linux/scripts/dtc/flattree.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * (C) Copyright David Gibson <dwg@au1.ibm.com>, IBM Corporation.  2005.
   4 */
   5
   6#include "dtc.h"
   7#include "srcpos.h"
   8
   9#define FTF_FULLPATH    0x1
  10#define FTF_VARALIGN    0x2
  11#define FTF_NAMEPROPS   0x4
  12#define FTF_BOOTCPUID   0x8
  13#define FTF_STRTABSIZE  0x10
  14#define FTF_STRUCTSIZE  0x20
  15#define FTF_NOPS        0x40
  16
  17static struct version_info {
  18        int version;
  19        int last_comp_version;
  20        int hdr_size;
  21        int flags;
  22} version_table[] = {
  23        {1, 1, FDT_V1_SIZE,
  24         FTF_FULLPATH|FTF_VARALIGN|FTF_NAMEPROPS},
  25        {2, 1, FDT_V2_SIZE,
  26         FTF_FULLPATH|FTF_VARALIGN|FTF_NAMEPROPS|FTF_BOOTCPUID},
  27        {3, 1, FDT_V3_SIZE,
  28         FTF_FULLPATH|FTF_VARALIGN|FTF_NAMEPROPS|FTF_BOOTCPUID|FTF_STRTABSIZE},
  29        {16, 16, FDT_V3_SIZE,
  30         FTF_BOOTCPUID|FTF_STRTABSIZE|FTF_NOPS},
  31        {17, 16, FDT_V17_SIZE,
  32         FTF_BOOTCPUID|FTF_STRTABSIZE|FTF_STRUCTSIZE|FTF_NOPS},
  33};
  34
  35struct emitter {
  36        void (*cell)(void *, cell_t);
  37        void (*string)(void *, const char *, int);
  38        void (*align)(void *, int);
  39        void (*data)(void *, struct data);
  40        void (*beginnode)(void *, struct label *labels);
  41        void (*endnode)(void *, struct label *labels);
  42        void (*property)(void *, struct label *labels);
  43};
  44
  45static void bin_emit_cell(void *e, cell_t val)
  46{
  47        struct data *dtbuf = e;
  48
  49        *dtbuf = data_append_cell(*dtbuf, val);
  50}
  51
  52static void bin_emit_string(void *e, const char *str, int len)
  53{
  54        struct data *dtbuf = e;
  55
  56        if (len == 0)
  57                len = strlen(str);
  58
  59        *dtbuf = data_append_data(*dtbuf, str, len);
  60        *dtbuf = data_append_byte(*dtbuf, '\0');
  61}
  62
  63static void bin_emit_align(void *e, int a)
  64{
  65        struct data *dtbuf = e;
  66
  67        *dtbuf = data_append_align(*dtbuf, a);
  68}
  69
  70static void bin_emit_data(void *e, struct data d)
  71{
  72        struct data *dtbuf = e;
  73
  74        *dtbuf = data_append_data(*dtbuf, d.val, d.len);
  75}
  76
  77static void bin_emit_beginnode(void *e, struct label *labels)
  78{
  79        bin_emit_cell(e, FDT_BEGIN_NODE);
  80}
  81
  82static void bin_emit_endnode(void *e, struct label *labels)
  83{
  84        bin_emit_cell(e, FDT_END_NODE);
  85}
  86
  87static void bin_emit_property(void *e, struct label *labels)
  88{
  89        bin_emit_cell(e, FDT_PROP);
  90}
  91
  92static struct emitter bin_emitter = {
  93        .cell = bin_emit_cell,
  94        .string = bin_emit_string,
  95        .align = bin_emit_align,
  96        .data = bin_emit_data,
  97        .beginnode = bin_emit_beginnode,
  98        .endnode = bin_emit_endnode,
  99        .property = bin_emit_property,
 100};
 101
 102static void emit_label(FILE *f, const char *prefix, const char *label)
 103{
 104        fprintf(f, "\t.globl\t%s_%s\n", prefix, label);
 105        fprintf(f, "%s_%s:\n", prefix, label);
 106        fprintf(f, "_%s_%s:\n", prefix, label);
 107}
 108
 109static void emit_offset_label(FILE *f, const char *label, int offset)
 110{
 111        fprintf(f, "\t.globl\t%s\n", label);
 112        fprintf(f, "%s\t= . + %d\n", label, offset);
 113}
 114
 115#define ASM_EMIT_BELONG(f, fmt, ...) \
 116        { \
 117                fprintf((f), "\t.byte\t((" fmt ") >> 24) & 0xff\n", __VA_ARGS__); \
 118                fprintf((f), "\t.byte\t((" fmt ") >> 16) & 0xff\n", __VA_ARGS__); \
 119                fprintf((f), "\t.byte\t((" fmt ") >> 8) & 0xff\n", __VA_ARGS__); \
 120                fprintf((f), "\t.byte\t(" fmt ") & 0xff\n", __VA_ARGS__); \
 121        }
 122
 123static void asm_emit_cell(void *e, cell_t val)
 124{
 125        FILE *f = e;
 126
 127        fprintf(f, "\t.byte\t0x%02x\n" "\t.byte\t0x%02x\n"
 128                "\t.byte\t0x%02x\n" "\t.byte\t0x%02x\n",
 129                (val >> 24) & 0xff, (val >> 16) & 0xff,
 130                (val >> 8) & 0xff, val & 0xff);
 131}
 132
 133static void asm_emit_string(void *e, const char *str, int len)
 134{
 135        FILE *f = e;
 136
 137        if (len != 0)
 138                fprintf(f, "\t.asciz\t\"%.*s\"\n", len, str);
 139        else
 140                fprintf(f, "\t.asciz\t\"%s\"\n", str);
 141}
 142
 143static void asm_emit_align(void *e, int a)
 144{
 145        FILE *f = e;
 146
 147        fprintf(f, "\t.balign\t%d, 0\n", a);
 148}
 149
 150static void asm_emit_data(void *e, struct data d)
 151{
 152        FILE *f = e;
 153        unsigned int off = 0;
 154        struct marker *m = d.markers;
 155
 156        for_each_marker_of_type(m, LABEL)
 157                emit_offset_label(f, m->ref, m->offset);
 158
 159        while ((d.len - off) >= sizeof(uint32_t)) {
 160                asm_emit_cell(e, dtb_ld32(d.val + off));
 161                off += sizeof(uint32_t);
 162        }
 163
 164        while ((d.len - off) >= 1) {
 165                fprintf(f, "\t.byte\t0x%hhx\n", d.val[off]);
 166                off += 1;
 167        }
 168
 169        assert(off == d.len);
 170}
 171
 172static void asm_emit_beginnode(void *e, struct label *labels)
 173{
 174        FILE *f = e;
 175        struct label *l;
 176
 177        for_each_label(labels, l) {
 178                fprintf(f, "\t.globl\t%s\n", l->label);
 179                fprintf(f, "%s:\n", l->label);
 180        }
 181        fprintf(f, "\t/* FDT_BEGIN_NODE */\n");
 182        asm_emit_cell(e, FDT_BEGIN_NODE);
 183}
 184
 185static void asm_emit_endnode(void *e, struct label *labels)
 186{
 187        FILE *f = e;
 188        struct label *l;
 189
 190        fprintf(f, "\t/* FDT_END_NODE */\n");
 191        asm_emit_cell(e, FDT_END_NODE);
 192        for_each_label(labels, l) {
 193                fprintf(f, "\t.globl\t%s_end\n", l->label);
 194                fprintf(f, "%s_end:\n", l->label);
 195        }
 196}
 197
 198static void asm_emit_property(void *e, struct label *labels)
 199{
 200        FILE *f = e;
 201        struct label *l;
 202
 203        for_each_label(labels, l) {
 204                fprintf(f, "\t.globl\t%s\n", l->label);
 205                fprintf(f, "%s:\n", l->label);
 206        }
 207        fprintf(f, "\t/* FDT_PROP */\n");
 208        asm_emit_cell(e, FDT_PROP);
 209}
 210
 211static struct emitter asm_emitter = {
 212        .cell = asm_emit_cell,
 213        .string = asm_emit_string,
 214        .align = asm_emit_align,
 215        .data = asm_emit_data,
 216        .beginnode = asm_emit_beginnode,
 217        .endnode = asm_emit_endnode,
 218        .property = asm_emit_property,
 219};
 220
 221static int stringtable_insert(struct data *d, const char *str)
 222{
 223        unsigned int i;
 224
 225        /* FIXME: do this more efficiently? */
 226
 227        for (i = 0; i < d->len; i++) {
 228                if (streq(str, d->val + i))
 229                        return i;
 230        }
 231
 232        *d = data_append_data(*d, str, strlen(str)+1);
 233        return i;
 234}
 235
 236static void flatten_tree(struct node *tree, struct emitter *emit,
 237                         void *etarget, struct data *strbuf,
 238                         struct version_info *vi)
 239{
 240        struct property *prop;
 241        struct node *child;
 242        bool seen_name_prop = false;
 243
 244        if (tree->deleted)
 245                return;
 246
 247        emit->beginnode(etarget, tree->labels);
 248
 249        if (vi->flags & FTF_FULLPATH)
 250                emit->string(etarget, tree->fullpath, 0);
 251        else
 252                emit->string(etarget, tree->name, 0);
 253
 254        emit->align(etarget, sizeof(cell_t));
 255
 256        for_each_property(tree, prop) {
 257                int nameoff;
 258
 259                if (streq(prop->name, "name"))
 260                        seen_name_prop = true;
 261
 262                nameoff = stringtable_insert(strbuf, prop->name);
 263
 264                emit->property(etarget, prop->labels);
 265                emit->cell(etarget, prop->val.len);
 266                emit->cell(etarget, nameoff);
 267
 268                if ((vi->flags & FTF_VARALIGN) && (prop->val.len >= 8))
 269                        emit->align(etarget, 8);
 270
 271                emit->data(etarget, prop->val);
 272                emit->align(etarget, sizeof(cell_t));
 273        }
 274
 275        if ((vi->flags & FTF_NAMEPROPS) && !seen_name_prop) {
 276                emit->property(etarget, NULL);
 277                emit->cell(etarget, tree->basenamelen+1);
 278                emit->cell(etarget, stringtable_insert(strbuf, "name"));
 279
 280                if ((vi->flags & FTF_VARALIGN) && ((tree->basenamelen+1) >= 8))
 281                        emit->align(etarget, 8);
 282
 283                emit->string(etarget, tree->name, tree->basenamelen);
 284                emit->align(etarget, sizeof(cell_t));
 285        }
 286
 287        for_each_child(tree, child) {
 288                flatten_tree(child, emit, etarget, strbuf, vi);
 289        }
 290
 291        emit->endnode(etarget, tree->labels);
 292}
 293
 294static struct data flatten_reserve_list(struct reserve_info *reservelist,
 295                                 struct version_info *vi)
 296{
 297        struct reserve_info *re;
 298        struct data d = empty_data;
 299        unsigned int j;
 300
 301        for (re = reservelist; re; re = re->next) {
 302                d = data_append_re(d, re->address, re->size);
 303        }
 304        /*
 305         * Add additional reserved slots if the user asked for them.
 306         */
 307        for (j = 0; j < reservenum; j++) {
 308                d = data_append_re(d, 0, 0);
 309        }
 310
 311        return d;
 312}
 313
 314static void make_fdt_header(struct fdt_header *fdt,
 315                            struct version_info *vi,
 316                            int reservesize, int dtsize, int strsize,
 317                            int boot_cpuid_phys)
 318{
 319        int reserve_off;
 320
 321        reservesize += sizeof(struct fdt_reserve_entry);
 322
 323        memset(fdt, 0xff, sizeof(*fdt));
 324
 325        fdt->magic = cpu_to_fdt32(FDT_MAGIC);
 326        fdt->version = cpu_to_fdt32(vi->version);
 327        fdt->last_comp_version = cpu_to_fdt32(vi->last_comp_version);
 328
 329        /* Reserve map should be doubleword aligned */
 330        reserve_off = ALIGN(vi->hdr_size, 8);
 331
 332        fdt->off_mem_rsvmap = cpu_to_fdt32(reserve_off);
 333        fdt->off_dt_struct = cpu_to_fdt32(reserve_off + reservesize);
 334        fdt->off_dt_strings = cpu_to_fdt32(reserve_off + reservesize
 335                                          + dtsize);
 336        fdt->totalsize = cpu_to_fdt32(reserve_off + reservesize + dtsize + strsize);
 337
 338        if (vi->flags & FTF_BOOTCPUID)
 339                fdt->boot_cpuid_phys = cpu_to_fdt32(boot_cpuid_phys);
 340        if (vi->flags & FTF_STRTABSIZE)
 341                fdt->size_dt_strings = cpu_to_fdt32(strsize);
 342        if (vi->flags & FTF_STRUCTSIZE)
 343                fdt->size_dt_struct = cpu_to_fdt32(dtsize);
 344}
 345
 346void dt_to_blob(FILE *f, struct dt_info *dti, int version)
 347{
 348        struct version_info *vi = NULL;
 349        unsigned int i;
 350        struct data blob       = empty_data;
 351        struct data reservebuf = empty_data;
 352        struct data dtbuf      = empty_data;
 353        struct data strbuf     = empty_data;
 354        struct fdt_header fdt;
 355        int padlen = 0;
 356
 357        for (i = 0; i < ARRAY_SIZE(version_table); i++) {
 358                if (version_table[i].version == version)
 359                        vi = &version_table[i];
 360        }
 361        if (!vi)
 362                die("Unknown device tree blob version %d\n", version);
 363
 364        flatten_tree(dti->dt, &bin_emitter, &dtbuf, &strbuf, vi);
 365        bin_emit_cell(&dtbuf, FDT_END);
 366
 367        reservebuf = flatten_reserve_list(dti->reservelist, vi);
 368
 369        /* Make header */
 370        make_fdt_header(&fdt, vi, reservebuf.len, dtbuf.len, strbuf.len,
 371                        dti->boot_cpuid_phys);
 372
 373        /*
 374         * If the user asked for more space than is used, adjust the totalsize.
 375         */
 376        if (minsize > 0) {
 377                padlen = minsize - fdt32_to_cpu(fdt.totalsize);
 378                if (padlen < 0) {
 379                        padlen = 0;
 380                        if (quiet < 1)
 381                                fprintf(stderr,
 382                                        "Warning: blob size %"PRIu32" >= minimum size %d\n",
 383                                        fdt32_to_cpu(fdt.totalsize), minsize);
 384                }
 385        }
 386
 387        if (padsize > 0)
 388                padlen = padsize;
 389
 390        if (alignsize > 0)
 391                padlen = ALIGN(fdt32_to_cpu(fdt.totalsize) + padlen, alignsize)
 392                        - fdt32_to_cpu(fdt.totalsize);
 393
 394        if (padlen > 0) {
 395                int tsize = fdt32_to_cpu(fdt.totalsize);
 396                tsize += padlen;
 397                fdt.totalsize = cpu_to_fdt32(tsize);
 398        }
 399
 400        /*
 401         * Assemble the blob: start with the header, add with alignment
 402         * the reserve buffer, add the reserve map terminating zeroes,
 403         * the device tree itself, and finally the strings.
 404         */
 405        blob = data_append_data(blob, &fdt, vi->hdr_size);
 406        blob = data_append_align(blob, 8);
 407        blob = data_merge(blob, reservebuf);
 408        blob = data_append_zeroes(blob, sizeof(struct fdt_reserve_entry));
 409        blob = data_merge(blob, dtbuf);
 410        blob = data_merge(blob, strbuf);
 411
 412        /*
 413         * If the user asked for more space than is used, pad out the blob.
 414         */
 415        if (padlen > 0)
 416                blob = data_append_zeroes(blob, padlen);
 417
 418        if (fwrite(blob.val, blob.len, 1, f) != 1) {
 419                if (ferror(f))
 420                        die("Error writing device tree blob: %s\n",
 421                            strerror(errno));
 422                else
 423                        die("Short write on device tree blob\n");
 424        }
 425
 426        /*
 427         * data_merge() frees the right-hand element so only the blob
 428         * remains to be freed.
 429         */
 430        data_free(blob);
 431}
 432
 433static void dump_stringtable_asm(FILE *f, struct data strbuf)
 434{
 435        const char *p;
 436        int len;
 437
 438        p = strbuf.val;
 439
 440        while (p < (strbuf.val + strbuf.len)) {
 441                len = strlen(p);
 442                fprintf(f, "\t.asciz \"%s\"\n", p);
 443                p += len+1;
 444        }
 445}
 446
 447void dt_to_asm(FILE *f, struct dt_info *dti, int version)
 448{
 449        struct version_info *vi = NULL;
 450        unsigned int i;
 451        struct data strbuf = empty_data;
 452        struct reserve_info *re;
 453        const char *symprefix = "dt";
 454
 455        for (i = 0; i < ARRAY_SIZE(version_table); i++) {
 456                if (version_table[i].version == version)
 457                        vi = &version_table[i];
 458        }
 459        if (!vi)
 460                die("Unknown device tree blob version %d\n", version);
 461
 462        fprintf(f, "/* autogenerated by dtc, do not edit */\n\n");
 463
 464        emit_label(f, symprefix, "blob_start");
 465        emit_label(f, symprefix, "header");
 466        fprintf(f, "\t/* magic */\n");
 467        asm_emit_cell(f, FDT_MAGIC);
 468        fprintf(f, "\t/* totalsize */\n");
 469        ASM_EMIT_BELONG(f, "_%s_blob_abs_end - _%s_blob_start",
 470                        symprefix, symprefix);
 471        fprintf(f, "\t/* off_dt_struct */\n");
 472        ASM_EMIT_BELONG(f, "_%s_struct_start - _%s_blob_start",
 473                symprefix, symprefix);
 474        fprintf(f, "\t/* off_dt_strings */\n");
 475        ASM_EMIT_BELONG(f, "_%s_strings_start - _%s_blob_start",
 476                symprefix, symprefix);
 477        fprintf(f, "\t/* off_mem_rsvmap */\n");
 478        ASM_EMIT_BELONG(f, "_%s_reserve_map - _%s_blob_start",
 479                symprefix, symprefix);
 480        fprintf(f, "\t/* version */\n");
 481        asm_emit_cell(f, vi->version);
 482        fprintf(f, "\t/* last_comp_version */\n");
 483        asm_emit_cell(f, vi->last_comp_version);
 484
 485        if (vi->flags & FTF_BOOTCPUID) {
 486                fprintf(f, "\t/* boot_cpuid_phys */\n");
 487                asm_emit_cell(f, dti->boot_cpuid_phys);
 488        }
 489
 490        if (vi->flags & FTF_STRTABSIZE) {
 491                fprintf(f, "\t/* size_dt_strings */\n");
 492                ASM_EMIT_BELONG(f, "_%s_strings_end - _%s_strings_start",
 493                                symprefix, symprefix);
 494        }
 495
 496        if (vi->flags & FTF_STRUCTSIZE) {
 497                fprintf(f, "\t/* size_dt_struct */\n");
 498                ASM_EMIT_BELONG(f, "_%s_struct_end - _%s_struct_start",
 499                        symprefix, symprefix);
 500        }
 501
 502        /*
 503         * Reserve map entries.
 504         * Align the reserve map to a doubleword boundary.
 505         * Each entry is an (address, size) pair of u64 values.
 506         * Always supply a zero-sized temination entry.
 507         */
 508        asm_emit_align(f, 8);
 509        emit_label(f, symprefix, "reserve_map");
 510
 511        fprintf(f, "/* Memory reserve map from source file */\n");
 512
 513        /*
 514         * Use .long on high and low halves of u64s to avoid .quad
 515         * as it appears .quad isn't available in some assemblers.
 516         */
 517        for (re = dti->reservelist; re; re = re->next) {
 518                struct label *l;
 519
 520                for_each_label(re->labels, l) {
 521                        fprintf(f, "\t.globl\t%s\n", l->label);
 522                        fprintf(f, "%s:\n", l->label);
 523                }
 524                ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->address >> 32));
 525                ASM_EMIT_BELONG(f, "0x%08x",
 526                                (unsigned int)(re->address & 0xffffffff));
 527                ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->size >> 32));
 528                ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->size & 0xffffffff));
 529        }
 530        for (i = 0; i < reservenum; i++) {
 531                fprintf(f, "\t.long\t0, 0\n\t.long\t0, 0\n");
 532        }
 533
 534        fprintf(f, "\t.long\t0, 0\n\t.long\t0, 0\n");
 535
 536        emit_label(f, symprefix, "struct_start");
 537        flatten_tree(dti->dt, &asm_emitter, f, &strbuf, vi);
 538
 539        fprintf(f, "\t/* FDT_END */\n");
 540        asm_emit_cell(f, FDT_END);
 541        emit_label(f, symprefix, "struct_end");
 542
 543        emit_label(f, symprefix, "strings_start");
 544        dump_stringtable_asm(f, strbuf);
 545        emit_label(f, symprefix, "strings_end");
 546
 547        emit_label(f, symprefix, "blob_end");
 548
 549        /*
 550         * If the user asked for more space than is used, pad it out.
 551         */
 552        if (minsize > 0) {
 553                fprintf(f, "\t.space\t%d - (_%s_blob_end - _%s_blob_start), 0\n",
 554                        minsize, symprefix, symprefix);
 555        }
 556        if (padsize > 0) {
 557                fprintf(f, "\t.space\t%d, 0\n", padsize);
 558        }
 559        if (alignsize > 0)
 560                asm_emit_align(f, alignsize);
 561        emit_label(f, symprefix, "blob_abs_end");
 562
 563        data_free(strbuf);
 564}
 565
 566struct inbuf {
 567        char *base, *limit, *ptr;
 568};
 569
 570static void inbuf_init(struct inbuf *inb, void *base, void *limit)
 571{
 572        inb->base = base;
 573        inb->limit = limit;
 574        inb->ptr = inb->base;
 575}
 576
 577static void flat_read_chunk(struct inbuf *inb, void *p, int len)
 578{
 579        if ((inb->ptr + len) > inb->limit)
 580                die("Premature end of data parsing flat device tree\n");
 581
 582        memcpy(p, inb->ptr, len);
 583
 584        inb->ptr += len;
 585}
 586
 587static uint32_t flat_read_word(struct inbuf *inb)
 588{
 589        fdt32_t val;
 590
 591        assert(((inb->ptr - inb->base) % sizeof(val)) == 0);
 592
 593        flat_read_chunk(inb, &val, sizeof(val));
 594
 595        return fdt32_to_cpu(val);
 596}
 597
 598static void flat_realign(struct inbuf *inb, int align)
 599{
 600        int off = inb->ptr - inb->base;
 601
 602        inb->ptr = inb->base + ALIGN(off, align);
 603        if (inb->ptr > inb->limit)
 604                die("Premature end of data parsing flat device tree\n");
 605}
 606
 607static char *flat_read_string(struct inbuf *inb)
 608{
 609        int len = 0;
 610        const char *p = inb->ptr;
 611        char *str;
 612
 613        do {
 614                if (p >= inb->limit)
 615                        die("Premature end of data parsing flat device tree\n");
 616                len++;
 617        } while ((*p++) != '\0');
 618
 619        str = xstrdup(inb->ptr);
 620
 621        inb->ptr += len;
 622
 623        flat_realign(inb, sizeof(uint32_t));
 624
 625        return str;
 626}
 627
 628static struct data flat_read_data(struct inbuf *inb, int len)
 629{
 630        struct data d = empty_data;
 631
 632        if (len == 0)
 633                return empty_data;
 634
 635        d = data_grow_for(d, len);
 636        d.len = len;
 637
 638        flat_read_chunk(inb, d.val, len);
 639
 640        flat_realign(inb, sizeof(uint32_t));
 641
 642        return d;
 643}
 644
 645static char *flat_read_stringtable(struct inbuf *inb, int offset)
 646{
 647        const char *p;
 648
 649        p = inb->base + offset;
 650        while (1) {
 651                if (p >= inb->limit || p < inb->base)
 652                        die("String offset %d overruns string table\n",
 653                            offset);
 654
 655                if (*p == '\0')
 656                        break;
 657
 658                p++;
 659        }
 660
 661        return xstrdup(inb->base + offset);
 662}
 663
 664static struct property *flat_read_property(struct inbuf *dtbuf,
 665                                           struct inbuf *strbuf, int flags)
 666{
 667        uint32_t proplen, stroff;
 668        char *name;
 669        struct data val;
 670
 671        proplen = flat_read_word(dtbuf);
 672        stroff = flat_read_word(dtbuf);
 673
 674        name = flat_read_stringtable(strbuf, stroff);
 675
 676        if ((flags & FTF_VARALIGN) && (proplen >= 8))
 677                flat_realign(dtbuf, 8);
 678
 679        val = flat_read_data(dtbuf, proplen);
 680
 681        return build_property(name, val, NULL);
 682}
 683
 684
 685static struct reserve_info *flat_read_mem_reserve(struct inbuf *inb)
 686{
 687        struct reserve_info *reservelist = NULL;
 688        struct reserve_info *new;
 689        struct fdt_reserve_entry re;
 690
 691        /*
 692         * Each entry is a pair of u64 (addr, size) values for 4 cell_t's.
 693         * List terminates at an entry with size equal to zero.
 694         *
 695         * First pass, count entries.
 696         */
 697        while (1) {
 698                uint64_t address, size;
 699
 700                flat_read_chunk(inb, &re, sizeof(re));
 701                address  = fdt64_to_cpu(re.address);
 702                size = fdt64_to_cpu(re.size);
 703                if (size == 0)
 704                        break;
 705
 706                new = build_reserve_entry(address, size);
 707                reservelist = add_reserve_entry(reservelist, new);
 708        }
 709
 710        return reservelist;
 711}
 712
 713
 714static char *nodename_from_path(const char *ppath, const char *cpath)
 715{
 716        int plen;
 717
 718        plen = strlen(ppath);
 719
 720        if (!strstarts(cpath, ppath))
 721                die("Path \"%s\" is not valid as a child of \"%s\"\n",
 722                    cpath, ppath);
 723
 724        /* root node is a special case */
 725        if (!streq(ppath, "/"))
 726                plen++;
 727
 728        return xstrdup(cpath + plen);
 729}
 730
 731static struct node *unflatten_tree(struct inbuf *dtbuf,
 732                                   struct inbuf *strbuf,
 733                                   const char *parent_flatname, int flags)
 734{
 735        struct node *node;
 736        char *flatname;
 737        uint32_t val;
 738
 739        node = build_node(NULL, NULL, NULL);
 740
 741        flatname = flat_read_string(dtbuf);
 742
 743        if (flags & FTF_FULLPATH)
 744                node->name = nodename_from_path(parent_flatname, flatname);
 745        else
 746                node->name = flatname;
 747
 748        do {
 749                struct property *prop;
 750                struct node *child;
 751
 752                val = flat_read_word(dtbuf);
 753                switch (val) {
 754                case FDT_PROP:
 755                        if (node->children)
 756                                fprintf(stderr, "Warning: Flat tree input has "
 757                                        "subnodes preceding a property.\n");
 758                        prop = flat_read_property(dtbuf, strbuf, flags);
 759                        add_property(node, prop);
 760                        break;
 761
 762                case FDT_BEGIN_NODE:
 763                        child = unflatten_tree(dtbuf,strbuf, flatname, flags);
 764                        add_child(node, child);
 765                        break;
 766
 767                case FDT_END_NODE:
 768                        break;
 769
 770                case FDT_END:
 771                        die("Premature FDT_END in device tree blob\n");
 772                        break;
 773
 774                case FDT_NOP:
 775                        if (!(flags & FTF_NOPS))
 776                                fprintf(stderr, "Warning: NOP tag found in flat tree"
 777                                        " version <16\n");
 778
 779                        /* Ignore */
 780                        break;
 781
 782                default:
 783                        die("Invalid opcode word %08x in device tree blob\n",
 784                            val);
 785                }
 786        } while (val != FDT_END_NODE);
 787
 788        if (node->name != flatname) {
 789                free(flatname);
 790        }
 791
 792        return node;
 793}
 794
 795
 796struct dt_info *dt_from_blob(const char *fname)
 797{
 798        FILE *f;
 799        fdt32_t magic_buf, totalsize_buf;
 800        uint32_t magic, totalsize, version, size_dt, boot_cpuid_phys;
 801        uint32_t off_dt, off_str, off_mem_rsvmap;
 802        int rc;
 803        char *blob;
 804        struct fdt_header *fdt;
 805        char *p;
 806        struct inbuf dtbuf, strbuf;
 807        struct inbuf memresvbuf;
 808        int sizeleft;
 809        struct reserve_info *reservelist;
 810        struct node *tree;
 811        uint32_t val;
 812        int flags = 0;
 813
 814        f = srcfile_relative_open(fname, NULL);
 815
 816        rc = fread(&magic_buf, sizeof(magic_buf), 1, f);
 817        if (ferror(f))
 818                die("Error reading DT blob magic number: %s\n",
 819                    strerror(errno));
 820        if (rc < 1) {
 821                if (feof(f))
 822                        die("EOF reading DT blob magic number\n");
 823                else
 824                        die("Mysterious short read reading magic number\n");
 825        }
 826
 827        magic = fdt32_to_cpu(magic_buf);
 828        if (magic != FDT_MAGIC)
 829                die("Blob has incorrect magic number\n");
 830
 831        rc = fread(&totalsize_buf, sizeof(totalsize_buf), 1, f);
 832        if (ferror(f))
 833                die("Error reading DT blob size: %s\n", strerror(errno));
 834        if (rc < 1) {
 835                if (feof(f))
 836                        die("EOF reading DT blob size\n");
 837                else
 838                        die("Mysterious short read reading blob size\n");
 839        }
 840
 841        totalsize = fdt32_to_cpu(totalsize_buf);
 842        if (totalsize < FDT_V1_SIZE)
 843                die("DT blob size (%d) is too small\n", totalsize);
 844
 845        blob = xmalloc(totalsize);
 846
 847        fdt = (struct fdt_header *)blob;
 848        fdt->magic = cpu_to_fdt32(magic);
 849        fdt->totalsize = cpu_to_fdt32(totalsize);
 850
 851        sizeleft = totalsize - sizeof(magic) - sizeof(totalsize);
 852        p = blob + sizeof(magic)  + sizeof(totalsize);
 853
 854        while (sizeleft) {
 855                if (feof(f))
 856                        die("EOF before reading %d bytes of DT blob\n",
 857                            totalsize);
 858
 859                rc = fread(p, 1, sizeleft, f);
 860                if (ferror(f))
 861                        die("Error reading DT blob: %s\n",
 862                            strerror(errno));
 863
 864                sizeleft -= rc;
 865                p += rc;
 866        }
 867
 868        off_dt = fdt32_to_cpu(fdt->off_dt_struct);
 869        off_str = fdt32_to_cpu(fdt->off_dt_strings);
 870        off_mem_rsvmap = fdt32_to_cpu(fdt->off_mem_rsvmap);
 871        version = fdt32_to_cpu(fdt->version);
 872        boot_cpuid_phys = fdt32_to_cpu(fdt->boot_cpuid_phys);
 873
 874        if (off_mem_rsvmap >= totalsize)
 875                die("Mem Reserve structure offset exceeds total size\n");
 876
 877        if (off_dt >= totalsize)
 878                die("DT structure offset exceeds total size\n");
 879
 880        if (off_str > totalsize)
 881                die("String table offset exceeds total size\n");
 882
 883        if (version >= 3) {
 884                uint32_t size_str = fdt32_to_cpu(fdt->size_dt_strings);
 885                if ((off_str+size_str < off_str) || (off_str+size_str > totalsize))
 886                        die("String table extends past total size\n");
 887                inbuf_init(&strbuf, blob + off_str, blob + off_str + size_str);
 888        } else {
 889                inbuf_init(&strbuf, blob + off_str, blob + totalsize);
 890        }
 891
 892        if (version >= 17) {
 893                size_dt = fdt32_to_cpu(fdt->size_dt_struct);
 894                if ((off_dt+size_dt < off_dt) || (off_dt+size_dt > totalsize))
 895                        die("Structure block extends past total size\n");
 896        }
 897
 898        if (version < 16) {
 899                flags |= FTF_FULLPATH | FTF_NAMEPROPS | FTF_VARALIGN;
 900        } else {
 901                flags |= FTF_NOPS;
 902        }
 903
 904        inbuf_init(&memresvbuf,
 905                   blob + off_mem_rsvmap, blob + totalsize);
 906        inbuf_init(&dtbuf, blob + off_dt, blob + totalsize);
 907
 908        reservelist = flat_read_mem_reserve(&memresvbuf);
 909
 910        val = flat_read_word(&dtbuf);
 911
 912        if (val != FDT_BEGIN_NODE)
 913                die("Device tree blob doesn't begin with FDT_BEGIN_NODE (begins with 0x%08x)\n", val);
 914
 915        tree = unflatten_tree(&dtbuf, &strbuf, "", flags);
 916
 917        val = flat_read_word(&dtbuf);
 918        if (val != FDT_END)
 919                die("Device tree blob doesn't end with FDT_END\n");
 920
 921        free(blob);
 922
 923        fclose(f);
 924
 925        return build_dt_info(DTSF_V1, reservelist, tree, boot_cpuid_phys);
 926}
 927