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