device. To maintain backwards compatibility, a command-line such as824"wd33c93=255" will be automatically translated to825"wd33c93=nosync:0xff". The default is to disable sync negotiation for826all devices, eg. nosync:0xff.827 8285.3.2) period829-------------830 831:Syntax: period:ns832 833`ns` is the minimum # of nanoseconds in a SCSI data transfer834period. Default is 500; acceptable values are 250 - 1000.835 8365.3.3) disconnect837-----------------838 839:Syntax: disconnect:x840 841Specify x = 0 to never allow disconnects, 2 to always allow them.842x = 1 does 'adaptive' disconnects, which is the default and generally843the best choice.844 8455.3.4) debug846------------847 848:Syntax: debug:x849 850If `DEBUGGING_ON` is defined, x is a bit mask that causes various851types of debug output to printed - see the DB_xxx defines in852wd33c93.h.853 8545.3.5) clock855------------856 857:Syntax: clock:x858 859x = clock input in MHz for WD33c93 chip. Normal values would be from8608 through 20. The default value depends on your hostadapter(s),861default for the A3000 internal controller is 14, for the A2091 it's 8862and for the GVP hostadapters it's either 8 or 14, depending on the863hostadapter and the SCSI-clock jumper present on some GVP864hostadapters.865 8665.3.6) next867-----------868 869No argument. Used to separate blocks of keywords when there's more870than one wd33c93-based host adapter in the system.871 8725.3.7) nodma873------------874 875:Syntax: nodma:x876 877If x is 1 (or if the option is just written as "nodma"), the WD33c93878controller will not use DMA (= direct memory access) to access the879Amiga's memory. This is useful for some systems (like A3000's and880A4000's with the A3640 accelerator, revision 3.0) that have problems881using DMA to chip memory. The default is 0, i.e. to use DMA if882possible.883 884 8855.4) gvp11=886-----------887 888:Syntax: gvp11=<addr-mask>889 890The earlier versions of the GVP driver did not handle DMA891address-mask settings correctly which made it necessary for some892people to use this option, in order to get their GVP controller893running under Linux. These problems have hopefully been solved and the894use of this option is now highly unrecommended!895 896Incorrect use can lead to unpredictable behavior, so please only use897this option if you *know* what you are doing and have a reason to do898so. In any case if you experience problems and need to use this899option, please inform us about it by mailing to the Linux/68k kernel900mailing list.901 902The address mask set by this option specifies which addresses are903valid for DMA with the GVP Series II SCSI controller. An address is904valid, if no bits are set except the bits that are set in the mask,905too.906 907Some versions of the GVP can only DMA into a 24 bit address range,908some can address a 25 bit address range while others can use the whole90932 bit address range for DMA. The correct setting depends on your910controller and should be autodetected by the driver. An example is the91124 bit region which is specified by a mask of 0x00fffffe.912