• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <assert.h>
18 #include <fcntl.h>
19 #include <gelf.h>
20 #include <libelf.h>
21 #include <sys/types.h>
22 #include <stdbool.h>
23 #include <unistd.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <stdint.h>
27 #include <stdio.h>
28 #include <stddef.h>
29 #include <errno.h>
30 
31 #include <nanohub/nanohub.h>
32 #include <nanohub/nanoapp.h>
33 #include <nanohub/appRelocFormat.h>
34 
35 //This code assumes it is run on a LE CPU with unaligned access abilities. Sorry.
36 
37 #define FLASH_BASE  0x10000000
38 #define RAM_BASE    0x80000000
39 
40 #define FLASH_SIZE  0x10000000  //256MB ought to be enough for everyone
41 #define RAM_SIZE    0x10000000  //256MB ought to be enough for everyone
42 
43 //caution: double evaluation
44 #define IS_IN_RANGE_E(_val, _rstart, _rend) (((_val) >= (_rstart)) && ((_val) < (_rend)))
45 #define IS_IN_RANGE(_val, _rstart, _rsz)    IS_IN_RANGE_E((_val), (_rstart), ((_rstart) + (_rsz)))
46 #define IS_IN_RAM(_val)              IS_IN_RANGE(_val, RAM_BASE, RAM_SIZE)
47 #define IS_IN_FLASH(_val)            IS_IN_RANGE(_val, FLASH_BASE, FLASH_SIZE)
48 
49 
50 #define NANO_RELOC_TYPE_RAM    0
51 #define NANO_RELOC_TYPE_FLASH  1
52 #define NANO_RELOC_LAST        2 //must be <= (RELOC_TYPE_MASK >> RELOC_TYPE_SHIFT)
53 
54 struct RelocEntry {
55     uint32_t where;
56     uint32_t info;  //bottom 8 bits is type, top 24 is sym idx
57 };
58 
59 #define RELOC_TYPE_ABS_S    2
60 #define RELOC_TYPE_ABS_D    21
61 #define RELOC_TYPE_SECT     23
62 
63 
64 struct SymtabEntry {
65     uint32_t a;
66     uint32_t addr;
67     uint32_t b, c;
68 };
69 
70 struct NanoRelocEntry {
71     uint32_t ofstInRam;
72     uint8_t type;
73 };
74 
75 #ifndef ARRAY_SIZE
76 #define ARRAY_SIZE(ary) (sizeof(ary) / sizeof((ary)[0]))
77 #endif
78 
79 #define DBG(fmt, ...) printf(fmt "\n", ##__VA_ARGS__)
80 #define ERR(fmt, ...) fprintf(stderr, fmt "\n", ##__VA_ARGS__)
81 
82 // Prints the given message followed by the most recent libelf error
83 #define ELF_ERR(fmt, ...) ERR(fmt ": %s\n", ##__VA_ARGS__, elf_errmsg(-1))
84 
85 struct ElfAppSection {
86     void  *data;
87     size_t size;
88 };
89 
90 struct ElfNanoApp {
91     struct ElfAppSection flash;
92     struct ElfAppSection data;
93     struct ElfAppSection relocs;
94     struct ElfAppSection symtab;
95 
96     // Not parsed from file, but constructed via genElfNanoRelocs
97     struct ElfAppSection packedNanoRelocs;
98 };
99 
fatalUsage(const char * name,const char * msg,const char * arg)100 static void fatalUsage(const char *name, const char *msg, const char *arg)
101 {
102     if (msg && arg)
103         fprintf(stderr, "Error: %s: %s\n\n", msg, arg);
104     else if (msg)
105         fprintf(stderr, "Error: %s\n\n", msg);
106 
107     fprintf(stderr, "USAGE: %s [-v] [-k <key id>] [-a <app id>] [-r] [-n <layout name>] [-i <layout id>] <input file> [<output file>]\n"
108                     "       -v               : be verbose\n"
109                     "       -n <layout name> : app, os, key\n"
110                     "       -i <layout id>   : 1 (app), 2 (key), 3 (os)\n"
111                     "       -f <layout flags>: 16-bit hex value, stored as layout-specific flags\n"
112                     "       -a <app ID>      : 64-bit hex number != 0\n"
113                     "       -k <key ID>      : 64-bit hex number != 0\n"
114                     "       -r               : bare (no AOSP header); used only for inner OS image generation\n"
115                     "       -s               : treat input as statically linked ELF (app layout only)\n"
116                     "       layout ID and layout name control the same parameter, so only one of them needs to be used\n"
117                     , name);
118     exit(1);
119 }
120 
packNanoRelocs(struct NanoRelocEntry * nanoRelocs,uint32_t outNumRelocs,uint32_t * finalPackedNanoRelocSz,bool verbose)121 static uint8_t *packNanoRelocs(struct NanoRelocEntry *nanoRelocs, uint32_t outNumRelocs, uint32_t *finalPackedNanoRelocSz, bool verbose)
122 {
123     uint32_t i, j, k;
124     uint8_t *packedNanoRelocs;
125     uint32_t packedNanoRelocSz;
126     uint32_t lastOutType = 0, origin = 0;
127 
128     //sort by type and then offset
129     for (i = 0; i < outNumRelocs; i++) {
130         struct NanoRelocEntry t;
131 
132         for (k = i, j = k + 1; j < outNumRelocs; j++) {
133             if (nanoRelocs[j].type > nanoRelocs[k].type)
134                 continue;
135             if ((nanoRelocs[j].type < nanoRelocs[k].type) || (nanoRelocs[j].ofstInRam < nanoRelocs[k].ofstInRam))
136                 k = j;
137         }
138         memcpy(&t, nanoRelocs + i, sizeof(struct NanoRelocEntry));
139         memcpy(nanoRelocs + i, nanoRelocs + k, sizeof(struct NanoRelocEntry));
140         memcpy(nanoRelocs + k, &t, sizeof(struct NanoRelocEntry));
141 
142         if (verbose)
143             fprintf(stderr, "SortedReloc[%3" PRIu32 "] = {0x%08" PRIX32 ",0x%02" PRIX8 "}\n", i, nanoRelocs[i].ofstInRam, nanoRelocs[i].type);
144     }
145 
146     //produce output nanorelocs in packed format
147     packedNanoRelocs = malloc(outNumRelocs * 6); //definitely big enough
148     packedNanoRelocSz = 0;
149     for (i = 0; i < outNumRelocs; i++) {
150         uint32_t displacement;
151 
152         if (lastOutType != nanoRelocs[i].type) {  //output type if ti changed
153             if (nanoRelocs[i].type - lastOutType == 1) {
154                 packedNanoRelocs[packedNanoRelocSz++] = TOKEN_RELOC_TYPE_NEXT;
155                 if (verbose)
156                     fprintf(stderr, "Out: RelocTC (1) // to 0x%02" PRIX8 "\n", nanoRelocs[i].type);
157             }
158             else {
159                 packedNanoRelocs[packedNanoRelocSz++] = TOKEN_RELOC_TYPE_CHG;
160                 packedNanoRelocs[packedNanoRelocSz++] = nanoRelocs[i].type - lastOutType - 1;
161                 if (verbose)
162                     fprintf(stderr, "Out: RelocTC (0x%02" PRIX8 ")  // to 0x%02" PRIX8 "\n", (uint8_t)(nanoRelocs[i].type - lastOutType - 1), nanoRelocs[i].type);
163             }
164             lastOutType = nanoRelocs[i].type;
165             origin = 0;
166         }
167         displacement = nanoRelocs[i].ofstInRam - origin;
168         origin = nanoRelocs[i].ofstInRam + 4;
169         if (displacement & 3) {
170             fprintf(stderr, "Unaligned relocs are not possible!\n");
171             exit(-5);
172         }
173         displacement /= 4;
174 
175         //might be start of a run. look into that
176         if (!displacement) {
177             for (j = 1; j + i < outNumRelocs && j < MAX_RUN_LEN && nanoRelocs[j + i].type == lastOutType && nanoRelocs[j + i].ofstInRam - nanoRelocs[j + i - 1].ofstInRam == 4; j++);
178             if (j >= MIN_RUN_LEN) {
179                 if (verbose)
180                     fprintf(stderr, "Out: Reloc0  x%" PRIX32 "\n", j);
181                 packedNanoRelocs[packedNanoRelocSz++] = TOKEN_CONSECUTIVE;
182                 packedNanoRelocs[packedNanoRelocSz++] = j - MIN_RUN_LEN;
183                 origin = nanoRelocs[j + i - 1].ofstInRam + 4;  //reset origin to last one
184                 i += j - 1;  //loop will increment anyways, hence +1
185                 continue;
186             }
187         }
188 
189         //produce output
190         if (displacement <= MAX_8_BIT_NUM) {
191             if (verbose)
192                 fprintf(stderr, "Out: Reloc8  0x%02" PRIX32 "\n", displacement);
193             packedNanoRelocs[packedNanoRelocSz++] = displacement;
194         }
195         else if (displacement <= MAX_16_BIT_NUM) {
196             if (verbose)
197                 fprintf(stderr, "Out: Reloc16 0x%06" PRIX32 "\n", displacement);
198                         displacement -= MAX_8_BIT_NUM;
199             packedNanoRelocs[packedNanoRelocSz++] = TOKEN_16BIT_OFST;
200             packedNanoRelocs[packedNanoRelocSz++] = displacement;
201             packedNanoRelocs[packedNanoRelocSz++] = displacement >> 8;
202         }
203         else if (displacement <= MAX_24_BIT_NUM) {
204             if (verbose)
205                 fprintf(stderr, "Out: Reloc24 0x%08" PRIX32 "\n", displacement);
206                         displacement -= MAX_16_BIT_NUM;
207             packedNanoRelocs[packedNanoRelocSz++] = TOKEN_24BIT_OFST;
208             packedNanoRelocs[packedNanoRelocSz++] = displacement;
209             packedNanoRelocs[packedNanoRelocSz++] = displacement >> 8;
210             packedNanoRelocs[packedNanoRelocSz++] = displacement >> 16;
211         }
212         else  {
213             if (verbose)
214                 fprintf(stderr, "Out: Reloc32 0x%08" PRIX32 "\n", displacement);
215             packedNanoRelocs[packedNanoRelocSz++] = TOKEN_32BIT_OFST;
216             packedNanoRelocs[packedNanoRelocSz++] = displacement;
217             packedNanoRelocs[packedNanoRelocSz++] = displacement >> 8;
218             packedNanoRelocs[packedNanoRelocSz++] = displacement >> 16;
219             packedNanoRelocs[packedNanoRelocSz++] = displacement >> 24;
220         }
221     }
222 
223     *finalPackedNanoRelocSz = packedNanoRelocSz;
224     return packedNanoRelocs;
225 }
226 
finalizeAndWrite(uint8_t * buf,uint32_t bufUsed,uint32_t bufSz,FILE * out,uint32_t layoutFlags,uint64_t appId)227 static int finalizeAndWrite(uint8_t *buf, uint32_t bufUsed, uint32_t bufSz, FILE *out, uint32_t layoutFlags, uint64_t appId)
228 {
229     int ret;
230     struct AppInfo app;
231     struct SectInfo *sect;
232     struct BinHdr *bin = (struct BinHdr *) buf;
233     struct ImageHeader outHeader = {
234         .aosp = (struct nano_app_binary_t) {
235             .header_version = 1,
236             .magic = NANOAPP_AOSP_MAGIC,
237             .app_id = appId,
238             .app_version = bin->hdr.appVer,
239             .flags       = 0, // encrypted (1), signed (2) (will be set by other tools)
240         },
241         .layout = (struct ImageLayout) {
242             .magic = GOOGLE_LAYOUT_MAGIC,
243             .version = 1,
244             .payload = LAYOUT_APP,
245             .flags = layoutFlags,
246         },
247     };
248     uint32_t dataOffset = sizeof(outHeader) + sizeof(app);
249     uint32_t hdrDiff = dataOffset - sizeof(*bin);
250     app.sect = bin->sect;
251     app.vec  = bin->vec;
252 
253     assertMem(bufUsed + hdrDiff, bufSz);
254 
255     memmove(buf + dataOffset, buf + sizeof(*bin), bufUsed - sizeof(*bin));
256     bufUsed += hdrDiff;
257     memcpy(buf, &outHeader, sizeof(outHeader));
258     memcpy(buf + sizeof(outHeader), &app, sizeof(app));
259     sect = &app.sect;
260 
261     //if we have any bytes to output, show stats
262     if (bufUsed) {
263         uint32_t codeAndRoDataSz = sect->data_data;
264         uint32_t relocsSz = sect->rel_end - sect->rel_start;
265         uint32_t gotSz = sect->got_end - sect->data_start;
266         uint32_t bssSz = sect->bss_end - sect->bss_start;
267 
268         fprintf(stderr,"Final binary size %" PRIu32 " bytes\n", bufUsed);
269         fprintf(stderr, "\n");
270         fprintf(stderr, "       FW header size (flash):      %6zu bytes\n", FLASH_RELOC_OFFSET);
271         fprintf(stderr, "       Code + RO data (flash):      %6" PRIu32 " bytes\n", codeAndRoDataSz);
272         fprintf(stderr, "       Relocs (flash):              %6" PRIu32 " bytes\n", relocsSz);
273         fprintf(stderr, "       GOT + RW data (flash & RAM): %6" PRIu32 " bytes\n", gotSz);
274         fprintf(stderr, "       BSS (RAM):                   %6" PRIu32 " bytes\n", bssSz);
275         fprintf(stderr, "\n");
276         fprintf(stderr,"Runtime flash use: %" PRIu32 " bytes\n", (uint32_t)(codeAndRoDataSz + relocsSz + gotSz + FLASH_RELOC_OFFSET));
277         fprintf(stderr,"Runtime RAM use: %" PRIu32 " bytes\n", gotSz + bssSz);
278     }
279 
280     ret = fwrite(buf, bufUsed, 1, out) == 1 ? 0 : 2;
281     if (ret)
282         fprintf(stderr, "Failed to write output file: %s\n", strerror(errno));
283 
284     return ret;
285 }
286 
handleApp(uint8_t ** pbuf,uint32_t bufUsed,FILE * out,uint32_t layoutFlags,uint64_t appId,bool verbose)287 static int handleApp(uint8_t **pbuf, uint32_t bufUsed, FILE *out, uint32_t layoutFlags, uint64_t appId, bool verbose)
288 {
289     uint32_t i, numRelocs, numSyms, outNumRelocs = 0, packedNanoRelocSz;
290     struct NanoRelocEntry *nanoRelocs = NULL;
291     struct RelocEntry *relocs;
292     struct SymtabEntry *syms;
293     uint8_t *packedNanoRelocs;
294     uint32_t t;
295     struct BinHdr *bin;
296     int ret = -1;
297     struct SectInfo *sect;
298     uint8_t *buf = *pbuf;
299     uint32_t bufSz = bufUsed * 3 /2;
300 
301     //make buffer 50% bigger than bufUsed in case relocs grow out of hand
302     buf = reallocOrDie(buf, bufSz);
303     *pbuf = buf;
304 
305     //sanity checks
306     bin = (struct BinHdr*)buf;
307     if (bufUsed < sizeof(*bin)) {
308         fprintf(stderr, "File size too small\n");
309         goto out;
310     }
311 
312     if (bin->hdr.magic != NANOAPP_FW_MAGIC) {
313         fprintf(stderr, "Magic value is wrong: found %08" PRIX32
314                         "; expected %08" PRIX32 "\n",
315                         bin->hdr.magic, NANOAPP_FW_MAGIC);
316         goto out;
317     }
318 
319     sect = &bin->sect;
320 
321     //do some math
322     relocs = (struct RelocEntry*)(buf + sect->rel_start - FLASH_BASE);
323     syms = (struct SymtabEntry*)(buf + sect->rel_end - FLASH_BASE);
324     numRelocs = (sect->rel_end - sect->rel_start) / sizeof(struct RelocEntry);
325     numSyms = (bufUsed + FLASH_BASE - sect->rel_end) / sizeof(struct SymtabEntry);
326 
327     //sanity
328     if (numRelocs * sizeof(struct RelocEntry) + sect->rel_start != sect->rel_end) {
329         fprintf(stderr, "Relocs of nonstandard size\n");
330         goto out;
331     }
332     if (numSyms * sizeof(struct SymtabEntry) + sect->rel_end != bufUsed + FLASH_BASE) {
333         fprintf(stderr, "Syms of nonstandard size\n");
334         goto out;
335     }
336 
337     //show some info
338     fprintf(stderr, "\nRead %" PRIu32 " bytes of binary.\n", bufUsed);
339 
340     if (verbose)
341         fprintf(stderr, "Found %" PRIu32 " relocs and a %" PRIu32 "-entry symbol table\n", numRelocs, numSyms);
342 
343     //handle relocs
344     nanoRelocs = malloc(sizeof(struct NanoRelocEntry[numRelocs]));
345     if (!nanoRelocs) {
346         fprintf(stderr, "Failed to allocate a nano-reloc table\n");
347         goto out;
348     }
349 
350     for (i = 0; i < numRelocs; i++) {
351         uint32_t relocType = relocs[i].info & 0xff;
352         uint32_t whichSym = relocs[i].info >> 8;
353         uint32_t *valThereP;
354 
355         if (whichSym >= numSyms) {
356             fprintf(stderr, "Reloc %" PRIu32 " references a nonexistent symbol!\n"
357                             "INFO:\n"
358                             "        Where: 0x%08" PRIX32 "\n"
359                             "        type: %" PRIu32 "\n"
360                             "        sym: %" PRIu32 "\n",
361                 i, relocs[i].where, relocs[i].info & 0xff, whichSym);
362             goto out;
363         }
364 
365         if (verbose) {
366             const char *seg;
367 
368             fprintf(stderr, "Reloc[%3" PRIu32 "]:\n {@0x%08" PRIX32 ", type %3" PRIu32 ", -> sym[%3" PRIu32 "]: {@0x%08" PRIX32 "}, ",
369                 i, relocs[i].where, relocs[i].info & 0xff, whichSym, syms[whichSym].addr);
370 
371             if (IS_IN_RANGE_E(relocs[i].where, sect->bss_start, sect->bss_end))
372                 seg = ".bss";
373             else if (IS_IN_RANGE_E(relocs[i].where, sect->data_start, sect->data_end))
374                 seg = ".data";
375             else if (IS_IN_RANGE_E(relocs[i].where, sect->got_start, sect->got_end))
376                 seg = ".got";
377             else if (IS_IN_RANGE_E(relocs[i].where, FLASH_BASE, FLASH_BASE + sizeof(struct BinHdr)))
378                 seg = "APPHDR";
379             else
380                 seg = "???";
381 
382             fprintf(stderr, "in   %s}\n", seg);
383         }
384         /* handle relocs inside the header */
385         if (IS_IN_FLASH(relocs[i].where) && relocs[i].where - FLASH_BASE < sizeof(struct BinHdr) && relocType == RELOC_TYPE_SECT) {
386             /* relocs in header are special - runtime corrects for them */
387             if (syms[whichSym].addr) {
388                 fprintf(stderr, "Weird in-header sect reloc %" PRIu32 " to symbol %" PRIu32 " with nonzero addr 0x%08" PRIX32 "\n",
389                         i, whichSym, syms[whichSym].addr);
390                 goto out;
391             }
392 
393             valThereP = (uint32_t*)(buf + relocs[i].where - FLASH_BASE);
394             if (!IS_IN_FLASH(*valThereP)) {
395                 fprintf(stderr, "In-header reloc %" PRIu32 " of location 0x%08" PRIX32 " is outside of FLASH!\n"
396                                 "INFO:\n"
397                                 "        type: %" PRIu32 "\n"
398                                 "        sym: %" PRIu32 "\n"
399                                 "        Sym Addr: 0x%08" PRIX32 "\n",
400                                 i, relocs[i].where, relocType, whichSym, syms[whichSym].addr);
401                 goto out;
402             }
403 
404             // binary header generated by objcopy, .napp header and final FW header in flash are of different size.
405             // we subtract binary header offset here, so all the entry points are relative to beginning of "sect".
406             // FW will use &sect as a base to call these vectors; no more problems with different header sizes;
407             // Assumption: offsets between sect & vec, vec & code are the same in all images (or, in a simpler words, { sect, vec, code }
408             // must go together). this is enforced by linker script, and maintained by all tools and FW download code in the OS.
409             *valThereP -= FLASH_BASE + BINARY_RELOC_OFFSET;
410 
411             if (verbose)
412                 fprintf(stderr, "  -> Nano reloc skipped for in-header reloc\n");
413 
414             continue; /* do not produce an output reloc */
415         }
416 
417         if (!IS_IN_RAM(relocs[i].where)) {
418             fprintf(stderr, "In-header reloc %" PRIu32 " of location 0x%08" PRIX32 " is outside of RAM!\n"
419                             "INFO:\n"
420                             "        type: %" PRIu32 "\n"
421                             "        sym: %" PRIu32 "\n"
422                             "        Sym Addr: 0x%08" PRIX32 "\n",
423                             i, relocs[i].where, relocType, whichSym, syms[whichSym].addr);
424             goto out;
425         }
426 
427         valThereP = (uint32_t*)(buf + relocs[i].where + sect->data_data - RAM_BASE - FLASH_BASE);
428 
429         nanoRelocs[outNumRelocs].ofstInRam = relocs[i].where - RAM_BASE;
430 
431         switch (relocType) {
432             case RELOC_TYPE_ABS_S:
433             case RELOC_TYPE_ABS_D:
434                 t = *valThereP;
435 
436                 (*valThereP) += syms[whichSym].addr;
437 
438                 if (IS_IN_FLASH(syms[whichSym].addr)) {
439                     (*valThereP) -= FLASH_BASE + BINARY_RELOC_OFFSET;
440                     nanoRelocs[outNumRelocs].type = NANO_RELOC_TYPE_FLASH;
441                 }
442                 else if (IS_IN_RAM(syms[whichSym].addr)) {
443                     (*valThereP) -= RAM_BASE;
444                     nanoRelocs[outNumRelocs].type = NANO_RELOC_TYPE_RAM;
445                 }
446                 else {
447                     fprintf(stderr, "Weird reloc %" PRIu32 " to symbol %" PRIu32 " in unknown memory space (addr 0x%08" PRIX32 ")\n",
448                             i, whichSym, syms[whichSym].addr);
449                     goto out;
450                 }
451                 if (verbose)
452                     fprintf(stderr, "  -> Abs reference fixed up 0x%08" PRIX32 " -> 0x%08" PRIX32 "\n", t, *valThereP);
453                 break;
454 
455             case RELOC_TYPE_SECT:
456                 if (syms[whichSym].addr) {
457                     fprintf(stderr, "Weird sect reloc %" PRIu32 " to symbol %" PRIu32 " with nonzero addr 0x%08" PRIX32 "\n",
458                             i, whichSym, syms[whichSym].addr);
459                     goto out;
460                 }
461 
462                 t = *valThereP;
463 
464                 if (IS_IN_FLASH(*valThereP)) {
465                     nanoRelocs[outNumRelocs].type = NANO_RELOC_TYPE_FLASH;
466                     *valThereP -= FLASH_BASE + BINARY_RELOC_OFFSET;
467                 }
468                 else if (IS_IN_RAM(*valThereP)) {
469                     nanoRelocs[outNumRelocs].type = NANO_RELOC_TYPE_RAM;
470                     *valThereP -= RAM_BASE;
471                 }
472                 else {
473                     fprintf(stderr, "Weird sec reloc %" PRIu32 " to symbol %" PRIu32
474                                     " in unknown memory space (addr 0x%08" PRIX32 ")\n",
475                                     i, whichSym, *valThereP);
476                     goto out;
477                 }
478                 if (verbose)
479                     fprintf(stderr, "  -> Sect reference fixed up 0x%08" PRIX32 " -> 0x%08" PRIX32 "\n", t, *valThereP);
480                 break;
481 
482             default:
483                 fprintf(stderr, "Weird reloc %" PRIX32 " type %" PRIX32 " to symbol %" PRIX32 "\n", i, relocType, whichSym);
484                 goto out;
485         }
486 
487         if (verbose)
488             fprintf(stderr, "  -> Nano reloc calculated as 0x%08" PRIX32 ",0x%02" PRIX8 "\n", nanoRelocs[i].ofstInRam, nanoRelocs[i].type);
489         outNumRelocs++;
490     }
491 
492     packedNanoRelocs = packNanoRelocs(nanoRelocs, outNumRelocs, &packedNanoRelocSz, verbose);
493 
494     //overwrite original relocs and symtab with nanorelocs and adjust sizes
495     memcpy(relocs, packedNanoRelocs, packedNanoRelocSz);
496     bufUsed -= sizeof(struct RelocEntry[numRelocs]);
497     bufUsed -= sizeof(struct SymtabEntry[numSyms]);
498     bufUsed += packedNanoRelocSz;
499     assertMem(bufUsed, bufSz);
500     sect->rel_end = sect->rel_start + packedNanoRelocSz;
501 
502     //sanity
503     if (sect->rel_end - FLASH_BASE != bufUsed) {
504         fprintf(stderr, "Relocs end and file end not coincident\n");
505         goto out;
506     }
507 
508     //adjust headers for easy access (RAM)
509     if (!IS_IN_RAM(sect->data_start) || !IS_IN_RAM(sect->data_end) || !IS_IN_RAM(sect->bss_start) ||
510         !IS_IN_RAM(sect->bss_end) || !IS_IN_RAM(sect->got_start) || !IS_IN_RAM(sect->got_end)) {
511         fprintf(stderr, "data, bss, or got not in ram\n");
512         goto out;
513     }
514     sect->data_start -= RAM_BASE;
515     sect->data_end -= RAM_BASE;
516     sect->bss_start -= RAM_BASE;
517     sect->bss_end -= RAM_BASE;
518     sect->got_start -= RAM_BASE;
519     sect->got_end -= RAM_BASE;
520 
521     //adjust headers for easy access (FLASH)
522     if (!IS_IN_FLASH(sect->data_data) || !IS_IN_FLASH(sect->rel_start) || !IS_IN_FLASH(sect->rel_end)) {
523         fprintf(stderr, "data.data, or rel not in flash\n");
524         goto out;
525     }
526     sect->data_data -= FLASH_BASE + BINARY_RELOC_OFFSET;
527     sect->rel_start -= FLASH_BASE + BINARY_RELOC_OFFSET;
528     sect->rel_end -= FLASH_BASE + BINARY_RELOC_OFFSET;
529 
530     ret = finalizeAndWrite(buf, bufUsed, bufSz, out, layoutFlags, appId);
531 out:
532     free(nanoRelocs);
533     return ret;
534 }
535 
elfExtractSectionPointer(const Elf_Data * data,const char * name,struct ElfNanoApp * app)536 static void elfExtractSectionPointer(const Elf_Data *data, const char *name, struct ElfNanoApp *app)
537 {
538     // Maps section names to their byte offset in struct ElfNanoApp. Note that
539     // this assumes that the linker script puts text/code in the .flash section,
540     // RW data in .data, that relocs for .data are included in .rel.data, and
541     // the symbol table is emitted in .symtab
542     const struct SectionMap {
543         const char *name;
544         size_t offset;
545     } sectionMap[] = {
546         {
547             .name = ".flash",
548             .offset = offsetof(struct ElfNanoApp, flash),
549         },
550         {
551             .name = ".data",
552             .offset = offsetof(struct ElfNanoApp, data),
553         },
554         {
555             .name = ".rel.data",
556             .offset = offsetof(struct ElfNanoApp, relocs),
557         },
558         {
559             .name = ".symtab",
560             .offset = offsetof(struct ElfNanoApp, symtab),
561         },
562     };
563     struct ElfAppSection *appSection;
564     uint8_t *appBytes = (uint8_t *) app;
565 
566     for (size_t i = 0; i < ARRAY_SIZE(sectionMap); i++) {
567         if (strcmp(name, sectionMap[i].name) != 0) {
568             continue;
569         }
570         appSection = (struct ElfAppSection *) &appBytes[sectionMap[i].offset];
571 
572         appSection->data = data->d_buf;
573         appSection->size = data->d_size;
574 
575         DBG("Found section %s with size %zu", name, appSection->size);
576         break;
577     }
578 }
579 
580 // Populates a struct ElfNanoApp with data parsed from the ELF
elfParse(Elf * elf,struct ElfNanoApp * app)581 static bool elfParse(Elf *elf, struct ElfNanoApp *app)
582 {
583     size_t shdrstrndx;
584     Elf_Scn *scn = NULL;
585     GElf_Shdr shdr;
586     char *sectionName;
587     Elf_Data *elf_data;
588 
589     memset(app, 0, sizeof(*app));
590     if (elf_getshdrstrndx(elf, &shdrstrndx) != 0) {
591         ELF_ERR("Couldn't get section name string table index");
592         return false;
593     }
594 
595     while ((scn = elf_nextscn(elf, scn)) != NULL) {
596         if (gelf_getshdr(scn, &shdr) != &shdr) {
597             ELF_ERR("Error getting section header");
598             return false;
599         }
600         sectionName = elf_strptr(elf, shdrstrndx, shdr.sh_name);
601 
602         elf_data = elf_getdata(scn, NULL);
603         if (!elf_data) {
604             ELF_ERR("Error getting data for section %s", sectionName);
605             return false;
606         }
607 
608         elfExtractSectionPointer(elf_data, sectionName, app);
609     }
610 
611     return true;
612 }
613 
loadNanoappElfFile(const char * fileName,struct ElfNanoApp * app)614 static bool loadNanoappElfFile(const char *fileName, struct ElfNanoApp *app)
615 {
616     int fd;
617     Elf *elf;
618 
619     if (elf_version(EV_CURRENT) == EV_NONE) {
620         ELF_ERR("Failed to initialize ELF library");
621         return false;
622     }
623 
624     fd = open(fileName, O_RDONLY, 0);
625     if (fd < 0) {
626         ERR("Failed to open file %s for reading: %s", fileName, strerror(errno));
627         return false;
628     }
629 
630     elf = elf_begin(fd, ELF_C_READ, NULL);
631     if (elf == NULL) {
632         ELF_ERR("Failed to open ELF");
633         return false;
634     }
635 
636     if (!elfParse(elf, app)) {
637         ERR("Failed to parse ELF file");
638         return false;
639     }
640 
641     return true;
642 }
643 
644 // Subtracts the fixed memory region offset from an absolute address and returns
645 // the associated NANO_RELOC_* value, or NANO_RELOC_LAST if the address is not
646 // in the expected range.
647 // Not strictly tied to ELF usage, but handled slightly differently.
fixupAddrElf(uint32_t * addr)648 static uint8_t fixupAddrElf(uint32_t *addr)
649 {
650     uint8_t type;
651 
652     // TODO: this assumes that the host running this tool has the same
653     // endianness as the image file/target processor
654     if (IS_IN_FLASH(*addr)) {
655         DBG("Fixup addr 0x%08" PRIX32 " (flash) --> 0x%08" PRIX32, *addr,
656             (uint32_t) (*addr - (FLASH_BASE + BINARY_RELOC_OFFSET)));
657         *addr -= FLASH_BASE + BINARY_RELOC_OFFSET;
658         type = NANO_RELOC_TYPE_FLASH;
659     } else if (IS_IN_RAM(*addr)) {
660         DBG("Fixup addr 0x%08" PRIX32 " (ram)   --> 0x%08" PRIX32, *addr,
661             *addr - RAM_BASE);
662         *addr -= RAM_BASE;
663         type = NANO_RELOC_TYPE_RAM;
664     } else {
665         DBG("Error: invalid address 0x%08" PRIX32, *addr);
666         type = NANO_RELOC_LAST;
667     }
668 
669     return type;
670 }
671 
672 // Fixup addresses in the header to be relative. Not strictly tied to the ELF
673 // format, but used only in that program flow in the current implementation.
fixupHeaderElf(const struct ElfNanoApp * app)674 static bool fixupHeaderElf(const struct ElfNanoApp *app)
675 {
676     struct BinHdr *hdr = (struct BinHdr *) app->flash.data;
677 
678     DBG("Appyling fixups to header");
679     if (fixupAddrElf(&hdr->sect.data_start) != NANO_RELOC_TYPE_RAM ||
680         fixupAddrElf(&hdr->sect.data_end)   != NANO_RELOC_TYPE_RAM ||
681         fixupAddrElf(&hdr->sect.bss_start)  != NANO_RELOC_TYPE_RAM ||
682         fixupAddrElf(&hdr->sect.bss_end)    != NANO_RELOC_TYPE_RAM ||
683         fixupAddrElf(&hdr->sect.got_start)  != NANO_RELOC_TYPE_RAM ||
684         fixupAddrElf(&hdr->sect.got_end)    != NANO_RELOC_TYPE_RAM) {
685         ERR(".data, .bss, or .got not in RAM address space!");
686         return false;
687     }
688 
689     if (fixupAddrElf(&hdr->sect.rel_start) != NANO_RELOC_TYPE_FLASH ||
690         fixupAddrElf(&hdr->sect.rel_end)   != NANO_RELOC_TYPE_FLASH ||
691         fixupAddrElf(&hdr->sect.data_data) != NANO_RELOC_TYPE_FLASH) {
692         ERR(".data loadaddr, or .relocs not in flash address space!");
693         return false;
694     }
695 
696     if (fixupAddrElf(&hdr->vec.init)   != NANO_RELOC_TYPE_FLASH ||
697         fixupAddrElf(&hdr->vec.end)    != NANO_RELOC_TYPE_FLASH ||
698         fixupAddrElf(&hdr->vec.handle) != NANO_RELOC_TYPE_FLASH) {
699         ERR("Entry point(s) not in flash address space!");
700         return false;
701     }
702 
703     return true;
704 }
705 
706 // Fixup addresses in .data, .init_array/.fini_array, and .got, and generates
707 // packed array of nano reloc entries. The app header must have already been
708 // fixed up.
genElfNanoRelocs(struct ElfNanoApp * app,bool verbose)709 static bool genElfNanoRelocs(struct ElfNanoApp *app, bool verbose)
710 {
711     const struct BinHdr *hdr = (const struct BinHdr *) app->flash.data;
712     const struct SectInfo *sect = &hdr->sect;
713     bool success = false;
714 
715     size_t numDataRelocs = app->relocs.size / sizeof(Elf32_Rel);
716     size_t gotCount = (sect->got_end - sect->got_start) / sizeof(uint32_t);
717     size_t numInitFuncs  = (sect->bss_start - sect->data_end) / sizeof(uint32_t);
718 
719     size_t totalRelocCount = (numDataRelocs + numInitFuncs + gotCount);
720     struct NanoRelocEntry *nanoRelocs = malloc(
721         totalRelocCount * sizeof(struct NanoRelocEntry));
722     if (!nanoRelocs) {
723         ERR("Couldn't allocate memory for nano relocs! Needed %zu bytes",
724             totalRelocCount * sizeof(struct NanoRelocEntry));
725         return false;
726     }
727 
728     uint8_t *data = app->data.data;
729     const Elf32_Rel *relocs = (const Elf32_Rel *) app->relocs.data;
730     const Elf32_Sym *syms   = (const Elf32_Sym *) app->symtab.data;
731     size_t numRelocs = 0;
732 
733     DBG("Parsing relocs for .data (%zu):", numDataRelocs);
734     for (size_t i = 0; i < numDataRelocs; i++) {
735         uint32_t type = ELF32_R_TYPE(relocs[i].r_info);
736         uint32_t sym = ELF32_R_SYM(relocs[i].r_info);
737 
738         DBG(" [%3zu] 0x%08" PRIx32 " type %2" PRIu32 " symIdx %3" PRIu32
739             " --> 0x%08" PRIx32, i, relocs[i].r_offset, type, sym,
740             syms[sym].st_value);
741         // Note that R_ARM_TARGET1 is used for .init_array/.fini_array support,
742         // and can be interpreted either as ABS32 or REL32, depending on the
743         // runtime; we expect it to be ABS32.
744         if (type == R_ARM_ABS32 || type == R_ARM_TARGET1) {
745             if (!IS_IN_RAM(relocs[i].r_offset)) {
746                 ERR("Reloc for .data not in RAM address range!");
747                 goto out;
748             }
749             uint32_t offset = relocs[i].r_offset - RAM_BASE;
750             uint32_t *addr = (uint32_t *) &data[offset];
751 
752             nanoRelocs[numRelocs].type = fixupAddrElf(addr);
753             nanoRelocs[numRelocs].ofstInRam = offset;
754             numRelocs++;
755         } else {
756             // TODO: Assuming that the ELF only contains absolute addresses in
757             // the .data section; may need to handle other relocation types in
758             // the future
759             ERR("Error: Unexpected reloc type %" PRIu32 " at index %zu",
760                 type, i);
761             goto out;
762         }
763     }
764 
765     DBG("Updating GOT entries (%zu):", gotCount);
766     for (uint32_t offset = sect->got_start; offset < sect->got_end;
767             offset += sizeof(uint32_t)) {
768         uint32_t *addr = (uint32_t *) &data[offset];
769         // Skip values that are set to 0, these seem to be padding (?)
770         if (*addr) {
771             nanoRelocs[numRelocs].type = fixupAddrElf(addr);
772             nanoRelocs[numRelocs].ofstInRam = offset;
773             numRelocs++;
774         }
775     }
776 
777     uint32_t packedNanoRelocSz = 0;
778     app->packedNanoRelocs.data = packNanoRelocs(
779         nanoRelocs, numRelocs, &packedNanoRelocSz, verbose);
780     app->packedNanoRelocs.size = packedNanoRelocSz;
781     success = true;
782 out:
783     free(nanoRelocs);
784     return success;
785 }
786 
handleAppStatic(const char * fileName,FILE * out,uint32_t layoutFlags,uint64_t appId,bool verbose)787 static int handleAppStatic(const char *fileName, FILE *out, uint32_t layoutFlags, uint64_t appId, bool verbose)
788 {
789     struct ElfNanoApp app;
790 
791     if (!loadNanoappElfFile(fileName, &app)
792             || !fixupHeaderElf(&app)
793             || !genElfNanoRelocs(&app, verbose)) {
794         exit(2);
795     }
796 
797     // Construct a single contiguous buffer, with extra room to fit the
798     // ImageHeader that will be prepended by finalizeAndWrite(). Note that this
799     // will allocate a bit more space than is needed, because some of the data
800     // from BinHdr will get discarded.
801     // TODO: this should be refactored to just write the binary components in
802     // order rather than allocating a big buffer, and moving data around
803     size_t bufSize = app.flash.size + app.data.size + app.packedNanoRelocs.size
804         + sizeof(struct ImageHeader);
805     uint8_t *buf = malloc(bufSize);
806     if (!buf) {
807         ERR("Failed to allocate %zu bytes for final app", bufSize);
808         exit(2);
809     }
810 
811     size_t offset = 0;
812     memcpy(buf, app.flash.data, app.flash.size);
813     offset += app.flash.size;
814     memcpy(&buf[offset], app.data.data, app.data.size);
815     offset += app.data.size;
816     memcpy(&buf[offset], app.packedNanoRelocs.data, app.packedNanoRelocs.size);
817     offset += app.packedNanoRelocs.size;
818 
819     // Update rel_end in the header to reflect the packed reloc size
820     struct BinHdr *hdr = (struct BinHdr *) buf;
821     hdr->sect.rel_end = hdr->sect.rel_start + app.packedNanoRelocs.size;
822 
823     return finalizeAndWrite(buf, offset, bufSize, out, layoutFlags, appId);
824     // TODO: should free all memory we allocated... just letting the OS handle
825     // it for now
826 }
827 
handleKey(uint8_t ** pbuf,uint32_t bufUsed,FILE * out,uint32_t layoutFlags,uint64_t appId,uint64_t keyId)828 static int handleKey(uint8_t **pbuf, uint32_t bufUsed, FILE *out, uint32_t layoutFlags, uint64_t appId, uint64_t keyId)
829 {
830     uint8_t *buf = *pbuf;
831     struct KeyInfo ki = { .data = keyId };
832     bool good = true;
833 
834     struct ImageHeader outHeader = {
835         .aosp = (struct nano_app_binary_t) {
836             .header_version = 1,
837             .magic = NANOAPP_AOSP_MAGIC,
838             .app_id = appId,
839         },
840         .layout = (struct ImageLayout) {
841             .magic = GOOGLE_LAYOUT_MAGIC,
842             .version = 1,
843             .payload = LAYOUT_KEY,
844             .flags = layoutFlags,
845         },
846     };
847 
848     good = good && fwrite(&outHeader, sizeof(outHeader), 1, out) == 1;
849     good = good && fwrite(&ki, sizeof(ki), 1, out) ==  1;
850     good = good && fwrite(buf, bufUsed, 1, out) == 1;
851 
852     return good ? 0 : 2;
853 }
854 
handleOs(uint8_t ** pbuf,uint32_t bufUsed,FILE * out,uint32_t layoutFlags,bool bare)855 static int handleOs(uint8_t **pbuf, uint32_t bufUsed, FILE *out, uint32_t layoutFlags, bool bare)
856 {
857     uint8_t *buf = *pbuf;
858     bool good;
859 
860     struct OsUpdateHdr os = {
861         .magic = OS_UPDT_MAGIC,
862         .marker = OS_UPDT_MARKER_INPROGRESS,
863         .size = bufUsed
864     };
865 
866     struct ImageHeader outHeader = {
867         .aosp = (struct nano_app_binary_t) {
868             .header_version = 1,
869             .magic = NANOAPP_AOSP_MAGIC,
870         },
871         .layout = (struct ImageLayout) {
872             .magic = GOOGLE_LAYOUT_MAGIC,
873             .version = 1,
874             .payload = LAYOUT_OS,
875             .flags = layoutFlags,
876         },
877     };
878 
879     if (!bare)
880         good = fwrite(&outHeader, sizeof(outHeader), 1, out) == 1;
881     else
882         good = fwrite(&os, sizeof(os), 1, out) == 1;
883     good = good && fwrite(buf, bufUsed, 1, out) == 1;
884 
885     return good ? 0 : 2;
886 }
887 
main(int argc,char ** argv)888 int main(int argc, char **argv)
889 {
890     uint32_t bufUsed = 0;
891     bool verbose = false;
892     uint8_t *buf = NULL;
893     uint64_t appId = 0;
894     uint64_t keyId = 0;
895     uint32_t layoutId = 0;
896     uint32_t layoutFlags = 0;
897     int ret = -1;
898     uint32_t *u32Arg = NULL;
899     uint64_t *u64Arg = NULL;
900     const char **strArg = NULL;
901     const char *appName = argv[0];
902     int posArgCnt = 0;
903     const char *posArg[2] = { NULL };
904     FILE *out = NULL;
905     const char *layoutName = "app";
906     const char *prev = NULL;
907     bool bareData = false;
908     bool staticElf = false;
909 
910     for (int i = 1; i < argc; i++) {
911         char *end = NULL;
912         if (argv[i][0] == '-') {
913             prev = argv[i];
914             if (!strcmp(argv[i], "-v"))
915                 verbose = true;
916             else if (!strcmp(argv[i], "-r"))
917                 bareData = true;
918             else if (!strcmp(argv[i], "-s"))
919                 staticElf = true;
920             else if (!strcmp(argv[i], "-a"))
921                 u64Arg = &appId;
922             else if (!strcmp(argv[i], "-k"))
923                 u64Arg = &keyId;
924             else if (!strcmp(argv[i], "-n"))
925                 strArg = &layoutName;
926             else if (!strcmp(argv[i], "-i"))
927                 u32Arg = &layoutId;
928             else if (!strcmp(argv[i], "-f"))
929                 u32Arg = &layoutFlags;
930             else
931                 fatalUsage(appName, "unknown argument", argv[i]);
932         } else {
933             if (u64Arg) {
934                 uint64_t tmp = strtoull(argv[i], &end, 16);
935                 if (*end == '\0')
936                     *u64Arg = tmp;
937                 u64Arg = NULL;
938             } else if (u32Arg) {
939                 uint32_t tmp = strtoul(argv[i], &end, 16);
940                 if (*end == '\0')
941                     *u32Arg = tmp;
942                 u32Arg = NULL;
943             } else if (strArg) {
944                     *strArg = argv[i];
945                 strArg = NULL;
946             } else {
947                 if (posArgCnt < 2)
948                     posArg[posArgCnt++] = argv[i];
949                 else
950                     fatalUsage(appName, "too many positional arguments", argv[i]);
951             }
952             prev = NULL;
953         }
954     }
955     if (prev)
956         fatalUsage(appName, "missing argument after", prev);
957 
958     if (!posArgCnt)
959         fatalUsage(appName, "missing input file name", NULL);
960 
961     if (!layoutId) {
962         if (strcmp(layoutName, "app") == 0)
963             layoutId = LAYOUT_APP;
964         else if (strcmp(layoutName, "os") == 0)
965             layoutId = LAYOUT_OS;
966         else if (strcmp(layoutName, "key") == 0)
967             layoutId = LAYOUT_KEY;
968         else
969             fatalUsage(appName, "Invalid layout name", layoutName);
970     }
971 
972     if (staticElf && layoutId != LAYOUT_APP)
973         fatalUsage(appName, "Only app layout is supported for static option", NULL);
974 
975     if (layoutId == LAYOUT_APP && !appId)
976         fatalUsage(appName, "App layout requires app ID", NULL);
977     if (layoutId == LAYOUT_KEY && !keyId)
978         fatalUsage(appName, "Key layout requires key ID", NULL);
979     if (layoutId == LAYOUT_OS && (keyId || appId))
980         fatalUsage(appName, "OS layout does not need any ID", NULL);
981 
982     if (!staticElf) {
983         buf = loadFile(posArg[0], &bufUsed);
984         fprintf(stderr, "Read %" PRIu32 " bytes\n", bufUsed);
985     }
986 
987     if (!posArg[1])
988         out = stdout;
989     else
990         out = fopen(posArg[1], "w");
991     if (!out)
992         fatalUsage(appName, "failed to create/open output file", posArg[1]);
993 
994     switch(layoutId) {
995     case LAYOUT_APP:
996         if (staticElf) {
997             ret = handleAppStatic(posArg[0], out, layoutFlags, appId, verbose);
998         } else {
999             ret = handleApp(&buf, bufUsed, out, layoutFlags, appId, verbose);
1000         }
1001         break;
1002     case LAYOUT_KEY:
1003         ret = handleKey(&buf, bufUsed, out, layoutFlags, appId, keyId);
1004         break;
1005     case LAYOUT_OS:
1006         ret = handleOs(&buf, bufUsed, out, layoutFlags, bareData);
1007         break;
1008     }
1009 
1010     free(buf);
1011     fclose(out);
1012     return ret;
1013 }
1014