scripts/kallsyms.c

   1 /* 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 > symbols.S
   9  */
  10
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14
  15 struct sym_entry {
  16         unsigned long long addr;
  17         char type;
  18         char *sym;
  19 };
  20
  21
  22 static struct sym_entry *table;
  23 static int size, cnt;
  24 static unsigned long long _stext, _etext, _sinittext, _einittext;
  25
  26 static void
  27 usage(void)
  28 {
  29         fprintf(stderr, "Usage: kallsyms < in.map > out.S\n");
  30         exit(1);
  31 }
  32
  33 static int
  34 read_symbol(FILE *in, struct sym_entry *s)
  35 {
  36         char str[500];
  37         int rc;
  38
  39         rc = fscanf(in, "%llx %c %499s\n", &s->addr, &s->type, str);
  40         if (rc != 3) {
  41                 if (rc != EOF) {
  42                         /* skip line */
  43                         fgets(str, 500, in);
  44                 }
  45                 return -1;
  46         }
  47         s->sym = strdup(str);
  48         return 0;
  49 }
  50
  51 static int
  52 symbol_valid(struct sym_entry *s)
  53 {
  54         if ((s->addr < _stext || s->addr > _etext)
  55             && (s->addr < _sinittext || s->addr > _einittext))
  56                 return 0;
  57
  58         if (strstr(s->sym, "_compiled."))
  59                 return 0;
  60
  61         return 1;
  62 }
  63
  64 static void
  65 read_map(FILE *in)
  66 {
  67         int i;
  68
  69         while (!feof(in)) {
  70                 if (cnt >= size) {
  71                         size += 10000;
  72                         table = realloc(table, sizeof(*table) * size);
  73                         if (!table) {
  74                                 fprintf(stderr, "out of memory\n");
  75                                 exit (1);
  76                         }
  77                 }
  78                 if (read_symbol(in, &table[cnt]) == 0)
  79                         cnt++;
  80         }
  81         for (i = 0; i < cnt; i++) {
  82                 if (strcmp(table[i].sym, "_stext") == 0)
  83                         _stext = table[i].addr;
  84                 if (strcmp(table[i].sym, "_etext") == 0)
  85                         _etext = table[i].addr;
  86                 if (strcmp(table[i].sym, "_sinittext") == 0)
  87                         _sinittext = table[i].addr;
  88                 if (strcmp(table[i].sym, "_einittext") == 0)
  89                         _einittext = table[i].addr;
  90         }
  91 }
  92
  93 static void
  94 write_src(void)
  95 {
  96         unsigned long long last_addr;
  97         int i, valid = 0;
  98         char *prev;
  99
 100         printf("#include <asm/types.h>\n");
 101         printf("#if BITS_PER_LONG == 64\n");
 102         printf("#define PTR .quad\n");
 103         printf("#define ALGN .align 8\n");
 104         printf("#else\n");
 105         printf("#define PTR .long\n");
 106         printf("#define ALGN .align 4\n");
 107         printf("#endif\n");
 108
 109         printf(".data\n");
 110
 111         printf(".globl kallsyms_addresses\n");
 112         printf("\tALGN\n");
 113         printf("kallsyms_addresses:\n");
 114         for (i = 0, last_addr = 0; i < cnt; i++) {
 115                 if (!symbol_valid(&table[i]))
 116                         continue;
 117
 118                 if (table[i].addr == last_addr)
 119                         continue;
 120
 121                 printf("\tPTR\t%#llx\n", table[i].addr);
 122                 valid++;
 123                 last_addr = table[i].addr;
 124         }
 125         printf("\n");
 126
 127         printf(".globl kallsyms_num_syms\n");
 128         printf("\tALGN\n");
 129         printf("kallsyms_num_syms:\n");
 130         printf("\tPTR\t%d\n", valid);
 131         printf("\n");
 132
 133         printf(".globl kallsyms_names\n");
 134         printf("\tALGN\n");
 135         printf("kallsyms_names:\n");
 136         prev = "";
 137         for (i = 0, last_addr = 0; i < cnt; i++) {
 138                 int k;
 139
 140                 if (!symbol_valid(&table[i]))
 141                         continue;
 142
 143                 if (table[i].addr == last_addr)
 144                         continue;
 145
 146                 for (k = 0; table[i].sym[k] && table[i].sym[k] == prev[k]; ++k)
 147                         ;
 148
 149                 printf("\t.byte 0x%02x\n\t.asciz\t\"%s\"\n", k, table[i].sym + k);
 150                 last_addr = table[i].addr;
 151                 prev = table[i].sym;
 152         }
 153         printf("\n");
 154 }
 155
 156 int
 157 main(int argc, char **argv)
 158 {
 159         if (argc != 1)
 160                 usage();
 161
 162         read_map(stdin);
 163         write_src();
 164
 165         return 0;
 166 }
 167