arch/powerpc/platforms/powermac/bootx_init.c

   1 /*
   2  *  Early boot support code for BootX bootloader
   3  *
   4  *  Copyright (C) 2005 Ben. Herrenschmidt (benh@kernel.crashing.org)
   5  *
   6  *  This program is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU General Public License
   8  *  as published by the Free Software Foundation; either version
   9  *  2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/string.h>
  14 #include <linux/init.h>
  15 #include <generated/utsrelease.h>
  16 #include <asm/sections.h>
  17 #include <asm/prom.h>
  18 #include <asm/page.h>
  19 #include <asm/bootx.h>
  20 #include <asm/btext.h>
  21 #include <asm/io.h>
  22 #include <asm/setup.h>
  23
  24 #undef DEBUG
  25 #define SET_BOOT_BAT
  26
  27 #ifdef DEBUG
  28 #define DBG(fmt...) do { bootx_printf(fmt); } while(0)
  29 #else
  30 #define DBG(fmt...) do { } while(0)
  31 #endif
  32
  33 extern void __start(unsigned long r3, unsigned long r4, unsigned long r5);
  34
  35 static unsigned long __initdata bootx_dt_strbase;
  36 static unsigned long __initdata bootx_dt_strend;
  37 static unsigned long __initdata bootx_node_chosen;
  38 static boot_infos_t * __initdata bootx_info;
  39 static char __initdata bootx_disp_path[256];
  40
  41 /* Is boot-info compatible ? */
  42 #define BOOT_INFO_IS_COMPATIBLE(bi) \
  43         ((bi)->compatible_version <= BOOT_INFO_VERSION)
  44 #define BOOT_INFO_IS_V2_COMPATIBLE(bi)  ((bi)->version >= 2)
  45 #define BOOT_INFO_IS_V4_COMPATIBLE(bi)  ((bi)->version >= 4)
  46
  47 #ifdef CONFIG_BOOTX_TEXT
  48 static void __init bootx_printf(const char *format, ...)
  49 {
  50         const char *p, *q, *s;
  51         va_list args;
  52         unsigned long v;
  53
  54         va_start(args, format);
  55         for (p = format; *p != 0; p = q) {
  56                 for (q = p; *q != 0 && *q != '\n' && *q != '%'; ++q)
  57                         ;
  58                 if (q > p)
  59                         btext_drawtext(p, q - p);
  60                 if (*q == 0)
  61                         break;
  62                 if (*q == '\n') {
  63                         ++q;
  64                         btext_flushline();
  65                         btext_drawstring("\r\n");
  66                         btext_flushline();
  67                         continue;
  68                 }
  69                 ++q;
  70                 if (*q == 0)
  71                         break;
  72                 switch (*q) {
  73                 case 's':
  74                         ++q;
  75                         s = va_arg(args, const char *);
  76                         if (s == NULL)
  77                                 s = "<NULL>";
  78                         btext_drawstring(s);
  79                         break;
  80                 case 'x':
  81                         ++q;
  82                         v = va_arg(args, unsigned long);
  83                         btext_drawhex(v);
  84                         break;
  85                 }
  86         }
  87 }
  88 #else /* CONFIG_BOOTX_TEXT */
  89 static void __init bootx_printf(const char *format, ...) {}
  90 #endif /* CONFIG_BOOTX_TEXT */
  91
  92 static void * __init bootx_early_getprop(unsigned long base,
  93                                          unsigned long node,
  94                                          char *prop)
  95 {
  96         struct bootx_dt_node *np = (struct bootx_dt_node *)(base + node);
  97         u32 *ppp = &np->properties;
  98
  99         while(*ppp) {
 100                 struct bootx_dt_prop *pp =
 101                         (struct bootx_dt_prop *)(base + *ppp);
 102
 103                 if (strcmp((char *)((unsigned long)pp->name + base),
 104                            prop) == 0) {
 105                         return (void *)((unsigned long)pp->value + base);
 106                 }
 107                 ppp = &pp->next;
 108         }
 109         return NULL;
 110 }
 111
 112 #define dt_push_token(token, mem) \
 113         do { \
 114                 *(mem) = _ALIGN_UP(*(mem),4); \
 115                 *((u32 *)*(mem)) = token; \
 116                 *(mem) += 4; \
 117         } while(0)
 118
 119 static unsigned long __init bootx_dt_find_string(char *str)
 120 {
 121         char *s, *os;
 122
 123         s = os = (char *)bootx_dt_strbase;
 124         s += 4;
 125         while (s <  (char *)bootx_dt_strend) {
 126                 if (strcmp(s, str) == 0)
 127                         return s - os;
 128                 s += strlen(s) + 1;
 129         }
 130         return 0;
 131 }
 132
 133 static void __init bootx_dt_add_prop(char *name, void *data, int size,
 134                                   unsigned long *mem_end)
 135 {
 136         unsigned long soff = bootx_dt_find_string(name);
 137         if (data == NULL)
 138                 size = 0;
 139         if (soff == 0) {
 140                 bootx_printf("WARNING: Can't find string index for <%s>\n",
 141                              name);
 142                 return;
 143         }
 144         if (size > 0x20000) {
 145                 bootx_printf("WARNING: ignoring large property ");
 146                 bootx_printf("%s length 0x%x\n", name, size);
 147                 return;
 148         }
 149         dt_push_token(OF_DT_PROP, mem_end);
 150         dt_push_token(size, mem_end);
 151         dt_push_token(soff, mem_end);
 152
 153         /* push property content */
 154         if (size && data) {
 155                 memcpy((void *)*mem_end, data, size);
 156                 *mem_end = _ALIGN_UP(*mem_end + size, 4);
 157         }
 158 }
 159
 160 static void __init bootx_add_chosen_props(unsigned long base,
 161                                           unsigned long *mem_end)
 162 {
 163         u32 val;
 164
 165         bootx_dt_add_prop("linux,bootx", NULL, 0, mem_end);
 166
 167         if (bootx_info->kernelParamsOffset) {
 168                 char *args = (char *)((unsigned long)bootx_info) +
 169                         bootx_info->kernelParamsOffset;
 170                 bootx_dt_add_prop("bootargs", args, strlen(args) + 1, mem_end);
 171         }
 172         if (bootx_info->ramDisk) {
 173                 val = ((unsigned long)bootx_info) + bootx_info->ramDisk;
 174                 bootx_dt_add_prop("linux,initrd-start", &val, 4, mem_end);
 175                 val += bootx_info->ramDiskSize;
 176                 bootx_dt_add_prop("linux,initrd-end", &val, 4, mem_end);
 177         }
 178         if (strlen(bootx_disp_path))
 179                 bootx_dt_add_prop("linux,stdout-path", bootx_disp_path,
 180                                   strlen(bootx_disp_path) + 1, mem_end);
 181 }
 182
 183 static void __init bootx_add_display_props(unsigned long base,
 184                                            unsigned long *mem_end,
 185                                            int has_real_node)
 186 {
 187         boot_infos_t *bi = bootx_info;
 188         u32 tmp;
 189
 190         if (has_real_node) {
 191                 bootx_dt_add_prop("linux,boot-display", NULL, 0, mem_end);
 192                 bootx_dt_add_prop("linux,opened", NULL, 0, mem_end);
 193         } else
 194                 bootx_dt_add_prop("linux,bootx-noscreen", NULL, 0, mem_end);
 195
 196         tmp = bi->dispDeviceDepth;
 197         bootx_dt_add_prop("linux,bootx-depth", &tmp, 4, mem_end);
 198         tmp = bi->dispDeviceRect[2] - bi->dispDeviceRect[0];
 199         bootx_dt_add_prop("linux,bootx-width", &tmp, 4, mem_end);
 200         tmp = bi->dispDeviceRect[3] - bi->dispDeviceRect[1];
 201         bootx_dt_add_prop("linux,bootx-height", &tmp, 4, mem_end);
 202         tmp = bi->dispDeviceRowBytes;
 203         bootx_dt_add_prop("linux,bootx-linebytes", &tmp, 4, mem_end);
 204         tmp = (u32)bi->dispDeviceBase;
 205         if (tmp == 0)
 206                 tmp = (u32)bi->logicalDisplayBase;
 207         tmp += bi->dispDeviceRect[1] * bi->dispDeviceRowBytes;
 208         tmp += bi->dispDeviceRect[0] * ((bi->dispDeviceDepth + 7) / 8);
 209         bootx_dt_add_prop("linux,bootx-addr", &tmp, 4, mem_end);
 210 }
 211
 212 static void __init bootx_dt_add_string(char *s, unsigned long *mem_end)
 213 {
 214         unsigned int l = strlen(s) + 1;
 215         memcpy((void *)*mem_end, s, l);
 216         bootx_dt_strend = *mem_end = *mem_end + l;
 217 }
 218
 219 static void __init bootx_scan_dt_build_strings(unsigned long base,
 220                                                unsigned long node,
 221                                                unsigned long *mem_end)
 222 {
 223         struct bootx_dt_node *np = (struct bootx_dt_node *)(base + node);
 224         u32 *cpp, *ppp = &np->properties;
 225         unsigned long soff;
 226         char *namep;
 227
 228         /* Keep refs to known nodes */
 229         namep = np->full_name ? (char *)(base + np->full_name) : NULL;
 230         if (namep == NULL) {
 231                 bootx_printf("Node without a full name !\n");
 232                 namep = "";
 233         }
 234         DBG("* strings: %s\n", namep);
 235
 236         if (!strcmp(namep, "/chosen")) {
 237                 DBG(" detected /chosen ! adding properties names !\n");
 238                 bootx_dt_add_string("linux,bootx", mem_end);
 239                 bootx_dt_add_string("linux,stdout-path", mem_end);
 240                 bootx_dt_add_string("linux,initrd-start", mem_end);
 241                 bootx_dt_add_string("linux,initrd-end", mem_end);
 242                 bootx_dt_add_string("bootargs", mem_end);
 243                 bootx_node_chosen = node;
 244         }
 245         if (node == bootx_info->dispDeviceRegEntryOffset) {
 246                 DBG(" detected display ! adding properties names !\n");
 247                 bootx_dt_add_string("linux,boot-display", mem_end);
 248                 bootx_dt_add_string("linux,opened", mem_end);
 249                 strncpy(bootx_disp_path, namep, 255);
 250         }
 251
 252         /* get and store all property names */
 253         while (*ppp) {
 254                 struct bootx_dt_prop *pp =
 255                         (struct bootx_dt_prop *)(base + *ppp);
 256
 257                 namep = pp->name ? (char *)(base + pp->name) : NULL;
 258                 if (namep == NULL || strcmp(namep, "name") == 0)
 259                         goto next;
 260                 /* get/create string entry */
 261                 soff = bootx_dt_find_string(namep);
 262                 if (soff == 0)
 263                         bootx_dt_add_string(namep, mem_end);
 264         next:
 265                 ppp = &pp->next;
 266         }
 267
 268         /* do all our children */
 269         cpp = &np->child;
 270         while(*cpp) {
 271                 np = (struct bootx_dt_node *)(base + *cpp);
 272                 bootx_scan_dt_build_strings(base, *cpp, mem_end);
 273                 cpp = &np->sibling;
 274         }
 275 }
 276
 277 static void __init bootx_scan_dt_build_struct(unsigned long base,
 278                                               unsigned long node,
 279                                               unsigned long *mem_end)
 280 {
 281         struct bootx_dt_node *np = (struct bootx_dt_node *)(base + node);
 282         u32 *cpp, *ppp = &np->properties;
 283         char *namep, *p, *ep, *lp;
 284         int l;
 285
 286         dt_push_token(OF_DT_BEGIN_NODE, mem_end);
 287
 288         /* get the node's full name */
 289         namep = np->full_name ? (char *)(base + np->full_name) : NULL;
 290         if (namep == NULL)
 291                 namep = "";
 292         l = strlen(namep);
 293
 294         DBG("* struct: %s\n", namep);
 295
 296         /* Fixup an Apple bug where they have bogus \0 chars in the
 297          * middle of the path in some properties, and extract
 298          * the unit name (everything after the last '/').
 299          */
 300         memcpy((void *)*mem_end, namep, l + 1);
 301         namep = (char *)*mem_end;
 302         for (lp = p = namep, ep = namep + l; p < ep; p++) {
 303                 if (*p == '/')
 304                         lp = namep;
 305                 else if (*p != 0)
 306                         *lp++ = *p;
 307         }
 308         *lp = 0;
 309         *mem_end = _ALIGN_UP((unsigned long)lp + 1, 4);
 310
 311         /* get and store all properties */
 312         while (*ppp) {
 313                 struct bootx_dt_prop *pp =
 314                         (struct bootx_dt_prop *)(base + *ppp);
 315
 316                 namep = pp->name ? (char *)(base + pp->name) : NULL;
 317                 /* Skip "name" */
 318                 if (namep == NULL || !strcmp(namep, "name"))
 319                         goto next;
 320                 /* Skip "bootargs" in /chosen too as we replace it */
 321                 if (node == bootx_node_chosen && !strcmp(namep, "bootargs"))
 322                         goto next;
 323
 324                 /* push property head */
 325                 bootx_dt_add_prop(namep,
 326                                   pp->value ? (void *)(base + pp->value): NULL,
 327                                   pp->length, mem_end);
 328         next:
 329                 ppp = &pp->next;
 330         }
 331
 332         if (node == bootx_node_chosen) {
 333                 bootx_add_chosen_props(base, mem_end);
 334                 if (bootx_info->dispDeviceRegEntryOffset == 0)
 335                         bootx_add_display_props(base, mem_end, 0);
 336         }
 337         else if (node == bootx_info->dispDeviceRegEntryOffset)
 338                 bootx_add_display_props(base, mem_end, 1);
 339
 340         /* do all our children */
 341         cpp = &np->child;
 342         while(*cpp) {
 343                 np = (struct bootx_dt_node *)(base + *cpp);
 344                 bootx_scan_dt_build_struct(base, *cpp, mem_end);
 345                 cpp = &np->sibling;
 346         }
 347
 348         dt_push_token(OF_DT_END_NODE, mem_end);
 349 }
 350
 351 static unsigned long __init bootx_flatten_dt(unsigned long start)
 352 {
 353         boot_infos_t *bi = bootx_info;
 354         unsigned long mem_start, mem_end;
 355         struct boot_param_header *hdr;
 356         unsigned long base;
 357         u64 *rsvmap;
 358
 359         /* Start using memory after the big blob passed by BootX, get
 360          * some space for the header
 361          */
 362         mem_start = mem_end = _ALIGN_UP(((unsigned long)bi) + start, 4);
 363         DBG("Boot params header at: %x\n", mem_start);
 364         hdr = (struct boot_param_header *)mem_start;
 365         mem_end += sizeof(struct boot_param_header);
 366         rsvmap = (u64 *)(_ALIGN_UP(mem_end, 8));
 367         hdr->off_mem_rsvmap = ((unsigned long)rsvmap) - mem_start;
 368         mem_end = ((unsigned long)rsvmap) + 8 * sizeof(u64);
 369
 370         /* Get base of tree */
 371         base = ((unsigned long)bi) + bi->deviceTreeOffset;
 372
 373         /* Build string array */
 374         DBG("Building string array at: %x\n", mem_end);
 375         DBG("Device Tree Base=%x\n", base);
 376         bootx_dt_strbase = mem_end;
 377         mem_end += 4;
 378         bootx_dt_strend = mem_end;
 379         bootx_scan_dt_build_strings(base, 4, &mem_end);
 380         /* Add some strings */
 381         bootx_dt_add_string("linux,bootx-noscreen", &mem_end);
 382         bootx_dt_add_string("linux,bootx-depth", &mem_end);
 383         bootx_dt_add_string("linux,bootx-width", &mem_end);
 384         bootx_dt_add_string("linux,bootx-height", &mem_end);
 385         bootx_dt_add_string("linux,bootx-linebytes", &mem_end);
 386         bootx_dt_add_string("linux,bootx-addr", &mem_end);
 387         /* Wrap up strings */
 388         hdr->off_dt_strings = bootx_dt_strbase - mem_start;
 389         hdr->dt_strings_size = bootx_dt_strend - bootx_dt_strbase;
 390
 391         /* Build structure */
 392         mem_end = _ALIGN(mem_end, 16);
 393         DBG("Building device tree structure at: %x\n", mem_end);
 394         hdr->off_dt_struct = mem_end - mem_start;
 395         bootx_scan_dt_build_struct(base, 4, &mem_end);
 396         dt_push_token(OF_DT_END, &mem_end);
 397
 398         /* Finish header */
 399         hdr->boot_cpuid_phys = 0;
 400         hdr->magic = OF_DT_HEADER;
 401         hdr->totalsize = mem_end - mem_start;
 402         hdr->version = OF_DT_VERSION;
 403         /* Version 16 is not backward compatible */
 404         hdr->last_comp_version = 0x10;
 405
 406         /* Reserve the whole thing and copy the reserve map in, we
 407          * also bump mem_reserve_cnt to cause further reservations to
 408          * fail since it's too late.
 409          */
 410         mem_end = _ALIGN(mem_end, PAGE_SIZE);
 411         DBG("End of boot params: %x\n", mem_end);
 412         rsvmap[0] = mem_start;
 413         rsvmap[1] = mem_end;
 414         if (bootx_info->ramDisk) {
 415                 rsvmap[2] = ((unsigned long)bootx_info) + bootx_info->ramDisk;
 416                 rsvmap[3] = rsvmap[2] + bootx_info->ramDiskSize;
 417                 rsvmap[4] = 0;
 418                 rsvmap[5] = 0;
 419         } else {
 420                 rsvmap[2] = 0;
 421                 rsvmap[3] = 0;
 422         }
 423
 424         return (unsigned long)hdr;
 425 }
 426
 427
 428 #ifdef CONFIG_BOOTX_TEXT
 429 static void __init btext_welcome(boot_infos_t *bi)
 430 {
 431         unsigned long flags;
 432         unsigned long pvr;
 433
 434         bootx_printf("Welcome to Linux, kernel " UTS_RELEASE "\n");
 435         bootx_printf("\nlinked at        : 0x%x", KERNELBASE);
 436         bootx_printf("\nframe buffer at  : 0x%x", bi->dispDeviceBase);
 437         bootx_printf(" (phys), 0x%x", bi->logicalDisplayBase);
 438         bootx_printf(" (log)");
 439         bootx_printf("\nklimit           : 0x%x",(unsigned long)klimit);
 440         bootx_printf("\nboot_info at     : 0x%x", bi);
 441         __asm__ __volatile__ ("mfmsr %0" : "=r" (flags));
 442         bootx_printf("\nMSR              : 0x%x", flags);
 443         __asm__ __volatile__ ("mfspr %0, 287" : "=r" (pvr));
 444         bootx_printf("\nPVR              : 0x%x", pvr);
 445         pvr >>= 16;
 446         if (pvr > 1) {
 447             __asm__ __volatile__ ("mfspr %0, 1008" : "=r" (flags));
 448             bootx_printf("\nHID0             : 0x%x", flags);
 449         }
 450         if (pvr == 8 || pvr == 12 || pvr == 0x800c) {
 451             __asm__ __volatile__ ("mfspr %0, 1019" : "=r" (flags));
 452             bootx_printf("\nICTC             : 0x%x", flags);
 453         }
 454 #ifdef DEBUG
 455         bootx_printf("\n\n");
 456         bootx_printf("bi->deviceTreeOffset   : 0x%x\n",
 457                      bi->deviceTreeOffset);
 458         bootx_printf("bi->deviceTreeSize     : 0x%x\n",
 459                      bi->deviceTreeSize);
 460 #endif
 461         bootx_printf("\n\n");
 462 }
 463 #endif /* CONFIG_BOOTX_TEXT */
 464
 465 void __init bootx_init(unsigned long r3, unsigned long r4)
 466 {
 467         boot_infos_t *bi = (boot_infos_t *) r4;
 468         unsigned long hdr;
 469         unsigned long space;
 470         unsigned long ptr, x;
 471         char *model;
 472         unsigned long offset = reloc_offset();
 473
 474         reloc_got2(offset);
 475
 476         bootx_info = bi;
 477
 478         /* We haven't cleared any bss at this point, make sure
 479          * what we need is initialized
 480          */
 481         bootx_dt_strbase = bootx_dt_strend = 0;
 482         bootx_node_chosen = 0;
 483         bootx_disp_path[0] = 0;
 484
 485         if (!BOOT_INFO_IS_V2_COMPATIBLE(bi))
 486                 bi->logicalDisplayBase = bi->dispDeviceBase;
 487
 488         /* Fixup depth 16 -> 15 as that's what MacOS calls 16bpp */
 489         if (bi->dispDeviceDepth == 16)
 490                 bi->dispDeviceDepth = 15;
 491
 492
 493 #ifdef CONFIG_BOOTX_TEXT
 494         ptr = (unsigned long)bi->logicalDisplayBase;
 495         ptr += bi->dispDeviceRect[1] * bi->dispDeviceRowBytes;
 496         ptr += bi->dispDeviceRect[0] * ((bi->dispDeviceDepth + 7) / 8);
 497         btext_setup_display(bi->dispDeviceRect[2] - bi->dispDeviceRect[0],
 498                             bi->dispDeviceRect[3] - bi->dispDeviceRect[1],
 499                             bi->dispDeviceDepth, bi->dispDeviceRowBytes,
 500                             (unsigned long)bi->logicalDisplayBase);
 501         btext_clearscreen();
 502         btext_flushscreen();
 503 #endif /* CONFIG_BOOTX_TEXT */
 504
 505         /*
 506          * Test if boot-info is compatible.  Done only in config
 507          * CONFIG_BOOTX_TEXT since there is nothing much we can do
 508          * with an incompatible version, except display a message
 509          * and eventually hang the processor...
 510          *
 511          * I'll try to keep enough of boot-info compatible in the
 512          * future to always allow display of this message;
 513          */
 514         if (!BOOT_INFO_IS_COMPATIBLE(bi)) {
 515                 bootx_printf(" !!! WARNING - Incompatible version"
 516                              " of BootX !!!\n\n\n");
 517                 for (;;)
 518                         ;
 519         }
 520         if (bi->architecture != BOOT_ARCH_PCI) {
 521                 bootx_printf(" !!! WARNING - Usupported machine"
 522                              " architecture !\n");
 523                 for (;;)
 524                         ;
 525         }
 526
 527 #ifdef CONFIG_BOOTX_TEXT
 528         btext_welcome(bi);
 529 #endif
 530
 531         /* New BootX enters kernel with MMU off, i/os are not allowed
 532          * here. This hack will have been done by the boostrap anyway.
 533          */
 534         if (bi->version < 4) {
 535                 /*
 536                  * XXX If this is an iMac, turn off the USB controller.
 537                  */
 538                 model = (char *) bootx_early_getprop(r4 + bi->deviceTreeOffset,
 539                                                      4, "model");
 540                 if (model
 541                     && (strcmp(model, "iMac,1") == 0
 542                         || strcmp(model, "PowerMac1,1") == 0)) {
 543                         bootx_printf("iMac,1 detected, shutting down USB\n");
 544                         out_le32((unsigned __iomem *)0x80880008, 1);    /* XXX */
 545                 }
 546         }
 547
 548         /* Get a pointer that points above the device tree, args, ramdisk,
 549          * etc... to use for generating the flattened tree
 550          */
 551         if (bi->version < 5) {
 552                 space = bi->deviceTreeOffset + bi->deviceTreeSize;
 553                 if (bi->ramDisk >= space)
 554                         space = bi->ramDisk + bi->ramDiskSize;
 555         } else
 556                 space = bi->totalParamsSize;
 557
 558         bootx_printf("Total space used by parameters & ramdisk: 0x%x\n", space);
 559
 560         /* New BootX will have flushed all TLBs and enters kernel with
 561          * MMU switched OFF, so this should not be useful anymore.
 562          */
 563         if (bi->version < 4) {
 564                 bootx_printf("Touching pages...\n");
 565
 566                 /*
 567                  * Touch each page to make sure the PTEs for them
 568                  * are in the hash table - the aim is to try to avoid
 569                  * getting DSI exceptions while copying the kernel image.
 570                  */
 571                 for (ptr = ((unsigned long) &_stext) & PAGE_MASK;
 572                      ptr < (unsigned long)bi + space; ptr += PAGE_SIZE)
 573                         x = *(volatile unsigned long *)ptr;
 574         }
 575
 576         /* Ok, now we need to generate a flattened device-tree to pass
 577          * to the kernel
 578          */
 579         bootx_printf("Preparing boot params...\n");
 580
 581         hdr = bootx_flatten_dt(space);
 582
 583 #ifdef CONFIG_BOOTX_TEXT
 584 #ifdef SET_BOOT_BAT
 585         bootx_printf("Preparing BAT...\n");
 586         btext_prepare_BAT();
 587 #else
 588         btext_unmap();
 589 #endif
 590 #endif
 591
 592         reloc_got2(-offset);
 593
 594         __start(hdr, KERNELBASE + offset, 0);
 595 }