Based on kernel version 3.9. Page generated on 2013-05-02 23:10 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@informatik.uni-erlangen.de (Roman Hodek) 9 Update: jds@kom.auc.dk (Jes Sorensen) and faq@linux-m68k.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 I hope, this document supplies all the 17 answers... 18 19 Note that some options might be outdated, their descriptions being 20 incomplete or missing.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 In addition to major and minor numbers, if the device containing your 133 root partition uses a partition table format with unique partition 134 identifiers, then you may use them. For instance, 135 "root=PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF". It is also 136 possible to reference another partition on the same device using a 137 known partition UUID as the starting point. For example, 138 if partition 5 of the device has the UUID of 139 00112233-4455-6677-8899-AABBCCDDEEFF then partition 3 may be found as 140 follows: 141 PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF/PARTNROFF=-2 142 143 Authoritative information can be found in 144 "Documentation/kernel-parameters.txt". 145 146 147 2.2) ro, rw 148 ----------- 149 150 Syntax: ro 151 or: rw 152 153 These two options tell the kernel whether it should mount the root 154 filesystem read-only or read-write. The default is read-only, except 155 for ramdisks, which default to read-write. 156 157 158 2.3) debug 159 ---------- 160 161 Syntax: debug 162 163 This raises the kernel log level to 10 (the default is 7). This is the 164 same level as set by the "dmesg" command, just that the maximum level 165 selectable by dmesg is 8. 166 167 168 2.4) debug= 169 ----------- 170 171 Syntax: debug=<device> 172 173 This option causes certain kernel messages be printed to the selected 174 debugging device. This can aid debugging the kernel, since the 175 messages can be captured and analyzed on some other machine. Which 176 devices are possible depends on the machine type. There are no checks 177 for the validity of the device name. If the device isn't implemented, 178 nothing happens. 179 180 Messages logged this way are in general stack dumps after kernel 181 memory faults or bad kernel traps, and kernel panics. To be exact: all 182 messages of level 0 (panic messages) and all messages printed while 183 the log level is 8 or more (their level doesn't matter). Before stack 184 dumps, the kernel sets the log level to 10 automatically. A level of 185 at least 8 can also be set by the "debug" command line option (see 186 2.3) and at run time with "dmesg -n 8". 187 188 Devices possible for Amiga: 189 190 - "ser": built-in serial port; parameters: 9600bps, 8N1 191 - "mem": Save the messages to a reserved area in chip mem. After 192 rebooting, they can be read under AmigaOS with the tool 193 'dmesg'. 194 195 Devices possible for Atari: 196 197 - "ser1": ST-MFP serial port ("Modem1"); parameters: 9600bps, 8N1 198 - "ser2": SCC channel B serial port ("Modem2"); parameters: 9600bps, 8N1 199 - "ser" : default serial port 200 This is "ser2" for a Falcon, and "ser1" for any other machine 201 - "midi": The MIDI port; parameters: 31250bps, 8N1 202 - "par" : parallel port 203 The printing routine for this implements a timeout for the 204 case there's no printer connected (else the kernel would 205 lock up). The timeout is not exact, but usually a few 206 seconds. 207 208 209 2.6) ramdisk_size= 210 ------------- 211 212 Syntax: ramdisk_size=<size> 213 214 This option instructs the kernel to set up a ramdisk of the given 215 size in KBytes. Do not use this option if the ramdisk contents are 216 passed by bootstrap! In this case, the size is selected automatically 217 and should not be overwritten. 218 219 The only application is for root filesystems on floppy disks, that 220 should be loaded into memory. To do that, select the corresponding 221 size of the disk as ramdisk size, and set the root device to the disk 222 drive (with "root="). 223 224 225 2.7) swap= 226 2.8) buff= 227 ----------- 228 229 I can't find any sign of these options in 2.2.6. 230 231 232 3) General Device Options (Amiga and Atari) 233 =========================================== 234 235 3.1) ether= 236 ----------- 237 238 Syntax: ether=[<irq>[,<base_addr>[,<mem_start>[,<mem_end>]]]],<dev-name> 239 240 <dev-name> is the name of a net driver, as specified in 241 drivers/net/Space.c in the Linux source. Most prominent are eth0, ... 242 eth3, sl0, ... sl3, ppp0, ..., ppp3, dummy, and lo. 243 244 The non-ethernet drivers (sl, ppp, dummy, lo) obviously ignore the 245 settings by this options. Also, the existing ethernet drivers for 246 Linux/m68k (ariadne, a2065, hydra) don't use them because Zorro boards 247 are really Plug-'n-Play, so the "ether=" option is useless altogether 248 for Linux/m68k. 249 250 251 3.2) hd= 252 -------- 253 254 Syntax: hd=<cylinders>,<heads>,<sectors> 255 256 This option sets the disk geometry of an IDE disk. The first hd= 257 option is for the first IDE disk, the second for the second one. 258 (I.e., you can give this option twice.) In most cases, you won't have 259 to use this option, since the kernel can obtain the geometry data 260 itself. It exists just for the case that this fails for one of your 261 disks. 262 263 264 3.3) max_scsi_luns= 265 ------------------- 266 267 Syntax: max_scsi_luns=<n> 268 269 Sets the maximum number of LUNs (logical units) of SCSI devices to 270 be scanned. Valid values for <n> are between 1 and 8. Default is 8 if 271 "Probe all LUNs on each SCSI device" was selected during the kernel 272 configuration, else 1. 273 274 275 3.4) st= 276 -------- 277 278 Syntax: st=<buffer_size>,[<write_thres>,[<max_buffers>]] 279 280 Sets several parameters of the SCSI tape driver. <buffer_size> is 281 the number of 512-byte buffers reserved for tape operations for each 282 device. <write_thres> sets the number of blocks which must be filled 283 to start an actual write operation to the tape. Maximum value is the 284 total number of buffers. <max_buffer> limits the total number of 285 buffers allocated for all tape devices. 286 287 288 3.5) dmasound= 289 -------------- 290 291 Syntax: dmasound=[<buffers>,<buffer-size>[,<catch-radius>]] 292 293 This option controls some configurations of the Linux/m68k DMA sound 294 driver (Amiga and Atari): <buffers> is the number of buffers you want 295 to use (minimum 4, default 4), <buffer-size> is the size of each 296 buffer in kilobytes (minimum 4, default 32) and <catch-radius> says 297 how much percent of error will be tolerated when setting a frequency 298 (maximum 10, default 0). For example with 3% you can play 8000Hz 299 AU-Files on the Falcon with its hardware frequency of 8195Hz and thus 300 don't need to expand the sound. 301 302 303 304 4) Options for Atari Only 305 ========================= 306 307 4.1) video= 308 ----------- 309 310 Syntax: video=<fbname>:<sub-options...> 311 312 The <fbname> parameter specifies the name of the frame buffer, 313 eg. most atari users will want to specify `atafb' here. The 314 <sub-options> is a comma-separated list of the sub-options listed 315 below. 316 317 NB: Please notice that this option was renamed from `atavideo' to 318 `video' during the development of the 1.3.x kernels, thus you 319 might need to update your boot-scripts if upgrading to 2.x from 320 an 1.2.x kernel. 321 322 NBB: The behavior of video= was changed in 2.1.57 so the recommended 323 option is to specify the name of the frame buffer. 324 325 4.1.1) Video Mode 326 ----------------- 327 328 This sub-option may be any of the predefined video modes, as listed 329 in atari/atafb.c in the Linux/m68k source tree. The kernel will 330 activate the given video mode at boot time and make it the default 331 mode, if the hardware allows. Currently defined names are: 332 333 - stlow : 320x200x4 334 - stmid, default5 : 640x200x2 335 - sthigh, default4: 640x400x1 336 - ttlow : 320x480x8, TT only 337 - ttmid, default1 : 640x480x4, TT only 338 - tthigh, default2: 1280x960x1, TT only 339 - vga2 : 640x480x1, Falcon only 340 - vga4 : 640x480x2, Falcon only 341 - vga16, default3 : 640x480x4, Falcon only 342 - vga256 : 640x480x8, Falcon only 343 - falh2 : 896x608x1, Falcon only 344 - falh16 : 896x608x4, Falcon only 345 346 If no video mode is given on the command line, the kernel tries the 347 modes names "default<n>" in turn, until one is possible with the 348 hardware in use. 349 350 A video mode setting doesn't make sense, if the external driver is 351 activated by a "external:" sub-option. 352 353 4.1.2) inverse 354 -------------- 355 356 Invert the display. This affects both, text (consoles) and graphics 357 (X) display. Usually, the background is chosen to be black. With this 358 option, you can make the background white. 359 360 4.1.3) font 361 ----------- 362 363 Syntax: font:<fontname> 364 365 Specify the font to use in text modes. Currently you can choose only 366 between `VGA8x8', `VGA8x16' and `PEARL8x8'. `VGA8x8' is default, if the 367 vertical size of the display is less than 400 pixel rows. Otherwise, the 368 `VGA8x16' font is the default. 369 370 4.1.4) hwscroll_ 371 ---------------- 372 373 Syntax: hwscroll_<n> 374 375 The number of additional lines of video memory to reserve for 376 speeding up the scrolling ("hardware scrolling"). Hardware scrolling 377 is possible only if the kernel can set the video base address in steps 378 fine enough. This is true for STE, MegaSTE, TT, and Falcon. It is not 379 possible with plain STs and graphics cards (The former because the 380 base address must be on a 256 byte boundary there, the latter because 381 the kernel doesn't know how to set the base address at all.) 382 383 By default, <n> is set to the number of visible text lines on the 384 display. Thus, the amount of video memory is doubled, compared to no 385 hardware scrolling. You can turn off the hardware scrolling altogether 386 by setting <n> to 0. 387 388 4.1.5) internal: 389 ---------------- 390 391 Syntax: internal:<xres>;<yres>[;<xres_max>;<yres_max>;<offset>] 392 393 This option specifies the capabilities of some extended internal video 394 hardware, like e.g. OverScan. <xres> and <yres> give the (extended) 395 dimensions of the screen. 396 397 If your OverScan needs a black border, you have to write the last 398 three arguments of the "internal:". <xres_max> is the maximum line 399 length the hardware allows, <yres_max> the maximum number of lines. 400 <offset> is the offset of the visible part of the screen memory to its 401 physical start, in bytes. 402 403 Often, extended interval video hardware has to be activated somehow. 404 For this, see the "sw_*" options below. 405 406 4.1.6) external: 407 ---------------- 408 409 Syntax: 410 external:<xres>;<yres>;<depth>;<org>;<scrmem>[;<scrlen>[;<vgabase>\ 411 [;<colw>[;<coltype>[;<xres_virtual>]]]]] 412 413 [I had to break this line...] 414 415 This is probably the most complicated parameter... It specifies that 416 you have some external video hardware (a graphics board), and how to 417 use it under Linux/m68k. The kernel cannot know more about the hardware 418 than you tell it here! The kernel also is unable to set or change any 419 video modes, since it doesn't know about any board internal. So, you 420 have to switch to that video mode before you start Linux, and cannot 421 switch to another mode once Linux has started. 422 423 The first 3 parameters of this sub-option should be obvious: <xres>, 424 <yres> and <depth> give the dimensions of the screen and the number of 425 planes (depth). The depth is the logarithm to base 2 of the number 426 of colors possible. (Or, the other way round: The number of colors is 427 2^depth). 428 429 You have to tell the kernel furthermore how the video memory is 430 organized. This is done by a letter as <org> parameter: 431 432 'n': "normal planes", i.e. one whole plane after another 433 'i': "interleaved planes", i.e. 16 bit of the first plane, than 16 bit 434 of the next, and so on... This mode is used only with the 435 built-in Atari video modes, I think there is no card that 436 supports this mode. 437 'p': "packed pixels", i.e. <depth> consecutive bits stand for all 438 planes of one pixel; this is the most common mode for 8 planes 439 (256 colors) on graphic cards 440 't': "true color" (more or less packed pixels, but without a color 441 lookup table); usually depth is 24 442 443 For monochrome modes (i.e., <depth> is 1), the <org> letter has a 444 different meaning: 445 446 'n': normal colors, i.e. 0=white, 1=black 447 'i': inverted colors, i.e. 0=black, 1=white 448 449 The next important information about the video hardware is the base 450 address of the video memory. That is given in the <scrmem> parameter, 451 as a hexadecimal number with a "0x" prefix. You have to find out this 452 address in the documentation of your hardware. 453 454 The next parameter, <scrlen>, tells the kernel about the size of the 455 video memory. If it's missing, the size is calculated from <xres>, 456 <yres>, and <depth>. For now, it is not useful to write a value here. 457 It would be used only for hardware scrolling (which isn't possible 458 with the external driver, because the kernel cannot set the video base 459 address), or for virtual resolutions under X (which the X server 460 doesn't support yet). So, it's currently best to leave this field 461 empty, either by ending the "external:" after the video address or by 462 writing two consecutive semicolons, if you want to give a <vgabase> 463 (it is allowed to leave this parameter empty). 464 465 The <vgabase> parameter is optional. If it is not given, the kernel 466 cannot read or write any color registers of the video hardware, and 467 thus you have to set appropriate colors before you start Linux. But if 468 your card is somehow VGA compatible, you can tell the kernel the base 469 address of the VGA register set, so it can change the color lookup 470 table. You have to look up this address in your board's documentation. 471 To avoid misunderstandings: <vgabase> is the _base_ address, i.e. a 4k 472 aligned address. For read/writing the color registers, the kernel 473 uses the addresses vgabase+0x3c7...vgabase+0x3c9. The <vgabase> 474 parameter is written in hexadecimal with a "0x" prefix, just as 475 <scrmem>. 476 477 <colw> is meaningful only if <vgabase> is specified. It tells the 478 kernel how wide each of the color register is, i.e. the number of bits 479 per single color (red/green/blue). Default is 6, another quite usual 480 value is 8. 481 482 Also <coltype> is used together with <vgabase>. It tells the kernel 483 about the color register model of your gfx board. Currently, the types 484 "vga" (which is also the default) and "mv300" (SANG MV300) are 485 implemented. 486 487 Parameter <xres_virtual> is required for ProMST or ET4000 cards where 488 the physical linelength differs from the visible length. With ProMST, 489 xres_virtual must be set to 2048. For ET4000, xres_virtual depends on the 490 initialisation of the video-card. 491 If you're missing a corresponding yres_virtual: the external part is legacy, 492 therefore we don't support hardware-dependent functions like hardware-scroll, 493 panning or blanking. 494 495 4.1.7) eclock: 496 -------------- 497 498 The external pixel clock attached to the Falcon VIDEL shifter. This 499 currently works only with the ScreenWonder! 500 501 4.1.8) monitorcap: 502 ------------------- 503 504 Syntax: monitorcap:<vmin>;<vmax>;<hmin>;<hmax> 505 506 This describes the capabilities of a multisync monitor. Don't use it 507 with a fixed-frequency monitor! For now, only the Falcon frame buffer 508 uses the settings of "monitorcap:". 509 510 <vmin> and <vmax> are the minimum and maximum, resp., vertical frequencies 511 your monitor can work with, in Hz. <hmin> and <hmax> are the same for 512 the horizontal frequency, in kHz. 513 514 The defaults are 58;62;31;32 (VGA compatible). 515 516 The defaults for TV/SC1224/SC1435 cover both PAL and NTSC standards. 517 518 4.1.9) keep 519 ------------ 520 521 If this option is given, the framebuffer device doesn't do any video 522 mode calculations and settings on its own. The only Atari fb device 523 that does this currently is the Falcon. 524 525 What you reach with this: Settings for unknown video extensions 526 aren't overridden by the driver, so you can still use the mode found 527 when booting, when the driver doesn't know to set this mode itself. 528 But this also means, that you can't switch video modes anymore... 529 530 An example where you may want to use "keep" is the ScreenBlaster for 531 the Falcon. 532 533 534 4.2) atamouse= 535 -------------- 536 537 Syntax: atamouse=<x-threshold>,[<y-threshold>] 538 539 With this option, you can set the mouse movement reporting threshold. 540 This is the number of pixels of mouse movement that have to accumulate 541 before the IKBD sends a new mouse packet to the kernel. Higher values 542 reduce the mouse interrupt load and thus reduce the chance of keyboard 543 overruns. Lower values give a slightly faster mouse responses and 544 slightly better mouse tracking. 545 546 You can set the threshold in x and y separately, but usually this is 547 of little practical use. If there's just one number in the option, it 548 is used for both dimensions. The default value is 2 for both 549 thresholds. 550 551 552 4.3) ataflop= 553 ------------- 554 555 Syntax: ataflop=<drive type>[,<trackbuffering>[,<steprateA>[,<steprateB>]]] 556 557 The drive type may be 0, 1, or 2, for DD, HD, and ED, resp. This 558 setting affects how many buffers are reserved and which formats are 559 probed (see also below). The default is 1 (HD). Only one drive type 560 can be selected. If you have two disk drives, select the "better" 561 type. 562 563 The second parameter <trackbuffer> tells the kernel whether to use 564 track buffering (1) or not (0). The default is machine-dependent: 565 no for the Medusa and yes for all others. 566 567 With the two following parameters, you can change the default 568 steprate used for drive A and B, resp. 569 570 571 4.4) atascsi= 572 ------------- 573 574 Syntax: atascsi=<can_queue>[,<cmd_per_lun>[,<scat-gat>[,<host-id>[,<tagged>]]]] 575 576 This option sets some parameters for the Atari native SCSI driver. 577 Generally, any number of arguments can be omitted from the end. And 578 for each of the numbers, a negative value means "use default". The 579 defaults depend on whether TT-style or Falcon-style SCSI is used. 580 Below, defaults are noted as n/m, where the first value refers to 581 TT-SCSI and the latter to Falcon-SCSI. If an illegal value is given 582 for one parameter, an error message is printed and that one setting is 583 ignored (others aren't affected). 584 585 <can_queue>: 586 This is the maximum number of SCSI commands queued internally to the 587 Atari SCSI driver. A value of 1 effectively turns off the driver 588 internal multitasking (if it causes problems). Legal values are >= 589 1. <can_queue> can be as high as you like, but values greater than 590 <cmd_per_lun> times the number of SCSI targets (LUNs) you have 591 don't make sense. Default: 16/8. 592 593 <cmd_per_lun>: 594 Maximum number of SCSI commands issued to the driver for one 595 logical unit (LUN, usually one SCSI target). Legal values start 596 from 1. If tagged queuing (see below) is not used, values greater 597 than 2 don't make sense, but waste memory. Otherwise, the maximum 598 is the number of command tags available to the driver (currently 599 32). Default: 8/1. (Note: Values > 1 seem to cause problems on a 600 Falcon, cause not yet known.) 601 602 The <cmd_per_lun> value at a great part determines the amount of 603 memory SCSI reserves for itself. The formula is rather 604 complicated, but I can give you some hints: 605 no scatter-gather : cmd_per_lun * 232 bytes 606 full scatter-gather: cmd_per_lun * approx. 17 Kbytes 607 608 <scat-gat>: 609 Size of the scatter-gather table, i.e. the number of requests 610 consecutive on the disk that can be merged into one SCSI command. 611 Legal values are between 0 and 255. Default: 255/0. Note: This 612 value is forced to 0 on a Falcon, since scatter-gather isn't 613 possible with the ST-DMA. Not using scatter-gather hurts 614 performance significantly. 615 616 <host-id>: 617 The SCSI ID to be used by the initiator (your Atari). This is 618 usually 7, the highest possible ID. Every ID on the SCSI bus must 619 be unique. Default: determined at run time: If the NV-RAM checksum 620 is valid, and bit 7 in byte 30 of the NV-RAM is set, the lower 3 621 bits of this byte are used as the host ID. (This method is defined 622 by Atari and also used by some TOS HD drivers.) If the above 623 isn't given, the default ID is 7. (both, TT and Falcon). 624 625 <tagged>: 626 0 means turn off tagged queuing support, all other values > 0 mean 627 use tagged queuing for targets that support it. Default: currently 628 off, but this may change when tagged queuing handling has been 629 proved to be reliable. 630 631 Tagged queuing means that more than one command can be issued to 632 one LUN, and the SCSI device itself orders the requests so they 633 can be performed in optimal order. Not all SCSI devices support 634 tagged queuing (:-(). 635 636 4.5 switches= 637 ------------- 638 639 Syntax: switches=<list of switches> 640 641 With this option you can switch some hardware lines that are often 642 used to enable/disable certain hardware extensions. Examples are 643 OverScan, overclocking, ... 644 645 The <list of switches> is a comma-separated list of the following 646 items: 647 648 ikbd: set RTS of the keyboard ACIA high 649 midi: set RTS of the MIDI ACIA high 650 snd6: set bit 6 of the PSG port A 651 snd7: set bit 6 of the PSG port A 652 653 It doesn't make sense to mention a switch more than once (no 654 difference to only once), but you can give as many switches as you 655 want to enable different features. The switch lines are set as early 656 as possible during kernel initialization (even before determining the 657 present hardware.) 658 659 All of the items can also be prefixed with "ov_", i.e. "ov_ikbd", 660 "ov_midi", ... These options are meant for switching on an OverScan 661 video extension. The difference to the bare option is that the 662 switch-on is done after video initialization, and somehow synchronized 663 to the HBLANK. A speciality is that ov_ikbd and ov_midi are switched 664 off before rebooting, so that OverScan is disabled and TOS boots 665 correctly. 666 667 If you give an option both, with and without the "ov_" prefix, the 668 earlier initialization ("ov_"-less) takes precedence. But the 669 switching-off on reset still happens in this case. 670 671 5) Options for Amiga Only: 672 ========================== 673 674 5.1) video= 675 ----------- 676 677 Syntax: video=<fbname>:<sub-options...> 678 679 The <fbname> parameter specifies the name of the frame buffer, valid 680 options are `amifb', `cyber', 'virge', `retz3' and `clgen', provided 681 that the respective frame buffer devices have been compiled into the 682 kernel (or compiled as loadable modules). The behavior of the <fbname> 683 option was changed in 2.1.57 so it is now recommended to specify this 684 option. 685 686 The <sub-options> is a comma-separated list of the sub-options listed 687 below. This option is organized similar to the Atari version of the 688 "video"-option (4.1), but knows fewer sub-options. 689 690 5.1.1) video mode 691 ----------------- 692 693 Again, similar to the video mode for the Atari (see 4.1.1). Predefined 694 modes depend on the used frame buffer device. 695 696 OCS, ECS and AGA machines all use the color frame buffer. The following 697 predefined video modes are available: 698 699 NTSC modes: 700 - ntsc : 640x200, 15 kHz, 60 Hz 701 - ntsc-lace : 640x400, 15 kHz, 60 Hz interlaced 702 PAL modes: 703 - pal : 640x256, 15 kHz, 50 Hz 704 - pal-lace : 640x512, 15 kHz, 50 Hz interlaced 705 ECS modes: 706 - multiscan : 640x480, 29 kHz, 57 Hz 707 - multiscan-lace : 640x960, 29 kHz, 57 Hz interlaced 708 - euro36 : 640x200, 15 kHz, 72 Hz 709 - euro36-lace : 640x400, 15 kHz, 72 Hz interlaced 710 - euro72 : 640x400, 29 kHz, 68 Hz 711 - euro72-lace : 640x800, 29 kHz, 68 Hz interlaced 712 - super72 : 800x300, 23 kHz, 70 Hz 713 - super72-lace : 800x600, 23 kHz, 70 Hz interlaced 714 - dblntsc-ff : 640x400, 27 kHz, 57 Hz 715 - dblntsc-lace : 640x800, 27 kHz, 57 Hz interlaced 716 - dblpal-ff : 640x512, 27 kHz, 47 Hz 717 - dblpal-lace : 640x1024, 27 kHz, 47 Hz interlaced 718 - dblntsc : 640x200, 27 kHz, 57 Hz doublescan 719 - dblpal : 640x256, 27 kHz, 47 Hz doublescan 720 VGA modes: 721 - vga : 640x480, 31 kHz, 60 Hz 722 - vga70 : 640x400, 31 kHz, 70 Hz 723 724 Please notice that the ECS and VGA modes require either an ECS or AGA 725 chipset, and that these modes are limited to 2-bit color for the ECS 726 chipset and 8-bit color for the AGA chipset. 727 728 5.1.2) depth 729 ------------ 730 731 Syntax: depth:<nr. of bit-planes> 732 733 Specify the number of bit-planes for the selected video-mode. 734 735 5.1.3) inverse 736 -------------- 737 738 Use inverted display (black on white). Functionally the same as the 739 "inverse" sub-option for the Atari. 740 741 5.1.4) font 742 ----------- 743 744 Syntax: font:<fontname> 745 746 Specify the font to use in text modes. Functionally the same as the 747 "font" sub-option for the Atari, except that `PEARL8x8' is used instead 748 of `VGA8x8' if the vertical size of the display is less than 400 pixel 749 rows. 750 751 5.1.5) monitorcap: 752 ------------------- 753 754 Syntax: monitorcap:<vmin>;<vmax>;<hmin>;<hmax> 755 756 This describes the capabilities of a multisync monitor. For now, only 757 the color frame buffer uses the settings of "monitorcap:". 758 759 <vmin> and <vmax> are the minimum and maximum, resp., vertical frequencies 760 your monitor can work with, in Hz. <hmin> and <hmax> are the same for 761 the horizontal frequency, in kHz. 762 763 The defaults are 50;90;15;38 (Generic Amiga multisync monitor). 764 765 766 5.2) fd_def_df0= 767 ---------------- 768 769 Syntax: fd_def_df0=<value> 770 771 Sets the df0 value for "silent" floppy drives. The value should be in 772 hexadecimal with "0x" prefix. 773 774 775 5.3) wd33c93= 776 ------------- 777 778 Syntax: wd33c93=<sub-options...> 779 780 These options affect the A590/A2091, A3000 and GVP Series II SCSI 781 controllers. 782 783 The <sub-options> is a comma-separated list of the sub-options listed 784 below. 785 786 5.3.1) nosync 787 ------------- 788 789 Syntax: nosync:bitmask 790 791 bitmask is a byte where the 1st 7 bits correspond with the 7 792 possible SCSI devices. Set a bit to prevent sync negotiation on that 793 device. To maintain backwards compatibility, a command-line such as 794 "wd33c93=255" will be automatically translated to 795 "wd33c93=nosync:0xff". The default is to disable sync negotiation for 796 all devices, eg. nosync:0xff. 797 798 5.3.2) period 799 ------------- 800 801 Syntax: period:ns 802 803 `ns' is the minimum # of nanoseconds in a SCSI data transfer 804 period. Default is 500; acceptable values are 250 - 1000. 805 806 5.3.3) disconnect 807 ----------------- 808 809 Syntax: disconnect:x 810 811 Specify x = 0 to never allow disconnects, 2 to always allow them. 812 x = 1 does 'adaptive' disconnects, which is the default and generally 813 the best choice. 814 815 5.3.4) debug 816 ------------ 817 818 Syntax: debug:x 819 820 If `DEBUGGING_ON' is defined, x is a bit mask that causes various 821 types of debug output to printed - see the DB_xxx defines in 822 wd33c93.h. 823 824 5.3.5) clock 825 ------------ 826 827 Syntax: clock:x 828 829 x = clock input in MHz for WD33c93 chip. Normal values would be from 830 8 through 20. The default value depends on your hostadapter(s), 831 default for the A3000 internal controller is 14, for the A2091 it's 8 832 and for the GVP hostadapters it's either 8 or 14, depending on the 833 hostadapter and the SCSI-clock jumper present on some GVP 834 hostadapters. 835 836 5.3.6) next 837 ----------- 838 839 No argument. Used to separate blocks of keywords when there's more 840 than one wd33c93-based host adapter in the system. 841 842 5.3.7) nodma 843 ------------ 844 845 Syntax: nodma:x 846 847 If x is 1 (or if the option is just written as "nodma"), the WD33c93 848 controller will not use DMA (= direct memory access) to access the 849 Amiga's memory. This is useful for some systems (like A3000's and 850 A4000's with the A3640 accelerator, revision 3.0) that have problems 851 using DMA to chip memory. The default is 0, i.e. to use DMA if 852 possible. 853 854 855 5.4) gvp11= 856 ----------- 857 858 Syntax: gvp11=<addr-mask> 859 860 The earlier versions of the GVP driver did not handle DMA 861 address-mask settings correctly which made it necessary for some 862 people to use this option, in order to get their GVP controller 863 running under Linux. These problems have hopefully been solved and the 864 use of this option is now highly unrecommended! 865 866 Incorrect use can lead to unpredictable behavior, so please only use 867 this option if you *know* what you are doing and have a reason to do 868 so. In any case if you experience problems and need to use this 869 option, please inform us about it by mailing to the Linux/68k kernel 870 mailing list. 871 872 The address mask set by this option specifies which addresses are 873 valid for DMA with the GVP Series II SCSI controller. An address is 874 valid, if no bits are set except the bits that are set in the mask, 875 too. 876 877 Some versions of the GVP can only DMA into a 24 bit address range, 878 some can address a 25 bit address range while others can use the whole 879 32 bit address range for DMA. The correct setting depends on your 880 controller and should be autodetected by the driver. An example is the 881 24 bit region which is specified by a mask of 0x00fffffe. 882 883 884 /* Local Variables: */ 885 /* mode: text */ 886 /* End: */