blob: 967522ab4f3902b0c8914bf7038b588741b64d91 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* Generate assembler source containing symbol information
2 *
3 * Copyright 2002 by Kai Germaschewski
4 *
5 * This software may be used and distributed according to the terms
6 * of the GNU General Public License, incorporated herein by reference.
7 *
8 * Usage: nm -n vmlinux | scripts/kallsyms [--all-symbols] > symbols.S
9 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 * Table compression uses all the unused char codes on the symbols and
11 * maps these to the most used substrings (tokens). For instance, it might
12 * map char code 0xF7 to represent "write_" and then in every symbol where
13 * "write_" appears it can be replaced by 0xF7, saving 5 bytes.
14 * The used codes themselves are also placed in the table so that the
15 * decompresion can work without "special cases".
16 * Applied to kernel symbols, this usually produces a compression ratio
17 * of about 50%.
18 *
19 */
20
21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24#include <ctype.h>
25
Mike Frysinger17b1f0d2009-06-08 19:12:13 -040026#ifndef ARRAY_SIZE
27#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))
28#endif
29
Andi Kleenf3462aa2013-10-23 15:07:53 +020030#define KSYM_NAME_LEN 255
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
Linus Torvalds1da177e2005-04-16 15:20:36 -070032struct sym_entry {
33 unsigned long long addr;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -070034 unsigned int len;
Paulo Marquesf2df3f62008-02-06 01:37:33 -080035 unsigned int start_pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 unsigned char *sym;
37};
38
Mike Frysinger17b1f0d2009-06-08 19:12:13 -040039struct text_range {
40 const char *stext, *etext;
41 unsigned long long start, end;
42};
43
44static unsigned long long _text;
45static struct text_range text_ranges[] = {
46 { "_stext", "_etext" },
47 { "_sinittext", "_einittext" },
48 { "_stext_l1", "_etext_l1" }, /* Blackfin on-chip L1 inst SRAM */
49 { "_stext_l2", "_etext_l2" }, /* Blackfin on-chip L2 SRAM */
50};
51#define text_range_text (&text_ranges[0])
52#define text_range_inittext (&text_ranges[1])
53
Linus Torvalds1da177e2005-04-16 15:20:36 -070054static struct sym_entry *table;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -070055static unsigned int table_size, table_cnt;
Linus Torvalds1da177e2005-04-16 15:20:36 -070056static int all_symbols = 0;
Yoshinori Sato41f11a42005-05-01 08:59:06 -070057static char symbol_prefix_char = '\0';
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -070059int token_profit[0x10000];
Linus Torvalds1da177e2005-04-16 15:20:36 -070060
61/* the table that holds the result of the compression */
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -070062unsigned char best_table[256][2];
Linus Torvalds1da177e2005-04-16 15:20:36 -070063unsigned char best_table_len[256];
64
65
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -070066static void usage(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070067{
Yoshinori Sato41f11a42005-05-01 08:59:06 -070068 fprintf(stderr, "Usage: kallsyms [--all-symbols] [--symbol-prefix=<prefix char>] < in.map > out.S\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 exit(1);
70}
71
72/*
73 * This ignores the intensely annoying "mapping symbols" found
74 * in ARM ELF files: $a, $t and $d.
75 */
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -070076static inline int is_arm_mapping_symbol(const char *str)
Linus Torvalds1da177e2005-04-16 15:20:36 -070077{
78 return str[0] == '$' && strchr("atd", str[1])
79 && (str[2] == '\0' || str[2] == '.');
80}
81
Mike Frysinger17b1f0d2009-06-08 19:12:13 -040082static int read_symbol_tr(const char *sym, unsigned long long addr)
83{
84 size_t i;
85 struct text_range *tr;
86
87 for (i = 0; i < ARRAY_SIZE(text_ranges); ++i) {
88 tr = &text_ranges[i];
89
90 if (strcmp(sym, tr->stext) == 0) {
91 tr->start = addr;
92 return 0;
93 } else if (strcmp(sym, tr->etext) == 0) {
94 tr->end = addr;
95 return 0;
96 }
97 }
98
99 return 1;
100}
101
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700102static int read_symbol(FILE *in, struct sym_entry *s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103{
104 char str[500];
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700105 char *sym, stype;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 int rc;
107
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700108 rc = fscanf(in, "%llx %c %499s\n", &s->addr, &stype, str);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 if (rc != 3) {
Jean Sacrenef894872010-09-10 23:13:33 -0600110 if (rc != EOF && fgets(str, 500, in) == NULL)
111 fprintf(stderr, "Read error or end of file.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 return -1;
113 }
Andi Kleenf3462aa2013-10-23 15:07:53 +0200114 if (strlen(str) > KSYM_NAME_LEN) {
115 fprintf(stderr, "Symbol %s too long for kallsyms (%lu vs %d).\n"
116 "Please increase KSYM_NAME_LEN both in kernel and kallsyms.c\n",
117 str, strlen(str), KSYM_NAME_LEN);
118 return -1;
119 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700121 sym = str;
122 /* skip prefix char */
123 if (symbol_prefix_char && str[0] == symbol_prefix_char)
124 sym++;
125
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 /* Ignore most absolute/undefined (?) symbols. */
Eric W. Biedermanfd593d12006-12-07 02:14:04 +0100127 if (strcmp(sym, "_text") == 0)
128 _text = s->addr;
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400129 else if (read_symbol_tr(sym, s->addr) == 0)
130 /* nothing to do */;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700131 else if (toupper(stype) == 'A')
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 {
133 /* Keep these useful absolute symbols */
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700134 if (strcmp(sym, "__kernel_syscall_via_break") &&
135 strcmp(sym, "__kernel_syscall_via_epc") &&
136 strcmp(sym, "__kernel_sigtramp") &&
137 strcmp(sym, "__gp"))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 return -1;
139
140 }
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700141 else if (toupper(stype) == 'U' ||
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700142 is_arm_mapping_symbol(sym))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 return -1;
Ralf Baechle6f00df22005-09-06 15:16:41 -0700144 /* exclude also MIPS ELF local symbols ($L123 instead of .L123) */
145 else if (str[0] == '$')
146 return -1;
Sam Ravnborgaab34ac2008-05-19 20:07:58 +0200147 /* exclude debugging symbols */
148 else if (stype == 'N')
149 return -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150
151 /* include the type field in the symbol name, so that it gets
152 * compressed together */
153 s->len = strlen(str) + 1;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700154 s->sym = malloc(s->len + 1);
Jesper Juhlf1a136e2006-03-25 03:07:46 -0800155 if (!s->sym) {
156 fprintf(stderr, "kallsyms failure: "
157 "unable to allocate required amount of memory\n");
158 exit(EXIT_FAILURE);
159 }
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700160 strcpy((char *)s->sym + 1, str);
161 s->sym[0] = stype;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
163 return 0;
164}
165
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400166static int symbol_valid_tr(struct sym_entry *s)
167{
168 size_t i;
169 struct text_range *tr;
170
171 for (i = 0; i < ARRAY_SIZE(text_ranges); ++i) {
172 tr = &text_ranges[i];
173
Mike Frysingerac6ca5c2009-06-15 07:52:48 -0400174 if (s->addr >= tr->start && s->addr <= tr->end)
175 return 1;
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400176 }
177
Mike Frysingerac6ca5c2009-06-15 07:52:48 -0400178 return 0;
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400179}
180
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700181static int symbol_valid(struct sym_entry *s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182{
183 /* Symbols which vary between passes. Passes 1 and 2 must have
Sam Ravnborg2ea03892009-01-14 21:38:20 +0100184 * identical symbol lists. The kallsyms_* symbols below are only added
185 * after pass 1, they would be included in pass 2 when --all-symbols is
186 * specified so exclude them to get a stable symbol list.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 */
188 static char *special_symbols[] = {
Sam Ravnborg2ea03892009-01-14 21:38:20 +0100189 "kallsyms_addresses",
190 "kallsyms_num_syms",
191 "kallsyms_names",
192 "kallsyms_markers",
193 "kallsyms_token_table",
194 "kallsyms_token_index",
195
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 /* Exclude linker generated symbols which vary between passes */
197 "_SDA_BASE_", /* ppc */
198 "_SDA2_BASE_", /* ppc */
199 NULL };
200 int i;
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700201 int offset = 1;
202
203 /* skip prefix char */
204 if (symbol_prefix_char && *(s->sym + 1) == symbol_prefix_char)
205 offset++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206
207 /* if --all-symbols is not specified, then symbols outside the text
208 * and inittext sections are discarded */
209 if (!all_symbols) {
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400210 if (symbol_valid_tr(s) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 return 0;
212 /* Corner case. Discard any symbols with the same value as
Robin Getza3b81112008-02-06 01:36:26 -0800213 * _etext _einittext; they can move between pass 1 and 2 when
214 * the kallsyms data are added. If these symbols move then
215 * they may get dropped in pass 2, which breaks the kallsyms
216 * rules.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 */
Mike Frysinger17b1f0d2009-06-08 19:12:13 -0400218 if ((s->addr == text_range_text->end &&
219 strcmp((char *)s->sym + offset, text_range_text->etext)) ||
220 (s->addr == text_range_inittext->end &&
221 strcmp((char *)s->sym + offset, text_range_inittext->etext)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 return 0;
223 }
224
225 /* Exclude symbols which vary between passes. */
Sam Ravnborg2ea03892009-01-14 21:38:20 +0100226 if (strstr((char *)s->sym + offset, "_compiled."))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 return 0;
228
229 for (i = 0; special_symbols[i]; i++)
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700230 if( strcmp((char *)s->sym + offset, special_symbols[i]) == 0 )
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 return 0;
232
233 return 1;
234}
235
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700236static void read_map(FILE *in)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237{
238 while (!feof(in)) {
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700239 if (table_cnt >= table_size) {
240 table_size += 10000;
241 table = realloc(table, sizeof(*table) * table_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 if (!table) {
243 fprintf(stderr, "out of memory\n");
244 exit (1);
245 }
246 }
Paulo Marquesf2df3f62008-02-06 01:37:33 -0800247 if (read_symbol(in, &table[table_cnt]) == 0) {
248 table[table_cnt].start_pos = table_cnt;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700249 table_cnt++;
Paulo Marquesf2df3f62008-02-06 01:37:33 -0800250 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 }
252}
253
254static void output_label(char *label)
255{
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700256 if (symbol_prefix_char)
257 printf(".globl %c%s\n", symbol_prefix_char, label);
258 else
259 printf(".globl %s\n", label);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 printf("\tALGN\n");
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700261 if (symbol_prefix_char)
262 printf("%c%s:\n", symbol_prefix_char, label);
263 else
264 printf("%s:\n", label);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265}
266
267/* uncompress a compressed symbol. When this function is called, the best table
268 * might still be compressed itself, so the function needs to be recursive */
269static int expand_symbol(unsigned char *data, int len, char *result)
270{
271 int c, rlen, total=0;
272
273 while (len) {
274 c = *data;
275 /* if the table holds a single char that is the same as the one
276 * we are looking for, then end the search */
277 if (best_table[c][0]==c && best_table_len[c]==1) {
278 *result++ = c;
279 total++;
280 } else {
281 /* if not, recurse and expand */
282 rlen = expand_symbol(best_table[c], best_table_len[c], result);
283 total += rlen;
284 result += rlen;
285 }
286 data++;
287 len--;
288 }
289 *result=0;
290
291 return total;
292}
293
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700294static void write_src(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295{
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700296 unsigned int i, k, off;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 unsigned int best_idx[256];
298 unsigned int *markers;
Tejun Heo9281ace2007-07-17 04:03:51 -0700299 char buf[KSYM_NAME_LEN];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300
301 printf("#include <asm/types.h>\n");
302 printf("#if BITS_PER_LONG == 64\n");
303 printf("#define PTR .quad\n");
304 printf("#define ALGN .align 8\n");
305 printf("#else\n");
306 printf("#define PTR .long\n");
307 printf("#define ALGN .align 4\n");
308 printf("#endif\n");
309
Jan Beulichaad09472006-12-08 02:35:57 -0800310 printf("\t.section .rodata, \"a\"\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311
Eric W. Biedermanfd593d12006-12-07 02:14:04 +0100312 /* Provide proper symbols relocatability by their '_text'
313 * relativeness. The symbol names cannot be used to construct
314 * normal symbol references as the list of symbols contains
315 * symbols that are declared static and are private to their
316 * .o files. This prevents .tmp_kallsyms.o or any other
317 * object from referencing them.
318 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 output_label("kallsyms_addresses");
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700320 for (i = 0; i < table_cnt; i++) {
Eric W. Biedermanfd593d12006-12-07 02:14:04 +0100321 if (toupper(table[i].sym[0]) != 'A') {
Vivek Goyal2c22d8b2006-12-07 02:14:10 +0100322 if (_text <= table[i].addr)
323 printf("\tPTR\t_text + %#llx\n",
324 table[i].addr - _text);
325 else
326 printf("\tPTR\t_text - %#llx\n",
327 _text - table[i].addr);
Eric W. Biedermanfd593d12006-12-07 02:14:04 +0100328 } else {
329 printf("\tPTR\t%#llx\n", table[i].addr);
330 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 }
332 printf("\n");
333
334 output_label("kallsyms_num_syms");
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700335 printf("\tPTR\t%d\n", table_cnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 printf("\n");
337
338 /* table of offset markers, that give the offset in the compressed stream
339 * every 256 symbols */
Jesper Juhlf1a136e2006-03-25 03:07:46 -0800340 markers = malloc(sizeof(unsigned int) * ((table_cnt + 255) / 256));
341 if (!markers) {
342 fprintf(stderr, "kallsyms failure: "
343 "unable to allocate required memory\n");
344 exit(EXIT_FAILURE);
345 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346
347 output_label("kallsyms_names");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 off = 0;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700349 for (i = 0; i < table_cnt; i++) {
350 if ((i & 0xFF) == 0)
351 markers[i >> 8] = off;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352
353 printf("\t.byte 0x%02x", table[i].len);
354 for (k = 0; k < table[i].len; k++)
355 printf(", 0x%02x", table[i].sym[k]);
356 printf("\n");
357
358 off += table[i].len + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 }
360 printf("\n");
361
362 output_label("kallsyms_markers");
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700363 for (i = 0; i < ((table_cnt + 255) >> 8); i++)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 printf("\tPTR\t%d\n", markers[i]);
365 printf("\n");
366
367 free(markers);
368
369 output_label("kallsyms_token_table");
370 off = 0;
371 for (i = 0; i < 256; i++) {
372 best_idx[i] = off;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700373 expand_symbol(best_table[i], best_table_len[i], buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 printf("\t.asciz\t\"%s\"\n", buf);
375 off += strlen(buf) + 1;
376 }
377 printf("\n");
378
379 output_label("kallsyms_token_index");
380 for (i = 0; i < 256; i++)
381 printf("\t.short\t%d\n", best_idx[i]);
382 printf("\n");
383}
384
385
386/* table lookup compression functions */
387
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388/* count all the possible tokens in a symbol */
389static void learn_symbol(unsigned char *symbol, int len)
390{
391 int i;
392
393 for (i = 0; i < len - 1; i++)
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700394 token_profit[ symbol[i] + (symbol[i + 1] << 8) ]++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395}
396
397/* decrease the count for all the possible tokens in a symbol */
398static void forget_symbol(unsigned char *symbol, int len)
399{
400 int i;
401
402 for (i = 0; i < len - 1; i++)
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700403 token_profit[ symbol[i] + (symbol[i + 1] << 8) ]--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404}
405
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700406/* remove all the invalid symbols from the table and do the initial token count */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407static void build_initial_tok_table(void)
408{
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700409 unsigned int i, pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700411 pos = 0;
412 for (i = 0; i < table_cnt; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 if ( symbol_valid(&table[i]) ) {
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700414 if (pos != i)
415 table[pos] = table[i];
416 learn_symbol(table[pos].sym, table[pos].len);
417 pos++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 }
419 }
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700420 table_cnt = pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421}
422
Paulo Marques7c5d2492007-06-20 18:09:00 +0100423static void *find_token(unsigned char *str, int len, unsigned char *token)
424{
425 int i;
426
427 for (i = 0; i < len - 1; i++) {
428 if (str[i] == token[0] && str[i+1] == token[1])
429 return &str[i];
430 }
431 return NULL;
432}
433
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434/* replace a given token in all the valid symbols. Use the sampled symbols
435 * to update the counts */
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700436static void compress_symbols(unsigned char *str, int idx)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437{
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700438 unsigned int i, len, size;
439 unsigned char *p1, *p2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700441 for (i = 0; i < table_cnt; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442
443 len = table[i].len;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700444 p1 = table[i].sym;
445
446 /* find the token on the symbol */
Paulo Marques7c5d2492007-06-20 18:09:00 +0100447 p2 = find_token(p1, len, str);
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700448 if (!p2) continue;
449
450 /* decrease the counts for this symbol's tokens */
451 forget_symbol(table[i].sym, len);
452
453 size = len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454
455 do {
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700456 *p2 = idx;
457 p2++;
458 size -= (p2 - p1);
459 memmove(p2, p2 + 1, size);
460 p1 = p2;
461 len--;
462
463 if (size < 2) break;
464
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 /* find the token on the symbol */
Paulo Marques7c5d2492007-06-20 18:09:00 +0100466 p2 = find_token(p1, size, str);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700468 } while (p2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700470 table[i].len = len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700472 /* increase the counts for this symbol's new tokens */
473 learn_symbol(table[i].sym, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 }
475}
476
477/* search the token with the maximum profit */
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700478static int find_best_token(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479{
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700480 int i, best, bestprofit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481
482 bestprofit=-10000;
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700483 best = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700485 for (i = 0; i < 0x10000; i++) {
486 if (token_profit[i] > bestprofit) {
487 best = i;
488 bestprofit = token_profit[i];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 return best;
492}
493
494/* this is the core of the algorithm: calculate the "best" table */
495static void optimize_result(void)
496{
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700497 int i, best;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498
499 /* using the '\0' symbol last allows compress_symbols to use standard
500 * fast string functions */
501 for (i = 255; i >= 0; i--) {
502
503 /* if this table slot is empty (it is not used by an actual
504 * original char code */
505 if (!best_table_len[i]) {
506
507 /* find the token with the breates profit value */
508 best = find_best_token();
Xiaochen Wange0a04b12011-05-01 11:41:41 +0800509 if (token_profit[best] == 0)
510 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511
512 /* place it in the "best" table */
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700513 best_table_len[i] = 2;
514 best_table[i][0] = best & 0xFF;
515 best_table[i][1] = (best >> 8) & 0xFF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516
517 /* replace this token in all the valid symbols */
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700518 compress_symbols(best_table[i], i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 }
520 }
521}
522
523/* start by placing the symbols that are actually used on the table */
524static void insert_real_symbols_in_table(void)
525{
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700526 unsigned int i, j, c;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527
528 memset(best_table, 0, sizeof(best_table));
529 memset(best_table_len, 0, sizeof(best_table_len));
530
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700531 for (i = 0; i < table_cnt; i++) {
532 for (j = 0; j < table[i].len; j++) {
533 c = table[i].sym[j];
534 best_table[c][0]=c;
535 best_table_len[c]=1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 }
537 }
538}
539
540static void optimize_token_table(void)
541{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 build_initial_tok_table();
543
544 insert_real_symbols_in_table();
545
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700546 /* When valid symbol is not registered, exit to error */
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700547 if (!table_cnt) {
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700548 fprintf(stderr, "No valid symbol.\n");
549 exit(1);
550 }
551
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 optimize_result();
553}
554
Lai Jiangshanb478b782009-03-13 15:10:26 +0800555/* guess for "linker script provide" symbol */
556static int may_be_linker_script_provide_symbol(const struct sym_entry *se)
557{
558 const char *symbol = (char *)se->sym + 1;
559 int len = se->len - 1;
560
561 if (len < 8)
562 return 0;
563
564 if (symbol[0] != '_' || symbol[1] != '_')
565 return 0;
566
567 /* __start_XXXXX */
568 if (!memcmp(symbol + 2, "start_", 6))
569 return 1;
570
571 /* __stop_XXXXX */
572 if (!memcmp(symbol + 2, "stop_", 5))
573 return 1;
574
575 /* __end_XXXXX */
576 if (!memcmp(symbol + 2, "end_", 4))
577 return 1;
578
579 /* __XXXXX_start */
580 if (!memcmp(symbol + len - 6, "_start", 6))
581 return 1;
582
583 /* __XXXXX_end */
584 if (!memcmp(symbol + len - 4, "_end", 4))
585 return 1;
586
587 return 0;
588}
589
590static int prefix_underscores_count(const char *str)
591{
592 const char *tail = str;
593
Paul Mundta9ece532009-09-22 16:44:12 -0700594 while (*tail == '_')
Lai Jiangshanb478b782009-03-13 15:10:26 +0800595 tail++;
596
597 return tail - str;
598}
599
Paulo Marquesf2df3f62008-02-06 01:37:33 -0800600static int compare_symbols(const void *a, const void *b)
601{
602 const struct sym_entry *sa;
603 const struct sym_entry *sb;
604 int wa, wb;
605
606 sa = a;
607 sb = b;
608
609 /* sort by address first */
610 if (sa->addr > sb->addr)
611 return 1;
612 if (sa->addr < sb->addr)
613 return -1;
614
615 /* sort by "weakness" type */
616 wa = (sa->sym[0] == 'w') || (sa->sym[0] == 'W');
617 wb = (sb->sym[0] == 'w') || (sb->sym[0] == 'W');
618 if (wa != wb)
619 return wa - wb;
620
Lai Jiangshanb478b782009-03-13 15:10:26 +0800621 /* sort by "linker script provide" type */
622 wa = may_be_linker_script_provide_symbol(sa);
623 wb = may_be_linker_script_provide_symbol(sb);
624 if (wa != wb)
625 return wa - wb;
626
627 /* sort by the number of prefix underscores */
628 wa = prefix_underscores_count((const char *)sa->sym + 1);
629 wb = prefix_underscores_count((const char *)sb->sym + 1);
630 if (wa != wb)
631 return wa - wb;
632
Paulo Marquesf2df3f62008-02-06 01:37:33 -0800633 /* sort by initial order, so that other symbols are left undisturbed */
634 return sa->start_pos - sb->start_pos;
635}
636
637static void sort_symbols(void)
638{
639 qsort(table, table_cnt, sizeof(struct sym_entry), compare_symbols);
640}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641
Paulo Marquesb3dbb4e2005-09-06 15:16:31 -0700642int main(int argc, char **argv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643{
Yoshinori Sato41f11a42005-05-01 08:59:06 -0700644 if (argc >= 2) {
645 int i;
646 for (i = 1; i < argc; i++) {
647 if(strcmp(argv[i], "--all-symbols") == 0)
648 all_symbols = 1;
649 else if (strncmp(argv[i], "--symbol-prefix=", 16) == 0) {
650 char *p = &argv[i][16];
651 /* skip quote */
652 if ((*p == '"' && *(p+2) == '"') || (*p == '\'' && *(p+2) == '\''))
653 p++;
654 symbol_prefix_char = *p;
655 } else
656 usage();
657 }
658 } else if (argc != 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 usage();
660
661 read_map(stdin);
Sam Ravnborg2ea03892009-01-14 21:38:20 +0100662 sort_symbols();
663 optimize_token_table();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664 write_src();
665
666 return 0;
667}