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1/*␊
2 * Copyright (c) 1999-2003 Apple Computer, Inc. All rights reserved.␊
3 *␊
4 * @APPLE_LICENSE_HEADER_START@␊
5 * ␊
6 * Portions Copyright (c) 1999-2003 Apple Computer, Inc. All Rights␊
7 * Reserved. This file contains Original Code and/or Modifications of␊
8 * Original Code as defined in and that are subject to the Apple Public␊
9 * Source License Version 2.0 (the "License"). You may not use this file␊
10 * except in compliance with the License. Please obtain a copy of the␊
11 * License at http://www.apple.com/publicsource and read it before using␊
12 * this file.␊
13 * ␊
14 * The Original Code and all software distributed under the License are␊
15 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER␊
16 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,␊
17 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,␊
18 * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT. Please see the␊
19 * License for the specific language governing rights and limitations␊
20 * under the License.␊
21 * ␊
22 * @APPLE_LICENSE_HEADER_END@␊
23 */␊
24/* ␊
25 * Mach Operating System␊
26 * Copyright (c) 1990 Carnegie-Mellon University␊
27 * Copyright (c) 1989 Carnegie-Mellon University␊
28 * All rights reserved. The CMU software License Agreement specifies␊
29 * the terms and conditions for use and redistribution.␊
30 */␊
31␊
32/*␊
33 * INTEL CORPORATION PROPRIETARY INFORMATION␊
34 *␊
35 * This software is supplied under the terms of a license agreement or ␊
36 * nondisclosure agreement with Intel Corporation and may not be copied ␊
37 * nor disclosed except in accordance with the terms of that agreement.␊
38 *␊
39 * Copyright 1988, 1989 by Intel Corporation␊
40 */␊
41␊
42/*␊
43 * Copyright 1993 NeXT Computer, Inc.␊
44 * All rights reserved.␊
45 */␊
46 ␊
47/*␊
48 * Completely reworked by Sam Streeper (sam_s@NeXT.com)␊
49 * Reworked again by Curtis Galloway (galloway@NeXT.com)␊
50 */␊
51␊
52␊
53#include "boot.h"␊
54#include "bootstruct.h"␊
55#include "fake_efi.h"␊
56#include "sl.h"␊
57#include "libsa.h"␊
58#include "ramdisk.h"␊
59#include "gui.h"␊
60#include "platform.h"␊
61␊
62long gBootMode; /* defaults to 0 == kBootModeNormal */␊
63bool gOverrideKernel;␊
64static char gBootKernelCacheFile[512];␊
65static char gCacheNameAdler[64 + 256];␊
66char *gPlatformName = gCacheNameAdler;␊
67char gRootDevice[512];␊
68char gMKextName[512];␊
69char gMacOSVersion[8];␊
70bool gEnableCDROMRescan;␊
71bool gScanSingleDrive;␊
72␊
73int bvCount = 0;␊
74//int␉␉menucount = 0;␊
75int gDeviceCount = 0; ␊
76␊
77BVRef bvr;␊
78BVRef menuBVR;␊
79BVRef bvChain;␊
80bool useGUI;␊
81␊
82//static void selectBiosDevice(void);␊
83static unsigned long Adler32(unsigned char *buffer, long length);␊
84␊
85␊
86static bool gUnloadPXEOnExit = false;␊
87␊
88/*␊
89 * How long to wait (in seconds) to load the␊
90 * kernel after displaying the "boot:" prompt.␊
91 */␊
92#define kBootErrorTimeout 5␊
93␊
94/*␊
95 * Default path to kernel cache file␊
96 */␊
97#define kDefaultCachePath "/System/Library/Caches/com.apple.kernelcaches/kernelcache"␊
98␊
99//==========================================================================␊
100// Zero the BSS.␊
101␊
102static void zeroBSS(void)␊
103{␊
104␉extern char _DATA__bss__begin, _DATA__bss__end;␊
105␉extern char _DATA__common__begin, _DATA__common__end;␊
106␊
107␉bzero(&_DATA__bss__begin, (&_DATA__bss__end - &_DATA__bss__begin));␊
108␉bzero(&_DATA__common__begin, (&_DATA__common__end - &_DATA__common__begin));␊
109}␊
110␊
111//==========================================================================␊
112// Malloc error function␊
113␊
114static void malloc_error(char *addr, size_t size, const char *file, int line)␊
115{␊
116␉stop("\nMemory allocation error! Addr=0x%x, Size=0x%x, File=%s, Line=%d\n", (unsigned)addr, (unsigned)size, file, line);␊
117}␊
118␊
119//==========================================================================␊
120//Initializes the runtime. Right now this means zeroing the BSS and initializing malloc.␊
121//␊
122void initialize_runtime(void)␊
123{␊
124␉zeroBSS();␊
125␉malloc_init(0, 0, 0, malloc_error);␊
126}␊
127␊
128//==========================================================================␊
129// execKernel - Load the kernel image (mach-o) and jump to its entry point.␊
130␊
131static int ExecKernel(void *binary)␊
132{␊
133 entry_t kernelEntry;␊
134 int ret;␊
135␊
136 bootArgs->kaddr = bootArgs->ksize = 0;␊
137␊
138 ret = DecodeKernel(binary,␊
139 &kernelEntry,␊
140 (char **) &bootArgs->kaddr,␊
141 (int *)&bootArgs->ksize );␊
142␊
143 if ( ret != 0 )␊
144 return ret;␊
145␊
146 // Reserve space for boot args␊
147 reserveKernBootStruct();␊
148␊
149 // Load boot drivers from the specifed root path.␊
150␊
151 if (!gHaveKernelCache) {␊
152 LoadDrivers("/");␊
153 }␊
154␊
155 clearActivityIndicator();␊
156␊
157 if (gErrors) {␊
158 printf("Errors encountered while starting up the computer.\n");␊
159 printf("Pausing %d seconds...\n", kBootErrorTimeout);␊
160 sleep(kBootErrorTimeout);␊
161 }␊
162␊
163 setupFakeEfi();␊
164␊
165 md0Ramdisk();␊
166␊
167 verbose("Starting Darwin %s\n",( archCpuType == CPU_TYPE_I386 ) ? "x86" : "x86_64");␊
168␊
169 // Cleanup the PXE base code.␊
170␊
171 if ( (gBootFileType == kNetworkDeviceType) && gUnloadPXEOnExit ) {␊
172␉␉if ( (ret = nbpUnloadBaseCode()) != nbpStatusSuccess )␊
173 {␊
174 ␉printf("nbpUnloadBaseCode error %d\n", (int) ret);␊
175 sleep(2);␊
176 }␊
177 }␊
178␊
179 bool dummyVal;␊
180␉if (getBoolForKey(kWaitForKeypressKey, &dummyVal, &bootInfo->bootConfig) && dummyVal) {␊
181␉␉printf("Press any key to continue...");␊
182␉␉getc();␊
183␉}␊
184␊
185␉usb_loop();␊
186␊
187 // If we were in text mode, switch to graphics mode.␊
188 // This will draw the boot graphics unless we are in␊
189 // verbose mode.␊
190␊
191 if(gVerboseMode)␊
192 setVideoMode( GRAPHICS_MODE, 0 );␊
193 else␊
194 drawBootGraphics();␊
195␉␊
196 finalizeBootStruct();␊
197 ␊
198 // Jump to kernel's entry point. There's no going back now.␊
199␊
200 startprog( kernelEntry, bootArgs );␊
201␊
202 // Not reached␊
203␊
204 return 0;␊
205}␊
206␊
207//==========================================================================␊
208// This is the entrypoint from real-mode which functions exactly as it did␊
209// before. Multiboot does its own runtime initialization, does some of its␊
210// own things, and then calls common_boot.␊
211void boot(int biosdev)␊
212{␊
213␉initialize_runtime();␊
214␉// Enable A20 gate before accessing memory above 1Mb.␊
215␉enableA20();␊
216␉common_boot(biosdev);␊
217}␊
218␊
219//==========================================================================␊
220// The 'main' function for the booter. Called by boot0 when booting␊
221// from a block device, or by the network booter.␊
222//␊
223// arguments:␊
224// biosdev - Value passed from boot1/NBP to specify the device␊
225// that the booter was loaded from.␊
226//␊
227// If biosdev is kBIOSDevNetwork, then this function will return if␊
228// booting was unsuccessful. This allows the PXE firmware to try the␊
229// next boot device on its list.␊
230void common_boot(int biosdev)␊
231{␊
232 int status;␊
233 char *bootFile;␊
234 unsigned long adler32;␊
235 bool quiet;␊
236 bool firstRun = true;␊
237 bool instantMenu;␊
238 bool rescanPrompt;␊
239 unsigned int allowBVFlags = kBVFlagSystemVolume|kBVFlagForeignBoot;␊
240 unsigned int denyBVFlags = kBVFlagEFISystem;␊
241␊
242 // Set reminder to unload the PXE base code. Neglect to unload␊
243 // the base code will result in a hang or kernel panic.␊
244 gUnloadPXEOnExit = true;␊
245␊
246 // Record the device that the booter was loaded from.␊
247 gBIOSDev = biosdev & kBIOSDevMask;␊
248␊
249 // Initialize boot info structure.␊
250 initKernBootStruct();␊
251␊
252 // Setup VGA text mode.␊
253 // Not sure if it is safe to call setVideoMode() before the␊
254 // config table has been loaded. Call video_mode() instead.␊
255#if DEBUG␊
256 printf("before video_mode\n");␊
257#endif␊
258 video_mode( 2 ); // 80x25 mono text mode.␊
259#if DEBUG␊
260 printf("after video_mode\n");␊
261#endif␊
262␊
263 // Scan and record the system's hardware information.␊
264 scan_platform();␊
265␊
266 // First get info for boot volume.␊
267 scanBootVolumes(gBIOSDev, 0);␊
268 bvChain = getBVChainForBIOSDev(gBIOSDev);␊
269 setBootGlobals(bvChain);␊
270 ␊
271 // Load boot.plist config file␊
272 status = loadSystemConfig(&bootInfo->bootConfig);␊
273␊
274 if (getBoolForKey(kQuietBootKey, &quiet, &bootInfo->bootConfig) && quiet) {␊
275 gBootMode |= kBootModeQuiet;␊
276 }␊
277␊
278 // Override firstRun to get to the boot menu instantly by setting "Instant Menu"=y in system config␊
279 if (getBoolForKey(kInsantMenuKey, &instantMenu, &bootInfo->bootConfig) && instantMenu) {␊
280 firstRun = false;␊
281 }␊
282␊
283 // Loading preboot ramdisk if exists.␊
284 loadPrebootRAMDisk();␊
285␊
286 // Disable rescan option by default␊
287 gEnableCDROMRescan = false;␊
288␊
289 // Enable it with Rescan=y in system config␊
290 if (getBoolForKey(kRescanKey, &gEnableCDROMRescan, &bootInfo->bootConfig) && gEnableCDROMRescan) {␊
291 gEnableCDROMRescan = true;␊
292 }␊
293␊
294 // Ask the user for Rescan option by setting "Rescan Prompt"=y in system config.␊
295 rescanPrompt = false;␊
296 if (getBoolForKey(kRescanPromptKey, &rescanPrompt , &bootInfo->bootConfig) && rescanPrompt && biosDevIsCDROM(gBIOSDev)) {␊
297 gEnableCDROMRescan = promptForRescanOption();␊
298 }␊
299␊
300 // Enable touching a single BIOS device only if "Scan Single Drive"=y is set in system config.␊
301 if (getBoolForKey(kScanSingleDriveKey, &gScanSingleDrive, &bootInfo->bootConfig) && gScanSingleDrive) {␊
302 gScanSingleDrive = true;␊
303 }␊
304␊
305 // Create a list of partitions on device(s).␊
306 if (gScanSingleDrive) {␊
307 scanBootVolumes(gBIOSDev, &bvCount);␊
308 } else {␊
309 scanDisks(gBIOSDev, &bvCount);␊
310 }␊
311␊
312 // Create a separated bvr chain using the specified filters.␊
313 bvChain = newFilteredBVChain(0x80, 0xFF, allowBVFlags, denyBVFlags, &gDeviceCount);␊
314␊
315 gBootVolume = selectBootVolume(bvChain);␊
316␊
317#if DEBUG␊
318 printf(" Default: %d, ->biosdev: %d, ->part_no: %d ->flags: %d\n", gBootVolume, gBootVolume->biosdev, gBootVolume->part_no, gBootVolume->flags);␊
319 printf(" bt(0,0): %d, ->biosdev: %d, ->part_no: %d ->flags: %d\n", gBIOSBootVolume, gBIOSBootVolume->biosdev, gBIOSBootVolume->part_no, gBIOSBootVolume->flags);␊
320 getc();␊
321#endif␊
322␊
323␉useGUI = true;␊
324␉// Override useGUI default␊
325␉getBoolForKey(kGUIKey, &useGUI, &bootInfo->bootConfig);␊
326␉if (useGUI && initGUI())␊
327␉{␊
328␉␉// initGUI() returned with an error, disabling GUI.␊
329␉␉useGUI = false;␊
330␉}␊
331␊
332 setBootGlobals(bvChain);␊
333␊
334 // Parse args, load and start kernel.␊
335 while (1) {␊
336 const char *val;␊
337 int len;␊
338 int trycache;␊
339 long flags, cachetime, kerneltime, exttime, sleeptime, time;␊
340 int ret = -1;␊
341 void *binary = (void *)kLoadAddr;␊
342 bool tryresume;␊
343 bool tryresumedefault;␊
344 bool forceresume;␊
345␊
346 config_file_t systemVersion;␉␉// system.plist of booting partition␊
347␊
348 // additional variable for testing alternate kernel image locations on boot helper partitions.␊
349 char bootFileSpec[512];␊
350␉␉␊
351 // Initialize globals.␊
352␊
353 sysConfigValid = false;␊
354 gErrors = false;␊
355␊
356 status = getBootOptions(firstRun);␊
357 firstRun = false;␊
358 if (status == -1) continue;␊
359␉␉ ␊
360 status = processBootOptions();␊
361 // Status==1 means to chainboot␊
362 if ( status == 1 ) break;␊
363 // Status==-1 means that the config file couldn't be loaded or that gBootVolume is NULL␊
364 if ( status == -1 )␊
365 {␊
366 // gBootVolume == NULL usually means the user hit escape.␊
367 if(gBootVolume == NULL)␊
368 {␊
369 freeFilteredBVChain(bvChain);␊
370␊
371 if (gEnableCDROMRescan)␊
372 rescanBIOSDevice(gBIOSDev);␊
373 ␊
374 bvChain = newFilteredBVChain(0x80, 0xFF, allowBVFlags, denyBVFlags, &gDeviceCount);␊
375 setBootGlobals(bvChain);␊
376 }␊
377 continue;␊
378 }␊
379␉␉␊
380 // Other status (e.g. 0) means that we should proceed with boot.␊
381␉␉␊
382␉␉// Turn off any GUI elements␊
383␉␉if( bootArgs->Video.v_display == GRAPHICS_MODE )␊
384␉␉{␊
385␉␉␉gui.devicelist.draw = false;␊
386␉␉␉gui.bootprompt.draw = false;␊
387␉␉␉gui.menu.draw = false;␊
388␉␉␉gui.infobox.draw = false;␊
389␉␉␉gui.logo.draw = false;␊
390␉␉␉drawBackground();␊
391␉␉␉updateVRAM();␊
392␉␉}␊
393␉␉␊
394␉␉// Find out which version mac os we're booting.␊
395␉␉if (!loadConfigFile("System/Library/CoreServices/SystemVersion.plist", &systemVersion)) {␊
396␉␉␉if (getValueForKey(kProductVersion, &val, &len, &systemVersion)) {␉␊
397␉␉␉␉// getValueForKey uses const char for val␊
398␉␉␉␉// so copy it and trim␊
399␉␉␉␉strncpy(gMacOSVersion, val, MIN(len, 4));␊
400␉␉␉␉gMacOSVersion[MIN(len, 4)] = '\0';␊
401␉␉␉}␊
402␉␉}␊
403␊
404␉␉if (platformCPUFeature(CPU_FEATURE_EM64T)) {␊
405␉␉␉archCpuType = CPU_TYPE_X86_64;␊
406␉␉} else {␊
407␉␉␉archCpuType = CPU_TYPE_I386;␊
408␉␉}␊
409␉␉if (getValueForKey(karch, &val, &len, &bootInfo->bootConfig)) {␊
410␉␉␉if (strncmp(val, "i386", 4) == 0) {␊
411␉␉␉␉archCpuType = CPU_TYPE_I386;␊
412␉␉␉}␊
413␉␉}␊
414␉␉if (getValueForKey(k32BitModeFlag, &val, &len, &bootInfo->bootConfig)) {␊
415␉␉␉archCpuType = CPU_TYPE_I386;␊
416␉␉}␊
417␉␉␊
418␉␉if (!getBoolForKey (kWake, &tryresume, &bootInfo->bootConfig)) {␊
419␉␉␉tryresume = true;␊
420␉␉␉tryresumedefault = true;␊
421␉␉} else {␊
422␉␉␉tryresumedefault = false;␊
423␉␉}␊
424␊
425␉␉if (!getBoolForKey (kForceWake, &forceresume, &bootInfo->bootConfig)) {␊
426␉␉␉forceresume = false;␊
427␉␉}␊
428␉␉␊
429␉␉if (forceresume) {␊
430␉␉␉tryresume = true;␊
431␉␉␉tryresumedefault = false;␊
432␉␉}␊
433␉␉␊
434␉␉while (tryresume) {␊
435␉␉␉const char *tmp;␊
436␉␉␉BVRef bvr;␊
437␉␉␉if (!getValueForKey(kWakeImage, &val, &len, &bootInfo->bootConfig))␊
438␉␉␉␉val="/private/var/vm/sleepimage";␊
439␉␉␉␊
440␉␉␉// Do this first to be sure that root volume is mounted␊
441␉␉␉ret = GetFileInfo(0, val, &flags, &sleeptime);␊
442␊
443␉␉␉if ((bvr = getBootVolumeRef(val, &tmp)) == NULL)␊
444␉␉␉␉break;␊
445␉␉␉␊
446␉␉␉// Can't check if it was hibernation Wake=y is required␊
447␉␉␉if (bvr->modTime == 0 && tryresumedefault)␊
448␉␉␉␉break;␊
449␉␉␉␊
450␉␉␉if ((ret != 0) || ((flags & kFileTypeMask) != kFileTypeFlat))␊
451␉␉␉␉break;␊
452␉␉␉␊
453␉␉␉if (!forceresume && ((sleeptime+3)<bvr->modTime)) {␊
454␉␉␉␉printf ("Hibernate image is too old by %d seconds. Use ForceWake=y to override\n",bvr->modTime-sleeptime);␊
455␉␉␉␉break;␊
456␉␉␉}␊
457␉␉␉␉␊
458␉␉␉HibernateBoot((char *)val);␊
459␉␉␉break;␊
460␉␉}␊
461␊
462 // Reset cache name.␊
463 bzero(gCacheNameAdler + 64, sizeof(gCacheNameAdler) - 64);␊
464␊
465 sprintf(gCacheNameAdler + 64, "%s,%s", gRootDevice, bootInfo->bootFile);␊
466␊
467 adler32 = Adler32((unsigned char *)gCacheNameAdler, sizeof(gCacheNameAdler));␊
468␊
469 if (getValueForKey(kKernelCacheKey, &val, &len, &bootInfo->bootConfig)) {␊
470 strlcpy(gBootKernelCacheFile, val, len+1);␊
471 } else {␊
472 sprintf(gBootKernelCacheFile, "%s.%08lX", kDefaultCachePath, adler32);␊
473 }␊
474␊
475 // Check for cache file.␊
476 trycache = (((gBootMode & kBootModeSafe) == 0) &&␊
477 !gOverrideKernel &&␊
478 (gBootFileType == kBlockDeviceType) &&␊
479 (gMKextName[0] == '\0') &&␊
480 (gBootKernelCacheFile[0] != '\0'));␊
481␊
482␉␉verbose("Loading Darwin %s\n", gMacOSVersion);␊
483␉␉␊
484 if (trycache) do {␊
485 ␊
486 // if we haven't found the kernel yet, don't use the cache␊
487 ret = GetFileInfo(NULL, bootInfo->bootFile, &flags, &kerneltime);␊
488 if ((ret != 0) || ((flags & kFileTypeMask) != kFileTypeFlat)) {␊
489 trycache = 0;␊
490 break;␊
491 }␊
492 ret = GetFileInfo(NULL, gBootKernelCacheFile, &flags, &cachetime);␊
493 if ((ret != 0) || ((flags & kFileTypeMask) != kFileTypeFlat)␊
494 || (cachetime < kerneltime)) {␊
495 trycache = 0;␊
496 break;␊
497 }␊
498 ret = GetFileInfo("/System/Library/", "Extensions", &flags, &exttime);␊
499 if ((ret == 0) && ((flags & kFileTypeMask) == kFileTypeDirectory)␊
500 && (cachetime < exttime)) {␊
501 trycache = 0;␊
502 break;␊
503 }␊
504 if (kerneltime > exttime) {␊
505 exttime = kerneltime;␊
506 }␊
507 if (cachetime != (exttime + 1)) {␊
508 trycache = 0;␊
509 break;␊
510 }␊
511 } while (0);␊
512␊
513 do {␊
514 if (trycache) {␊
515 bootFile = gBootKernelCacheFile;␊
516 verbose("Loading kernel cache %s\n", bootFile);␊
517 ret = LoadFile(bootFile);␊
518 binary = (void *)kLoadAddr;␊
519 if (ret >= 0) {␊
520 break;␊
521 }␊
522 }␊
523 bootFile = bootInfo->bootFile;␊
524␊
525 // Try to load kernel image from alternate locations on boot helper partitions.␊
526 sprintf(bootFileSpec, "com.apple.boot.P/%s", bootFile);␊
527 ret = GetFileInfo(NULL, bootFileSpec, &flags, &time); ␊
528 ␉ ␉ if (ret == -1)␊
529 ␉ ␉ {␊
530 sprintf(bootFileSpec, "com.apple.boot.R/%s", bootFile);␊
531 ret = GetFileInfo(NULL, bootFileSpec, &flags, &time); ␊
532 if (ret == -1)␊
533 {␊
534 sprintf(bootFileSpec, "com.apple.boot.S/%s", bootFile);␊
535 ret = GetFileInfo(NULL, bootFileSpec, &flags, &time); ␊
536 if (ret == -1)␊
537 {␊
538 // Not found any alternate locations, using the original kernel image path.␊
539 strcpy(bootFileSpec, bootFile);␊
540 }␊
541 }␊
542 }␊
543 ␉␉␉␊
544 verbose("Loading kernel %s\n", bootFileSpec);␊
545 ret = LoadThinFatFile(bootFileSpec, &binary);␊
546 if (ret <= 0 && archCpuType == CPU_TYPE_X86_64)␊
547 {␊
548 archCpuType = CPU_TYPE_I386;␊
549 ret = LoadThinFatFile(bootFileSpec, &binary);␉␉␉␉␊
550 }␊
551␉␉␉␊
552 } while (0);␊
553␊
554 clearActivityIndicator();␊
555#if DEBUG␊
556 printf("Pausing...");␊
557 sleep(8);␊
558#endif␊
559␊
560 if (ret <= 0) {␊
561␉␉␉printf("Can't find %s\n", bootFile);␊
562␊
563␉␉␉sleep(1);␊
564␊
565 if (gBootFileType == kNetworkDeviceType) {␊
566 // Return control back to PXE. Don't unload PXE base code.␊
567 gUnloadPXEOnExit = false;␊
568 break;␊
569 }␊
570 } else {␊
571 /* Won't return if successful. */␊
572 ret = ExecKernel(binary);␊
573 }␊
574 }␊
575 ␊
576 // chainboot␊
577 if (status==1) {␊
578␉if (getVideoMode() == GRAPHICS_MODE) {␉// if we are already in graphics-mode,␊
579␉␉setVideoMode(VGA_TEXT_MODE, 0);␉// switch back to text mode␊
580␉}␊
581 }␊
582␉␊
583 if ((gBootFileType == kNetworkDeviceType) && gUnloadPXEOnExit) {␊
584␉nbpUnloadBaseCode();␊
585 }␊
586}␊
587␊
588/*!␊
589 Selects a new BIOS device, taking care to update the global state appropriately.␊
590 */␊
591/*␊
592static void selectBiosDevice(void)␊
593{␊
594 struct DiskBVMap *oldMap = diskResetBootVolumes(gBIOSDev);␊
595 CacheReset();␊
596 diskFreeMap(oldMap);␊
597 oldMap = NULL;␊
598␊
599 int dev = selectAlternateBootDevice(gBIOSDev);␊
600␊
601 BVRef bvchain = scanBootVolumes(dev, 0);␊
602 BVRef bootVol = selectBootVolume(bvchain);␊
603 gBootVolume = bootVol;␊
604 setRootVolume(bootVol);␊
605 gBIOSDev = dev;␊
606}␊
607*/␊
608␊
609#define BASE 65521L /* largest prime smaller than 65536 */␊
610#define NMAX 5000␊
611// NMAX (was 5521) the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1␊
612␊
613#define DO1(buf,i) {s1 += buf[i]; s2 += s1;}␊
614#define DO2(buf,i) DO1(buf,i); DO1(buf,i+1);␊
615#define DO4(buf,i) DO2(buf,i); DO2(buf,i+2);␊
616#define DO8(buf,i) DO4(buf,i); DO4(buf,i+4);␊
617#define DO16(buf) DO8(buf,0); DO8(buf,8);␊
618␊
619unsigned long Adler32(unsigned char *buf, long len)␊
620{␊
621 unsigned long s1 = 1; // adler & 0xffff;␊
622 unsigned long s2 = 0; // (adler >> 16) & 0xffff;␊
623 unsigned long result;␊
624 int k;␊
625␊
626 while (len > 0) {␊
627 k = len < NMAX ? len : NMAX;␊
628 len -= k;␊
629 while (k >= 16) {␊
630 DO16(buf);␊
631 buf += 16;␊
632 k -= 16;␊
633 }␊
634 if (k != 0) do {␊
635 s1 += *buf++;␊
636 s2 += s1;␊
637 } while (--k);␊
638 s1 %= BASE;␊
639 s2 %= BASE;␊
640 }␊
641 result = (s2 << 16) | s1;␊
642 return OSSwapHostToBigInt32(result);␊
643}␊
644

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