//--------------------------------------------------------------------------------
static int convElfToMiniFile(char* elffilename, char* melffilename)
{
int fdelf, fdmelf, modhdrsymndx;
Elf* elf;
Elf32_Ehdr *ehdr;
Elf_Scn *relatextscn, *textscn, *symtabscn, *strtabscn;
Melf_Scn *m_relatextscn, *m_textscn, *m_symtabscn;
Melf* melf;
symbol_map_t* symmap;
Melf_Data *relatextdata, *symtabdata, *textdata;
symbol_map_t symmap_storage;
printf("ELF File: %s\n", elffilename);
printf("Mini-ELF File: %s\n", melffilename);
symmap = &symmap_storage;
// Open ELF file for reading
if ((fdelf = open(elffilename, O_RDONLY)) < 0){
fprintf(stderr, "%s: ", elffilename);
perror("convElfToMini -> fopen: ");
exit(EXIT_FAILURE);
}
// Open Mini-ELF file for writing
if ((fdmelf = open(melffilename, (O_RDWR | O_CREAT | O_EXCL), (S_IRWXU | S_IRWXG | S_IRWXO))) < 0){
fprintf(stderr, "%s: ", melffilename);
perror("convElfToMini -> fopen: ");
exit(EXIT_FAILURE);
}
// Check version of ELF Library
if (elf_version(EV_CURRENT) == EV_NONE){
fprintf(stderr, "Library version is out of date.\n");
exit(EXIT_FAILURE);
}
// Get the ELF descriptor
elf = elf_begin(fdelf, ELF_C_READ, NULL);
if (NULL == elf){
fprintf(stderr, "elf_begin: Error getting elf descriptor\n");
exit(EXIT_FAILURE);
}
// Ensure that it is an ELF format file
if (elf_kind(elf) != ELF_K_ELF){
fprintf(stderr, "This program can only read ELF format files.\n");
exit(EXIT_FAILURE);
}
// Get the ELF Header
ehdr = elf32_getehdr(elf);
if (NULL == ehdr){
fprintf(stderr, "Error reading ELF header\n");
exit(EXIT_FAILURE);
}
// Verify if the ELF is AVR specific
if (ehdr->e_machine != EM_AVR && ehdr->e_machine != EM_MSP430){
fprintf(stderr, "This ELF binary is not supported.\n");
exit(EXIT_FAILURE);
}
e_machine = ehdr->e_machine;
// Create a new Mini-ELF (MELF) descriptor
if ((melf = melf_new(fdmelf)) == NULL){
fprintf(stderr, "Error creating a new MELF descriptor\n");
exit(EXIT_FAILURE);
}
// Get the pointer to .symtab section
if ((symtabscn = getELFSectionByName(elf, ".symtab")) == NULL){
fprintf(stderr, "Error getting .symtab section.\n");
exit(EXIT_FAILURE);
}
// Get the pointer to .rela.text section
/*
if ((relatextscn = getELFSectionByName(elf, ".rela.text")) == NULL){
fprintf(stderr, "Error getting .rela.text section.\n");
exit(EXIT_FAILURE);
}
*/
relatextscn = getELFSectionByName(elf, ".rela.text");
// Get the pointer to .text section
if ((textscn = getELFSectionByName(elf, ".text")) == NULL){
fprintf(stderr, "Error getting .text section.\n");
exit(EXIT_FAILURE);
}
if ((strtabscn = getELFSectionByName(elf, ".strtab")) == NULL ) {
fprintf(stderr, "Error getting .strtab section. \n");
exit(EXIT_FAILURE);
}
// DEBUG info. to verify we have the correct sections
DEBUG("Section Number (.text): %d\n", (int)elf_ndxscn(textscn));
if( relatextscn != NULL ) {
DEBUG("Section Number (.rela.text): %d\n", (int)elf_ndxscn(relatextscn));
}
DEBUG("Section Number (.symtab): %d\n", (int)elf_ndxscn(symtabscn));
// Initialize Symbol Map
if (initSymbolMap(symmap, symtabscn) < 0){
fprintf(stderr, "Error initializing symbol map.\n");
exit(EXIT_FAILURE);
}
//
// Set string table to symbol map
//
addStrTabToSymbolMap( symmap, strtabscn );
addTxtScnToSymbolMap( symmap, textscn );
// Convert Relocation Table
// Simon: convert relocation before text section
// because some symbols will be patched in .text section
if( relatextscn != NULL ) {
if ((relatextdata = convRelaScn(relatextscn, symmap)) == NULL){
fprintf(stderr, "Error converting Rela table.\n");
exit(EXIT_FAILURE);
}
}
// Convert Text Section
if ((textdata = convProgbitsScn(textscn)) == NULL){
fprintf(stderr, "Error converting text section.\n");
exit(EXIT_FAILURE);
}
// Add mod_header symbol
if ((modhdrsymndx = getELFSymbolTableNdx(elf, "mod_header")) == -1){
fprintf(stderr, "Could not locate symbol: mod_header. Not a valid SOS module\n");
exit(EXIT_FAILURE);
}
addMelfSymbol(symmap, modhdrsymndx);
melf_setModHdrSymNdx(melf, symmap->etommap[modhdrsymndx]);
// Convert Symbol Table
if ((symtabdata = convSymScn(symmap)) == NULL){
fprintf(stderr, "Error convering symbol table.\n");
exit(EXIT_FAILURE);
}
// Create a new MELF Symbol table section
if ((m_symtabscn = melf_new_scn(melf)) == NULL){
fprintf(stderr, "Error creating symbol table MELF section.\n");
exit(EXIT_FAILURE);
}
convElfHdr(m_symtabscn, symtabscn);
melf_add_data_to_scn(m_symtabscn, symtabdata);
// Create a new MELF Relocation table section
if( relatextscn != NULL ) {
if ((m_relatextscn = melf_new_scn(melf)) == NULL){
fprintf(stderr, "Error creating relocation table MELF section.\n");
exit(EXIT_FAILURE);
}
convElfHdr(m_relatextscn, relatextscn);
melf_add_data_to_scn(m_relatextscn, relatextdata);
}
// Create a new MELF Symbol table section
if ((m_textscn = melf_new_scn(melf)) == NULL){
fprintf(stderr, "Error creating .text MELF section.\n");
exit(EXIT_FAILURE);
}
convElfHdr(m_textscn, textscn);
melf_add_data_to_scn(m_textscn, textdata);
// Sort the MELF Sections (Enable single pass writing on the nodes)
melf_sortScn(melf);
// Set the section offsets
melf_setScnOffsets(melf);
// Write the MELF File
melf_write(melf);
#ifdef DBGMODE
prettyPrintMELF(melf);
#endif
// Close ELF Descriptor
elf_end(elf);
// Close ELF File
close(fdelf);
// Close MELF File
close(fdmelf);
return 0;
}
//-------------------------------------------------------------------
static void avr_create_new_symbol_table(Elf_Data* nedata, Elf* elf, Elf* nelf,
Elf32_Shdr *nshdr, uint32_t startaddr, bblklist_t* blist)
{
Elf32_Ehdr* ehdr;
Elf32_Sym* nsym;
Elf_Data* nreladata;
Elf32_Rela *nerela;
int numSyms, numRecs, i, txtscnndx, btxtscnfound;
Elf_Scn *txtscn, *nrelascn;
Elf32_Shdr *txtshdr, *nrelashdr;
DEBUG("Determine .text section index ...\n");
// Get the ELF Header
if ((ehdr = elf32_getehdr(elf)) == NULL){
fprintf(stderr, "avr_create_new_symbol_table: Error reading ELF header\n");
exit(EXIT_FAILURE);
}
txtscn = NULL;
txtscnndx = 1;
btxtscnfound = 0;
while ((txtscn = elf_nextscn(elf, txtscn)) != NULL){
if ((txtshdr = elf32_getshdr(txtscn)) != NULL){
char* CurrSecName = NULL;
CurrSecName = elf_strptr(elf, ehdr->e_shstrndx, txtshdr->sh_name);
if (strcmp(CurrSecName, ".text") == 0){
btxtscnfound = 1;
break;
}
}
txtscnndx++;
}
if (0 == btxtscnfound){
fprintf(stderr, "avr_create_new_symbol_table: Cannot find .text section.\n");
exit(EXIT_FAILURE);
}
DEBUG(".text section index: %d\n", txtscnndx);
// Get .rela.text section
nrelascn = getELFSectionByName(nelf, ".rela.text");
nrelashdr = elf32_getshdr(nrelascn);
nreladata = NULL;
nreladata = elf_getdata(nrelascn, nreladata);
numRecs = nreladata->d_size/nrelashdr->sh_entsize;
numSyms = nedata->d_size/nshdr->sh_entsize;
nsym = (Elf32_Sym*)(nedata->d_buf);
for (i = 0; i < numSyms; i++){
if ((nsym->st_shndx == txtscnndx) && (ELF32_ST_TYPE(nsym->st_info) != STT_SECTION)){
if (nsym->st_value > startaddr){
uint32_t oldValue = nsym->st_value;
nsym->st_value = find_updated_address(blist, oldValue);
// Check if we have to further modify this symbol (if it is used as a call target value)
int j;
nerela = (Elf32_Rela*)nreladata->d_buf;
for (j = 0; j < numRecs; j++){
if ((ELF32_R_SYM(nerela->r_info) == i) && ((ELF32_R_TYPE(nerela->r_info) == R_AVR_CALL)||
(ELF32_R_TYPE(nerela->r_info) == R_AVR_13_PCREL))){
// Check if it is indeed a call instruction before changing the symbol
avr_instr_t instr;
instr = find_instr_at_new_addr(blist, nerela->r_offset);
if (((instr.rawVal & OP_TYPE10_MASK) == OP_CALL) || ((instr.rawVal & OP_TYPE17_MASK) == OP_RCALL)){
nsym->st_value -= sizeof(avr_instr_t) * 2;
DEBUG("Call target symbol. Modify to accomodate safe stack store.\n");
}
else
DEBUG("Jmp target symbol. No modification to symbol required.\n");
break;
}
// Follwing is only for producing a more readable elf.lst
if ((ELF32_ST_BIND(nsym->st_info) == STB_LOCAL) &&
(ELF32_ST_TYPE(nsym->st_info) == STT_FUNC) &&
((ELF32_R_TYPE(nerela->r_info) == R_AVR_CALL) || (ELF32_R_TYPE(nerela->r_info) == R_AVR_13_PCREL)) &&
(nerela->r_addend == (nsym->st_value - (2*sizeof(avr_instr_t))))){
nsym->st_value -= sizeof(avr_instr_t) * 2;
DEBUG("Call target symbol. Modified for ELF pretty print.\n");
}
nerela++;
}
DEBUG("Entry: %d Old Value: 0x%x New Value: 0x%x\n", i, (int)oldValue, (int)nsym->st_value);
}
}
nsym++;
}
return;
}
