Based on kernel version 4.16.1. Page generated on 2018-04-09 11:53 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 I hope, this document supplies all the 17 answers... 18 19 Note that some options might be outdated, their descriptions being 20 incomplete or missing.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 84 The name must be followed by a decimal number, that stands for the 85 partition number. Internally, the value of the number is just 86 added to the device number mentioned in the table above. The 87 exceptions are /dev/ram and /dev/fd, where /dev/ram refers to an 88 initial ramdisk loaded by your bootstrap program (please consult the 89 instructions for your bootstrap program to find out how to load an 90 initial ramdisk). As of kernel version 2.0.18 you must specify 91 /dev/ram as the root device if you want to boot from an initial 92 ramdisk. For the floppy devices, /dev/fd, the number stands for the 93 floppy drive number (there are no partitions on floppy disks). I.e., 94 /dev/fd0 stands for the first drive, /dev/fd1 for the second, and so 95 on. Since the number is just added, you can also force the disk format 96 by adding a number greater than 3. If you look into your /dev 97 directory, use can see the /dev/fd0D720 has major 2 and minor 16. You 98 can specify this device for the root FS by writing "root=/dev/fd16" on 99 the kernel command line. 100 101 [Strange and maybe uninteresting stuff ON] 102 103 This unusual translation of device names has some strange 104 consequences: If, for example, you have a symbolic link from /dev/fd 105 to /dev/fd0D720 as an abbreviation for floppy driver #0 in DD format, 106 you cannot use this name for specifying the root device, because the 107 kernel cannot see this symlink before mounting the root FS and it 108 isn't in the table above. If you use it, the root device will not be 109 set at all, without an error message. Another example: You cannot use a 110 partition on e.g. the sixth SCSI disk as the root filesystem, if you 111 want to specify it by name. This is, because only the devices up to 112 /dev/sde are in the table above, but not /dev/sdf. Although, you can 113 use the sixth SCSI disk for the root FS, but you have to specify the 114 device by number... (see below). Or, even more strange, you can use the 115 fact that there is no range checking of the partition number, and your 116 knowledge that each disk uses 16 minors, and write "root=/dev/sde17" 117 (for /dev/sdf1). 118 119 [Strange and maybe uninteresting stuff OFF] 120 121 If the device containing your root partition isn't in the table 122 above, you can also specify it by major and minor numbers. These are 123 written in hex, with no prefix and no separator between. E.g., if you 124 have a CD with contents appropriate as a root filesystem in the first 125 SCSI CD-ROM drive, you boot from it by "root=0b00". Here, hex "0b" = 126 decimal 11 is the major of SCSI CD-ROMs, and the minor 0 stands for 127 the first of these. You can find out all valid major numbers by 128 looking into include/linux/major.h. 129 130 In addition to major and minor numbers, if the device containing your 131 root partition uses a partition table format with unique partition 132 identifiers, then you may use them. For instance, 133 "root=PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF". It is also 134 possible to reference another partition on the same device using a 135 known partition UUID as the starting point. For example, 136 if partition 5 of the device has the UUID of 137 00112233-4455-6677-8899-AABBCCDDEEFF then partition 3 may be found as 138 follows: 139 PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF/PARTNROFF=-2 140 141 Authoritative information can be found in 142 "Documentation/admin-guide/kernel-parameters.rst". 143 144 145 2.2) ro, rw 146 ----------- 147 148 Syntax: ro 149 or: rw 150 151 These two options tell the kernel whether it should mount the root 152 filesystem read-only or read-write. The default is read-only, except 153 for ramdisks, which default to read-write. 154 155 156 2.3) debug 157 ---------- 158 159 Syntax: debug 160 161 This raises the kernel log level to 10 (the default is 7). This is the 162 same level as set by the "dmesg" command, just that the maximum level 163 selectable by dmesg is 8. 164 165 166 2.4) debug= 167 ----------- 168 169 Syntax: debug=<device> 170 171 This option causes certain kernel messages be printed to the selected 172 debugging device. This can aid debugging the kernel, since the 173 messages can be captured and analyzed on some other machine. Which 174 devices are possible depends on the machine type. There are no checks 175 for the validity of the device name. If the device isn't implemented, 176 nothing happens. 177 178 Messages logged this way are in general stack dumps after kernel 179 memory faults or bad kernel traps, and kernel panics. To be exact: all 180 messages of level 0 (panic messages) and all messages printed while 181 the log level is 8 or more (their level doesn't matter). Before stack 182 dumps, the kernel sets the log level to 10 automatically. A level of 183 at least 8 can also be set by the "debug" command line option (see 184 2.3) and at run time with "dmesg -n 8". 185 186 Devices possible for Amiga: 187 188 - "ser": built-in serial port; parameters: 9600bps, 8N1 189 - "mem": Save the messages to a reserved area in chip mem. After 190 rebooting, they can be read under AmigaOS with the tool 191 'dmesg'. 192 193 Devices possible for Atari: 194 195 - "ser1": ST-MFP serial port ("Modem1"); parameters: 9600bps, 8N1 196 - "ser2": SCC channel B serial port ("Modem2"); parameters: 9600bps, 8N1 197 - "ser" : default serial port 198 This is "ser2" for a Falcon, and "ser1" for any other machine 199 - "midi": The MIDI port; parameters: 31250bps, 8N1 200 - "par" : parallel port 201 The printing routine for this implements a timeout for the 202 case there's no printer connected (else the kernel would 203 lock up). The timeout is not exact, but usually a few 204 seconds. 205 206 207 2.6) ramdisk_size= 208 ------------- 209 210 Syntax: ramdisk_size=<size> 211 212 This option instructs the kernel to set up a ramdisk of the given 213 size in KBytes. Do not use this option if the ramdisk contents are 214 passed by bootstrap! In this case, the size is selected automatically 215 and should not be overwritten. 216 217 The only application is for root filesystems on floppy disks, that 218 should be loaded into memory. To do that, select the corresponding 219 size of the disk as ramdisk size, and set the root device to the disk 220 drive (with "root="). 221 222 223 2.7) swap= 224 2.8) buff= 225 ----------- 226 227 I can't find any sign of these options in 2.2.6. 228 229 230 3) General Device Options (Amiga and Atari) 231 =========================================== 232 233 3.1) ether= 234 ----------- 235 236 Syntax: ether=[<irq>[,<base_addr>[,<mem_start>[,<mem_end>]]]],<dev-name> 237 238 <dev-name> is the name of a net driver, as specified in 239 drivers/net/Space.c in the Linux source. Most prominent are eth0, ... 240 eth3, sl0, ... sl3, ppp0, ..., ppp3, dummy, and lo. 241 242 The non-ethernet drivers (sl, ppp, dummy, lo) obviously ignore the 243 settings by this options. Also, the existing ethernet drivers for 244 Linux/m68k (ariadne, a2065, hydra) don't use them because Zorro boards 245 are really Plug-'n-Play, so the "ether=" option is useless altogether 246 for Linux/m68k. 247 248 249 3.2) hd= 250 -------- 251 252 Syntax: hd=<cylinders>,<heads>,<sectors> 253 254 This option sets the disk geometry of an IDE disk. The first hd= 255 option is for the first IDE disk, the second for the second one. 256 (I.e., you can give this option twice.) In most cases, you won't have 257 to use this option, since the kernel can obtain the geometry data 258 itself. It exists just for the case that this fails for one of your 259 disks. 260 261 262 3.3) max_scsi_luns= 263 ------------------- 264 265 Syntax: max_scsi_luns=<n> 266 267 Sets the maximum number of LUNs (logical units) of SCSI devices to 268 be scanned. Valid values for <n> are between 1 and 8. Default is 8 if 269 "Probe all LUNs on each SCSI device" was selected during the kernel 270 configuration, else 1. 271 272 273 3.4) st= 274 -------- 275 276 Syntax: st=<buffer_size>,[<write_thres>,[<max_buffers>]] 277 278 Sets several parameters of the SCSI tape driver. <buffer_size> is 279 the number of 512-byte buffers reserved for tape operations for each 280 device. <write_thres> sets the number of blocks which must be filled 281 to start an actual write operation to the tape. Maximum value is the 282 total number of buffers. <max_buffer> limits the total number of 283 buffers allocated for all tape devices. 284 285 286 3.5) dmasound= 287 -------------- 288 289 Syntax: dmasound=[<buffers>,<buffer-size>[,<catch-radius>]] 290 291 This option controls some configurations of the Linux/m68k DMA sound 292 driver (Amiga and Atari): <buffers> is the number of buffers you want 293 to use (minimum 4, default 4), <buffer-size> is the size of each 294 buffer in kilobytes (minimum 4, default 32) and <catch-radius> says 295 how much percent of error will be tolerated when setting a frequency 296 (maximum 10, default 0). For example with 3% you can play 8000Hz 297 AU-Files on the Falcon with its hardware frequency of 8195Hz and thus 298 don't need to expand the sound. 299 300 301 302 4) Options for Atari Only 303 ========================= 304 305 4.1) video= 306 ----------- 307 308 Syntax: video=<fbname>:<sub-options...> 309 310 The <fbname> parameter specifies the name of the frame buffer, 311 eg. most atari users will want to specify `atafb' here. The 312 <sub-options> is a comma-separated list of the sub-options listed 313 below. 314 315 NB: Please notice that this option was renamed from `atavideo' to 316 `video' during the development of the 1.3.x kernels, thus you 317 might need to update your boot-scripts if upgrading to 2.x from 318 an 1.2.x kernel. 319 320 NBB: The behavior of video= was changed in 2.1.57 so the recommended 321 option is to specify the name of the frame buffer. 322 323 4.1.1) Video Mode 324 ----------------- 325 326 This sub-option may be any of the predefined video modes, as listed 327 in atari/atafb.c in the Linux/m68k source tree. The kernel will 328 activate the given video mode at boot time and make it the default 329 mode, if the hardware allows. Currently defined names are: 330 331 - stlow : 320x200x4 332 - stmid, default5 : 640x200x2 333 - sthigh, default4: 640x400x1 334 - ttlow : 320x480x8, TT only 335 - ttmid, default1 : 640x480x4, TT only 336 - tthigh, default2: 1280x960x1, TT only 337 - vga2 : 640x480x1, Falcon only 338 - vga4 : 640x480x2, Falcon only 339 - vga16, default3 : 640x480x4, Falcon only 340 - vga256 : 640x480x8, Falcon only 341 - falh2 : 896x608x1, Falcon only 342 - falh16 : 896x608x4, Falcon only 343 344 If no video mode is given on the command line, the kernel tries the 345 modes names "default<n>" in turn, until one is possible with the 346 hardware in use. 347 348 A video mode setting doesn't make sense, if the external driver is 349 activated by a "external:" sub-option. 350 351 4.1.2) inverse 352 -------------- 353 354 Invert the display. This affects both, text (consoles) and graphics 355 (X) display. Usually, the background is chosen to be black. With this 356 option, you can make the background white. 357 358 4.1.3) font 359 ----------- 360 361 Syntax: font:<fontname> 362 363 Specify the font to use in text modes. Currently you can choose only 364 between `VGA8x8', `VGA8x16' and `PEARL8x8'. `VGA8x8' is default, if the 365 vertical size of the display is less than 400 pixel rows. Otherwise, the 366 `VGA8x16' font is the default. 367 368 4.1.4) hwscroll_ 369 ---------------- 370 371 Syntax: hwscroll_<n> 372 373 The number of additional lines of video memory to reserve for 374 speeding up the scrolling ("hardware scrolling"). Hardware scrolling 375 is possible only if the kernel can set the video base address in steps 376 fine enough. This is true for STE, MegaSTE, TT, and Falcon. It is not 377 possible with plain STs and graphics cards (The former because the 378 base address must be on a 256 byte boundary there, the latter because 379 the kernel doesn't know how to set the base address at all.) 380 381 By default, <n> is set to the number of visible text lines on the 382 display. Thus, the amount of video memory is doubled, compared to no 383 hardware scrolling. You can turn off the hardware scrolling altogether 384 by setting <n> to 0. 385 386 4.1.5) internal: 387 ---------------- 388 389 Syntax: internal:<xres>;<yres>[;<xres_max>;<yres_max>;<offset>] 390 391 This option specifies the capabilities of some extended internal video 392 hardware, like e.g. OverScan. <xres> and <yres> give the (extended) 393 dimensions of the screen. 394 395 If your OverScan needs a black border, you have to write the last 396 three arguments of the "internal:". <xres_max> is the maximum line 397 length the hardware allows, <yres_max> the maximum number of lines. 398 <offset> is the offset of the visible part of the screen memory to its 399 physical start, in bytes. 400 401 Often, extended interval video hardware has to be activated somehow. 402 For this, see the "sw_*" options below. 403 404 4.1.6) external: 405 ---------------- 406 407 Syntax: 408 external:<xres>;<yres>;<depth>;<org>;<scrmem>[;<scrlen>[;<vgabase>\ 409 [;<colw>[;<coltype>[;<xres_virtual>]]]]] 410 411 [I had to break this line...] 412 413 This is probably the most complicated parameter... It specifies that 414 you have some external video hardware (a graphics board), and how to 415 use it under Linux/m68k. The kernel cannot know more about the hardware 416 than you tell it here! The kernel also is unable to set or change any 417 video modes, since it doesn't know about any board internal. So, you 418 have to switch to that video mode before you start Linux, and cannot 419 switch to another mode once Linux has started. 420 421 The first 3 parameters of this sub-option should be obvious: <xres>, 422 <yres> and <depth> give the dimensions of the screen and the number of 423 planes (depth). The depth is the logarithm to base 2 of the number 424 of colors possible. (Or, the other way round: The number of colors is 425 2^depth). 426 427 You have to tell the kernel furthermore how the video memory is 428 organized. This is done by a letter as <org> parameter: 429 430 'n': "normal planes", i.e. one whole plane after another 431 'i': "interleaved planes", i.e. 16 bit of the first plane, than 16 bit 432 of the next, and so on... This mode is used only with the 433 built-in Atari video modes, I think there is no card that 434 supports this mode. 435 'p': "packed pixels", i.e. <depth> consecutive bits stand for all 436 planes of one pixel; this is the most common mode for 8 planes 437 (256 colors) on graphic cards 438 't': "true color" (more or less packed pixels, but without a color 439 lookup table); usually depth is 24 440 441 For monochrome modes (i.e., <depth> is 1), the <org> letter has a 442 different meaning: 443 444 'n': normal colors, i.e. 0=white, 1=black 445 'i': inverted colors, i.e. 0=black, 1=white 446 447 The next important information about the video hardware is the base 448 address of the video memory. That is given in the <scrmem> parameter, 449 as a hexadecimal number with a "0x" prefix. You have to find out this 450 address in the documentation of your hardware. 451 452 The next parameter, <scrlen>, tells the kernel about the size of the 453 video memory. If it's missing, the size is calculated from <xres>, 454 <yres>, and <depth>. For now, it is not useful to write a value here. 455 It would be used only for hardware scrolling (which isn't possible 456 with the external driver, because the kernel cannot set the video base 457 address), or for virtual resolutions under X (which the X server 458 doesn't support yet). So, it's currently best to leave this field 459 empty, either by ending the "external:" after the video address or by 460 writing two consecutive semicolons, if you want to give a <vgabase> 461 (it is allowed to leave this parameter empty). 462 463 The <vgabase> parameter is optional. If it is not given, the kernel 464 cannot read or write any color registers of the video hardware, and 465 thus you have to set appropriate colors before you start Linux. But if 466 your card is somehow VGA compatible, you can tell the kernel the base 467 address of the VGA register set, so it can change the color lookup 468 table. You have to look up this address in your board's documentation. 469 To avoid misunderstandings: <vgabase> is the _base_ address, i.e. a 4k 470 aligned address. For read/writing the color registers, the kernel 471 uses the addresses vgabase+0x3c7...vgabase+0x3c9. The <vgabase> 472 parameter is written in hexadecimal with a "0x" prefix, just as 473 <scrmem>. 474 475 <colw> is meaningful only if <vgabase> is specified. It tells the 476 kernel how wide each of the color register is, i.e. the number of bits 477 per single color (red/green/blue). Default is 6, another quite usual 478 value is 8. 479 480 Also <coltype> is used together with <vgabase>. It tells the kernel 481 about the color register model of your gfx board. Currently, the types 482 "vga" (which is also the default) and "mv300" (SANG MV300) are 483 implemented. 484 485 Parameter <xres_virtual> is required for ProMST or ET4000 cards where 486 the physical linelength differs from the visible length. With ProMST, 487 xres_virtual must be set to 2048. For ET4000, xres_virtual depends on the 488 initialisation of the video-card. 489 If you're missing a corresponding yres_virtual: the external part is legacy, 490 therefore we don't support hardware-dependent functions like hardware-scroll, 491 panning or blanking. 492 493 4.1.7) eclock: 494 -------------- 495 496 The external pixel clock attached to the Falcon VIDEL shifter. This 497 currently works only with the ScreenWonder! 498 499 4.1.8) monitorcap: 500 ------------------- 501 502 Syntax: monitorcap:<vmin>;<vmax>;<hmin>;<hmax> 503 504 This describes the capabilities of a multisync monitor. Don't use it 505 with a fixed-frequency monitor! For now, only the Falcon frame buffer 506 uses the settings of "monitorcap:". 507 508 <vmin> and <vmax> are the minimum and maximum, resp., vertical frequencies 509 your monitor can work with, in Hz. <hmin> and <hmax> are the same for 510 the horizontal frequency, in kHz. 511 512 The defaults are 58;62;31;32 (VGA compatible). 513 514 The defaults for TV/SC1224/SC1435 cover both PAL and NTSC standards. 515 516 4.1.9) keep 517 ------------ 518 519 If this option is given, the framebuffer device doesn't do any video 520 mode calculations and settings on its own. The only Atari fb device 521 that does this currently is the Falcon. 522 523 What you reach with this: Settings for unknown video extensions 524 aren't overridden by the driver, so you can still use the mode found 525 when booting, when the driver doesn't know to set this mode itself. 526 But this also means, that you can't switch video modes anymore... 527 528 An example where you may want to use "keep" is the ScreenBlaster for 529 the Falcon. 530 531 532 4.2) atamouse= 533 -------------- 534 535 Syntax: atamouse=<x-threshold>,[<y-threshold>] 536 537 With this option, you can set the mouse movement reporting threshold. 538 This is the number of pixels of mouse movement that have to accumulate 539 before the IKBD sends a new mouse packet to the kernel. Higher values 540 reduce the mouse interrupt load and thus reduce the chance of keyboard 541 overruns. Lower values give a slightly faster mouse responses and 542 slightly better mouse tracking. 543 544 You can set the threshold in x and y separately, but usually this is 545 of little practical use. If there's just one number in the option, it 546 is used for both dimensions. The default value is 2 for both 547 thresholds. 548 549 550 4.3) ataflop= 551 ------------- 552 553 Syntax: ataflop=<drive type>[,<trackbuffering>[,<steprateA>[,<steprateB>]]] 554 555 The drive type may be 0, 1, or 2, for DD, HD, and ED, resp. This 556 setting affects how many buffers are reserved and which formats are 557 probed (see also below). The default is 1 (HD). Only one drive type 558 can be selected. If you have two disk drives, select the "better" 559 type. 560 561 The second parameter <trackbuffer> tells the kernel whether to use 562 track buffering (1) or not (0). The default is machine-dependent: 563 no for the Medusa and yes for all others. 564 565 With the two following parameters, you can change the default 566 steprate used for drive A and B, resp. 567 568 569 4.4) atascsi= 570 ------------- 571 572 Syntax: atascsi=<can_queue>[,<cmd_per_lun>[,<scat-gat>[,<host-id>[,<tagged>]]]] 573 574 This option sets some parameters for the Atari native SCSI driver. 575 Generally, any number of arguments can be omitted from the end. And 576 for each of the numbers, a negative value means "use default". The 577 defaults depend on whether TT-style or Falcon-style SCSI is used. 578 Below, defaults are noted as n/m, where the first value refers to 579 TT-SCSI and the latter to Falcon-SCSI. If an illegal value is given 580 for one parameter, an error message is printed and that one setting is 581 ignored (others aren't affected). 582 583 <can_queue>: 584 This is the maximum number of SCSI commands queued internally to the 585 Atari SCSI driver. A value of 1 effectively turns off the driver 586 internal multitasking (if it causes problems). Legal values are >= 587 1. <can_queue> can be as high as you like, but values greater than 588 <cmd_per_lun> times the number of SCSI targets (LUNs) you have 589 don't make sense. Default: 16/8. 590 591 <cmd_per_lun>: 592 Maximum number of SCSI commands issued to the driver for one 593 logical unit (LUN, usually one SCSI target). Legal values start 594 from 1. If tagged queuing (see below) is not used, values greater 595 than 2 don't make sense, but waste memory. Otherwise, the maximum 596 is the number of command tags available to the driver (currently 597 32). Default: 8/1. (Note: Values > 1 seem to cause problems on a 598 Falcon, cause not yet known.) 599 600 The <cmd_per_lun> value at a great part determines the amount of 601 memory SCSI reserves for itself. The formula is rather 602 complicated, but I can give you some hints: 603 no scatter-gather : cmd_per_lun * 232 bytes 604 full scatter-gather: cmd_per_lun * approx. 17 Kbytes 605 606 <scat-gat>: 607 Size of the scatter-gather table, i.e. the number of requests 608 consecutive on the disk that can be merged into one SCSI command. 609 Legal values are between 0 and 255. Default: 255/0. Note: This 610 value is forced to 0 on a Falcon, since scatter-gather isn't 611 possible with the ST-DMA. Not using scatter-gather hurts 612 performance significantly. 613 614 <host-id>: 615 The SCSI ID to be used by the initiator (your Atari). This is 616 usually 7, the highest possible ID. Every ID on the SCSI bus must 617 be unique. Default: determined at run time: If the NV-RAM checksum 618 is valid, and bit 7 in byte 30 of the NV-RAM is set, the lower 3 619 bits of this byte are used as the host ID. (This method is defined 620 by Atari and also used by some TOS HD drivers.) If the above 621 isn't given, the default ID is 7. (both, TT and Falcon). 622 623 <tagged>: 624 0 means turn off tagged queuing support, all other values > 0 mean 625 use tagged queuing for targets that support it. Default: currently 626 off, but this may change when tagged queuing handling has been 627 proved to be reliable. 628 629 Tagged queuing means that more than one command can be issued to 630 one LUN, and the SCSI device itself orders the requests so they 631 can be performed in optimal order. Not all SCSI devices support 632 tagged queuing (:-(). 633 634 4.5 switches= 635 ------------- 636 637 Syntax: switches=<list of switches> 638 639 With this option you can switch some hardware lines that are often 640 used to enable/disable certain hardware extensions. Examples are 641 OverScan, overclocking, ... 642 643 The <list of switches> is a comma-separated list of the following 644 items: 645 646 ikbd: set RTS of the keyboard ACIA high 647 midi: set RTS of the MIDI ACIA high 648 snd6: set bit 6 of the PSG port A 649 snd7: set bit 6 of the PSG port A 650 651 It doesn't make sense to mention a switch more than once (no 652 difference to only once), but you can give as many switches as you 653 want to enable different features. The switch lines are set as early 654 as possible during kernel initialization (even before determining the 655 present hardware.) 656 657 All of the items can also be prefixed with "ov_", i.e. "ov_ikbd", 658 "ov_midi", ... These options are meant for switching on an OverScan 659 video extension. The difference to the bare option is that the 660 switch-on is done after video initialization, and somehow synchronized 661 to the HBLANK. A speciality is that ov_ikbd and ov_midi are switched 662 off before rebooting, so that OverScan is disabled and TOS boots 663 correctly. 664 665 If you give an option both, with and without the "ov_" prefix, the 666 earlier initialization ("ov_"-less) takes precedence. But the 667 switching-off on reset still happens in this case. 668 669 5) Options for Amiga Only: 670 ========================== 671 672 5.1) video= 673 ----------- 674 675 Syntax: video=<fbname>:<sub-options...> 676 677 The <fbname> parameter specifies the name of the frame buffer, valid 678 options are `amifb', `cyber', 'virge', `retz3' and `clgen', provided 679 that the respective frame buffer devices have been compiled into the 680 kernel (or compiled as loadable modules). The behavior of the <fbname> 681 option was changed in 2.1.57 so it is now recommended to specify this 682 option. 683 684 The <sub-options> is a comma-separated list of the sub-options listed 685 below. This option is organized similar to the Atari version of the 686 "video"-option (4.1), but knows fewer sub-options. 687 688 5.1.1) video mode 689 ----------------- 690 691 Again, similar to the video mode for the Atari (see 4.1.1). Predefined 692 modes depend on the used frame buffer device. 693 694 OCS, ECS and AGA machines all use the color frame buffer. The following 695 predefined video modes are available: 696 697 NTSC modes: 698 - ntsc : 640x200, 15 kHz, 60 Hz 699 - ntsc-lace : 640x400, 15 kHz, 60 Hz interlaced 700 PAL modes: 701 - pal : 640x256, 15 kHz, 50 Hz 702 - pal-lace : 640x512, 15 kHz, 50 Hz interlaced 703 ECS modes: 704 - multiscan : 640x480, 29 kHz, 57 Hz 705 - multiscan-lace : 640x960, 29 kHz, 57 Hz interlaced 706 - euro36 : 640x200, 15 kHz, 72 Hz 707 - euro36-lace : 640x400, 15 kHz, 72 Hz interlaced 708 - euro72 : 640x400, 29 kHz, 68 Hz 709 - euro72-lace : 640x800, 29 kHz, 68 Hz interlaced 710 - super72 : 800x300, 23 kHz, 70 Hz 711 - super72-lace : 800x600, 23 kHz, 70 Hz interlaced 712 - dblntsc-ff : 640x400, 27 kHz, 57 Hz 713 - dblntsc-lace : 640x800, 27 kHz, 57 Hz interlaced 714 - dblpal-ff : 640x512, 27 kHz, 47 Hz 715 - dblpal-lace : 640x1024, 27 kHz, 47 Hz interlaced 716 - dblntsc : 640x200, 27 kHz, 57 Hz doublescan 717 - dblpal : 640x256, 27 kHz, 47 Hz doublescan 718 VGA modes: 719 - vga : 640x480, 31 kHz, 60 Hz 720 - vga70 : 640x400, 31 kHz, 70 Hz 721 722 Please notice that the ECS and VGA modes require either an ECS or AGA 723 chipset, and that these modes are limited to 2-bit color for the ECS 724 chipset and 8-bit color for the AGA chipset. 725 726 5.1.2) depth 727 ------------ 728 729 Syntax: depth:<nr. of bit-planes> 730 731 Specify the number of bit-planes for the selected video-mode. 732 733 5.1.3) inverse 734 -------------- 735 736 Use inverted display (black on white). Functionally the same as the 737 "inverse" sub-option for the Atari. 738 739 5.1.4) font 740 ----------- 741 742 Syntax: font:<fontname> 743 744 Specify the font to use in text modes. Functionally the same as the 745 "font" sub-option for the Atari, except that `PEARL8x8' is used instead 746 of `VGA8x8' if the vertical size of the display is less than 400 pixel 747 rows. 748 749 5.1.5) monitorcap: 750 ------------------- 751 752 Syntax: monitorcap:<vmin>;<vmax>;<hmin>;<hmax> 753 754 This describes the capabilities of a multisync monitor. For now, only 755 the color frame buffer uses the settings of "monitorcap:". 756 757 <vmin> and <vmax> are the minimum and maximum, resp., vertical frequencies 758 your monitor can work with, in Hz. <hmin> and <hmax> are the same for 759 the horizontal frequency, in kHz. 760 761 The defaults are 50;90;15;38 (Generic Amiga multisync monitor). 762 763 764 5.2) fd_def_df0= 765 ---------------- 766 767 Syntax: fd_def_df0=<value> 768 769 Sets the df0 value for "silent" floppy drives. The value should be in 770 hexadecimal with "0x" prefix. 771 772 773 5.3) wd33c93= 774 ------------- 775 776 Syntax: wd33c93=<sub-options...> 777 778 These options affect the A590/A2091, A3000 and GVP Series II SCSI 779 controllers. 780 781 The <sub-options> is a comma-separated list of the sub-options listed 782 below. 783 784 5.3.1) nosync 785 ------------- 786 787 Syntax: nosync:bitmask 788 789 bitmask is a byte where the 1st 7 bits correspond with the 7 790 possible SCSI devices. Set a bit to prevent sync negotiation on that 791 device. To maintain backwards compatibility, a command-line such as 792 "wd33c93=255" will be automatically translated to 793 "wd33c93=nosync:0xff". The default is to disable sync negotiation for 794 all devices, eg. nosync:0xff. 795 796 5.3.2) period 797 ------------- 798 799 Syntax: period:ns 800 801 `ns' is the minimum # of nanoseconds in a SCSI data transfer 802 period. Default is 500; acceptable values are 250 - 1000. 803 804 5.3.3) disconnect 805 ----------------- 806 807 Syntax: disconnect:x 808 809 Specify x = 0 to never allow disconnects, 2 to always allow them. 810 x = 1 does 'adaptive' disconnects, which is the default and generally 811 the best choice. 812 813 5.3.4) debug 814 ------------ 815 816 Syntax: debug:x 817 818 If `DEBUGGING_ON' is defined, x is a bit mask that causes various 819 types of debug output to printed - see the DB_xxx defines in 820 wd33c93.h. 821 822 5.3.5) clock 823 ------------ 824 825 Syntax: clock:x 826 827 x = clock input in MHz for WD33c93 chip. Normal values would be from 828 8 through 20. The default value depends on your hostadapter(s), 829 default for the A3000 internal controller is 14, for the A2091 it's 8 830 and for the GVP hostadapters it's either 8 or 14, depending on the 831 hostadapter and the SCSI-clock jumper present on some GVP 832 hostadapters. 833 834 5.3.6) next 835 ----------- 836 837 No argument. Used to separate blocks of keywords when there's more 838 than one wd33c93-based host adapter in the system. 839 840 5.3.7) nodma 841 ------------ 842 843 Syntax: nodma:x 844 845 If x is 1 (or if the option is just written as "nodma"), the WD33c93 846 controller will not use DMA (= direct memory access) to access the 847 Amiga's memory. This is useful for some systems (like A3000's and 848 A4000's with the A3640 accelerator, revision 3.0) that have problems 849 using DMA to chip memory. The default is 0, i.e. to use DMA if 850 possible. 851 852 853 5.4) gvp11= 854 ----------- 855 856 Syntax: gvp11=<addr-mask> 857 858 The earlier versions of the GVP driver did not handle DMA 859 address-mask settings correctly which made it necessary for some 860 people to use this option, in order to get their GVP controller 861 running under Linux. These problems have hopefully been solved and the 862 use of this option is now highly unrecommended! 863 864 Incorrect use can lead to unpredictable behavior, so please only use 865 this option if you *know* what you are doing and have a reason to do 866 so. In any case if you experience problems and need to use this 867 option, please inform us about it by mailing to the Linux/68k kernel 868 mailing list. 869 870 The address mask set by this option specifies which addresses are 871 valid for DMA with the GVP Series II SCSI controller. An address is 872 valid, if no bits are set except the bits that are set in the mask, 873 too. 874 875 Some versions of the GVP can only DMA into a 24 bit address range, 876 some can address a 25 bit address range while others can use the whole 877 32 bit address range for DMA. The correct setting depends on your 878 controller and should be autodetected by the driver. An example is the 879 24 bit region which is specified by a mask of 0x00fffffe. 880 881 882 /* Local Variables: */ 883 /* mode: text */ 884 /* End: */