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