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      1 /*
      2  * (C) Copyright David Gibson <dwg (at) au1.ibm.com>, IBM Corporation.  2005.
      3  *
      4  *
      5  * This program is free software; you can redistribute it and/or
      6  * modify it under the terms of the GNU General Public License as
      7  * published by the Free Software Foundation; either version 2 of the
      8  * License, or (at your option) any later version.
      9  *
     10  *  This program is distributed in the hope that it will be useful,
     11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
     12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     13  *  General Public License for more details.
     14  *
     15  *  You should have received a copy of the GNU General Public License
     16  *  along with this program; if not, write to the Free Software
     17  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
     18  *                                                                   USA
     19  */
     20 
     21 #include "dtc.h"
     22 #include "srcpos.h"
     23 
     24 #define FTF_FULLPATH	0x1
     25 #define FTF_VARALIGN	0x2
     26 #define FTF_NAMEPROPS	0x4
     27 #define FTF_BOOTCPUID	0x8
     28 #define FTF_STRTABSIZE	0x10
     29 #define FTF_STRUCTSIZE	0x20
     30 #define FTF_NOPS	0x40
     31 
     32 static struct version_info {
     33 	int version;
     34 	int last_comp_version;
     35 	int hdr_size;
     36 	int flags;
     37 } version_table[] = {
     38 	{1, 1, FDT_V1_SIZE,
     39 	 FTF_FULLPATH|FTF_VARALIGN|FTF_NAMEPROPS},
     40 	{2, 1, FDT_V2_SIZE,
     41 	 FTF_FULLPATH|FTF_VARALIGN|FTF_NAMEPROPS|FTF_BOOTCPUID},
     42 	{3, 1, FDT_V3_SIZE,
     43 	 FTF_FULLPATH|FTF_VARALIGN|FTF_NAMEPROPS|FTF_BOOTCPUID|FTF_STRTABSIZE},
     44 	{16, 16, FDT_V3_SIZE,
     45 	 FTF_BOOTCPUID|FTF_STRTABSIZE|FTF_NOPS},
     46 	{17, 16, FDT_V17_SIZE,
     47 	 FTF_BOOTCPUID|FTF_STRTABSIZE|FTF_STRUCTSIZE|FTF_NOPS},
     48 };
     49 
     50 struct emitter {
     51 	void (*cell)(void *, cell_t);
     52 	void (*string)(void *, char *, int);
     53 	void (*align)(void *, int);
     54 	void (*data)(void *, struct data);
     55 	void (*beginnode)(void *, struct label *labels);
     56 	void (*endnode)(void *, struct label *labels);
     57 	void (*property)(void *, struct label *labels);
     58 };
     59 
     60 static void bin_emit_cell(void *e, cell_t val)
     61 {
     62 	struct data *dtbuf = e;
     63 
     64 	*dtbuf = data_append_cell(*dtbuf, val);
     65 }
     66 
     67 static void bin_emit_string(void *e, char *str, int len)
     68 {
     69 	struct data *dtbuf = e;
     70 
     71 	if (len == 0)
     72 		len = strlen(str);
     73 
     74 	*dtbuf = data_append_data(*dtbuf, str, len);
     75 	*dtbuf = data_append_byte(*dtbuf, '\0');
     76 }
     77 
     78 static void bin_emit_align(void *e, int a)
     79 {
     80 	struct data *dtbuf = e;
     81 
     82 	*dtbuf = data_append_align(*dtbuf, a);
     83 }
     84 
     85 static void bin_emit_data(void *e, struct data d)
     86 {
     87 	struct data *dtbuf = e;
     88 
     89 	*dtbuf = data_append_data(*dtbuf, d.val, d.len);
     90 }
     91 
     92 static void bin_emit_beginnode(void *e, struct label *labels)
     93 {
     94 	bin_emit_cell(e, FDT_BEGIN_NODE);
     95 }
     96 
     97 static void bin_emit_endnode(void *e, struct label *labels)
     98 {
     99 	bin_emit_cell(e, FDT_END_NODE);
    100 }
    101 
    102 static void bin_emit_property(void *e, struct label *labels)
    103 {
    104 	bin_emit_cell(e, FDT_PROP);
    105 }
    106 
    107 static struct emitter bin_emitter = {
    108 	.cell = bin_emit_cell,
    109 	.string = bin_emit_string,
    110 	.align = bin_emit_align,
    111 	.data = bin_emit_data,
    112 	.beginnode = bin_emit_beginnode,
    113 	.endnode = bin_emit_endnode,
    114 	.property = bin_emit_property,
    115 };
    116 
    117 static void emit_label(FILE *f, const char *prefix, const char *label)
    118 {
    119 	fprintf(f, "\t.globl\t%s_%s\n", prefix, label);
    120 	fprintf(f, "%s_%s:\n", prefix, label);
    121 	fprintf(f, "_%s_%s:\n", prefix, label);
    122 }
    123 
    124 static void emit_offset_label(FILE *f, const char *label, int offset)
    125 {
    126 	fprintf(f, "\t.globl\t%s\n", label);
    127 	fprintf(f, "%s\t= . + %d\n", label, offset);
    128 }
    129 
    130 #define ASM_EMIT_BELONG(f, fmt, ...) \
    131 	{ \
    132 		fprintf((f), "\t.byte\t((" fmt ") >> 24) & 0xff\n", __VA_ARGS__); \
    133 		fprintf((f), "\t.byte\t((" fmt ") >> 16) & 0xff\n", __VA_ARGS__); \
    134 		fprintf((f), "\t.byte\t((" fmt ") >> 8) & 0xff\n", __VA_ARGS__); \
    135 		fprintf((f), "\t.byte\t(" fmt ") & 0xff\n", __VA_ARGS__); \
    136 	}
    137 
    138 static void asm_emit_cell(void *e, cell_t val)
    139 {
    140 	FILE *f = e;
    141 
    142 	fprintf(f, "\t.byte 0x%02x; .byte 0x%02x; .byte 0x%02x; .byte 0x%02x\n",
    143 		(val >> 24) & 0xff, (val >> 16) & 0xff,
    144 		(val >> 8) & 0xff, val & 0xff);
    145 }
    146 
    147 static void asm_emit_string(void *e, char *str, int len)
    148 {
    149 	FILE *f = e;
    150 	char c = 0;
    151 
    152 	if (len != 0) {
    153 		/* XXX: ewww */
    154 		c = str[len];
    155 		str[len] = '\0';
    156 	}
    157 
    158 	fprintf(f, "\t.string\t\"%s\"\n", str);
    159 
    160 	if (len != 0) {
    161 		str[len] = c;
    162 	}
    163 }
    164 
    165 static void asm_emit_align(void *e, int a)
    166 {
    167 	FILE *f = e;
    168 
    169 	fprintf(f, "\t.balign\t%d, 0\n", a);
    170 }
    171 
    172 static void asm_emit_data(void *e, struct data d)
    173 {
    174 	FILE *f = e;
    175 	int off = 0;
    176 	struct marker *m = d.markers;
    177 
    178 	for_each_marker_of_type(m, LABEL)
    179 		emit_offset_label(f, m->ref, m->offset);
    180 
    181 	while ((d.len - off) >= sizeof(uint32_t)) {
    182 		asm_emit_cell(e, fdt32_to_cpu(*((uint32_t *)(d.val+off))));
    183 		off += sizeof(uint32_t);
    184 	}
    185 
    186 	while ((d.len - off) >= 1) {
    187 		fprintf(f, "\t.byte\t0x%hhx\n", d.val[off]);
    188 		off += 1;
    189 	}
    190 
    191 	assert(off == d.len);
    192 }
    193 
    194 static void asm_emit_beginnode(void *e, struct label *labels)
    195 {
    196 	FILE *f = e;
    197 	struct label *l;
    198 
    199 	for_each_label(labels, l) {
    200 		fprintf(f, "\t.globl\t%s\n", l->label);
    201 		fprintf(f, "%s:\n", l->label);
    202 	}
    203 	fprintf(f, "\t/* FDT_BEGIN_NODE */\n");
    204 	asm_emit_cell(e, FDT_BEGIN_NODE);
    205 }
    206 
    207 static void asm_emit_endnode(void *e, struct label *labels)
    208 {
    209 	FILE *f = e;
    210 	struct label *l;
    211 
    212 	fprintf(f, "\t/* FDT_END_NODE */\n");
    213 	asm_emit_cell(e, FDT_END_NODE);
    214 	for_each_label(labels, l) {
    215 		fprintf(f, "\t.globl\t%s_end\n", l->label);
    216 		fprintf(f, "%s_end:\n", l->label);
    217 	}
    218 }
    219 
    220 static void asm_emit_property(void *e, struct label *labels)
    221 {
    222 	FILE *f = e;
    223 	struct label *l;
    224 
    225 	for_each_label(labels, l) {
    226 		fprintf(f, "\t.globl\t%s\n", l->label);
    227 		fprintf(f, "%s:\n", l->label);
    228 	}
    229 	fprintf(f, "\t/* FDT_PROP */\n");
    230 	asm_emit_cell(e, FDT_PROP);
    231 }
    232 
    233 static struct emitter asm_emitter = {
    234 	.cell = asm_emit_cell,
    235 	.string = asm_emit_string,
    236 	.align = asm_emit_align,
    237 	.data = asm_emit_data,
    238 	.beginnode = asm_emit_beginnode,
    239 	.endnode = asm_emit_endnode,
    240 	.property = asm_emit_property,
    241 };
    242 
    243 static int stringtable_insert(struct data *d, const char *str)
    244 {
    245 	int i;
    246 
    247 	/* FIXME: do this more efficiently? */
    248 
    249 	for (i = 0; i < d->len; i++) {
    250 		if (streq(str, d->val + i))
    251 			return i;
    252 	}
    253 
    254 	*d = data_append_data(*d, str, strlen(str)+1);
    255 	return i;
    256 }
    257 
    258 static void flatten_tree(struct node *tree, struct emitter *emit,
    259 			 void *etarget, struct data *strbuf,
    260 			 struct version_info *vi)
    261 {
    262 	struct property *prop;
    263 	struct node *child;
    264 	bool seen_name_prop = false;
    265 
    266 	if (tree->deleted)
    267 		return;
    268 
    269 	emit->beginnode(etarget, tree->labels);
    270 
    271 	if (vi->flags & FTF_FULLPATH)
    272 		emit->string(etarget, tree->fullpath, 0);
    273 	else
    274 		emit->string(etarget, tree->name, 0);
    275 
    276 	emit->align(etarget, sizeof(cell_t));
    277 
    278 	for_each_property(tree, prop) {
    279 		int nameoff;
    280 
    281 		if (streq(prop->name, "name"))
    282 			seen_name_prop = true;
    283 
    284 		nameoff = stringtable_insert(strbuf, prop->name);
    285 
    286 		emit->property(etarget, prop->labels);
    287 		emit->cell(etarget, prop->val.len);
    288 		emit->cell(etarget, nameoff);
    289 
    290 		if ((vi->flags & FTF_VARALIGN) && (prop->val.len >= 8))
    291 			emit->align(etarget, 8);
    292 
    293 		emit->data(etarget, prop->val);
    294 		emit->align(etarget, sizeof(cell_t));
    295 	}
    296 
    297 	if ((vi->flags & FTF_NAMEPROPS) && !seen_name_prop) {
    298 		emit->property(etarget, NULL);
    299 		emit->cell(etarget, tree->basenamelen+1);
    300 		emit->cell(etarget, stringtable_insert(strbuf, "name"));
    301 
    302 		if ((vi->flags & FTF_VARALIGN) && ((tree->basenamelen+1) >= 8))
    303 			emit->align(etarget, 8);
    304 
    305 		emit->string(etarget, tree->name, tree->basenamelen);
    306 		emit->align(etarget, sizeof(cell_t));
    307 	}
    308 
    309 	for_each_child(tree, child) {
    310 		flatten_tree(child, emit, etarget, strbuf, vi);
    311 	}
    312 
    313 	emit->endnode(etarget, tree->labels);
    314 }
    315 
    316 static struct data flatten_reserve_list(struct reserve_info *reservelist,
    317 				 struct version_info *vi)
    318 {
    319 	struct reserve_info *re;
    320 	struct data d = empty_data;
    321 	static struct fdt_reserve_entry null_re = {0,0};
    322 	int    j;
    323 
    324 	for (re = reservelist; re; re = re->next) {
    325 		d = data_append_re(d, &re->re);
    326 	}
    327 	/*
    328 	 * Add additional reserved slots if the user asked for them.
    329 	 */
    330 	for (j = 0; j < reservenum; j++) {
    331 		d = data_append_re(d, &null_re);
    332 	}
    333 
    334 	return d;
    335 }
    336 
    337 static void make_fdt_header(struct fdt_header *fdt,
    338 			    struct version_info *vi,
    339 			    int reservesize, int dtsize, int strsize,
    340 			    int boot_cpuid_phys)
    341 {
    342 	int reserve_off;
    343 
    344 	reservesize += sizeof(struct fdt_reserve_entry);
    345 
    346 	memset(fdt, 0xff, sizeof(*fdt));
    347 
    348 	fdt->magic = cpu_to_fdt32(FDT_MAGIC);
    349 	fdt->version = cpu_to_fdt32(vi->version);
    350 	fdt->last_comp_version = cpu_to_fdt32(vi->last_comp_version);
    351 
    352 	/* Reserve map should be doubleword aligned */
    353 	reserve_off = ALIGN(vi->hdr_size, 8);
    354 
    355 	fdt->off_mem_rsvmap = cpu_to_fdt32(reserve_off);
    356 	fdt->off_dt_struct = cpu_to_fdt32(reserve_off + reservesize);
    357 	fdt->off_dt_strings = cpu_to_fdt32(reserve_off + reservesize
    358 					  + dtsize);
    359 	fdt->totalsize = cpu_to_fdt32(reserve_off + reservesize + dtsize + strsize);
    360 
    361 	if (vi->flags & FTF_BOOTCPUID)
    362 		fdt->boot_cpuid_phys = cpu_to_fdt32(boot_cpuid_phys);
    363 	if (vi->flags & FTF_STRTABSIZE)
    364 		fdt->size_dt_strings = cpu_to_fdt32(strsize);
    365 	if (vi->flags & FTF_STRUCTSIZE)
    366 		fdt->size_dt_struct = cpu_to_fdt32(dtsize);
    367 }
    368 
    369 void dt_to_blob(FILE *f, struct dt_info *dti, int version)
    370 {
    371 	struct version_info *vi = NULL;
    372 	int i;
    373 	struct data blob       = empty_data;
    374 	struct data reservebuf = empty_data;
    375 	struct data dtbuf      = empty_data;
    376 	struct data strbuf     = empty_data;
    377 	struct fdt_header fdt;
    378 	int padlen = 0;
    379 
    380 	for (i = 0; i < ARRAY_SIZE(version_table); i++) {
    381 		if (version_table[i].version == version)
    382 			vi = &version_table[i];
    383 	}
    384 	if (!vi)
    385 		die("Unknown device tree blob version %d\n", version);
    386 
    387 	flatten_tree(dti->dt, &bin_emitter, &dtbuf, &strbuf, vi);
    388 	bin_emit_cell(&dtbuf, FDT_END);
    389 
    390 	reservebuf = flatten_reserve_list(dti->reservelist, vi);
    391 
    392 	/* Make header */
    393 	make_fdt_header(&fdt, vi, reservebuf.len, dtbuf.len, strbuf.len,
    394 			dti->boot_cpuid_phys);
    395 
    396 	/*
    397 	 * If the user asked for more space than is used, adjust the totalsize.
    398 	 */
    399 	if (minsize > 0) {
    400 		padlen = minsize - fdt32_to_cpu(fdt.totalsize);
    401 		if (padlen < 0) {
    402 			padlen = 0;
    403 			if (quiet < 1)
    404 				fprintf(stderr,
    405 					"Warning: blob size %d >= minimum size %d\n",
    406 					fdt32_to_cpu(fdt.totalsize), minsize);
    407 		}
    408 	}
    409 
    410 	if (padsize > 0)
    411 		padlen = padsize;
    412 
    413 	if (alignsize > 0)
    414 		padlen = ALIGN(fdt32_to_cpu(fdt.totalsize) + padlen, alignsize)
    415 			- fdt32_to_cpu(fdt.totalsize);
    416 
    417 	if (padlen > 0) {
    418 		int tsize = fdt32_to_cpu(fdt.totalsize);
    419 		tsize += padlen;
    420 		fdt.totalsize = cpu_to_fdt32(tsize);
    421 	}
    422 
    423 	/*
    424 	 * Assemble the blob: start with the header, add with alignment
    425 	 * the reserve buffer, add the reserve map terminating zeroes,
    426 	 * the device tree itself, and finally the strings.
    427 	 */
    428 	blob = data_append_data(blob, &fdt, vi->hdr_size);
    429 	blob = data_append_align(blob, 8);
    430 	blob = data_merge(blob, reservebuf);
    431 	blob = data_append_zeroes(blob, sizeof(struct fdt_reserve_entry));
    432 	blob = data_merge(blob, dtbuf);
    433 	blob = data_merge(blob, strbuf);
    434 
    435 	/*
    436 	 * If the user asked for more space than is used, pad out the blob.
    437 	 */
    438 	if (padlen > 0)
    439 		blob = data_append_zeroes(blob, padlen);
    440 
    441 	if (fwrite(blob.val, blob.len, 1, f) != 1) {
    442 		if (ferror(f))
    443 			die("Error writing device tree blob: %s\n",
    444 			    strerror(errno));
    445 		else
    446 			die("Short write on device tree blob\n");
    447 	}
    448 
    449 	/*
    450 	 * data_merge() frees the right-hand element so only the blob
    451 	 * remains to be freed.
    452 	 */
    453 	data_free(blob);
    454 }
    455 
    456 static void dump_stringtable_asm(FILE *f, struct data strbuf)
    457 {
    458 	const char *p;
    459 	int len;
    460 
    461 	p = strbuf.val;
    462 
    463 	while (p < (strbuf.val + strbuf.len)) {
    464 		len = strlen(p);
    465 		fprintf(f, "\t.string \"%s\"\n", p);
    466 		p += len+1;
    467 	}
    468 }
    469 
    470 void dt_to_asm(FILE *f, struct dt_info *dti, int version)
    471 {
    472 	struct version_info *vi = NULL;
    473 	int i;
    474 	struct data strbuf = empty_data;
    475 	struct reserve_info *re;
    476 	const char *symprefix = "dt";
    477 
    478 	for (i = 0; i < ARRAY_SIZE(version_table); i++) {
    479 		if (version_table[i].version == version)
    480 			vi = &version_table[i];
    481 	}
    482 	if (!vi)
    483 		die("Unknown device tree blob version %d\n", version);
    484 
    485 	fprintf(f, "/* autogenerated by dtc, do not edit */\n\n");
    486 
    487 	emit_label(f, symprefix, "blob_start");
    488 	emit_label(f, symprefix, "header");
    489 	fprintf(f, "\t/* magic */\n");
    490 	asm_emit_cell(f, FDT_MAGIC);
    491 	fprintf(f, "\t/* totalsize */\n");
    492 	ASM_EMIT_BELONG(f, "_%s_blob_abs_end - _%s_blob_start",
    493 			symprefix, symprefix);
    494 	fprintf(f, "\t/* off_dt_struct */\n");
    495 	ASM_EMIT_BELONG(f, "_%s_struct_start - _%s_blob_start",
    496 		symprefix, symprefix);
    497 	fprintf(f, "\t/* off_dt_strings */\n");
    498 	ASM_EMIT_BELONG(f, "_%s_strings_start - _%s_blob_start",
    499 		symprefix, symprefix);
    500 	fprintf(f, "\t/* off_mem_rsvmap */\n");
    501 	ASM_EMIT_BELONG(f, "_%s_reserve_map - _%s_blob_start",
    502 		symprefix, symprefix);
    503 	fprintf(f, "\t/* version */\n");
    504 	asm_emit_cell(f, vi->version);
    505 	fprintf(f, "\t/* last_comp_version */\n");
    506 	asm_emit_cell(f, vi->last_comp_version);
    507 
    508 	if (vi->flags & FTF_BOOTCPUID) {
    509 		fprintf(f, "\t/* boot_cpuid_phys */\n");
    510 		asm_emit_cell(f, dti->boot_cpuid_phys);
    511 	}
    512 
    513 	if (vi->flags & FTF_STRTABSIZE) {
    514 		fprintf(f, "\t/* size_dt_strings */\n");
    515 		ASM_EMIT_BELONG(f, "_%s_strings_end - _%s_strings_start",
    516 				symprefix, symprefix);
    517 	}
    518 
    519 	if (vi->flags & FTF_STRUCTSIZE) {
    520 		fprintf(f, "\t/* size_dt_struct */\n");
    521 		ASM_EMIT_BELONG(f, "_%s_struct_end - _%s_struct_start",
    522 			symprefix, symprefix);
    523 	}
    524 
    525 	/*
    526 	 * Reserve map entries.
    527 	 * Align the reserve map to a doubleword boundary.
    528 	 * Each entry is an (address, size) pair of u64 values.
    529 	 * Always supply a zero-sized temination entry.
    530 	 */
    531 	asm_emit_align(f, 8);
    532 	emit_label(f, symprefix, "reserve_map");
    533 
    534 	fprintf(f, "/* Memory reserve map from source file */\n");
    535 
    536 	/*
    537 	 * Use .long on high and low halfs of u64s to avoid .quad
    538 	 * as it appears .quad isn't available in some assemblers.
    539 	 */
    540 	for (re = dti->reservelist; re; re = re->next) {
    541 		struct label *l;
    542 
    543 		for_each_label(re->labels, l) {
    544 			fprintf(f, "\t.globl\t%s\n", l->label);
    545 			fprintf(f, "%s:\n", l->label);
    546 		}
    547 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->re.address >> 32));
    548 		ASM_EMIT_BELONG(f, "0x%08x",
    549 				(unsigned int)(re->re.address & 0xffffffff));
    550 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->re.size >> 32));
    551 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->re.size & 0xffffffff));
    552 	}
    553 	for (i = 0; i < reservenum; i++) {
    554 		fprintf(f, "\t.long\t0, 0\n\t.long\t0, 0\n");
    555 	}
    556 
    557 	fprintf(f, "\t.long\t0, 0\n\t.long\t0, 0\n");
    558 
    559 	emit_label(f, symprefix, "struct_start");
    560 	flatten_tree(dti->dt, &asm_emitter, f, &strbuf, vi);
    561 
    562 	fprintf(f, "\t/* FDT_END */\n");
    563 	asm_emit_cell(f, FDT_END);
    564 	emit_label(f, symprefix, "struct_end");
    565 
    566 	emit_label(f, symprefix, "strings_start");
    567 	dump_stringtable_asm(f, strbuf);
    568 	emit_label(f, symprefix, "strings_end");
    569 
    570 	emit_label(f, symprefix, "blob_end");
    571 
    572 	/*
    573 	 * If the user asked for more space than is used, pad it out.
    574 	 */
    575 	if (minsize > 0) {
    576 		fprintf(f, "\t.space\t%d - (_%s_blob_end - _%s_blob_start), 0\n",
    577 			minsize, symprefix, symprefix);
    578 	}
    579 	if (padsize > 0) {
    580 		fprintf(f, "\t.space\t%d, 0\n", padsize);
    581 	}
    582 	if (alignsize > 0)
    583 		asm_emit_align(f, alignsize);
    584 	emit_label(f, symprefix, "blob_abs_end");
    585 
    586 	data_free(strbuf);
    587 }
    588 
    589 struct inbuf {
    590 	char *base, *limit, *ptr;
    591 };
    592 
    593 static void inbuf_init(struct inbuf *inb, void *base, void *limit)
    594 {
    595 	inb->base = base;
    596 	inb->limit = limit;
    597 	inb->ptr = inb->base;
    598 }
    599 
    600 static void flat_read_chunk(struct inbuf *inb, void *p, int len)
    601 {
    602 	if ((inb->ptr + len) > inb->limit)
    603 		die("Premature end of data parsing flat device tree\n");
    604 
    605 	memcpy(p, inb->ptr, len);
    606 
    607 	inb->ptr += len;
    608 }
    609 
    610 static uint32_t flat_read_word(struct inbuf *inb)
    611 {
    612 	uint32_t val;
    613 
    614 	assert(((inb->ptr - inb->base) % sizeof(val)) == 0);
    615 
    616 	flat_read_chunk(inb, &val, sizeof(val));
    617 
    618 	return fdt32_to_cpu(val);
    619 }
    620 
    621 static void flat_realign(struct inbuf *inb, int align)
    622 {
    623 	int off = inb->ptr - inb->base;
    624 
    625 	inb->ptr = inb->base + ALIGN(off, align);
    626 	if (inb->ptr > inb->limit)
    627 		die("Premature end of data parsing flat device tree\n");
    628 }
    629 
    630 static char *flat_read_string(struct inbuf *inb)
    631 {
    632 	int len = 0;
    633 	const char *p = inb->ptr;
    634 	char *str;
    635 
    636 	do {
    637 		if (p >= inb->limit)
    638 			die("Premature end of data parsing flat device tree\n");
    639 		len++;
    640 	} while ((*p++) != '\0');
    641 
    642 	str = xstrdup(inb->ptr);
    643 
    644 	inb->ptr += len;
    645 
    646 	flat_realign(inb, sizeof(uint32_t));
    647 
    648 	return str;
    649 }
    650 
    651 static struct data flat_read_data(struct inbuf *inb, int len)
    652 {
    653 	struct data d = empty_data;
    654 
    655 	if (len == 0)
    656 		return empty_data;
    657 
    658 	d = data_grow_for(d, len);
    659 	d.len = len;
    660 
    661 	flat_read_chunk(inb, d.val, len);
    662 
    663 	flat_realign(inb, sizeof(uint32_t));
    664 
    665 	return d;
    666 }
    667 
    668 static char *flat_read_stringtable(struct inbuf *inb, int offset)
    669 {
    670 	const char *p;
    671 
    672 	p = inb->base + offset;
    673 	while (1) {
    674 		if (p >= inb->limit || p < inb->base)
    675 			die("String offset %d overruns string table\n",
    676 			    offset);
    677 
    678 		if (*p == '\0')
    679 			break;
    680 
    681 		p++;
    682 	}
    683 
    684 	return xstrdup(inb->base + offset);
    685 }
    686 
    687 static struct property *flat_read_property(struct inbuf *dtbuf,
    688 					   struct inbuf *strbuf, int flags)
    689 {
    690 	uint32_t proplen, stroff;
    691 	char *name;
    692 	struct data val;
    693 
    694 	proplen = flat_read_word(dtbuf);
    695 	stroff = flat_read_word(dtbuf);
    696 
    697 	name = flat_read_stringtable(strbuf, stroff);
    698 
    699 	if ((flags & FTF_VARALIGN) && (proplen >= 8))
    700 		flat_realign(dtbuf, 8);
    701 
    702 	val = flat_read_data(dtbuf, proplen);
    703 
    704 	return build_property(name, val);
    705 }
    706 
    707 
    708 static struct reserve_info *flat_read_mem_reserve(struct inbuf *inb)
    709 {
    710 	struct reserve_info *reservelist = NULL;
    711 	struct reserve_info *new;
    712 	struct fdt_reserve_entry re;
    713 
    714 	/*
    715 	 * Each entry is a pair of u64 (addr, size) values for 4 cell_t's.
    716 	 * List terminates at an entry with size equal to zero.
    717 	 *
    718 	 * First pass, count entries.
    719 	 */
    720 	while (1) {
    721 		flat_read_chunk(inb, &re, sizeof(re));
    722 		re.address  = fdt64_to_cpu(re.address);
    723 		re.size = fdt64_to_cpu(re.size);
    724 		if (re.size == 0)
    725 			break;
    726 
    727 		new = build_reserve_entry(re.address, re.size);
    728 		reservelist = add_reserve_entry(reservelist, new);
    729 	}
    730 
    731 	return reservelist;
    732 }
    733 
    734 
    735 static char *nodename_from_path(const char *ppath, const char *cpath)
    736 {
    737 	int plen;
    738 
    739 	plen = strlen(ppath);
    740 
    741 	if (!strneq(ppath, cpath, plen))
    742 		die("Path \"%s\" is not valid as a child of \"%s\"\n",
    743 		    cpath, ppath);
    744 
    745 	/* root node is a special case */
    746 	if (!streq(ppath, "/"))
    747 		plen++;
    748 
    749 	return xstrdup(cpath + plen);
    750 }
    751 
    752 static struct node *unflatten_tree(struct inbuf *dtbuf,
    753 				   struct inbuf *strbuf,
    754 				   const char *parent_flatname, int flags)
    755 {
    756 	struct node *node;
    757 	char *flatname;
    758 	uint32_t val;
    759 
    760 	node = build_node(NULL, NULL);
    761 
    762 	flatname = flat_read_string(dtbuf);
    763 
    764 	if (flags & FTF_FULLPATH)
    765 		node->name = nodename_from_path(parent_flatname, flatname);
    766 	else
    767 		node->name = flatname;
    768 
    769 	do {
    770 		struct property *prop;
    771 		struct node *child;
    772 
    773 		val = flat_read_word(dtbuf);
    774 		switch (val) {
    775 		case FDT_PROP:
    776 			if (node->children)
    777 				fprintf(stderr, "Warning: Flat tree input has "
    778 					"subnodes preceding a property.\n");
    779 			prop = flat_read_property(dtbuf, strbuf, flags);
    780 			add_property(node, prop);
    781 			break;
    782 
    783 		case FDT_BEGIN_NODE:
    784 			child = unflatten_tree(dtbuf,strbuf, flatname, flags);
    785 			add_child(node, child);
    786 			break;
    787 
    788 		case FDT_END_NODE:
    789 			break;
    790 
    791 		case FDT_END:
    792 			die("Premature FDT_END in device tree blob\n");
    793 			break;
    794 
    795 		case FDT_NOP:
    796 			if (!(flags & FTF_NOPS))
    797 				fprintf(stderr, "Warning: NOP tag found in flat tree"
    798 					" version <16\n");
    799 
    800 			/* Ignore */
    801 			break;
    802 
    803 		default:
    804 			die("Invalid opcode word %08x in device tree blob\n",
    805 			    val);
    806 		}
    807 	} while (val != FDT_END_NODE);
    808 
    809 	if (node->name != flatname) {
    810 		free(flatname);
    811 	}
    812 
    813 	return node;
    814 }
    815 
    816 
    817 struct dt_info *dt_from_blob(const char *fname)
    818 {
    819 	FILE *f;
    820 	uint32_t magic, totalsize, version, size_dt, boot_cpuid_phys;
    821 	uint32_t off_dt, off_str, off_mem_rsvmap;
    822 	int rc;
    823 	char *blob;
    824 	struct fdt_header *fdt;
    825 	char *p;
    826 	struct inbuf dtbuf, strbuf;
    827 	struct inbuf memresvbuf;
    828 	int sizeleft;
    829 	struct reserve_info *reservelist;
    830 	struct node *tree;
    831 	uint32_t val;
    832 	int flags = 0;
    833 
    834 	f = srcfile_relative_open(fname, NULL);
    835 
    836 	rc = fread(&magic, sizeof(magic), 1, f);
    837 	if (ferror(f))
    838 		die("Error reading DT blob magic number: %s\n",
    839 		    strerror(errno));
    840 	if (rc < 1) {
    841 		if (feof(f))
    842 			die("EOF reading DT blob magic number\n");
    843 		else
    844 			die("Mysterious short read reading magic number\n");
    845 	}
    846 
    847 	magic = fdt32_to_cpu(magic);
    848 	if (magic != FDT_MAGIC)
    849 		die("Blob has incorrect magic number\n");
    850 
    851 	rc = fread(&totalsize, sizeof(totalsize), 1, f);
    852 	if (ferror(f))
    853 		die("Error reading DT blob size: %s\n", strerror(errno));
    854 	if (rc < 1) {
    855 		if (feof(f))
    856 			die("EOF reading DT blob size\n");
    857 		else
    858 			die("Mysterious short read reading blob size\n");
    859 	}
    860 
    861 	totalsize = fdt32_to_cpu(totalsize);
    862 	if (totalsize < FDT_V1_SIZE)
    863 		die("DT blob size (%d) is too small\n", totalsize);
    864 
    865 	blob = xmalloc(totalsize);
    866 
    867 	fdt = (struct fdt_header *)blob;
    868 	fdt->magic = cpu_to_fdt32(magic);
    869 	fdt->totalsize = cpu_to_fdt32(totalsize);
    870 
    871 	sizeleft = totalsize - sizeof(magic) - sizeof(totalsize);
    872 	p = blob + sizeof(magic)  + sizeof(totalsize);
    873 
    874 	while (sizeleft) {
    875 		if (feof(f))
    876 			die("EOF before reading %d bytes of DT blob\n",
    877 			    totalsize);
    878 
    879 		rc = fread(p, 1, sizeleft, f);
    880 		if (ferror(f))
    881 			die("Error reading DT blob: %s\n",
    882 			    strerror(errno));
    883 
    884 		sizeleft -= rc;
    885 		p += rc;
    886 	}
    887 
    888 	off_dt = fdt32_to_cpu(fdt->off_dt_struct);
    889 	off_str = fdt32_to_cpu(fdt->off_dt_strings);
    890 	off_mem_rsvmap = fdt32_to_cpu(fdt->off_mem_rsvmap);
    891 	version = fdt32_to_cpu(fdt->version);
    892 	boot_cpuid_phys = fdt32_to_cpu(fdt->boot_cpuid_phys);
    893 
    894 	if (off_mem_rsvmap >= totalsize)
    895 		die("Mem Reserve structure offset exceeds total size\n");
    896 
    897 	if (off_dt >= totalsize)
    898 		die("DT structure offset exceeds total size\n");
    899 
    900 	if (off_str > totalsize)
    901 		die("String table offset exceeds total size\n");
    902 
    903 	if (version >= 3) {
    904 		uint32_t size_str = fdt32_to_cpu(fdt->size_dt_strings);
    905 		if ((off_str+size_str < off_str) || (off_str+size_str > totalsize))
    906 			die("String table extends past total size\n");
    907 		inbuf_init(&strbuf, blob + off_str, blob + off_str + size_str);
    908 	} else {
    909 		inbuf_init(&strbuf, blob + off_str, blob + totalsize);
    910 	}
    911 
    912 	if (version >= 17) {
    913 		size_dt = fdt32_to_cpu(fdt->size_dt_struct);
    914 		if ((off_dt+size_dt < off_dt) || (off_dt+size_dt > totalsize))
    915 			die("Structure block extends past total size\n");
    916 	}
    917 
    918 	if (version < 16) {
    919 		flags |= FTF_FULLPATH | FTF_NAMEPROPS | FTF_VARALIGN;
    920 	} else {
    921 		flags |= FTF_NOPS;
    922 	}
    923 
    924 	inbuf_init(&memresvbuf,
    925 		   blob + off_mem_rsvmap, blob + totalsize);
    926 	inbuf_init(&dtbuf, blob + off_dt, blob + totalsize);
    927 
    928 	reservelist = flat_read_mem_reserve(&memresvbuf);
    929 
    930 	val = flat_read_word(&dtbuf);
    931 
    932 	if (val != FDT_BEGIN_NODE)
    933 		die("Device tree blob doesn't begin with FDT_BEGIN_NODE (begins with 0x%08x)\n", val);
    934 
    935 	tree = unflatten_tree(&dtbuf, &strbuf, "", flags);
    936 
    937 	val = flat_read_word(&dtbuf);
    938 	if (val != FDT_END)
    939 		die("Device tree blob doesn't end with FDT_END\n");
    940 
    941 	free(blob);
    942 
    943 	fclose(f);
    944 
    945 	return build_dt_info(DTSF_V1, reservelist, tree, boot_cpuid_phys);
    946 }
    947