1/* 2 * fdtdump.c - Contributed by Pantelis Antoniou <pantelis.antoniou AT gmail.com> 3 */ 4 5#include <stdbool.h> 6#include <stdint.h> 7#include <stdio.h> 8#include <stdlib.h> 9#include <string.h> 10#include <ctype.h> 11 12#include <libfdt.h> 13#include <libfdt_env.h> 14#include <fdt.h> 15 16#include "util.h" 17 18#define FDT_MAGIC_SIZE 4 19#define MAX_VERSION 17 20 21#define ALIGN(x, a) (((x) + ((a) - 1)) & ~((a) - 1)) 22#define PALIGN(p, a) ((void *)(ALIGN((unsigned long)(p), (a)))) 23#define GET_CELL(p) (p += 4, *((const fdt32_t *)(p-4))) 24 25static const char *tagname(uint32_t tag) 26{ 27 static const char * const names[] = { 28#define TN(t) [t] = #t 29 TN(FDT_BEGIN_NODE), 30 TN(FDT_END_NODE), 31 TN(FDT_PROP), 32 TN(FDT_NOP), 33 TN(FDT_END), 34#undef TN 35 }; 36 if (tag < ARRAY_SIZE(names)) 37 if (names[tag]) 38 return names[tag]; 39 return "FDT_???"; 40} 41 42#define dumpf(fmt, args...) \ 43 do { if (debug) printf("// " fmt, ## args); } while (0) 44 45static void dump_blob(void *blob, bool debug) 46{ 47 uintptr_t blob_off = (uintptr_t)blob; 48 struct fdt_header *bph = blob; 49 uint32_t off_mem_rsvmap = fdt32_to_cpu(bph->off_mem_rsvmap); 50 uint32_t off_dt = fdt32_to_cpu(bph->off_dt_struct); 51 uint32_t off_str = fdt32_to_cpu(bph->off_dt_strings); 52 struct fdt_reserve_entry *p_rsvmap = 53 (struct fdt_reserve_entry *)((char *)blob + off_mem_rsvmap); 54 const char *p_struct = (const char *)blob + off_dt; 55 const char *p_strings = (const char *)blob + off_str; 56 uint32_t version = fdt32_to_cpu(bph->version); 57 uint32_t totalsize = fdt32_to_cpu(bph->totalsize); 58 uint32_t tag; 59 const char *p, *s, *t; 60 int depth, sz, shift; 61 int i; 62 uint64_t addr, size; 63 64 depth = 0; 65 shift = 4; 66 67 printf("/dts-v1/;\n"); 68 printf("// magic:\t\t0x%x\n", fdt32_to_cpu(bph->magic)); 69 printf("// totalsize:\t\t0x%x (%d)\n", totalsize, totalsize); 70 printf("// off_dt_struct:\t0x%x\n", off_dt); 71 printf("// off_dt_strings:\t0x%x\n", off_str); 72 printf("// off_mem_rsvmap:\t0x%x\n", off_mem_rsvmap); 73 printf("// version:\t\t%d\n", version); 74 printf("// last_comp_version:\t%d\n", 75 fdt32_to_cpu(bph->last_comp_version)); 76 if (version >= 2) 77 printf("// boot_cpuid_phys:\t0x%x\n", 78 fdt32_to_cpu(bph->boot_cpuid_phys)); 79 80 if (version >= 3) 81 printf("// size_dt_strings:\t0x%x\n", 82 fdt32_to_cpu(bph->size_dt_strings)); 83 if (version >= 17) 84 printf("// size_dt_struct:\t0x%x\n", 85 fdt32_to_cpu(bph->size_dt_struct)); 86 printf("\n"); 87 88 for (i = 0; ; i++) { 89 addr = fdt64_to_cpu(p_rsvmap[i].address); 90 size = fdt64_to_cpu(p_rsvmap[i].size); 91 if (addr == 0 && size == 0) 92 break; 93 94 printf("/memreserve/ %#llx %#llx;\n", 95 (unsigned long long)addr, (unsigned long long)size); 96 } 97 98 p = p_struct; 99 while ((tag = fdt32_to_cpu(GET_CELL(p))) != FDT_END) { 100 101 dumpf("%04zx: tag: 0x%08x (%s)\n", 102 (uintptr_t)p - blob_off - 4, tag, tagname(tag)); 103 104 if (tag == FDT_BEGIN_NODE) { 105 s = p; 106 p = PALIGN(p + strlen(s) + 1, 4); 107 108 if (*s == '\0') 109 s = "/"; 110 111 printf("%*s%s {\n", depth * shift, "", s); 112 113 depth++; 114 continue; 115 } 116 117 if (tag == FDT_END_NODE) { 118 depth--; 119 120 printf("%*s};\n", depth * shift, ""); 121 continue; 122 } 123 124 if (tag == FDT_NOP) { 125 printf("%*s// [NOP]\n", depth * shift, ""); 126 continue; 127 } 128 129 if (tag != FDT_PROP) { 130 fprintf(stderr, "%*s ** Unknown tag 0x%08x\n", depth * shift, "", tag); 131 break; 132 } 133 sz = fdt32_to_cpu(GET_CELL(p)); 134 s = p_strings + fdt32_to_cpu(GET_CELL(p)); 135 if (version < 16 && sz >= 8) 136 p = PALIGN(p, 8); 137 t = p; 138 139 p = PALIGN(p + sz, 4); 140 141 dumpf("%04zx: string: %s\n", (uintptr_t)s - blob_off, s); 142 dumpf("%04zx: value\n", (uintptr_t)t - blob_off); 143 printf("%*s%s", depth * shift, "", s); 144 utilfdt_print_data(t, sz); 145 printf(";\n"); 146 } 147} 148 149/* Usage related data. */ 150static const char usage_synopsis[] = "fdtdump [options] <file>"; 151static const char usage_short_opts[] = "ds" USAGE_COMMON_SHORT_OPTS; 152static struct option const usage_long_opts[] = { 153 {"debug", no_argument, NULL, 'd'}, 154 {"scan", no_argument, NULL, 's'}, 155 USAGE_COMMON_LONG_OPTS 156}; 157static const char * const usage_opts_help[] = { 158 "Dump debug information while decoding the file", 159 "Scan for an embedded fdt in file", 160 USAGE_COMMON_OPTS_HELP 161}; 162 163static bool valid_header(char *p, off_t len) 164{ 165 if (len < sizeof(struct fdt_header) || 166 fdt_magic(p) != FDT_MAGIC || 167 fdt_version(p) > MAX_VERSION || 168 fdt_last_comp_version(p) >= MAX_VERSION || 169 fdt_totalsize(p) >= len || 170 fdt_off_dt_struct(p) >= len || 171 fdt_off_dt_strings(p) >= len) 172 return 0; 173 else 174 return 1; 175} 176 177int main(int argc, char *argv[]) 178{ 179 int opt; 180 const char *file; 181 char *buf; 182 bool debug = false; 183 bool scan = false; 184 off_t len; 185 186 while ((opt = util_getopt_long()) != EOF) { 187 switch (opt) { 188 case_USAGE_COMMON_FLAGS 189 190 case 'd': 191 debug = true; 192 break; 193 case 's': 194 scan = true; 195 break; 196 } 197 } 198 if (optind != argc - 1) 199 usage("missing input filename"); 200 file = argv[optind]; 201 202 buf = utilfdt_read_len(file, &len); 203 if (!buf) 204 die("could not read: %s\n", file); 205 206 /* try and locate an embedded fdt in a bigger blob */ 207 if (scan) { 208 unsigned char smagic[FDT_MAGIC_SIZE]; 209 char *p = buf; 210 char *endp = buf + len; 211 212 fdt_set_magic(smagic, FDT_MAGIC); 213 214 /* poor man's memmem */ 215 while ((endp - p) >= FDT_MAGIC_SIZE) { 216 p = memchr(p, smagic[0], endp - p - FDT_MAGIC_SIZE); 217 if (!p) 218 break; 219 if (fdt_magic(p) == FDT_MAGIC) { 220 /* try and validate the main struct */ 221 off_t this_len = endp - p; 222 if (valid_header(p, this_len)) 223 break; 224 if (debug) 225 printf("%s: skipping fdt magic at offset %#zx\n", 226 file, p - buf); 227 } 228 ++p; 229 } 230 if (!p || endp - p < sizeof(struct fdt_header)) 231 die("%s: could not locate fdt magic\n", file); 232 printf("%s: found fdt at offset %#zx\n", file, p - buf); 233 buf = p; 234 } else if (!valid_header(buf, len)) 235 die("%s: header is not valid\n", file); 236 237 dump_blob(buf, debug); 238 239 return 0; 240} 241