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 void avr_load_firmware(avr_t * avr, elf_firmware_t * firmware)
  40 {
  41         if (firmware->frequency)
  42                 avr->frequency = firmware->frequency;
  43         if (firmware->vcc)
  44                 avr->vcc = firmware->vcc;
  45         if (firmware->avcc)
  46                 avr->avcc = firmware->avcc;
  47         if (firmware->aref)
  48                 avr->aref = firmware->aref;
  49 #if CONFIG_SIMAVR_TRACE
  50         avr->trace_data->codeline = firmware->codeline;
  51 #endif
  52
  53         avr_loadcode(avr, firmware->flash, firmware->flashsize, firmware->flashbase);
  54         avr->codeend = firmware->flashsize + firmware->flashbase - firmware->datasize;
  55         if (firmware->eeprom && firmware->eesize) {
  56                 avr_eeprom_desc_t d = { .ee = firmware->eeprom, .offset = 0, .size = firmware->eesize };
  57                 avr_ioctl(avr, AVR_IOCTL_EEPROM_SET, &d);
  58         }
  59
  60         avr_set_command_register(avr, firmware->command_register_addr);
  61         avr_set_console_register(avr, firmware->console_register_addr);
  62
  63         // rest is initialization of the VCD file
  64
  65         if (firmware->tracecount == 0)
  66                 return;
  67         avr->vcd = malloc(sizeof(*avr->vcd));
  68         memset(avr->vcd, 0, sizeof(*avr->vcd));
  69         avr_vcd_init(avr,
  70                 firmware->tracename[0] ? firmware->tracename: "gtkwave_trace.vcd",
  71                 avr->vcd,
  72                 firmware->traceperiod >= 1000 ? firmware->traceperiod : 1000);
  73
  74         printf("Creating VCD trace file '%s'\n", avr->vcd->filename);
  75         for (int ti = 0; ti < firmware->tracecount; ti++) {
  76                 if (firmware->trace[ti].mask == 0xff || firmware->trace[ti].mask == 0) {
  77                         // easy one
  78                         avr_irq_t * all = avr_iomem_getirq(avr, firmware->trace[ti].addr, AVR_IOMEM_IRQ_ALL);
  79                         if (!all) {
  80                                 printf("%s: unable to attach trace to address %04x\n",
  81                                         __FUNCTION__, firmware->trace[ti].addr);
  82                         } else {
  83                                 avr_vcd_add_signal(avr->vcd, all, 8, firmware->trace[ti].name);
  84                         }
  85                 } else {
  86                         int count = 0;
  87                         for (int bi = 0; bi < 8; bi++)
  88                                 if (firmware->trace[ti].mask & (1 << bi))
  89                                         count++;
  90                         for (int bi = 0; bi < 8; bi++)
  91                                 if (firmware->trace[ti].mask & (1 << bi)) {
  92                                         avr_irq_t * bit = avr_iomem_getirq(avr, firmware->trace[ti].addr, bi);
  93                                         if (!bit) {
  94                                                 printf("%s: unable to attach trace to address %04x\n",
  95                                                         __FUNCTION__, firmware->trace[ti].addr);
  96                                                 break;
  97                                         }
  98
  99                                         if (count == 1) {
 100                                                 avr_vcd_add_signal(avr->vcd, bit, 1, firmware->trace[ti].name);
 101                                                 break;
 102                                         }
 103                                         char comp[128];
 104                                         sprintf(comp, "%s.%d", firmware->trace[ti].name, bi);
 105                                         avr_vcd_add_signal(avr->vcd, bit, 1, firmware->trace[ti].name);
 106                                 }
 107                 }
 108         }
 109         // if the firmware has specified a command register, do NOT start the trace here
 110         // the firmware probably knows best when to start/stop it
 111         if (!firmware->command_register_addr)
 112                 avr_vcd_start(avr->vcd);
 113 }
 114
 115 static void elf_parse_mmcu_section(elf_firmware_t * firmware, uint8_t * src, uint32_t size)
 116 {
 117         while (size) {
 118                 uint8_t tag = *src++;
 119                 uint8_t ts = *src++;
 120                 int next = size > 2 + ts ? 2 + ts : size;
 121         //      printf("elf_parse_mmcu_section %d, %d / %d\n", tag, ts, size);
 122                 switch (tag) {
 123                         case AVR_MMCU_TAG_FREQUENCY:
 124                                 firmware->frequency =
 125                                         src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
 126                                 break;
 127                         case AVR_MMCU_TAG_NAME:
 128                                 strcpy(firmware->mmcu, (char*)src);
 129                                 break;
 130                         case AVR_MMCU_TAG_VCC:
 131                                 firmware->vcc =
 132                                         src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
 133                                 break;
 134                         case AVR_MMCU_TAG_AVCC:
 135                                 firmware->avcc =
 136                                         src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
 137                                 break;
 138                         case AVR_MMCU_TAG_AREF:
 139                                 firmware->aref =
 140                                         src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
 141                                 break;
 142                         case AVR_MMCU_TAG_VCD_TRACE: {
 143                                 uint8_t mask = src[0];
 144                                 uint16_t addr = src[1] | (src[2] << 8);
 145                                 char * name = (char*)src + 3;
 146                                 printf("AVR_MMCU_TAG_VCD_TRACE %04x:%02x - %s\n", addr, mask, name);
 147                                 firmware->trace[firmware->tracecount].mask = mask;
 148                                 firmware->trace[firmware->tracecount].addr = addr;
 149                                 strncpy(firmware->trace[firmware->tracecount].name, name,
 150                                         sizeof(firmware->trace[firmware->tracecount].name));
 151                                 firmware->tracecount++;
 152                         }       break;
 153                         case AVR_MMCU_TAG_VCD_FILENAME: {
 154                                 strcpy(firmware->tracename, (char*)src);
 155                         }       break;
 156                         case AVR_MMCU_TAG_VCD_PERIOD: {
 157                                 firmware->traceperiod =
 158                                         src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
 159                         }       break;
 160                         case AVR_MMCU_TAG_SIMAVR_COMMAND: {
 161                                 firmware->command_register_addr = src[0] | (src[1] << 8);
 162                         }       break;
 163                         case AVR_MMCU_TAG_SIMAVR_CONSOLE: {
 164                                 firmware->console_register_addr = src[0] | (src[1] << 8);
 165                         }       break;
 166                 }
 167                 size -= next;
 168                 src += next - 2; // already incremented
 169         }
 170 }
 171
 172 int elf_read_firmware(const char * file, elf_firmware_t * firmware)
 173 {
 174         Elf32_Ehdr elf_header;                  /* ELF header */
 175         Elf *elf = NULL;                       /* Our Elf pointer for libelf */
 176         int fd; // File Descriptor
 177
 178         if ((fd = open(file, O_RDONLY)) == -1 ||
 179                         (read(fd, &elf_header, sizeof(elf_header))) < sizeof(elf_header)) {
 180                 printf("could not read %s\n", file);
 181                 perror(file);
 182                 close(fd);
 183                 return -1;
 184         }
 185
 186         Elf_Data *data_data = NULL,
 187                 *data_text = NULL,
 188                 *data_ee = NULL;                /* Data Descriptor */
 189
 190         memset(firmware, 0, sizeof(*firmware));
 191 #if ELF_SYMBOLS
 192         //int bitesize = ((avr->flashend+1) >> 1) * sizeof(avr_symbol_t);
 193         firmware->codesize = 32768;
 194         int bitesize = firmware->codesize * sizeof(avr_symbol_t);
 195         firmware->codeline = malloc(bitesize);
 196         memset(firmware->codeline,0, bitesize);
 197 #endif
 198
 199         /* this is actually mandatory !! otherwise elf_begin() fails */
 200         if (elf_version(EV_CURRENT) == EV_NONE) {
 201                         /* library out of date - recover from error */
 202         }
 203         // Iterate through section headers again this time well stop when we find symbols
 204         elf = elf_begin(fd, ELF_C_READ, NULL);
 205         //printf("Loading elf %s : %p\n", file, elf);
 206
 207         Elf_Scn *scn = NULL;                   /* Section Descriptor */
 208
 209         while ((scn = elf_nextscn(elf, scn)) != NULL) {
 210                 GElf_Shdr shdr;                 /* Section Header */
 211                 gelf_getshdr(scn, &shdr);
 212                 char * name = elf_strptr(elf, elf_header.e_shstrndx, shdr.sh_name);
 213         //      printf("Walking elf section '%s'\n", name);
 214
 215                 if (!strcmp(name, ".text"))
 216                         data_text = elf_getdata(scn, NULL);
 217                 else if (!strcmp(name, ".data"))
 218                         data_data = elf_getdata(scn, NULL);
 219                 else if (!strcmp(name, ".eeprom"))
 220                         data_ee = elf_getdata(scn, NULL);
 221                 else if (!strcmp(name, ".bss")) {
 222                         Elf_Data *s = elf_getdata(scn, NULL);
 223                         firmware->bsssize = s->d_size;
 224                 } else if (!strcmp(name, ".mmcu")) {
 225                         Elf_Data *s = elf_getdata(scn, NULL);
 226                         elf_parse_mmcu_section(firmware, s->d_buf, s->d_size);
 227                         //printf("%s: avr_mcu_t size %ld / read %ld\n", __FUNCTION__, sizeof(struct avr_mcu_t), s->d_size);
 228                 //      avr->frequency = f_cpu;
 229                 }
 230 #if ELF_SYMBOLS
 231                 // When we find a section header marked SHT_SYMTAB stop and get symbols
 232                 if (shdr.sh_type == SHT_SYMTAB) {
 233                         // edata points to our symbol table
 234                         Elf_Data *edata = elf_getdata(scn, NULL);
 235
 236                         // how many symbols are there? this number comes from the size of
 237                         // the section divided by the entry size
 238                         int symbol_count = shdr.sh_size / shdr.sh_entsize;
 239
 240                         // loop through to grab all symbols
 241                         for (int i = 0; i < symbol_count; i++) {
 242                                 GElf_Sym sym;                   /* Symbol */
 243                                 // libelf grabs the symbol data using gelf_getsym()
 244                                 gelf_getsym(edata, i, &sym);
 245
 246                                 // print out the value and size
 247                         //      printf("%08x %08d ", sym.st_value, sym.st_size);
 248                                 if (ELF32_ST_BIND(sym.st_info) == STB_GLOBAL ||
 249                                                 ELF32_ST_TYPE(sym.st_info) == STT_FUNC ||
 250                                                 ELF32_ST_TYPE(sym.st_info) == STT_OBJECT) {
 251                                         const char * name = elf_strptr(elf, shdr.sh_link, sym.st_name);
 252
 253                                         // type of symbol
 254                                         if (sym.st_value & 0xfff00000) {
 255
 256                                         } else {
 257                                                 // code
 258                                                 if (firmware->codeline[sym.st_value >> 1] == NULL) {
 259                                                         avr_symbol_t * s = firmware->codeline[sym.st_value >> 1] = malloc(sizeof(avr_symbol_t));
 260                                                         s->symbol = strdup(name);
 261                                                         s->addr = sym.st_value;
 262                                                 }
 263                                         }
 264                                 }
 265                         }
 266                 }
 267 #endif
 268         }
 269 #if ELF_SYMBOLS
 270         avr_symbol_t * last = NULL;
 271         for (int i = 0; i < firmware->codesize; i++) {
 272                 if (!firmware->codeline[i])
 273                         firmware->codeline[i] = last;
 274                 else
 275                         last = firmware->codeline[i];
 276         }
 277 #endif
 278         uint32_t offset = 0;
 279         firmware->flashsize =
 280                         (data_text ? data_text->d_size : 0) +
 281                         (data_data ? data_data->d_size : 0);
 282         firmware->flash = malloc(firmware->flashsize);
 283         if (data_text) {
 284         //      hdump("code", data_text->d_buf, data_text->d_size);
 285                 memcpy(firmware->flash + offset, data_text->d_buf, data_text->d_size);
 286                 offset += data_text->d_size;
 287                 printf("Loaded %zu .text\n", data_text->d_size);
 288         }
 289         if (data_data) {
 290         //      hdump("data", data_data->d_buf, data_data->d_size);
 291                 memcpy(firmware->flash + offset, data_data->d_buf, data_data->d_size);
 292                 printf("Loaded %zu .data\n", data_data->d_size);
 293                 offset += data_data->d_size;
 294                 firmware->datasize = data_data->d_size;
 295         }
 296         if (data_ee) {
 297         //      hdump("eeprom", data_ee->d_buf, data_ee->d_size);
 298                 firmware->eeprom = malloc(data_ee->d_size);
 299                 memcpy(firmware->eeprom, data_ee->d_buf, data_ee->d_size);
 300                 printf("Loaded %zu .eeprom\n", data_ee->d_size);
 301                 firmware->eesize = data_ee->d_size;
 302         }
 303 //      hdump("flash", avr->flash, offset);
 304         elf_end(elf);
 305         close(fd);
 306         return 0;
 307 }
 308