git.rot13.org Git - simavr/blob - simavr/sim/sim_elf.c

   1 /*
   2         sim_elf.c
   3
   4         Loads a .elf file, extract the code, the data, the eeprom and
   5         the "mcu" specification section, also load usable code symbols
   6         to be able to print meaningful trace information.
   7
   8         Copyright 2008, 2009 Michel Pollet <buserror@gmail.com>
   9
  10         This file is part of simavr.
  11
  12         simavr is free software: you can redistribute it and/or modify
  13         it under the terms of the GNU General Public License as published by
  14         the Free Software Foundation, either version 3 of the License, or
  15         (at your option) any later version.
  16
  17         simavr is distributed in the hope that it will be useful,
  18         but WITHOUT ANY WARRANTY; without even the implied warranty of
  19         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20         GNU General Public License for more details.
  21
  22         You should have received a copy of the GNU General Public License
  23         along with simavr.  If not, see <http://www.gnu.org/licenses/>.
  24  */
  25
  26 #include <sys/stat.h>
  27 #include <fcntl.h>
  28 #include <unistd.h>
  29 #include <stdlib.h>
  30 #include <stdio.h>
  31 #include <string.h>
  32 #include <libelf.h>
  33 #include <gelf.h>
  34
  35 #include "sim_elf.h"
  36 #include "sim_vcd_file.h"
  37 #include "avr_eeprom.h"
  38
  39 #ifndef O_BINARY
  40 #define O_BINARY 0
  41 #endif
  42
  43 void avr_load_firmware(avr_t * avr, elf_firmware_t * firmware)
  44 {
  45         if (firmware->frequency)
  46                 avr->frequency = firmware->frequency;
  47         if (firmware->vcc)
  48                 avr->vcc = firmware->vcc;
  49         if (firmware->avcc)
  50                 avr->avcc = firmware->avcc;
  51         if (firmware->aref)
  52                 avr->aref = firmware->aref;
  53 #if CONFIG_SIMAVR_TRACE
  54         avr->trace_data->codeline = firmware->codeline;
  55 #endif
  56
  57         avr_loadcode(avr, firmware->flash, firmware->flashsize, firmware->flashbase);
  58         avr->codeend = firmware->flashsize + firmware->flashbase - firmware->datasize;
  59         if (firmware->eeprom && firmware->eesize) {
  60                 avr_eeprom_desc_t d = { .ee = firmware->eeprom, .offset = 0, .size = firmware->eesize };
  61                 avr_ioctl(avr, AVR_IOCTL_EEPROM_SET, &d);
  62         }
  63
  64         avr_set_command_register(avr, firmware->command_register_addr);
  65         avr_set_console_register(avr, firmware->console_register_addr);
  66
  67         // rest is initialization of the VCD file
  68
  69         if (firmware->tracecount == 0)
  70                 return;
  71         avr->vcd = malloc(sizeof(*avr->vcd));
  72         memset(avr->vcd, 0, sizeof(*avr->vcd));
  73         avr_vcd_init(avr,
  74                 firmware->tracename[0] ? firmware->tracename: "gtkwave_trace.vcd",
  75                 avr->vcd,
  76                 firmware->traceperiod >= 1000 ? firmware->traceperiod : 1000);
  77
  78         printf("Creating VCD trace file '%s'\n", avr->vcd->filename);
  79         for (int ti = 0; ti < firmware->tracecount; ti++) {
  80                 if (firmware->trace[ti].mask == 0xff || firmware->trace[ti].mask == 0) {
  81                         // easy one
  82                         avr_irq_t * all = avr_iomem_getirq(avr, firmware->trace[ti].addr, AVR_IOMEM_IRQ_ALL);
  83                         if (!all) {
  84                                 AVR_LOG(avr, LOG_ERROR, "ELF: %s: unable to attach trace to address %04x\n",
  85                                         __FUNCTION__, firmware->trace[ti].addr);
  86                         } else {
  87                                 avr_vcd_add_signal(avr->vcd, all, 8, firmware->trace[ti].name);
  88                         }
  89                 } else {
  90                         int count = 0;
  91                         for (int bi = 0; bi < 8; bi++)
  92                                 if (firmware->trace[ti].mask & (1 << bi))
  93                                         count++;
  94                         for (int bi = 0; bi < 8; bi++)
  95                                 if (firmware->trace[ti].mask & (1 << bi)) {
  96                                         avr_irq_t * bit = avr_iomem_getirq(avr, firmware->trace[ti].addr, bi);
  97                                         if (!bit) {
  98                                                 AVR_LOG(avr, LOG_ERROR, "ELF: %s: unable to attach trace to address %04x\n",
  99                                                         __FUNCTION__, firmware->trace[ti].addr);
 100                                                 break;
 101                                         }
 102
 103                                         if (count == 1) {
 104                                                 avr_vcd_add_signal(avr->vcd, bit, 1, firmware->trace[ti].name);
 105                                                 break;
 106                                         }
 107                                         char comp[128];
 108                                         sprintf(comp, "%s.%d", firmware->trace[ti].name, bi);
 109                                         avr_vcd_add_signal(avr->vcd, bit, 1, firmware->trace[ti].name);
 110                                 }
 111                 }
 112         }
 113         // if the firmware has specified a command register, do NOT start the trace here
 114         // the firmware probably knows best when to start/stop it
 115         if (!firmware->command_register_addr)
 116                 avr_vcd_start(avr->vcd);
 117 }
 118
 119 static void elf_parse_mmcu_section(elf_firmware_t * firmware, uint8_t * src, uint32_t size)
 120 {
 121         while (size) {
 122                 uint8_t tag = *src++;
 123                 uint8_t ts = *src++;
 124                 int next = size > 2 + ts ? 2 + ts : size;
 125         //      printf("elf_parse_mmcu_section %d, %d / %d\n", tag, ts, size);
 126                 switch (tag) {
 127                         case AVR_MMCU_TAG_FREQUENCY:
 128                                 firmware->frequency =
 129                                         src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
 130                                 break;
 131                         case AVR_MMCU_TAG_NAME:
 132                                 strcpy(firmware->mmcu, (char*)src);
 133                                 break;
 134                         case AVR_MMCU_TAG_VCC:
 135                                 firmware->vcc =
 136                                         src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
 137                                 break;
 138                         case AVR_MMCU_TAG_AVCC:
 139                                 firmware->avcc =
 140                                         src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
 141                                 break;
 142                         case AVR_MMCU_TAG_AREF:
 143                                 firmware->aref =
 144                                         src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
 145                                 break;
 146                         case AVR_MMCU_TAG_VCD_TRACE: {
 147                                 uint8_t mask = src[0];
 148                                 uint16_t addr = src[1] | (src[2] << 8);
 149                                 char * name = (char*)src + 3;
 150                                 printf("AVR_MMCU_TAG_VCD_TRACE %04x:%02x - %s\n", addr, mask, name);
 151                                 firmware->trace[firmware->tracecount].mask = mask;
 152                                 firmware->trace[firmware->tracecount].addr = addr;
 153                                 strncpy(firmware->trace[firmware->tracecount].name, name,
 154                                         sizeof(firmware->trace[firmware->tracecount].name));
 155                                 firmware->tracecount++;
 156                         }       break;
 157                         case AVR_MMCU_TAG_VCD_FILENAME: {
 158                                 strcpy(firmware->tracename, (char*)src);
 159                         }       break;
 160                         case AVR_MMCU_TAG_VCD_PERIOD: {
 161                                 firmware->traceperiod =
 162                                         src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
 163                         }       break;
 164                         case AVR_MMCU_TAG_SIMAVR_COMMAND: {
 165                                 firmware->command_register_addr = src[0] | (src[1] << 8);
 166                         }       break;
 167                         case AVR_MMCU_TAG_SIMAVR_CONSOLE: {
 168                                 firmware->console_register_addr = src[0] | (src[1] << 8);
 169                         }       break;
 170                 }
 171                 size -= next;
 172                 src += next - 2; // already incremented
 173         }
 174 }
 175
 176 int elf_read_firmware(const char * file, elf_firmware_t * firmware)
 177 {
 178         Elf32_Ehdr elf_header;                  /* ELF header */
 179         Elf *elf = NULL;                       /* Our Elf pointer for libelf */
 180         int fd; // File Descriptor
 181
 182         if ((fd = open(file, O_RDONLY | O_BINARY)) == -1 ||
 183                         (read(fd, &elf_header, sizeof(elf_header))) < sizeof(elf_header)) {
 184                 printf("could not read %s\n", file);
 185                 perror(file);
 186                 close(fd);
 187                 return -1;
 188         }
 189
 190         Elf_Data *data_data = NULL,
 191                 *data_text = NULL,
 192                 *data_ee = NULL;                /* Data Descriptor */
 193
 194         memset(firmware, 0, sizeof(*firmware));
 195 #if ELF_SYMBOLS
 196         //int bitesize = ((avr->flashend+1) >> 1) * sizeof(avr_symbol_t);
 197         firmware->codesize = 32768;
 198         int bitesize = firmware->codesize * sizeof(avr_symbol_t);
 199         firmware->codeline = malloc(bitesize);
 200         memset(firmware->codeline,0, bitesize);
 201 #endif
 202
 203         /* this is actually mandatory !! otherwise elf_begin() fails */
 204         if (elf_version(EV_CURRENT) == EV_NONE) {
 205                         /* library out of date - recover from error */
 206         }
 207         // Iterate through section headers again this time well stop when we find symbols
 208         elf = elf_begin(fd, ELF_C_READ, NULL);
 209         //printf("Loading elf %s : %p\n", file, elf);
 210
 211         Elf_Scn *scn = NULL;                   /* Section Descriptor */
 212
 213         while ((scn = elf_nextscn(elf, scn)) != NULL) {
 214                 GElf_Shdr shdr;                 /* Section Header */
 215                 gelf_getshdr(scn, &shdr);
 216                 char * name = elf_strptr(elf, elf_header.e_shstrndx, shdr.sh_name);
 217         //      printf("Walking elf section '%s'\n", name);
 218
 219                 if (!strcmp(name, ".text"))
 220                         data_text = elf_getdata(scn, NULL);
 221                 else if (!strcmp(name, ".data"))
 222                         data_data = elf_getdata(scn, NULL);
 223                 else if (!strcmp(name, ".eeprom"))
 224                         data_ee = elf_getdata(scn, NULL);
 225                 else if (!strcmp(name, ".bss")) {
 226                         Elf_Data *s = elf_getdata(scn, NULL);
 227                         firmware->bsssize = s->d_size;
 228                 } else if (!strcmp(name, ".mmcu")) {
 229                         Elf_Data *s = elf_getdata(scn, NULL);
 230                         elf_parse_mmcu_section(firmware, s->d_buf, s->d_size);
 231                         //printf("%s: avr_mcu_t size %ld / read %ld\n", __FUNCTION__, sizeof(struct avr_mcu_t), s->d_size);
 232                 //      avr->frequency = f_cpu;
 233                 }
 234 #if ELF_SYMBOLS
 235                 // When we find a section header marked SHT_SYMTAB stop and get symbols
 236                 if (shdr.sh_type == SHT_SYMTAB) {
 237                         // edata points to our symbol table
 238                         Elf_Data *edata = elf_getdata(scn, NULL);
 239
 240                         // how many symbols are there? this number comes from the size of
 241                         // the section divided by the entry size
 242                         int symbol_count = shdr.sh_size / shdr.sh_entsize;
 243
 244                         // loop through to grab all symbols
 245                         for (int i = 0; i < symbol_count; i++) {
 246                                 GElf_Sym sym;                   /* Symbol */
 247                                 // libelf grabs the symbol data using gelf_getsym()
 248                                 gelf_getsym(edata, i, &sym);
 249
 250                                 // print out the value and size
 251                         //      printf("%08x %08d ", sym.st_value, sym.st_size);
 252                                 if (ELF32_ST_BIND(sym.st_info) == STB_GLOBAL ||
 253                                                 ELF32_ST_TYPE(sym.st_info) == STT_FUNC ||
 254                                                 ELF32_ST_TYPE(sym.st_info) == STT_OBJECT) {
 255                                         const char * name = elf_strptr(elf, shdr.sh_link, sym.st_name);
 256
 257                                         // type of symbol
 258                                         if (sym.st_value & 0xfff00000) {
 259
 260                                         } else {
 261                                                 // code
 262                                                 if (firmware->codeline[sym.st_value >> 1] == NULL) {
 263                                                         avr_symbol_t * s = firmware->codeline[sym.st_value >> 1] = malloc(sizeof(avr_symbol_t));
 264                                                         s->symbol = strdup(name);
 265                                                         s->addr = sym.st_value;
 266                                                 }
 267                                         }
 268                                 }
 269                         }
 270                 }
 271 #endif
 272         }
 273 #if ELF_SYMBOLS
 274         avr_symbol_t * last = NULL;
 275         for (int i = 0; i < firmware->codesize; i++) {
 276                 if (!firmware->codeline[i])
 277                         firmware->codeline[i] = last;
 278                 else
 279                         last = firmware->codeline[i];
 280         }
 281 #endif
 282         uint32_t offset = 0;
 283         firmware->flashsize =
 284                         (data_text ? data_text->d_size : 0) +
 285                         (data_data ? data_data->d_size : 0);
 286         firmware->flash = malloc(firmware->flashsize);
 287
 288         // using unsigned int for output, since there is no AVR with 4GB
 289         if (data_text) {
 290         //      hdump("code", data_text->d_buf, data_text->d_size);
 291                 memcpy(firmware->flash + offset, data_text->d_buf, data_text->d_size);
 292                 offset += data_text->d_size;
 293                 printf("Loaded %u .text\n", (unsigned int)data_text->d_size);
 294         }
 295         if (data_data) {
 296         //      hdump("data", data_data->d_buf, data_data->d_size);
 297                 memcpy(firmware->flash + offset, data_data->d_buf, data_data->d_size);
 298                 printf("Loaded %u .data\n", (unsigned int)data_data->d_size);
 299                 offset += data_data->d_size;
 300                 firmware->datasize = data_data->d_size;
 301         }
 302         if (data_ee) {
 303         //      hdump("eeprom", data_ee->d_buf, data_ee->d_size);
 304                 firmware->eeprom = malloc(data_ee->d_size);
 305                 memcpy(firmware->eeprom, data_ee->d_buf, data_ee->d_size);
 306                 printf("Loaded %u .eeprom\n", (unsigned int)data_ee->d_size);
 307                 firmware->eesize = data_ee->d_size;
 308         }
 309 //      hdump("flash", avr->flash, offset);
 310         elf_end(elf);
 311         close(fd);
 312         return 0;
 313 }
 314