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bootloader/apps/elftosb/common/StELFFile.cpp
László Monda e6c1fce5b4 Add KBOOT.
2016-08-10 01:45:15 +02:00

534 lines
20 KiB
C++

/*
* File: StELFFile.cpp
*
* Copyright (c) Freescale Semiconductor, Inc. All rights reserved.
* See included license file for license details.
*/
#include "StELFFile.h"
#include <ios>
#include <stdexcept>
#include <stdio.h>
#include "EndianUtilities.h"
//! \exception StELFFileException is thrown if there is a problem with the file format.
//!
StELFFile::StELFFile(std::istream &inStream)
: m_stream(inStream)
{
readFileHeaders();
}
//! Disposes of the string table data.
StELFFile::~StELFFile()
{
SectionDataMap::iterator it = m_sectionDataCache.begin();
for (; it != m_sectionDataCache.end(); ++it)
{
SectionDataInfo &info = it->second;
if (info.m_data != NULL)
{
delete[] info.m_data;
}
}
}
//! \exception StELFFileException is thrown if the file is not an ELF file.
//!
void StELFFile::readFileHeaders()
{
// move read head to beginning of stream
m_stream.seekg(0, std::ios_base::beg);
// read ELF header
m_stream.read(reinterpret_cast<char *>(&m_header), sizeof(m_header));
if (m_stream.bad())
{
throw StELFFileException("could not read file header");
}
// convert endianness
m_header.e_type = ENDIAN_LITTLE_TO_HOST_U16(m_header.e_type);
m_header.e_machine = ENDIAN_LITTLE_TO_HOST_U16(m_header.e_machine);
m_header.e_version = ENDIAN_LITTLE_TO_HOST_U32(m_header.e_version);
m_header.e_entry = ENDIAN_LITTLE_TO_HOST_U32(m_header.e_entry);
m_header.e_phoff = ENDIAN_LITTLE_TO_HOST_U32(m_header.e_phoff);
m_header.e_shoff = ENDIAN_LITTLE_TO_HOST_U32(m_header.e_shoff);
m_header.e_flags = ENDIAN_LITTLE_TO_HOST_U32(m_header.e_flags);
m_header.e_ehsize = ENDIAN_LITTLE_TO_HOST_U16(m_header.e_ehsize);
m_header.e_phentsize = ENDIAN_LITTLE_TO_HOST_U16(m_header.e_phentsize);
m_header.e_phnum = ENDIAN_LITTLE_TO_HOST_U16(m_header.e_phnum);
m_header.e_shentsize = ENDIAN_LITTLE_TO_HOST_U16(m_header.e_shentsize);
m_header.e_shnum = ENDIAN_LITTLE_TO_HOST_U16(m_header.e_shnum);
m_header.e_shstrndx = ENDIAN_LITTLE_TO_HOST_U16(m_header.e_shstrndx);
// check magic number
if (!(m_header.e_ident[EI_MAG0] == ELFMAG0 && m_header.e_ident[EI_MAG1] == ELFMAG1 &&
m_header.e_ident[EI_MAG2] == ELFMAG2 && m_header.e_ident[EI_MAG3] == ELFMAG3))
{
throw StELFFileException("invalid magic number in ELF header");
}
try
{
int i;
// read section headers
if (m_header.e_shoff != 0 && m_header.e_shnum > 0)
{
Elf32_Shdr sectionHeader;
for (i = 0; i < m_header.e_shnum; ++i)
{
m_stream.seekg(m_header.e_shoff + m_header.e_shentsize * i, std::ios::beg);
m_stream.read(reinterpret_cast<char *>(&sectionHeader), sizeof(sectionHeader));
if (m_stream.bad())
{
throw StELFFileException("could not read section header");
}
// convert endianness
sectionHeader.sh_name = ENDIAN_LITTLE_TO_HOST_U32(sectionHeader.sh_name);
sectionHeader.sh_type = ENDIAN_LITTLE_TO_HOST_U32(sectionHeader.sh_type);
sectionHeader.sh_flags = ENDIAN_LITTLE_TO_HOST_U32(sectionHeader.sh_flags);
sectionHeader.sh_addr = ENDIAN_LITTLE_TO_HOST_U32(sectionHeader.sh_addr);
sectionHeader.sh_offset = ENDIAN_LITTLE_TO_HOST_U32(sectionHeader.sh_offset);
sectionHeader.sh_size = ENDIAN_LITTLE_TO_HOST_U32(sectionHeader.sh_size);
sectionHeader.sh_link = ENDIAN_LITTLE_TO_HOST_U32(sectionHeader.sh_link);
sectionHeader.sh_info = ENDIAN_LITTLE_TO_HOST_U32(sectionHeader.sh_info);
sectionHeader.sh_addralign = ENDIAN_LITTLE_TO_HOST_U32(sectionHeader.sh_addralign);
sectionHeader.sh_entsize = ENDIAN_LITTLE_TO_HOST_U32(sectionHeader.sh_entsize);
m_sectionHeaders.push_back(sectionHeader);
}
}
// read program headers
if (m_header.e_phoff != 0 && m_header.e_phnum > 0)
{
Elf32_Phdr programHeader;
for (i = 0; i < m_header.e_phnum; ++i)
{
m_stream.seekg(m_header.e_phoff + m_header.e_phentsize * i, std::ios::beg);
m_stream.read(reinterpret_cast<char *>(&programHeader), sizeof(programHeader));
if (m_stream.bad())
{
throw StELFFileException("could not read program header");
}
// convert endianness
programHeader.p_type = ENDIAN_LITTLE_TO_HOST_U32(programHeader.p_type);
programHeader.p_offset = ENDIAN_LITTLE_TO_HOST_U32(programHeader.p_type);
programHeader.p_vaddr = ENDIAN_LITTLE_TO_HOST_U32(programHeader.p_vaddr);
programHeader.p_paddr = ENDIAN_LITTLE_TO_HOST_U32(programHeader.p_paddr);
programHeader.p_filesz = ENDIAN_LITTLE_TO_HOST_U32(programHeader.p_filesz);
programHeader.p_memsz = ENDIAN_LITTLE_TO_HOST_U32(programHeader.p_memsz);
programHeader.p_flags = ENDIAN_LITTLE_TO_HOST_U32(programHeader.p_flags);
programHeader.p_align = ENDIAN_LITTLE_TO_HOST_U32(programHeader.p_align);
m_programHeaders.push_back(programHeader);
}
}
// look up symbol table section index
{
std::string symtab_section_name(SYMTAB_SECTION_NAME);
m_symbolTableIndex = getIndexOfSectionWithName(symtab_section_name);
}
}
catch (...)
{
throw StELFFileException("error reading file");
}
}
const Elf32_Shdr &StELFFile::getSectionAtIndex(unsigned inIndex) const
{
if (inIndex > m_sectionHeaders.size())
throw std::invalid_argument("inIndex");
return m_sectionHeaders[inIndex];
}
//! If there is not a matching section, then #SHN_UNDEF is returned instead.
//!
unsigned StELFFile::getIndexOfSectionWithName(const std::string &inName)
{
unsigned sectionIndex = 0;
const_section_iterator it = getSectionBegin();
for (; it != getSectionEnd(); ++it, ++sectionIndex)
{
const Elf32_Shdr &header = *it;
if (header.sh_name != 0)
{
std::string sectionName = getSectionNameAtIndex(header.sh_name);
if (inName == sectionName)
return sectionIndex;
}
}
// no matching section
return SHN_UNDEF;
}
//! The pointer returned from this method must be freed with the delete array operator (i.e., delete []).
//! If either the section data offset (sh_offset) or the section size (sh_size) are 0, then NULL will
//! be returned instead.
//!
//! The data is read directly from the input stream passed into the constructor. The stream must
//! still be open, or an exception will be thrown.
//!
//! \exception StELFFileException is thrown if an error occurs while reading the file.
//! \exception std::bad_alloc is thrown if memory for the data cannot be allocated.
uint8_t *StELFFile::getSectionDataAtIndex(unsigned inIndex)
{
return readSectionData(m_sectionHeaders[inIndex]);
}
//! The pointer returned from this method must be freed with the delete array operator (i.e., delete []).
//! If either the section data offset (sh_offset) or the section size (sh_size) are 0, then NULL will
//! be returned instead.
//!
//! The data is read directly from the input stream passed into the constructor. The stream must
//! still be open, or an exception will be thrown.
//!
//! \exception StELFFileException is thrown if an error occurs while reading the file.
//! \exception std::bad_alloc is thrown if memory for the data cannot be allocated.
uint8_t *StELFFile::getSectionData(const_section_iterator inSection)
{
return readSectionData(*inSection);
}
//! \exception StELFFileException is thrown if an error occurs while reading the file.
//! \exception std::bad_alloc is thrown if memory for the data cannot be allocated.
uint8_t *StELFFile::readSectionData(const Elf32_Shdr &inHeader)
{
// check for empty data
if (inHeader.sh_offset == 0 || inHeader.sh_size == 0)
return NULL;
uint8_t *sectionData = new uint8_t[inHeader.sh_size];
try
{
m_stream.seekg(inHeader.sh_offset, std::ios::beg);
m_stream.read(reinterpret_cast<char *>(sectionData), inHeader.sh_size);
if (m_stream.bad())
throw StELFFileException("could not read entire section");
}
catch (StELFFileException)
{
throw;
}
catch (...)
{
throw StELFFileException("error reading section data");
}
return sectionData;
}
const Elf32_Phdr &StELFFile::getSegmentAtIndex(unsigned inIndex) const
{
if (inIndex > m_programHeaders.size())
throw std::invalid_argument("inIndex");
return m_programHeaders[inIndex];
}
//! The pointer returned from this method must be freed with the delete array operator (i.e., delete []).
//! If either the segment offset (p_offset) or the segment file size (p_filesz) are 0, then NULL will
//! be returned instead.
//!
//! The data is read directly from the input stream passed into the constructor. The stream must
//! still be open, or an exception will be thrown.
//!
//! \exception StELFFileException is thrown if an error occurs while reading the file.
//! \exception std::bad_alloc is thrown if memory for the data cannot be allocated.
uint8_t *StELFFile::getSegmentDataAtIndex(unsigned inIndex)
{
return readSegmentData(m_programHeaders[inIndex]);
}
//! The pointer returned from this method must be freed with the delete array operator (i.e., delete []).
//! If either the segment offset (p_offset) or the segment file size (p_filesz) are 0, then NULL will
//! be returned instead.
//!
//! The data is read directly from the input stream passed into the constructor. The stream must
//! still be open, or an exception will be thrown.
//!
//! \exception StELFFileException is thrown if an error occurs while reading the file.
//! \exception std::bad_alloc is thrown if memory for the data cannot be allocated.
uint8_t *StELFFile::getSegmentData(const_segment_iterator inSegment)
{
return readSegmentData(*inSegment);
}
//! \exception StELFFileException is thrown if an error occurs while reading the file.
//! \exception std::bad_alloc is thrown if memory for the data cannot be allocated.
uint8_t *StELFFile::readSegmentData(const Elf32_Phdr &inHeader)
{
// check for empty data
if (inHeader.p_offset == 0 || inHeader.p_filesz == 0)
return NULL;
uint8_t *segmentData = new uint8_t[inHeader.p_filesz];
try
{
m_stream.seekg(inHeader.p_offset, std::ios::beg);
m_stream.read(reinterpret_cast<char *>(segmentData), inHeader.p_filesz);
if (m_stream.bad())
throw StELFFileException("could not read entire segment");
}
catch (StELFFileException)
{
throw;
}
catch (...)
{
throw StELFFileException("error reading segment data");
}
return segmentData;
}
//! If the index is out of range, or if there is no string table in the file, then
//! an empty string will be returned instead. This will also happen when the index
//! is either 0 or the last byte in the table, since the table begins and ends with
//! zero bytes.
std::string StELFFile::getSectionNameAtIndex(unsigned inIndex)
{
// make sure there's a section name string table
if (m_header.e_shstrndx == SHN_UNDEF)
return std::string("");
return getStringAtIndex(m_header.e_shstrndx, inIndex);
}
//! \exception std::invalid_argument is thrown if the section identified by \a
//! inStringTableSectionIndex is not actually a string table, or if \a
//! inStringIndex is out of range for the string table.
std::string StELFFile::getStringAtIndex(unsigned inStringTableSectionIndex, unsigned inStringIndex)
{
// check section type
const Elf32_Shdr &header = getSectionAtIndex(inStringTableSectionIndex);
if (header.sh_type != SHT_STRTAB)
throw std::invalid_argument("inStringTableSectionIndex");
if (inStringIndex >= header.sh_size)
throw std::invalid_argument("inStringTableSectionIndex");
// check cache
SectionDataInfo &info = getCachedSectionData(inStringTableSectionIndex);
return std::string(&reinterpret_cast<char *>(info.m_data)[inStringIndex]);
}
StELFFile::SectionDataInfo &StELFFile::getCachedSectionData(unsigned inSectionIndex)
{
// check cache
SectionDataMap::iterator it = m_sectionDataCache.find(inSectionIndex);
if (it != m_sectionDataCache.end())
return it->second;
// not in cache, add it
const Elf32_Shdr &header = getSectionAtIndex(inSectionIndex);
uint8_t *data = getSectionDataAtIndex(inSectionIndex);
SectionDataInfo info;
info.m_data = data;
info.m_size = header.sh_size;
m_sectionDataCache[inSectionIndex] = info;
return m_sectionDataCache[inSectionIndex];
}
//! The number of entries in the symbol table is the symbol table section size
//! divided by the size of each symbol entry (the #Elf32_Shdr::sh_entsize field of the
//! symbol table section header).
unsigned StELFFile::getSymbolCount()
{
if (m_symbolTableIndex == SHN_UNDEF)
return 0;
const Elf32_Shdr &header = getSectionAtIndex(m_symbolTableIndex);
return header.sh_size / header.sh_entsize;
}
//! \exception std::invalid_argument is thrown if \a inIndex is out of range.]
//!
const Elf32_Sym &StELFFile::getSymbolAtIndex(unsigned inIndex)
{
// get section data
const Elf32_Shdr &header = getSectionAtIndex(m_symbolTableIndex);
SectionDataInfo &info = getCachedSectionData(m_symbolTableIndex);
// has the symbol table been byte swapped yet?
if (!info.m_swapped)
{
byteSwapSymbolTable(header, info);
}
unsigned symbolOffset = header.sh_entsize * inIndex;
if (symbolOffset >= info.m_size)
{
throw std::invalid_argument("inIndex");
}
Elf32_Sym *symbol = reinterpret_cast<Elf32_Sym *>(&info.m_data[symbolOffset]);
return *symbol;
}
void StELFFile::byteSwapSymbolTable(const Elf32_Shdr &header, SectionDataInfo &info)
{
unsigned symbolCount = getSymbolCount();
unsigned i = 0;
unsigned symbolOffset = 0;
for (; i < symbolCount; ++i, symbolOffset += header.sh_entsize)
{
Elf32_Sym *symbol = reinterpret_cast<Elf32_Sym *>(&info.m_data[symbolOffset]);
symbol->st_name = ENDIAN_LITTLE_TO_HOST_U32(symbol->st_name);
symbol->st_value = ENDIAN_LITTLE_TO_HOST_U32(symbol->st_value);
symbol->st_size = ENDIAN_LITTLE_TO_HOST_U32(symbol->st_size);
symbol->st_shndx = ENDIAN_LITTLE_TO_HOST_U16(symbol->st_shndx);
}
// remember that we've byte swapped the symbols
info.m_swapped = true;
}
unsigned StELFFile::getSymbolNameStringTableIndex() const
{
const Elf32_Shdr &header = getSectionAtIndex(m_symbolTableIndex);
return header.sh_link;
}
std::string StELFFile::getSymbolName(const Elf32_Sym &inSymbol)
{
unsigned symbolStringTableIndex = getSymbolNameStringTableIndex();
return getStringAtIndex(symbolStringTableIndex, inSymbol.st_name);
}
//! Returns STN_UNDEF if it cannot find a symbol at the given \a symbolAddress.
unsigned StELFFile::getIndexOfSymbolAtAddress(uint32_t symbolAddress, bool strict)
{
unsigned symbolCount = getSymbolCount();
unsigned symbolIndex = 0;
for (; symbolIndex < symbolCount; ++symbolIndex)
{
const Elf32_Sym &symbol = getSymbolAtIndex(symbolIndex);
// the GHS toolchain puts in STT_FUNC symbols marking the beginning and ending of each
// file. if the entry point happens to be at the beginning of the file, the beginning-
// of-file symbol will have the same value and type. fortunately, the size of these
// symbols is 0 (or seems to be). we also ignore symbols that start with two dots just
// in case.
if (symbol.st_value == symbolAddress &&
(strict && ELF32_ST_TYPE(symbol.st_info) == STT_FUNC && symbol.st_size != 0))
{
std::string symbolName = getSymbolName(symbol);
// ignore symbols that start with two dots
if (symbolName[0] == '.' && symbolName[1] == '.')
continue;
// found the symbol!
return symbolIndex;
}
}
return STN_UNDEF;
}
ARMSymbolType_t StELFFile::getTypeOfSymbolAtIndex(unsigned symbolIndex)
{
ARMSymbolType_t symType = eARMSymbol;
const Elf32_Sym &symbol = getSymbolAtIndex(symbolIndex);
if (m_elfVariant == eGHSVariant)
{
if (symbol.st_other & STO_THUMB)
symType = eThumbSymbol;
}
else
{
unsigned mappingSymStart = 1;
unsigned mappingSymCount = getSymbolCount() - 1; // don't include first undefined symbol
bool mapSymsFirst = (m_header.e_flags & EF_ARM_MAPSYMSFIRST) != 0;
if (mapSymsFirst)
{
// first symbol '$m' is number of mapping syms
const Elf32_Sym &mappingSymCountSym = getSymbolAtIndex(1);
if (getSymbolName(mappingSymCountSym) == MAPPING_SYMBOL_COUNT_TAGSYM)
{
mappingSymCount = mappingSymCountSym.st_value;
mappingSymStart = 2;
}
}
uint32_t lastMappingSymAddress = 0;
unsigned mappingSymIndex = mappingSymStart;
for (; mappingSymIndex < mappingSymCount + mappingSymStart; ++mappingSymIndex)
{
const Elf32_Sym &mappingSym = getSymbolAtIndex(mappingSymIndex);
std::string mappingSymName = getSymbolName(mappingSym);
ARMSymbolType_t nextSymType = eUnknownSymbol;
if (mappingSymName == ARM_SEQUENCE_MAPSYM)
symType = eARMSymbol;
else if (mappingSymName == DATA_SEQUENCE_MAPSYM)
symType = eDataSymbol;
else if (mappingSymName == THUMB_SEQUENCE_MAPSYM)
symType = eThumbSymbol;
if (nextSymType != eUnknownSymbol)
{
if (symbol.st_value >= lastMappingSymAddress && symbol.st_value < mappingSym.st_value)
break;
symType = nextSymType;
lastMappingSymAddress = mappingSym.st_value;
}
}
}
return symType;
}
void StELFFile::dumpSections()
{
unsigned count = getSectionCount();
unsigned i = 0;
const char *sectionTypes[12] = { "NULL", "PROGBITS", "SYMTAB", "STRTAB", "RELA", "HASH",
"DYNAMIC", "NOTE", "NOBITS", "REL", "SHLIB", "DYNSYM" };
for (; i < count; ++i)
{
const Elf32_Shdr &header = getSectionAtIndex(i);
std::string name = getSectionNameAtIndex(header.sh_name);
printf("%s: %s, 0x%08x, 0x%08x, 0x%08x, %d, %d, %d\n", name.c_str(), sectionTypes[header.sh_type],
header.sh_addr, header.sh_offset, header.sh_size, header.sh_link, header.sh_info, header.sh_entsize);
}
}
void StELFFile::dumpSymbolTable()
{
const char *symbolTypes[5] = { "NOTYPE", "OBJECT", "FUNC", "SECTION", "FILE" };
const char *symbolBinding[3] = { "LOCAL", "GLOBAL", "WEAK" };
unsigned count = getSymbolCount();
unsigned i = 0;
for (; i < count; ++i)
{
const Elf32_Sym &symbol = getSymbolAtIndex(i);
std::string name = getSymbolName(symbol);
printf("'%s': %s, %s, 0x%08x, 0x%08x, %d. 0x%08x\n", name.c_str(), symbolTypes[ELF32_ST_TYPE(symbol.st_info)],
symbolBinding[ELF32_ST_BIND(symbol.st_info)], symbol.st_value, symbol.st_size, symbol.st_shndx,
symbol.st_other);
}
}