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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 *, const 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, const 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, const char *str, int len)
    148 {
    149 	FILE *f = e;
    150 
    151 	if (len != 0)
    152 		fprintf(f, "\t.string\t\"%.*s\"\n", len, str);
    153 	else
    154 		fprintf(f, "\t.string\t\"%s\"\n", str);
    155 }
    156 
    157 static void asm_emit_align(void *e, int a)
    158 {
    159 	FILE *f = e;
    160 
    161 	fprintf(f, "\t.balign\t%d, 0\n", a);
    162 }
    163 
    164 static void asm_emit_data(void *e, struct data d)
    165 {
    166 	FILE *f = e;
    167 	int off = 0;
    168 	struct marker *m = d.markers;
    169 
    170 	for_each_marker_of_type(m, LABEL)
    171 		emit_offset_label(f, m->ref, m->offset);
    172 
    173 	while ((d.len - off) >= sizeof(uint32_t)) {
    174 		asm_emit_cell(e, fdt32_to_cpu(*((fdt32_t *)(d.val+off))));
    175 		off += sizeof(uint32_t);
    176 	}
    177 
    178 	while ((d.len - off) >= 1) {
    179 		fprintf(f, "\t.byte\t0x%hhx\n", d.val[off]);
    180 		off += 1;
    181 	}
    182 
    183 	assert(off == d.len);
    184 }
    185 
    186 static void asm_emit_beginnode(void *e, struct label *labels)
    187 {
    188 	FILE *f = e;
    189 	struct label *l;
    190 
    191 	for_each_label(labels, l) {
    192 		fprintf(f, "\t.globl\t%s\n", l->label);
    193 		fprintf(f, "%s:\n", l->label);
    194 	}
    195 	fprintf(f, "\t/* FDT_BEGIN_NODE */\n");
    196 	asm_emit_cell(e, FDT_BEGIN_NODE);
    197 }
    198 
    199 static void asm_emit_endnode(void *e, struct label *labels)
    200 {
    201 	FILE *f = e;
    202 	struct label *l;
    203 
    204 	fprintf(f, "\t/* FDT_END_NODE */\n");
    205 	asm_emit_cell(e, FDT_END_NODE);
    206 	for_each_label(labels, l) {
    207 		fprintf(f, "\t.globl\t%s_end\n", l->label);
    208 		fprintf(f, "%s_end:\n", l->label);
    209 	}
    210 }
    211 
    212 static void asm_emit_property(void *e, struct label *labels)
    213 {
    214 	FILE *f = e;
    215 	struct label *l;
    216 
    217 	for_each_label(labels, l) {
    218 		fprintf(f, "\t.globl\t%s\n", l->label);
    219 		fprintf(f, "%s:\n", l->label);
    220 	}
    221 	fprintf(f, "\t/* FDT_PROP */\n");
    222 	asm_emit_cell(e, FDT_PROP);
    223 }
    224 
    225 static struct emitter asm_emitter = {
    226 	.cell = asm_emit_cell,
    227 	.string = asm_emit_string,
    228 	.align = asm_emit_align,
    229 	.data = asm_emit_data,
    230 	.beginnode = asm_emit_beginnode,
    231 	.endnode = asm_emit_endnode,
    232 	.property = asm_emit_property,
    233 };
    234 
    235 static int stringtable_insert(struct data *d, const char *str)
    236 {
    237 	int i;
    238 
    239 	/* FIXME: do this more efficiently? */
    240 
    241 	for (i = 0; i < d->len; i++) {
    242 		if (streq(str, d->val + i))
    243 			return i;
    244 	}
    245 
    246 	*d = data_append_data(*d, str, strlen(str)+1);
    247 	return i;
    248 }
    249 
    250 static void flatten_tree(struct node *tree, struct emitter *emit,
    251 			 void *etarget, struct data *strbuf,
    252 			 struct version_info *vi)
    253 {
    254 	struct property *prop;
    255 	struct node *child;
    256 	bool seen_name_prop = false;
    257 
    258 	if (tree->deleted)
    259 		return;
    260 
    261 	emit->beginnode(etarget, tree->labels);
    262 
    263 	if (vi->flags & FTF_FULLPATH)
    264 		emit->string(etarget, tree->fullpath, 0);
    265 	else
    266 		emit->string(etarget, tree->name, 0);
    267 
    268 	emit->align(etarget, sizeof(cell_t));
    269 
    270 	for_each_property(tree, prop) {
    271 		int nameoff;
    272 
    273 		if (streq(prop->name, "name"))
    274 			seen_name_prop = true;
    275 
    276 		nameoff = stringtable_insert(strbuf, prop->name);
    277 
    278 		emit->property(etarget, prop->labels);
    279 		emit->cell(etarget, prop->val.len);
    280 		emit->cell(etarget, nameoff);
    281 
    282 		if ((vi->flags & FTF_VARALIGN) && (prop->val.len >= 8))
    283 			emit->align(etarget, 8);
    284 
    285 		emit->data(etarget, prop->val);
    286 		emit->align(etarget, sizeof(cell_t));
    287 	}
    288 
    289 	if ((vi->flags & FTF_NAMEPROPS) && !seen_name_prop) {
    290 		emit->property(etarget, NULL);
    291 		emit->cell(etarget, tree->basenamelen+1);
    292 		emit->cell(etarget, stringtable_insert(strbuf, "name"));
    293 
    294 		if ((vi->flags & FTF_VARALIGN) && ((tree->basenamelen+1) >= 8))
    295 			emit->align(etarget, 8);
    296 
    297 		emit->string(etarget, tree->name, tree->basenamelen);
    298 		emit->align(etarget, sizeof(cell_t));
    299 	}
    300 
    301 	for_each_child(tree, child) {
    302 		flatten_tree(child, emit, etarget, strbuf, vi);
    303 	}
    304 
    305 	emit->endnode(etarget, tree->labels);
    306 }
    307 
    308 static struct data flatten_reserve_list(struct reserve_info *reservelist,
    309 				 struct version_info *vi)
    310 {
    311 	struct reserve_info *re;
    312 	struct data d = empty_data;
    313 	int    j;
    314 
    315 	for (re = reservelist; re; re = re->next) {
    316 		d = data_append_re(d, re->address, re->size);
    317 	}
    318 	/*
    319 	 * Add additional reserved slots if the user asked for them.
    320 	 */
    321 	for (j = 0; j < reservenum; j++) {
    322 		d = data_append_re(d, 0, 0);
    323 	}
    324 
    325 	return d;
    326 }
    327 
    328 static void make_fdt_header(struct fdt_header *fdt,
    329 			    struct version_info *vi,
    330 			    int reservesize, int dtsize, int strsize,
    331 			    int boot_cpuid_phys)
    332 {
    333 	int reserve_off;
    334 
    335 	reservesize += sizeof(struct fdt_reserve_entry);
    336 
    337 	memset(fdt, 0xff, sizeof(*fdt));
    338 
    339 	fdt->magic = cpu_to_fdt32(FDT_MAGIC);
    340 	fdt->version = cpu_to_fdt32(vi->version);
    341 	fdt->last_comp_version = cpu_to_fdt32(vi->last_comp_version);
    342 
    343 	/* Reserve map should be doubleword aligned */
    344 	reserve_off = ALIGN(vi->hdr_size, 8);
    345 
    346 	fdt->off_mem_rsvmap = cpu_to_fdt32(reserve_off);
    347 	fdt->off_dt_struct = cpu_to_fdt32(reserve_off + reservesize);
    348 	fdt->off_dt_strings = cpu_to_fdt32(reserve_off + reservesize
    349 					  + dtsize);
    350 	fdt->totalsize = cpu_to_fdt32(reserve_off + reservesize + dtsize + strsize);
    351 
    352 	if (vi->flags & FTF_BOOTCPUID)
    353 		fdt->boot_cpuid_phys = cpu_to_fdt32(boot_cpuid_phys);
    354 	if (vi->flags & FTF_STRTABSIZE)
    355 		fdt->size_dt_strings = cpu_to_fdt32(strsize);
    356 	if (vi->flags & FTF_STRUCTSIZE)
    357 		fdt->size_dt_struct = cpu_to_fdt32(dtsize);
    358 }
    359 
    360 void dt_to_blob(FILE *f, struct dt_info *dti, int version)
    361 {
    362 	struct version_info *vi = NULL;
    363 	int i;
    364 	struct data blob       = empty_data;
    365 	struct data reservebuf = empty_data;
    366 	struct data dtbuf      = empty_data;
    367 	struct data strbuf     = empty_data;
    368 	struct fdt_header fdt;
    369 	int padlen = 0;
    370 
    371 	for (i = 0; i < ARRAY_SIZE(version_table); i++) {
    372 		if (version_table[i].version == version)
    373 			vi = &version_table[i];
    374 	}
    375 	if (!vi)
    376 		die("Unknown device tree blob version %d\n", version);
    377 
    378 	flatten_tree(dti->dt, &bin_emitter, &dtbuf, &strbuf, vi);
    379 	bin_emit_cell(&dtbuf, FDT_END);
    380 
    381 	reservebuf = flatten_reserve_list(dti->reservelist, vi);
    382 
    383 	/* Make header */
    384 	make_fdt_header(&fdt, vi, reservebuf.len, dtbuf.len, strbuf.len,
    385 			dti->boot_cpuid_phys);
    386 
    387 	/*
    388 	 * If the user asked for more space than is used, adjust the totalsize.
    389 	 */
    390 	if (minsize > 0) {
    391 		padlen = minsize - fdt32_to_cpu(fdt.totalsize);
    392 		if (padlen < 0) {
    393 			padlen = 0;
    394 			if (quiet < 1)
    395 				fprintf(stderr,
    396 					"Warning: blob size %d >= minimum size %d\n",
    397 					fdt32_to_cpu(fdt.totalsize), minsize);
    398 		}
    399 	}
    400 
    401 	if (padsize > 0)
    402 		padlen = padsize;
    403 
    404 	if (alignsize > 0)
    405 		padlen = ALIGN(fdt32_to_cpu(fdt.totalsize) + padlen, alignsize)
    406 			- fdt32_to_cpu(fdt.totalsize);
    407 
    408 	if (padlen > 0) {
    409 		int tsize = fdt32_to_cpu(fdt.totalsize);
    410 		tsize += padlen;
    411 		fdt.totalsize = cpu_to_fdt32(tsize);
    412 	}
    413 
    414 	/*
    415 	 * Assemble the blob: start with the header, add with alignment
    416 	 * the reserve buffer, add the reserve map terminating zeroes,
    417 	 * the device tree itself, and finally the strings.
    418 	 */
    419 	blob = data_append_data(blob, &fdt, vi->hdr_size);
    420 	blob = data_append_align(blob, 8);
    421 	blob = data_merge(blob, reservebuf);
    422 	blob = data_append_zeroes(blob, sizeof(struct fdt_reserve_entry));
    423 	blob = data_merge(blob, dtbuf);
    424 	blob = data_merge(blob, strbuf);
    425 
    426 	/*
    427 	 * If the user asked for more space than is used, pad out the blob.
    428 	 */
    429 	if (padlen > 0)
    430 		blob = data_append_zeroes(blob, padlen);
    431 
    432 	if (fwrite(blob.val, blob.len, 1, f) != 1) {
    433 		if (ferror(f))
    434 			die("Error writing device tree blob: %s\n",
    435 			    strerror(errno));
    436 		else
    437 			die("Short write on device tree blob\n");
    438 	}
    439 
    440 	/*
    441 	 * data_merge() frees the right-hand element so only the blob
    442 	 * remains to be freed.
    443 	 */
    444 	data_free(blob);
    445 }
    446 
    447 static void dump_stringtable_asm(FILE *f, struct data strbuf)
    448 {
    449 	const char *p;
    450 	int len;
    451 
    452 	p = strbuf.val;
    453 
    454 	while (p < (strbuf.val + strbuf.len)) {
    455 		len = strlen(p);
    456 		fprintf(f, "\t.string \"%s\"\n", p);
    457 		p += len+1;
    458 	}
    459 }
    460 
    461 void dt_to_asm(FILE *f, struct dt_info *dti, int version)
    462 {
    463 	struct version_info *vi = NULL;
    464 	int i;
    465 	struct data strbuf = empty_data;
    466 	struct reserve_info *re;
    467 	const char *symprefix = "dt";
    468 
    469 	for (i = 0; i < ARRAY_SIZE(version_table); i++) {
    470 		if (version_table[i].version == version)
    471 			vi = &version_table[i];
    472 	}
    473 	if (!vi)
    474 		die("Unknown device tree blob version %d\n", version);
    475 
    476 	fprintf(f, "/* autogenerated by dtc, do not edit */\n\n");
    477 
    478 	emit_label(f, symprefix, "blob_start");
    479 	emit_label(f, symprefix, "header");
    480 	fprintf(f, "\t/* magic */\n");
    481 	asm_emit_cell(f, FDT_MAGIC);
    482 	fprintf(f, "\t/* totalsize */\n");
    483 	ASM_EMIT_BELONG(f, "_%s_blob_abs_end - _%s_blob_start",
    484 			symprefix, symprefix);
    485 	fprintf(f, "\t/* off_dt_struct */\n");
    486 	ASM_EMIT_BELONG(f, "_%s_struct_start - _%s_blob_start",
    487 		symprefix, symprefix);
    488 	fprintf(f, "\t/* off_dt_strings */\n");
    489 	ASM_EMIT_BELONG(f, "_%s_strings_start - _%s_blob_start",
    490 		symprefix, symprefix);
    491 	fprintf(f, "\t/* off_mem_rsvmap */\n");
    492 	ASM_EMIT_BELONG(f, "_%s_reserve_map - _%s_blob_start",
    493 		symprefix, symprefix);
    494 	fprintf(f, "\t/* version */\n");
    495 	asm_emit_cell(f, vi->version);
    496 	fprintf(f, "\t/* last_comp_version */\n");
    497 	asm_emit_cell(f, vi->last_comp_version);
    498 
    499 	if (vi->flags & FTF_BOOTCPUID) {
    500 		fprintf(f, "\t/* boot_cpuid_phys */\n");
    501 		asm_emit_cell(f, dti->boot_cpuid_phys);
    502 	}
    503 
    504 	if (vi->flags & FTF_STRTABSIZE) {
    505 		fprintf(f, "\t/* size_dt_strings */\n");
    506 		ASM_EMIT_BELONG(f, "_%s_strings_end - _%s_strings_start",
    507 				symprefix, symprefix);
    508 	}
    509 
    510 	if (vi->flags & FTF_STRUCTSIZE) {
    511 		fprintf(f, "\t/* size_dt_struct */\n");
    512 		ASM_EMIT_BELONG(f, "_%s_struct_end - _%s_struct_start",
    513 			symprefix, symprefix);
    514 	}
    515 
    516 	/*
    517 	 * Reserve map entries.
    518 	 * Align the reserve map to a doubleword boundary.
    519 	 * Each entry is an (address, size) pair of u64 values.
    520 	 * Always supply a zero-sized temination entry.
    521 	 */
    522 	asm_emit_align(f, 8);
    523 	emit_label(f, symprefix, "reserve_map");
    524 
    525 	fprintf(f, "/* Memory reserve map from source file */\n");
    526 
    527 	/*
    528 	 * Use .long on high and low halfs of u64s to avoid .quad
    529 	 * as it appears .quad isn't available in some assemblers.
    530 	 */
    531 	for (re = dti->reservelist; re; re = re->next) {
    532 		struct label *l;
    533 
    534 		for_each_label(re->labels, l) {
    535 			fprintf(f, "\t.globl\t%s\n", l->label);
    536 			fprintf(f, "%s:\n", l->label);
    537 		}
    538 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->address >> 32));
    539 		ASM_EMIT_BELONG(f, "0x%08x",
    540 				(unsigned int)(re->address & 0xffffffff));
    541 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->size >> 32));
    542 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->size & 0xffffffff));
    543 	}
    544 	for (i = 0; i < reservenum; i++) {
    545 		fprintf(f, "\t.long\t0, 0\n\t.long\t0, 0\n");
    546 	}
    547 
    548 	fprintf(f, "\t.long\t0, 0\n\t.long\t0, 0\n");
    549 
    550 	emit_label(f, symprefix, "struct_start");
    551 	flatten_tree(dti->dt, &asm_emitter, f, &strbuf, vi);
    552 
    553 	fprintf(f, "\t/* FDT_END */\n");
    554 	asm_emit_cell(f, FDT_END);
    555 	emit_label(f, symprefix, "struct_end");
    556 
    557 	emit_label(f, symprefix, "strings_start");
    558 	dump_stringtable_asm(f, strbuf);
    559 	emit_label(f, symprefix, "strings_end");
    560 
    561 	emit_label(f, symprefix, "blob_end");
    562 
    563 	/*
    564 	 * If the user asked for more space than is used, pad it out.
    565 	 */
    566 	if (minsize > 0) {
    567 		fprintf(f, "\t.space\t%d - (_%s_blob_end - _%s_blob_start), 0\n",
    568 			minsize, symprefix, symprefix);
    569 	}
    570 	if (padsize > 0) {
    571 		fprintf(f, "\t.space\t%d, 0\n", padsize);
    572 	}
    573 	if (alignsize > 0)
    574 		asm_emit_align(f, alignsize);
    575 	emit_label(f, symprefix, "blob_abs_end");
    576 
    577 	data_free(strbuf);
    578 }
    579 
    580 struct inbuf {
    581 	char *base, *limit, *ptr;
    582 };
    583 
    584 static void inbuf_init(struct inbuf *inb, void *base, void *limit)
    585 {
    586 	inb->base = base;
    587 	inb->limit = limit;
    588 	inb->ptr = inb->base;
    589 }
    590 
    591 static void flat_read_chunk(struct inbuf *inb, void *p, int len)
    592 {
    593 	if ((inb->ptr + len) > inb->limit)
    594 		die("Premature end of data parsing flat device tree\n");
    595 
    596 	memcpy(p, inb->ptr, len);
    597 
    598 	inb->ptr += len;
    599 }
    600 
    601 static uint32_t flat_read_word(struct inbuf *inb)
    602 {
    603 	fdt32_t val;
    604 
    605 	assert(((inb->ptr - inb->base) % sizeof(val)) == 0);
    606 
    607 	flat_read_chunk(inb, &val, sizeof(val));
    608 
    609 	return fdt32_to_cpu(val);
    610 }
    611 
    612 static void flat_realign(struct inbuf *inb, int align)
    613 {
    614 	int off = inb->ptr - inb->base;
    615 
    616 	inb->ptr = inb->base + ALIGN(off, align);
    617 	if (inb->ptr > inb->limit)
    618 		die("Premature end of data parsing flat device tree\n");
    619 }
    620 
    621 static char *flat_read_string(struct inbuf *inb)
    622 {
    623 	int len = 0;
    624 	const char *p = inb->ptr;
    625 	char *str;
    626 
    627 	do {
    628 		if (p >= inb->limit)
    629 			die("Premature end of data parsing flat device tree\n");
    630 		len++;
    631 	} while ((*p++) != '\0');
    632 
    633 	str = xstrdup(inb->ptr);
    634 
    635 	inb->ptr += len;
    636 
    637 	flat_realign(inb, sizeof(uint32_t));
    638 
    639 	return str;
    640 }
    641 
    642 static struct data flat_read_data(struct inbuf *inb, int len)
    643 {
    644 	struct data d = empty_data;
    645 
    646 	if (len == 0)
    647 		return empty_data;
    648 
    649 	d = data_grow_for(d, len);
    650 	d.len = len;
    651 
    652 	flat_read_chunk(inb, d.val, len);
    653 
    654 	flat_realign(inb, sizeof(uint32_t));
    655 
    656 	return d;
    657 }
    658 
    659 static char *flat_read_stringtable(struct inbuf *inb, int offset)
    660 {
    661 	const char *p;
    662 
    663 	p = inb->base + offset;
    664 	while (1) {
    665 		if (p >= inb->limit || p < inb->base)
    666 			die("String offset %d overruns string table\n",
    667 			    offset);
    668 
    669 		if (*p == '\0')
    670 			break;
    671 
    672 		p++;
    673 	}
    674 
    675 	return xstrdup(inb->base + offset);
    676 }
    677 
    678 static struct property *flat_read_property(struct inbuf *dtbuf,
    679 					   struct inbuf *strbuf, int flags)
    680 {
    681 	uint32_t proplen, stroff;
    682 	char *name;
    683 	struct data val;
    684 
    685 	proplen = flat_read_word(dtbuf);
    686 	stroff = flat_read_word(dtbuf);
    687 
    688 	name = flat_read_stringtable(strbuf, stroff);
    689 
    690 	if ((flags & FTF_VARALIGN) && (proplen >= 8))
    691 		flat_realign(dtbuf, 8);
    692 
    693 	val = flat_read_data(dtbuf, proplen);
    694 
    695 	return build_property(name, val);
    696 }
    697 
    698 
    699 static struct reserve_info *flat_read_mem_reserve(struct inbuf *inb)
    700 {
    701 	struct reserve_info *reservelist = NULL;
    702 	struct reserve_info *new;
    703 	struct fdt_reserve_entry re;
    704 
    705 	/*
    706 	 * Each entry is a pair of u64 (addr, size) values for 4 cell_t's.
    707 	 * List terminates at an entry with size equal to zero.
    708 	 *
    709 	 * First pass, count entries.
    710 	 */
    711 	while (1) {
    712 		uint64_t address, size;
    713 
    714 		flat_read_chunk(inb, &re, sizeof(re));
    715 		address  = fdt64_to_cpu(re.address);
    716 		size = fdt64_to_cpu(re.size);
    717 		if (size == 0)
    718 			break;
    719 
    720 		new = build_reserve_entry(address, size);
    721 		reservelist = add_reserve_entry(reservelist, new);
    722 	}
    723 
    724 	return reservelist;
    725 }
    726 
    727 
    728 static char *nodename_from_path(const char *ppath, const char *cpath)
    729 {
    730 	int plen;
    731 
    732 	plen = strlen(ppath);
    733 
    734 	if (!strstarts(cpath, ppath))
    735 		die("Path \"%s\" is not valid as a child of \"%s\"\n",
    736 		    cpath, ppath);
    737 
    738 	/* root node is a special case */
    739 	if (!streq(ppath, "/"))
    740 		plen++;
    741 
    742 	return xstrdup(cpath + plen);
    743 }
    744 
    745 static struct node *unflatten_tree(struct inbuf *dtbuf,
    746 				   struct inbuf *strbuf,
    747 				   const char *parent_flatname, int flags)
    748 {
    749 	struct node *node;
    750 	char *flatname;
    751 	uint32_t val;
    752 
    753 	node = build_node(NULL, NULL);
    754 
    755 	flatname = flat_read_string(dtbuf);
    756 
    757 	if (flags & FTF_FULLPATH)
    758 		node->name = nodename_from_path(parent_flatname, flatname);
    759 	else
    760 		node->name = flatname;
    761 
    762 	do {
    763 		struct property *prop;
    764 		struct node *child;
    765 
    766 		val = flat_read_word(dtbuf);
    767 		switch (val) {
    768 		case FDT_PROP:
    769 			if (node->children)
    770 				fprintf(stderr, "Warning: Flat tree input has "
    771 					"subnodes preceding a property.\n");
    772 			prop = flat_read_property(dtbuf, strbuf, flags);
    773 			add_property(node, prop);
    774 			break;
    775 
    776 		case FDT_BEGIN_NODE:
    777 			child = unflatten_tree(dtbuf,strbuf, flatname, flags);
    778 			add_child(node, child);
    779 			break;
    780 
    781 		case FDT_END_NODE:
    782 			break;
    783 
    784 		case FDT_END:
    785 			die("Premature FDT_END in device tree blob\n");
    786 			break;
    787 
    788 		case FDT_NOP:
    789 			if (!(flags & FTF_NOPS))
    790 				fprintf(stderr, "Warning: NOP tag found in flat tree"
    791 					" version <16\n");
    792 
    793 			/* Ignore */
    794 			break;
    795 
    796 		default:
    797 			die("Invalid opcode word %08x in device tree blob\n",
    798 			    val);
    799 		}
    800 	} while (val != FDT_END_NODE);
    801 
    802 	if (node->name != flatname) {
    803 		free(flatname);
    804 	}
    805 
    806 	return node;
    807 }
    808 
    809 
    810 struct dt_info *dt_from_blob(const char *fname)
    811 {
    812 	FILE *f;
    813 	fdt32_t magic_buf, totalsize_buf;
    814 	uint32_t magic, totalsize, version, size_dt, boot_cpuid_phys;
    815 	uint32_t off_dt, off_str, off_mem_rsvmap;
    816 	int rc;
    817 	char *blob;
    818 	struct fdt_header *fdt;
    819 	char *p;
    820 	struct inbuf dtbuf, strbuf;
    821 	struct inbuf memresvbuf;
    822 	int sizeleft;
    823 	struct reserve_info *reservelist;
    824 	struct node *tree;
    825 	uint32_t val;
    826 	int flags = 0;
    827 
    828 	f = srcfile_relative_open(fname, NULL);
    829 
    830 	rc = fread(&magic_buf, sizeof(magic_buf), 1, f);
    831 	if (ferror(f))
    832 		die("Error reading DT blob magic number: %s\n",
    833 		    strerror(errno));
    834 	if (rc < 1) {
    835 		if (feof(f))
    836 			die("EOF reading DT blob magic number\n");
    837 		else
    838 			die("Mysterious short read reading magic number\n");
    839 	}
    840 
    841 	magic = fdt32_to_cpu(magic_buf);
    842 	if (magic != FDT_MAGIC)
    843 		die("Blob has incorrect magic number\n");
    844 
    845 	rc = fread(&totalsize_buf, sizeof(totalsize_buf), 1, f);
    846 	if (ferror(f))
    847 		die("Error reading DT blob size: %s\n", strerror(errno));
    848 	if (rc < 1) {
    849 		if (feof(f))
    850 			die("EOF reading DT blob size\n");
    851 		else
    852 			die("Mysterious short read reading blob size\n");
    853 	}
    854 
    855 	totalsize = fdt32_to_cpu(totalsize_buf);
    856 	if (totalsize < FDT_V1_SIZE)
    857 		die("DT blob size (%d) is too small\n", totalsize);
    858 
    859 	blob = xmalloc(totalsize);
    860 
    861 	fdt = (struct fdt_header *)blob;
    862 	fdt->magic = cpu_to_fdt32(magic);
    863 	fdt->totalsize = cpu_to_fdt32(totalsize);
    864 
    865 	sizeleft = totalsize - sizeof(magic) - sizeof(totalsize);
    866 	p = blob + sizeof(magic)  + sizeof(totalsize);
    867 
    868 	while (sizeleft) {
    869 		if (feof(f))
    870 			die("EOF before reading %d bytes of DT blob\n",
    871 			    totalsize);
    872 
    873 		rc = fread(p, 1, sizeleft, f);
    874 		if (ferror(f))
    875 			die("Error reading DT blob: %s\n",
    876 			    strerror(errno));
    877 
    878 		sizeleft -= rc;
    879 		p += rc;
    880 	}
    881 
    882 	off_dt = fdt32_to_cpu(fdt->off_dt_struct);
    883 	off_str = fdt32_to_cpu(fdt->off_dt_strings);
    884 	off_mem_rsvmap = fdt32_to_cpu(fdt->off_mem_rsvmap);
    885 	version = fdt32_to_cpu(fdt->version);
    886 	boot_cpuid_phys = fdt32_to_cpu(fdt->boot_cpuid_phys);
    887 
    888 	if (off_mem_rsvmap >= totalsize)
    889 		die("Mem Reserve structure offset exceeds total size\n");
    890 
    891 	if (off_dt >= totalsize)
    892 		die("DT structure offset exceeds total size\n");
    893 
    894 	if (off_str > totalsize)
    895 		die("String table offset exceeds total size\n");
    896 
    897 	if (version >= 3) {
    898 		uint32_t size_str = fdt32_to_cpu(fdt->size_dt_strings);
    899 		if ((off_str+size_str < off_str) || (off_str+size_str > totalsize))
    900 			die("String table extends past total size\n");
    901 		inbuf_init(&strbuf, blob + off_str, blob + off_str + size_str);
    902 	} else {
    903 		inbuf_init(&strbuf, blob + off_str, blob + totalsize);
    904 	}
    905 
    906 	if (version >= 17) {
    907 		size_dt = fdt32_to_cpu(fdt->size_dt_struct);
    908 		if ((off_dt+size_dt < off_dt) || (off_dt+size_dt > totalsize))
    909 			die("Structure block extends past total size\n");
    910 	}
    911 
    912 	if (version < 16) {
    913 		flags |= FTF_FULLPATH | FTF_NAMEPROPS | FTF_VARALIGN;
    914 	} else {
    915 		flags |= FTF_NOPS;
    916 	}
    917 
    918 	inbuf_init(&memresvbuf,
    919 		   blob + off_mem_rsvmap, blob + totalsize);
    920 	inbuf_init(&dtbuf, blob + off_dt, blob + totalsize);
    921 
    922 	reservelist = flat_read_mem_reserve(&memresvbuf);
    923 
    924 	val = flat_read_word(&dtbuf);
    925 
    926 	if (val != FDT_BEGIN_NODE)
    927 		die("Device tree blob doesn't begin with FDT_BEGIN_NODE (begins with 0x%08x)\n", val);
    928 
    929 	tree = unflatten_tree(&dtbuf, &strbuf, "", flags);
    930 
    931 	val = flat_read_word(&dtbuf);
    932 	if (val != FDT_END)
    933 		die("Device tree blob doesn't end with FDT_END\n");
    934 
    935 	free(blob);
    936 
    937 	fclose(f);
    938 
    939 	return build_dt_info(DTSF_V1, reservelist, tree, boot_cpuid_phys);
    940 }
    941