ADDRESS DOS4GWBinaryFile::GetMainEntryPoint() {
ADDRESS aMain = GetAddressByName ("main", true);
if (aMain != NO_ADDRESS)
return aMain;
aMain = GetAddressByName ("__CMain", true);
if (aMain != NO_ADDRESS)
return aMain;
// Search with this crude pattern: call, sub ebp, ebp, call __Cmain in the first 0x300 bytes
// Start at program entry point
unsigned p = LMMH(m_pLXHeader->eip);
unsigned lim = p + 0x300;
unsigned char op1, op2;
ADDRESS addr;
//unsigned lastOrdCall = 0; //TODO: identify the point of setting this variable
bool gotSubEbp = false; // True if see sub ebp, ebp
bool lastWasCall = false; // True if the last instruction was a call
SectionInfo* si = GetSectionInfoByName("seg0"); // Assume the first section is text
if (si == nullptr) si = GetSectionInfoByName(".text");
if (si == nullptr) si = GetSectionInfoByName("CODE");
assert(si);
ADDRESS nativeOrigin = si->uNativeAddr;
unsigned textSize = si->uSectionSize;
if (textSize < 0x300)
lim = p + textSize;
while (p < lim) {
op1 = *(unsigned char*)(p + base);
op2 = *(unsigned char*)(p + base + 1);
//std::cerr << std::hex << "At " << p << ", ops " << (unsigned)op1 << ", " << (unsigned)op2 << std::dec << "\n";
switch (op1) {
case 0xE8: {
// An ordinary call
if (gotSubEbp) {
// This is the call we want. Get the offset from the call instruction
addr = nativeOrigin + p + 5 + LMMH(*(p + base + 1));
// std::cerr << "__CMain at " << std::hex << addr << "\n";
return addr;
}
//lastOrdCall = p;
lastWasCall = true;
break;
}
case 0x2B: // 0x2B 0xED is sub ebp,ebp
if (op2 == 0xED && lastWasCall)
gotSubEbp = true;
lastWasCall = false;
break;
default:
gotSubEbp = false;
lastWasCall = false;
break;
case 0xEB: // Short relative jump
if (op2 >= 0x80) // Branch backwards?
break; // Yes, just ignore it
// Otherwise, actually follow the branch. May have to modify this some time...
p += op2+2; // +2 for the instruction itself, and op2 for the displacement
continue; // Don't break, we have the new "pc" set already
}
int size = microX86Dis(p + base);
if (size == 0x40) {
fprintf(stderr, "Warning! Microdisassembler out of step at offset 0x%x\n", p);
size = 1;
}
p += size;
}
return NO_ADDRESS;
}
bool DOS4GWBinaryFile::RealLoad(const char* sName) {
m_pFileName = sName;
FILE *fp = fopen(sName,"rb");
DWord lxoffLE, lxoff;
fseek(fp, 0x3c, SEEK_SET);
fread(&lxoffLE, 4, 1, fp); // Note: peoffLE will be in Little Endian
lxoff = LMMH(lxoffLE);
fseek(fp, lxoff, SEEK_SET);
m_pLXHeader = new LXHeader;
fread(m_pLXHeader, sizeof(LXHeader), 1, fp);
if (m_pLXHeader->sigLo != 'L' || (m_pLXHeader->sigHi != 'X' && m_pLXHeader->sigHi != 'E')) {
fprintf(stderr,"error loading file %s, bad LE/LX magic\n", sName);
return false;
}
fseek(fp, lxoff + LMMH(m_pLXHeader->objtbloffset), SEEK_SET);
m_pLXObjects = new LXObject[LMMH(m_pLXHeader->numobjsinmodule)];
fread(m_pLXObjects, sizeof(LXObject), LMMH(m_pLXHeader->numobjsinmodule), fp);
// at this point we're supposed to read in the page table and fuss around with it
// but I'm just going to assume the file is flat.
#if 0
unsigned npagetblentries = 0;
m_cbImage = 0;
for (unsigned n = 0; n < LMMH(m_pLXHeader->numobjsinmodule); n++) {
if (LMMH(m_pLXObjects[n].PageTblIdx) + LMMH(m_pLXObjects[n].NumPageTblEntries) - 1 > npagetblentries)
npagetblentries = LMMH(m_pLXObjects[n].PageTblIdx) + LMMH(m_pLXObjects[n].NumPageTblEntries) - 1;
if (LMMH(m_pLXObjects[n].ObjectFlags) & 0x40)
if (LMMH(m_pLXObjects[n].RelocBaseAddr) + LMMH(m_pLXObjects[n].VirtualSize) > m_cbImage)
m_cbImage = LMMH(m_pLXObjects[n].RelocBaseAddr) + LMMH(m_pLXObjects[n].VirtualSize);
}
m_cbImage -= LMMH(m_pLXObjects[0].RelocBaseAddr);
fseek(fp, lxoff + LMMH(m_pLXHeader->objpagetbloffset), SEEK_SET);
m_pLXPages = new LXPage[npagetblentries];
fread(m_pLXPages, sizeof(LXPage), npagetblentries, fp);
#endif
unsigned npages = 0;
m_cbImage = 0;
for (unsigned n = 0; n < LMMH(m_pLXHeader->numobjsinmodule); n++)
if (LMMH(m_pLXObjects[n].ObjectFlags) & 0x40) {
if (LMMH(m_pLXObjects[n].PageTblIdx) + LMMH(m_pLXObjects[n].NumPageTblEntries) - 1 > npages)
npages = LMMH(m_pLXObjects[n].PageTblIdx) + LMMH(m_pLXObjects[n].NumPageTblEntries) - 1;
m_cbImage = LMMH(m_pLXObjects[n].RelocBaseAddr) + LMMH(m_pLXObjects[n].VirtualSize);
}
m_cbImage -= LMMH(m_pLXObjects[0].RelocBaseAddr);
base = (char *)malloc(m_cbImage);
m_iNumSections = LMMH(m_pLXHeader->numobjsinmodule);
m_pSections = new SectionInfo[m_iNumSections];
for (unsigned n = 0; n < LMMH(m_pLXHeader->numobjsinmodule); n++)
if (LMMH(m_pLXObjects[n].ObjectFlags) & 0x40){
printf("vsize %x reloc %x flags %x page %i npage %i\n",
LMMH(m_pLXObjects[n].VirtualSize), LMMH(m_pLXObjects[n].RelocBaseAddr),
LMMH(m_pLXObjects[n].ObjectFlags), LMMH(m_pLXObjects[n].PageTblIdx),
LMMH(m_pLXObjects[n].NumPageTblEntries));
m_pSections[n].pSectionName = new char[9];
sprintf(m_pSections[n].pSectionName, "seg%i", n); // no section names in LX
m_pSections[n].uNativeAddr = LMMH(m_pLXObjects[n].RelocBaseAddr);
m_pSections[n].uHostAddr = ADDRESS::host_ptr(base + (m_pSections[n].uNativeAddr - m_pSections[0].uNativeAddr).m_value);
m_pSections[n].uSectionSize=LMMH(m_pLXObjects[n].VirtualSize);
DWord Flags = LMMH(m_pLXObjects[n].ObjectFlags);
m_pSections[n].bBss = 0; // TODO
m_pSections[n].bCode = Flags&0x4?1:0;
m_pSections[n].bData = Flags&0x4?0:1;
m_pSections[n].bReadOnly = Flags&0x1?0:1;
fseek(fp, m_pLXHeader->datapagesoffset + (LMMH(m_pLXObjects[n].PageTblIdx) - 1) * LMMH(m_pLXHeader->pagesize), SEEK_SET);
char *p = base + LMMH(m_pLXObjects[n].RelocBaseAddr) - LMMH(m_pLXObjects[0].RelocBaseAddr);
fread(p, LMMH(m_pLXObjects[n].NumPageTblEntries), LMMH(m_pLXHeader->pagesize), fp);
}
// TODO: decode entry tables
#if 0
// you probably don't want this, it's a bunch of symbols I pulled out of a disassmbly of a binary I'm working on.
dlprocptrs[0x101ac] = "main";
dlprocptrs[0x10a24] = "vfprintf";
dlprocptrs[0x12d2c] = "atoi";
dlprocptrs[0x12d74] = "malloc";
dlprocptrs[0x12d84] = "__LastFree";
dlprocptrs[0x12eaa] = "__ExpandDGROUP";
dlprocptrs[0x130a7] = "free";
dlprocptrs[0x130b7] = "_nfree";
dlprocptrs[0x130dc] = "start";
dlprocptrs[0x132fa] = "__exit_";
dlprocptrs[0x132fc] = "__exit_with_msg_";
dlprocptrs[0x1332a] = "__GETDS";
dlprocptrs[0x13332] = "inp";
dlprocptrs[0x1333d] = "outp";
dlprocptrs[0x13349] = "_dos_getvect";
dlprocptrs[0x13383] = "_dos_setvect";
dlprocptrs[0x133ba] = "int386";
dlprocptrs[0x133f9] = "sprintf";
dlprocptrs[0x13423] = "vsprintf";
dlprocptrs[0x13430] = "segread";
dlprocptrs[0x1345d] = "int386x";
dlprocptrs[0x1347e] = "creat";
dlprocptrs[0x13493] = "setmode";
dlprocptrs[0x1355f] = "close";
dlprocptrs[0x1384a] = "read";
dlprocptrs[0x13940] = "write";
dlprocptrs[0x13b2e] = "filelength";
dlprocptrs[0x13b74] = "printf";
dlprocptrs[0x13b94] = "__null_int23_exit";
dlprocptrs[0x13b95] = "exit";
dlprocptrs[0x13bad] = "_exit";
dlprocptrs[0x13bc4] = "tell";
dlprocptrs[0x13cba] = "rewind";
dlprocptrs[0x13cd3] = "fread";
dlprocptrs[0x13fe1] = "strcat";
dlprocptrs[0x1401c] = "__open_flags";
dlprocptrs[0x141a8] = "fopen";
dlprocptrs[0x141d0] = "freopen";
dlprocptrs[0x142c4] = "__MemAllocator";
dlprocptrs[0x14374] = "__MemFree";
dlprocptrs[0x1447f] = "__nmemneed";
dlprocptrs[0x14487] = "sbrk";
dlprocptrs[0x14524] = "__brk";
dlprocptrs[0x145d0] = "__CMain";
dlprocptrs[0x145ff] = "_init_files";
dlprocptrs[0x1464c] = "__InitRtns";
dlprocptrs[0x1468b] = "__FiniRtns";
dlprocptrs[0x146ca] = "__prtf";
dlprocptrs[0x14f58] = "__int386x_";
dlprocptrs[0x14fb3] = "_DoINTR_";
dlprocptrs[0x15330] = "__Init_Argv";
dlprocptrs[0x15481] = "isatty";
dlprocptrs[0x154a1] = "_dosret0";
dlprocptrs[0x154bd] = "_dsretax";
dlprocptrs[0x154d4] = "_EINVAL";
dlprocptrs[0x154e5] = "_set_errno";
dlprocptrs[0x15551] = "__CHK";
dlprocptrs[0x15561] = "__STK";
dlprocptrs[0x15578] = "__STKOVERFLOW";
dlprocptrs[0x15588] = "__GRO";
dlprocptrs[0x155c2] = "__fprtf";
dlprocptrs[0x15640] = "__ioalloc";
dlprocptrs[0x156c3] = "__chktty";
dlprocptrs[0x156f0] = "__qread";
dlprocptrs[0x15721] = "fgetc";
dlprocptrs[0x1578f] = "__filbuf";
dlprocptrs[0x157b9] = "__fill_buffer";
dlprocptrs[0x15864] = "fflush";
dlprocptrs[0x1591c] = "ftell";
dlprocptrs[0x15957] = "tolower";
dlprocptrs[0x159b4] = "remove";
dlprocptrs[0x159e9] = "utoa";
dlprocptrs[0x15a36] = "itoa";
dlprocptrs[0x15a97] = "ultoa";
dlprocptrs[0x15ae4] = "ltoa";
dlprocptrs[0x15b14] = "toupper";
dlprocptrs[0x15b29] = "fputc";
dlprocptrs[0x15bca] = "__full_io_exit";
dlprocptrs[0x15c0b] = "fcloseall";
dlprocptrs[0x15c3e] = "flushall";
dlprocptrs[0x15c49] = "__flushall";
dlprocptrs[0x15c85] = "getche";
dlprocptrs[0x15caa] = "__qwrite";
dlprocptrs[0x15d1f] = "unlink";
dlprocptrs[0x15d43] = "putch";
#endif
// fixups
fseek(fp, LMMH(m_pLXHeader->fixuppagetbloffset) + lxoff, SEEK_SET);
unsigned int *fixuppagetbl = new unsigned int[npages+1];
fread(fixuppagetbl, sizeof(unsigned int), npages+1, fp);
//for (unsigned n = 0; n < npages; n++)
// printf("offset for page %i: %x\n", n + 1, fixuppagetbl[n]);
//printf("offset to end of fixup rec: %x\n", fixuppagetbl[npages]);
fseek(fp, LMMH(m_pLXHeader->fixuprecordtbloffset) + lxoff, SEEK_SET);
LXFixup fixup;
unsigned srcpage = 0;
do {
fread(&fixup, sizeof(fixup), 1, fp);
if (fixup.src != 7 || (fixup.flags & ~0x50)) {
fprintf(stderr, "unknown fixup type %02x %02x\n", fixup.src, fixup.flags);
return false;
}
//printf("srcpage = %i srcoff = %x object = %02x trgoff = %x\n", srcpage + 1, fixup.srcoff, fixup.object, fixup.trgoff);
unsigned long src = srcpage * LMMH(m_pLXHeader->pagesize) + (short)LMMHw(fixup.srcoff);
unsigned short object = 0;
if (fixup.flags & 0x40)
fread(&object, 2, 1, fp);
else
fread(&object, 1, 1, fp);
unsigned int trgoff = 0;
if (fixup.flags & 0x10)
fread(&trgoff, 4, 1, fp);
else
fread(&trgoff, 2, 1, fp);
unsigned long target = LMMH(m_pLXObjects[object - 1].RelocBaseAddr) + LMMHw(trgoff);
// printf("relocate dword at %x to point to %x\n", src, target);
*(unsigned int *)(base + src) = target;
while (ftell(fp) - (LMMH(m_pLXHeader->fixuprecordtbloffset) + lxoff) >= LMMH(fixuppagetbl[srcpage+1]))
srcpage++;
} while (srcpage < npages);
fclose(fp);
return true;
}
ADDRESS DOS4GWBinaryFile::GetEntryPoint() {
return ADDRESS::g((LMMH(m_pLXObjects[LMMH(m_pLXHeader->eipobjectnum)].RelocBaseAddr) + LMMH(m_pLXHeader->eip)));
}
BinaryFile* BinaryFileFactory::getInstanceFor(const char *sName)
{
FILE *f;
unsigned char buf[64];
std::string libName;
BinaryFile *res = NULL;
f = fopen(sName, "rb");
if (f == NULL)
{
fprintf(stderr, "Unable to open binary file: %s\n", sName);
return NULL;
}
fread(buf, sizeof (buf), 1, f);
if (TESTMAGIC4(buf, 0, '\177', 'E', 'L', 'F'))
{
/* ELF Binary */
libName = "ElfBinaryFile";
}
else if (TESTMAGIC2(buf, 0, 'M', 'Z')) /* DOS-based file */
{
int peoff = LMMH(buf[0x3C]);
if (peoff != 0 && fseek(f, peoff, SEEK_SET) != -1)
{
fread(buf, 4, 1, f);
if (TESTMAGIC4(buf, 0, 'P', 'E', 0, 0))
{
/* Win32 Binary */
libName = "Win32BinaryFile";
}
else if (TESTMAGIC2(buf, 0, 'N', 'E'))
{
/* Win16 / Old OS/2 Binary */
}
else if (TESTMAGIC2(buf, 0, 'L', 'E'))
{
/* Win32 VxD (Linear Executable) or DOS4GW app */
libName = "DOS4GWBinaryFile";
}
else if (TESTMAGIC2(buf, 0, 'L', 'X'))
{
/* New OS/2 Binary */
}
}
/* Assume MS-DOS Real-mode binary. */
if (libName.size() == 0)
libName = "ExeBinaryFile";
}
else if (TESTMAGIC4(buf, 0x3C, 'a', 'p', 'p', 'l') ||
TESTMAGIC4(buf, 0x3C, 'p', 'a', 'n', 'l'))
{
/* PRC Palm-pilot binary */
libName = "PalmBinaryFile";
}
else if ((buf[0] == 0xfe && buf[1] == 0xed && buf[2] == 0xfa && buf[3] == 0xce) ||
(buf[0] == 0xce && buf[1] == 0xfa && buf[2] == 0xed && buf[3] == 0xfe) ||
(buf[0] == 0xca && buf[1] == 0xfe && buf[2] == 0xba && buf[3] == 0xbe))
{
/* Mach-O Mac OS-X binary */
libName = "MachOBinaryFile";
#ifdef __CYGWIN__
fprintf(stderr, "Sorry, Cygwin-hosted Boomerang cannot compile the MachOBinaryFile module at present"
"\n");
fclose(f);
return NULL;
#endif
}
else if (buf[0] == 0x02 && buf[2] == 0x01 &&
(buf[1] == 0x10 || buf[1] == 0x0B) &&
(buf[3] == 0x07 || buf[3] == 0x08 || buf[4] == 0x0B))
{
/* HP Som binary (last as it's not really particularly good magic) */
libName = "HpSomBinaryFile";
}
else if (buf[0] == 0x4c && buf[1] == 0x01)
{
libName = "IntelCoffFile";
}
else
{
fprintf(stderr, "Unrecognised binary file\n");
fclose(f);
return NULL;
}
// Load the specific loader library
#ifndef _WIN32 // Cygwin, Unix/Linux
libName = std::string("lib/lib") + libName;
#ifdef __CYGWIN__
libName += ".dll"; // Cygwin wants .dll, but is otherwise like Unix
#else
#if HOST_OSX
libName += ".dylib";
#else
libName += ".so";
#endif
#endif
dlHandle = dlopen(libName.c_str(), RTLD_LAZY);
if (dlHandle == NULL)
{
fprintf(stderr, "Could not open dynamic loader library %s\n", libName.c_str());
fprintf(stderr, "%s\n", dlerror());
fclose(f);
return NULL;
}
// Use the handle to find the "construct" function
#if 0 // HOST_OSX_10_2 // Not sure when the underscore is really needed
#define UNDERSCORE "_" // Only OSX 10.2 seems to need this underscore
#else
#define UNDERSCORE
#endif
constructFcn pFcn = (constructFcn) dlsym(dlHandle, UNDERSCORE "construct");
#else // Else MSVC, MinGW
libName += ".dll"; // Example: ElfBinaryFile.dll (same dir as boomerang.exe)
#ifdef __MINGW32__
libName = "lib/lib" + libName;
#endif
hModule = LoadLibraryA(libName.c_str());
if (hModule == NULL)
{
int err = GetLastError();
fprintf(stderr, "Could not open dynamic loader library %s (error #%d)\n", libName.c_str(), err);
fclose(f);
return NULL;
}
// Use the handle to find the "construct" function
constructFcn pFcn = (constructFcn) GetProcAddress((HINSTANCE) hModule, "construct");
#endif
if (pFcn == NULL)
{
fprintf(stderr, "Loader library %s does not have a construct function\n", libName.c_str());
#ifndef _WIN32
fprintf(stderr, "dlerror returns %s\n", dlerror());
#endif
fclose(f);
return NULL;
}
// Call the construct function
res = (*pFcn)();
fclose(f);
return res;
}