1 /* 2 * CMOS/NV-RAM driver for Linux 3 * 4 * Copyright (C) 1997 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de> 5 * idea by and with help from Richard Jelinek <rj@suse.de> 6 * Portions copyright (c) 2001,2002 Sun Microsystems (thockin@sun.com) 7 * 8 * This driver allows you to access the contents of the non-volatile memory in 9 * the mc146818rtc.h real-time clock. This chip is built into all PCs and into 10 * many Atari machines. In the former it's called "CMOS-RAM", in the latter 11 * "NVRAM" (NV stands for non-volatile). 12 * 13 * The data are supplied as a (seekable) character device, /dev/nvram. The 14 * size of this file is dependent on the controller. The usual size is 114, 15 * the number of freely available bytes in the memory (i.e., not used by the 16 * RTC itself). 17 * 18 * Checksums over the NVRAM contents are managed by this driver. In case of a 19 * bad checksum, reads and writes return -EIO. The checksum can be initialized 20 * to a sane state either by ioctl(NVRAM_INIT) (clear whole NVRAM) or 21 * ioctl(NVRAM_SETCKS) (doesn't change contents, just makes checksum valid 22 * again; use with care!) 23 * 24 * This file also provides some functions for other parts of the kernel that 25 * want to access the NVRAM: nvram_{read,write,check_checksum,set_checksum}. 26 * Obviously this can be used only if this driver is always configured into 27 * the kernel and is not a module. Since the functions are used by some Atari 28 * drivers, this is the case on the Atari. 29 * 30 * 31 * 1.1 Cesar Barros: SMP locking fixes 32 * added changelog 33 * 1.2 Erik Gilling: Cobalt Networks support 34 * Tim Hockin: general cleanup, Cobalt support 35 * 1.3 Wim Van Sebroeck: convert PRINT_PROC to seq_file 36 */ 37 38 #define NVRAM_VERSION "1.3" 39 40 #include <linux/module.h> 41 #include <linux/nvram.h> 42 43 #define PC 1 44 #define ATARI 2 45 46 /* select machine configuration */ 47 #if defined(CONFIG_ATARI) 48 # define MACH ATARI 49 #elif defined(__i386__) || defined(__x86_64__) || defined(__arm__) /* and ?? */ 50 # define MACH PC 51 #else 52 # error Cannot build nvram driver for this machine configuration. 53 #endif 54 55 #if MACH == PC 56 57 /* RTC in a PC */ 58 #define CHECK_DRIVER_INIT() 1 59 60 /* On PCs, the checksum is built only over bytes 2..31 */ 61 #define PC_CKS_RANGE_START 2 62 #define PC_CKS_RANGE_END 31 63 #define PC_CKS_LOC 32 64 #define NVRAM_BYTES (128-NVRAM_FIRST_BYTE) 65 66 #define mach_check_checksum pc_check_checksum 67 #define mach_set_checksum pc_set_checksum 68 #define mach_proc_infos pc_proc_infos 69 70 #endif 71 72 #if MACH == ATARI 73 74 /* Special parameters for RTC in Atari machines */ 75 #include <asm/atarihw.h> 76 #include <asm/atariints.h> 77 #define RTC_PORT(x) (TT_RTC_BAS + 2*(x)) 78 #define CHECK_DRIVER_INIT() (MACH_IS_ATARI && ATARIHW_PRESENT(TT_CLK)) 79 80 #define NVRAM_BYTES 50 81 82 /* On Ataris, the checksum is over all bytes except the checksum bytes 83 * themselves; these are at the very end */ 84 #define ATARI_CKS_RANGE_START 0 85 #define ATARI_CKS_RANGE_END 47 86 #define ATARI_CKS_LOC 48 87 88 #define mach_check_checksum atari_check_checksum 89 #define mach_set_checksum atari_set_checksum 90 #define mach_proc_infos atari_proc_infos 91 92 #endif 93 94 /* Note that *all* calls to CMOS_READ and CMOS_WRITE must be done with 95 * rtc_lock held. Due to the index-port/data-port design of the RTC, we 96 * don't want two different things trying to get to it at once. (e.g. the 97 * periodic 11 min sync from time.c vs. this driver.) 98 */ 99 100 #include <linux/types.h> 101 #include <linux/errno.h> 102 #include <linux/miscdevice.h> 103 #include <linux/slab.h> 104 #include <linux/ioport.h> 105 #include <linux/fcntl.h> 106 #include <linux/mc146818rtc.h> 107 #include <linux/init.h> 108 #include <linux/proc_fs.h> 109 #include <linux/seq_file.h> 110 #include <linux/spinlock.h> 111 #include <linux/io.h> 112 #include <linux/uaccess.h> 113 #include <linux/smp_lock.h> 114 115 #include <asm/system.h> 116 117 static DEFINE_SPINLOCK(nvram_state_lock); 118 static int nvram_open_cnt; /* #times opened */ 119 static int nvram_open_mode; /* special open modes */ 120 #define NVRAM_WRITE 1 /* opened for writing (exclusive) */ 121 #define NVRAM_EXCL 2 /* opened with O_EXCL */ 122 123 static int mach_check_checksum(void); 124 static void mach_set_checksum(void); 125 126 #ifdef CONFIG_PROC_FS 127 static void mach_proc_infos(unsigned char *contents, struct seq_file *seq, 128 void *offset); 129 #endif 130 131 /* 132 * These functions are provided to be called internally or by other parts of 133 * the kernel. It's up to the caller to ensure correct checksum before reading 134 * or after writing (needs to be done only once). 135 * 136 * It is worth noting that these functions all access bytes of general 137 * purpose memory in the NVRAM - that is to say, they all add the 138 * NVRAM_FIRST_BYTE offset. Pass them offsets into NVRAM as if you did not 139 * know about the RTC cruft. 140 */ 141 142 unsigned char __nvram_read_byte(int i) 143 { 144 return CMOS_READ(NVRAM_FIRST_BYTE + i); 145 } 146 EXPORT_SYMBOL(__nvram_read_byte); 147 148 unsigned char nvram_read_byte(int i) 149 { 150 unsigned long flags; 151 unsigned char c; 152 153 spin_lock_irqsave(&rtc_lock, flags); 154 c = __nvram_read_byte(i); 155 spin_unlock_irqrestore(&rtc_lock, flags); 156 return c; 157 } 158 EXPORT_SYMBOL(nvram_read_byte); 159 160 /* This races nicely with trying to read with checksum checking (nvram_read) */ 161 void __nvram_write_byte(unsigned char c, int i) 162 { 163 CMOS_WRITE(c, NVRAM_FIRST_BYTE + i); 164 } 165 EXPORT_SYMBOL(__nvram_write_byte); 166 167 void nvram_write_byte(unsigned char c, int i) 168 { 169 unsigned long flags; 170 171 spin_lock_irqsave(&rtc_lock, flags); 172 __nvram_write_byte(c, i); 173 spin_unlock_irqrestore(&rtc_lock, flags); 174 } 175 EXPORT_SYMBOL(nvram_write_byte); 176 177 int __nvram_check_checksum(void) 178 { 179 return mach_check_checksum(); 180 } 181 EXPORT_SYMBOL(__nvram_check_checksum); 182 183 int nvram_check_checksum(void) 184 { 185 unsigned long flags; 186 int rv; 187 188 spin_lock_irqsave(&rtc_lock, flags); 189 rv = __nvram_check_checksum(); 190 spin_unlock_irqrestore(&rtc_lock, flags); 191 return rv; 192 } 193 EXPORT_SYMBOL(nvram_check_checksum); 194 195 static void __nvram_set_checksum(void) 196 { 197 mach_set_checksum(); 198 } 199 200 #if 0 201 void nvram_set_checksum(void) 202 { 203 unsigned long flags; 204 205 spin_lock_irqsave(&rtc_lock, flags); 206 __nvram_set_checksum(); 207 spin_unlock_irqrestore(&rtc_lock, flags); 208 } 209 #endif /* 0 */ 210 211 /* 212 * The are the file operation function for user access to /dev/nvram 213 */ 214 215 static loff_t nvram_llseek(struct file *file, loff_t offset, int origin) 216 { 217 switch (origin) { 218 case 0: 219 /* nothing to do */ 220 break; 221 case 1: 222 offset += file->f_pos; 223 break; 224 case 2: 225 offset += NVRAM_BYTES; 226 break; 227 } 228 229 return (offset >= 0) ? (file->f_pos = offset) : -EINVAL; 230 } 231 232 static ssize_t nvram_read(struct file *file, char __user *buf, 233 size_t count, loff_t *ppos) 234 { 235 unsigned char contents[NVRAM_BYTES]; 236 unsigned i = *ppos; 237 unsigned char *tmp; 238 239 spin_lock_irq(&rtc_lock); 240 241 if (!__nvram_check_checksum()) 242 goto checksum_err; 243 244 for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp) 245 *tmp = __nvram_read_byte(i); 246 247 spin_unlock_irq(&rtc_lock); 248 249 if (copy_to_user(buf, contents, tmp - contents)) 250 return -EFAULT; 251 252 *ppos = i; 253 254 return tmp - contents; 255 256 checksum_err: 257 spin_unlock_irq(&rtc_lock); 258 return -EIO; 259 } 260 261 static ssize_t nvram_write(struct file *file, const char __user *buf, 262 size_t count, loff_t *ppos) 263 { 264 unsigned char contents[NVRAM_BYTES]; 265 unsigned i = *ppos; 266 unsigned char *tmp; 267 268 if (i >= NVRAM_BYTES) 269 return 0; /* Past EOF */ 270 271 if (count > NVRAM_BYTES - i) 272 count = NVRAM_BYTES - i; 273 if (count > NVRAM_BYTES) 274 return -EFAULT; /* Can't happen, but prove it to gcc */ 275 276 if (copy_from_user(contents, buf, count)) 277 return -EFAULT; 278 279 spin_lock_irq(&rtc_lock); 280 281 if (!__nvram_check_checksum()) 282 goto checksum_err; 283 284 for (tmp = contents; count--; ++i, ++tmp) 285 __nvram_write_byte(*tmp, i); 286 287 __nvram_set_checksum(); 288 289 spin_unlock_irq(&rtc_lock); 290 291 *ppos = i; 292 293 return tmp - contents; 294 295 checksum_err: 296 spin_unlock_irq(&rtc_lock); 297 return -EIO; 298 } 299 300 static int nvram_ioctl(struct inode *inode, struct file *file, 301 unsigned int cmd, unsigned long arg) 302 { 303 int i; 304 305 switch (cmd) { 306 307 case NVRAM_INIT: 308 /* initialize NVRAM contents and checksum */ 309 if (!capable(CAP_SYS_ADMIN)) 310 return -EACCES; 311 312 spin_lock_irq(&rtc_lock); 313 314 for (i = 0; i < NVRAM_BYTES; ++i) 315 __nvram_write_byte(0, i); 316 __nvram_set_checksum(); 317 318 spin_unlock_irq(&rtc_lock); 319 return 0; 320 321 case NVRAM_SETCKS: 322 /* just set checksum, contents unchanged (maybe useful after 323 * checksum garbaged somehow...) */ 324 if (!capable(CAP_SYS_ADMIN)) 325 return -EACCES; 326 327 spin_lock_irq(&rtc_lock); 328 __nvram_set_checksum(); 329 spin_unlock_irq(&rtc_lock); 330 return 0; 331 332 default: 333 return -ENOTTY; 334 } 335 } 336 337 static int nvram_open(struct inode *inode, struct file *file) 338 { 339 spin_lock(&nvram_state_lock); 340 341 if ((nvram_open_cnt && (file->f_flags & O_EXCL)) || 342 (nvram_open_mode & NVRAM_EXCL) || 343 ((file->f_mode & FMODE_WRITE) && (nvram_open_mode & NVRAM_WRITE))) { 344 spin_unlock(&nvram_state_lock); 345 return -EBUSY; 346 } 347 348 if (file->f_flags & O_EXCL) 349 nvram_open_mode |= NVRAM_EXCL; 350 if (file->f_mode & FMODE_WRITE) 351 nvram_open_mode |= NVRAM_WRITE; 352 nvram_open_cnt++; 353 354 spin_unlock(&nvram_state_lock); 355 356 return 0; 357 } 358 359 static int nvram_release(struct inode *inode, struct file *file) 360 { 361 spin_lock(&nvram_state_lock); 362 363 nvram_open_cnt--; 364 365 /* if only one instance is open, clear the EXCL bit */ 366 if (nvram_open_mode & NVRAM_EXCL) 367 nvram_open_mode &= ~NVRAM_EXCL; 368 if (file->f_mode & FMODE_WRITE) 369 nvram_open_mode &= ~NVRAM_WRITE; 370 371 spin_unlock(&nvram_state_lock); 372 373 return 0; 374 } 375 376 #ifndef CONFIG_PROC_FS 377 static int nvram_add_proc_fs(void) 378 { 379 return 0; 380 } 381 382 #else 383 384 static int nvram_proc_read(struct seq_file *seq, void *offset) 385 { 386 unsigned char contents[NVRAM_BYTES]; 387 int i = 0; 388 389 spin_lock_irq(&rtc_lock); 390 for (i = 0; i < NVRAM_BYTES; ++i) 391 contents[i] = __nvram_read_byte(i); 392 spin_unlock_irq(&rtc_lock); 393 394 mach_proc_infos(contents, seq, offset); 395 396 return 0; 397 } 398 399 static int nvram_proc_open(struct inode *inode, struct file *file) 400 { 401 return single_open(file, nvram_proc_read, NULL); 402 } 403 404 static const struct file_operations nvram_proc_fops = { 405 .owner = THIS_MODULE, 406 .open = nvram_proc_open, 407 .read = seq_read, 408 .llseek = seq_lseek, 409 .release = single_release, 410 }; 411 412 static int nvram_add_proc_fs(void) 413 { 414 if (!proc_create("driver/nvram", 0, NULL, &nvram_proc_fops)) 415 return -ENOMEM; 416 return 0; 417 } 418 419 #endif /* CONFIG_PROC_FS */ 420 421 static const struct file_operations nvram_fops = { 422 .owner = THIS_MODULE, 423 .llseek = nvram_llseek, 424 .read = nvram_read, 425 .write = nvram_write, 426 .ioctl = nvram_ioctl, 427 .open = nvram_open, 428 .release = nvram_release, 429 }; 430 431 static struct miscdevice nvram_dev = { 432 NVRAM_MINOR, 433 "nvram", 434 &nvram_fops 435 }; 436 437 static int __init nvram_init(void) 438 { 439 int ret; 440 441 /* First test whether the driver should init at all */ 442 if (!CHECK_DRIVER_INIT()) 443 return -ENODEV; 444 445 ret = misc_register(&nvram_dev); 446 if (ret) { 447 printk(KERN_ERR "nvram: can't misc_register on minor=%d\n", 448 NVRAM_MINOR); 449 goto out; 450 } 451 ret = nvram_add_proc_fs(); 452 if (ret) { 453 printk(KERN_ERR "nvram: can't create /proc/driver/nvram\n"); 454 goto outmisc; 455 } 456 ret = 0; 457 printk(KERN_INFO "Non-volatile memory driver v" NVRAM_VERSION "\n"); 458 out: 459 return ret; 460 outmisc: 461 misc_deregister(&nvram_dev); 462 goto out; 463 } 464 465 static void __exit nvram_cleanup_module(void) 466 { 467 remove_proc_entry("driver/nvram", NULL); 468 misc_deregister(&nvram_dev); 469 } 470 471 module_init(nvram_init); 472 module_exit(nvram_cleanup_module); 473 474 /* 475 * Machine specific functions 476 */ 477 478 #if MACH == PC 479 480 static int pc_check_checksum(void) 481 { 482 int i; 483 unsigned short sum = 0; 484 unsigned short expect; 485 486 for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i) 487 sum += __nvram_read_byte(i); 488 expect = __nvram_read_byte(PC_CKS_LOC)<<8 | 489 __nvram_read_byte(PC_CKS_LOC+1); 490 return (sum & 0xffff) == expect; 491 } 492 493 static void pc_set_checksum(void) 494 { 495 int i; 496 unsigned short sum = 0; 497 498 for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i) 499 sum += __nvram_read_byte(i); 500 __nvram_write_byte(sum >> 8, PC_CKS_LOC); 501 __nvram_write_byte(sum & 0xff, PC_CKS_LOC + 1); 502 } 503 504 #ifdef CONFIG_PROC_FS 505 506 static char *floppy_types[] = { 507 "none", "5.25'' 360k", "5.25'' 1.2M", "3.5'' 720k", "3.5'' 1.44M", 508 "3.5'' 2.88M", "3.5'' 2.88M" 509 }; 510 511 static char *gfx_types[] = { 512 "EGA, VGA, ... (with BIOS)", 513 "CGA (40 cols)", 514 "CGA (80 cols)", 515 "monochrome", 516 }; 517 518 static void pc_proc_infos(unsigned char *nvram, struct seq_file *seq, 519 void *offset) 520 { 521 int checksum; 522 int type; 523 524 spin_lock_irq(&rtc_lock); 525 checksum = __nvram_check_checksum(); 526 spin_unlock_irq(&rtc_lock); 527 528 seq_printf(seq, "Checksum status: %svalid\n", checksum ? "" : "not "); 529 530 seq_printf(seq, "# floppies : %d\n", 531 (nvram[6] & 1) ? (nvram[6] >> 6) + 1 : 0); 532 seq_printf(seq, "Floppy 0 type : "); 533 type = nvram[2] >> 4; 534 if (type < ARRAY_SIZE(floppy_types)) 535 seq_printf(seq, "%s\n", floppy_types[type]); 536 else 537 seq_printf(seq, "%d (unknown)\n", type); 538 seq_printf(seq, "Floppy 1 type : "); 539 type = nvram[2] & 0x0f; 540 if (type < ARRAY_SIZE(floppy_types)) 541 seq_printf(seq, "%s\n", floppy_types[type]); 542 else 543 seq_printf(seq, "%d (unknown)\n", type); 544 545 seq_printf(seq, "HD 0 type : "); 546 type = nvram[4] >> 4; 547 if (type) 548 seq_printf(seq, "%02x\n", type == 0x0f ? nvram[11] : type); 549 else 550 seq_printf(seq, "none\n"); 551 552 seq_printf(seq, "HD 1 type : "); 553 type = nvram[4] & 0x0f; 554 if (type) 555 seq_printf(seq, "%02x\n", type == 0x0f ? nvram[12] : type); 556 else 557 seq_printf(seq, "none\n"); 558 559 seq_printf(seq, "HD type 48 data: %d/%d/%d C/H/S, precomp %d, lz %d\n", 560 nvram[18] | (nvram[19] << 8), 561 nvram[20], nvram[25], 562 nvram[21] | (nvram[22] << 8), nvram[23] | (nvram[24] << 8)); 563 seq_printf(seq, "HD type 49 data: %d/%d/%d C/H/S, precomp %d, lz %d\n", 564 nvram[39] | (nvram[40] << 8), 565 nvram[41], nvram[46], 566 nvram[42] | (nvram[43] << 8), nvram[44] | (nvram[45] << 8)); 567 568 seq_printf(seq, "DOS base memory: %d kB\n", nvram[7] | (nvram[8] << 8)); 569 seq_printf(seq, "Extended memory: %d kB (configured), %d kB (tested)\n", 570 nvram[9] | (nvram[10] << 8), nvram[34] | (nvram[35] << 8)); 571 572 seq_printf(seq, "Gfx adapter : %s\n", 573 gfx_types[(nvram[6] >> 4) & 3]); 574 575 seq_printf(seq, "FPU : %sinstalled\n", 576 (nvram[6] & 2) ? "" : "not "); 577 578 return; 579 } 580 #endif 581 582 #endif /* MACH == PC */ 583 584 #if MACH == ATARI 585 586 static int atari_check_checksum(void) 587 { 588 int i; 589 unsigned char sum = 0; 590 591 for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i) 592 sum += __nvram_read_byte(i); 593 return (__nvram_read_byte(ATARI_CKS_LOC) == (~sum & 0xff)) && 594 (__nvram_read_byte(ATARI_CKS_LOC + 1) == (sum & 0xff)); 595 } 596 597 static void atari_set_checksum(void) 598 { 599 int i; 600 unsigned char sum = 0; 601 602 for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i) 603 sum += __nvram_read_byte(i); 604 __nvram_write_byte(~sum, ATARI_CKS_LOC); 605 __nvram_write_byte(sum, ATARI_CKS_LOC + 1); 606 } 607 608 #ifdef CONFIG_PROC_FS 609 610 static struct { 611 unsigned char val; 612 char *name; 613 } boot_prefs[] = { 614 { 0x80, "TOS" }, 615 { 0x40, "ASV" }, 616 { 0x20, "NetBSD (?)" }, 617 { 0x10, "Linux" }, 618 { 0x00, "unspecified" } 619 }; 620 621 static char *languages[] = { 622 "English (US)", 623 "German", 624 "French", 625 "English (UK)", 626 "Spanish", 627 "Italian", 628 "6 (undefined)", 629 "Swiss (French)", 630 "Swiss (German)" 631 }; 632 633 static char *dateformat[] = { 634 "MM%cDD%cYY", 635 "DD%cMM%cYY", 636 "YY%cMM%cDD", 637 "YY%cDD%cMM", 638 "4 (undefined)", 639 "5 (undefined)", 640 "6 (undefined)", 641 "7 (undefined)" 642 }; 643 644 static char *colors[] = { 645 "2", "4", "16", "256", "65536", "??", "??", "??" 646 }; 647 648 static void atari_proc_infos(unsigned char *nvram, struct seq_file *seq, 649 void *offset) 650 { 651 int checksum = nvram_check_checksum(); 652 int i; 653 unsigned vmode; 654 655 seq_printf(seq, "Checksum status : %svalid\n", checksum ? "" : "not "); 656 657 seq_printf(seq, "Boot preference : "); 658 for (i = ARRAY_SIZE(boot_prefs) - 1; i >= 0; --i) { 659 if (nvram[1] == boot_prefs[i].val) { 660 seq_printf(seq, "%s\n", boot_prefs[i].name); 661 break; 662 } 663 } 664 if (i < 0) 665 seq_printf(seq, "0x%02x (undefined)\n", nvram[1]); 666 667 seq_printf(seq, "SCSI arbitration : %s\n", 668 (nvram[16] & 0x80) ? "on" : "off"); 669 seq_printf(seq, "SCSI host ID : "); 670 if (nvram[16] & 0x80) 671 seq_printf(seq, "%d\n", nvram[16] & 7); 672 else 673 seq_printf(seq, "n/a\n"); 674 675 /* the following entries are defined only for the Falcon */ 676 if ((atari_mch_cookie >> 16) != ATARI_MCH_FALCON) 677 return; 678 679 seq_printf(seq, "OS language : "); 680 if (nvram[6] < ARRAY_SIZE(languages)) 681 seq_printf(seq, "%s\n", languages[nvram[6]]); 682 else 683 seq_printf(seq, "%u (undefined)\n", nvram[6]); 684 seq_printf(seq, "Keyboard language: "); 685 if (nvram[7] < ARRAY_SIZE(languages)) 686 seq_printf(seq, "%s\n", languages[nvram[7]]); 687 else 688 seq_printf(seq, "%u (undefined)\n", nvram[7]); 689 seq_printf(seq, "Date format : "); 690 seq_printf(seq, dateformat[nvram[8] & 7], 691 nvram[9] ? nvram[9] : '/', nvram[9] ? nvram[9] : '/'); 692 seq_printf(seq, ", %dh clock\n", nvram[8] & 16 ? 24 : 12); 693 seq_printf(seq, "Boot delay : "); 694 if (nvram[10] == 0) 695 seq_printf(seq, "default"); 696 else 697 seq_printf(seq, "%ds%s\n", nvram[10], 698 nvram[10] < 8 ? ", no memory test" : ""); 699 700 vmode = (nvram[14] << 8) || nvram[15]; 701 seq_printf(seq, 702 "Video mode : %s colors, %d columns, %s %s monitor\n", 703 colors[vmode & 7], 704 vmode & 8 ? 80 : 40, 705 vmode & 16 ? "VGA" : "TV", vmode & 32 ? "PAL" : "NTSC"); 706 seq_printf(seq, " %soverscan, compat. mode %s%s\n", 707 vmode & 64 ? "" : "no ", 708 vmode & 128 ? "on" : "off", 709 vmode & 256 ? 710 (vmode & 16 ? ", line doubling" : ", half screen") : ""); 711 712 return; 713 } 714 #endif 715 716 #endif /* MACH == ATARI */ 717 718 MODULE_LICENSE("GPL"); 719 MODULE_ALIAS_MISCDEV(NVRAM_MINOR); 720