123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413 |
- #include "dcc.h"
- #include "DccFrontend.h"
- #include "project.h"
- #include "disassem.h"
- #include "CallGraph.h"
- #include <QtCore/QFileInfo>
- #include <QtCore/QDebug>
- #include <cstdio>
- class Loader
- {
- bool loadIntoProject(IProject *);
- };
- struct PSP { /* PSP structure */
- uint16_t int20h; /* interrupt 20h */
- uint16_t eof; /* segment, end of allocation block */
- uint8_t res1; /* reserved */
- uint8_t dosDisp[5]; /* far call to DOS function dispatcher */
- uint8_t int22h[4]; /* vector for terminate routine */
- uint8_t int23h[4]; /* vector for ctrl+break routine */
- uint8_t int24h[4]; /* vector for error routine */
- uint8_t res2[22]; /* reserved */
- uint16_t segEnv; /* segment address of environment block */
- uint8_t res3[34]; /* reserved */
- uint8_t int21h[6]; /* opcode for int21h and far return */
- uint8_t res4[6]; /* reserved */
- uint8_t fcb1[16]; /* default file control block 1 */
- uint8_t fcb2[16]; /* default file control block 2 */
- uint8_t res5[4]; /* reserved */
- uint8_t cmdTail[0x80]; /* command tail and disk transfer area */
- };
- static struct MZHeader { /* EXE file header */
- uint8_t sigLo; /* .EXE signature: 0x4D 0x5A */
- uint8_t sigHi;
- uint16_t lastPageSize; /* Size of the last page */
- uint16_t numPages; /* Number of pages in the file */
- uint16_t numReloc; /* Number of relocation items */
- uint16_t numParaHeader; /* # of paragraphs in the header */
- uint16_t minAlloc; /* Minimum number of paragraphs */
- uint16_t maxAlloc; /* Maximum number of paragraphs */
- uint16_t initSS; /* Segment displacement of stack */
- uint16_t initSP; /* Contents of SP at entry */
- uint16_t checkSum; /* Complemented checksum */
- uint16_t initIP; /* Contents of IP at entry */
- uint16_t initCS; /* Segment displacement of code */
- uint16_t relocTabOffset; /* Relocation table offset */
- uint16_t overlayNum; /* Overlay number */
- } header;
- #define EXE_RELOCATION 0x10 /* EXE images rellocated to above PSP */
- //static void LoadImage(char *filename);
- static void displayMemMap(void);
- /****************************************************************************
- * displayLoadInfo - Displays low level loader type info.
- ***************************************************************************/
- void PROG::displayLoadInfo(void)
- {
- int i;
- printf("File type is %s\n", (fCOM)?"COM":"EXE");
- if (! fCOM) {
- printf("Signature = %02X%02X\n", header.sigLo, header.sigHi);
- printf("File size %% 512 = %04X\n", LH(&header.lastPageSize));
- printf("File size / 512 = %04X pages\n", LH(&header.numPages));
- printf("# relocation items = %04X\n", LH(&header.numReloc));
- printf("Offset to load image = %04X paras\n", LH(&header.numParaHeader));
- printf("Minimum allocation = %04X paras\n", LH(&header.minAlloc));
- printf("Maximum allocation = %04X paras\n", LH(&header.maxAlloc));
- }
- printf("Load image size = %04" PRIiPTR "\n", cbImage - sizeof(PSP));
- printf("Initial SS:SP = %04X:%04X\n", initSS, initSP);
- printf("Initial CS:IP = %04X:%04X\n", initCS, initIP);
- if (option.VeryVerbose && cReloc)
- {
- printf("\nRelocation Table\n");
- for (i = 0; i < cReloc; i++)
- {
- printf("%06X -> [%04X]\n", relocTable[i],LH(image() + relocTable[i]));
- }
- }
- printf("\n");
- }
- /*****************************************************************************
- * fill - Fills line for displayMemMap()
- ****************************************************************************/
- static void fill(int ip, char *bf)
- {
- PROG &prog(Project::get()->prog);
- static uint8_t type[4] = {'.', 'd', 'c', 'x'};
- uint8_t i;
- for (i = 0; i < 16; i++, ip++)
- {
- *bf++ = ' ';
- *bf++ = (ip < prog.cbImage)? type[(prog.map[ip >> 2] >> ((ip & 3) * 2)) & 3]: ' ';
- }
- *bf = '\0';
- }
- /*****************************************************************************
- * displayMemMap - Displays the memory bitmap
- ****************************************************************************/
- static void displayMemMap(void)
- {
- PROG &prog(Project::get()->prog);
- char c, b1[33], b2[33], b3[33];
- uint8_t i;
- int ip = 0;
- printf("\nMemory Map\n");
- while (ip < prog.cbImage)
- {
- fill(ip, b1);
- printf("%06X %s\n", ip, b1);
- ip += 16;
- for (i = 3, c = b1[1]; i < 32 && c == b1[i]; i += 2)
- ; /* Check if all same */
- if (i > 32)
- {
- fill(ip, b2); /* Skip until next two are not same */
- fill(ip+16, b3);
- if (! (strcmp(b1, b2) || strcmp(b1, b3)))
- {
- printf(" :\n");
- do
- {
- ip += 16;
- fill(ip+16, b1);
- } while (! strcmp(b1, b2));
- }
- }
- }
- printf("\n");
- }
- DccFrontend::DccFrontend(QObject *parent) :
- QObject(parent)
- {
- }
- /*****************************************************************************
- * FrontEnd - invokes the loader, parser, disassembler (if asm1), icode
- * rewritter, and displays any useful information.
- ****************************************************************************/
- bool DccFrontend::FrontEnd ()
- {
- /* Do depth first flow analysis building call graph and procedure list,
- * and attaching the I-code to each procedure */
- parse (*Project::get());
- if (option.asm1)
- {
- qWarning() << "dcc: writing assembler file "<<asm1_name<<'\n';
- }
- /* Search through code looking for impure references and flag them */
- Disassembler ds(1);
- for(Function &f : Project::get()->pProcList)
- {
- f.markImpure();
- if (option.asm1)
- {
- ds.disassem(&f);
- }
- }
- if (option.Interact)
- {
- interactDis(&Project::get()->pProcList.front(), 0); /* Interactive disassembler */
- }
- /* Converts jump target addresses to icode offsets */
- for(Function &f : Project::get()->pProcList)
- {
- f.bindIcodeOff();
- }
- /* Print memory bitmap */
- if (option.Map)
- displayMemMap();
- return(true); // we no longer own proj !
- }
- struct DosLoader {
- protected:
- void prepareImage(PROG &prog,size_t sz,QFile &fp) {
- /* Allocate a block of memory for the program. */
- prog.cbImage = sz + sizeof(PSP);
- prog.Imagez = new uint8_t [prog.cbImage];
- prog.Imagez[0] = 0xCD; /* Fill in PSP int 20h location */
- prog.Imagez[1] = 0x20; /* for termination checking */
- /* Read in the image past where a PSP would go */
- if (sz != fp.read((char *)prog.Imagez + sizeof(PSP),sz))
- fatalError(CANNOT_READ, fp.fileName().toLocal8Bit().data());
- }
- };
- struct ComLoader : public DosLoader {
- bool canLoad(QFile &fp) {
- fp.seek(0);
- char sig[2];
- if(2==fp.read(sig,2)) {
- return not (sig[0] == 0x4D && sig[1] == 0x5A);
- }
- return false;
- }
- bool load(PROG &prog,QFile &fp) {
- fp.seek(0);
- /* COM file
- * In this case the load module size is just the file length
- */
- auto cb = fp.size();
- /* COM programs start off with an ORG 100H (to leave room for a PSP)
- * This is also the implied start address so if we load the image
- * at offset 100H addresses should all line up properly again.
- */
- prog.initCS = 0;
- prog.initIP = 0x100;
- prog.initSS = 0;
- prog.initSP = 0xFFFE;
- prog.cReloc = 0;
- prepareImage(prog,cb,fp);
- /* Set up memory map */
- cb = (prog.cbImage + 3) / 4;
- prog.map = (uint8_t *)malloc(cb);
- memset(prog.map, BM_UNKNOWN, (size_t)cb);
- return true;
- }
- };
- struct ExeLoader : public DosLoader {
- bool canLoad(QFile &fp) {
- if(fp.size()<sizeof(header))
- return false;
- MZHeader tmp_header;
- fp.seek(0);
- fp.read((char *)&tmp_header, sizeof(header));
- if(not (tmp_header.sigLo == 0x4D && tmp_header.sigHi == 0x5A))
- return false;
- /* This is a typical DOS kludge! */
- if (LH(&header.relocTabOffset) == 0x40)
- {
- qDebug() << "Don't understand new EXE format";
- return false;
- }
- return true;
- }
- bool load(PROG &prog,QFile &fp) {
- /* Read rest of header */
- fp.seek(0);
- if (fp.read((char *)&header, sizeof(header)) != sizeof(header))
- return false;
- /* Calculate the load module size.
- * This is the number of pages in the file
- * less the length of the header and reloc table
- * less the number of bytes unused on last page
- */
- uint32_t cb = (uint32_t)LH(&header.numPages) * 512 - (uint32_t)LH(&header.numParaHeader) * 16;
- if (header.lastPageSize)
- {
- cb -= 512 - LH(&header.lastPageSize);
- }
- /* We quietly ignore minAlloc and maxAlloc since for our
- * purposes it doesn't really matter where in real memory
- * the program would end up. EXE programs can't really rely on
- * their load location so setting the PSP segment to 0 is fine.
- * Certainly programs that prod around in DOS or BIOS are going
- * to have to load DS from a constant so it'll be pretty
- * obvious.
- */
- prog.initCS = (int16_t)LH(&header.initCS) + EXE_RELOCATION;
- prog.initIP = (int16_t)LH(&header.initIP);
- prog.initSS = (int16_t)LH(&header.initSS) + EXE_RELOCATION;
- prog.initSP = (int16_t)LH(&header.initSP);
- prog.cReloc = (int16_t)LH(&header.numReloc);
- /* Allocate the relocation table */
- if (prog.cReloc)
- {
- prog.relocTable.resize(prog.cReloc);
- fp.seek(LH(&header.relocTabOffset));
- /* Read in seg:offset pairs and convert to Image ptrs */
- uint8_t buf[4];
- for (int i = 0; i < prog.cReloc; i++)
- {
- fp.read((char *)buf,4);
- prog.relocTable[i] = LH(buf) + (((int)LH(buf+2) + EXE_RELOCATION)<<4);
- }
- }
- /* Seek to start of image */
- uint32_t start_of_image= LH(&header.numParaHeader) * 16;
- fp.seek(start_of_image);
- /* Allocate a block of memory for the program. */
- prepareImage(prog,cb,fp);
- /* Set up memory map */
- cb = (prog.cbImage + 3) / 4;
- prog.map = (uint8_t *)malloc(cb);
- memset(prog.map, BM_UNKNOWN, (size_t)cb);
- /* Relocate segment constants */
- for(uint32_t v : prog.relocTable) {
- uint8_t *p = &prog.Imagez[v];
- uint16_t w = (uint16_t)LH(p) + EXE_RELOCATION;
- *p++ = (uint8_t)(w & 0x00FF);
- *p = (uint8_t)((w & 0xFF00) >> 8);
- }
- return true;
- }
- };
- /*****************************************************************************
- * LoadImage
- ****************************************************************************/
- bool Project::load()
- {
- // addTask(loaderSelection,PreCond(BinaryImage))
- // addTask(applyLoader,PreCond(Loader))
- const char *fname = binary_path().toLocal8Bit().data();
- QFile finfo(binary_path());
- /* Open the input file */
- if(!finfo.open(QFile::ReadOnly)) {
- fatalError(CANNOT_OPEN, fname);
- }
- /* Read in first 2 bytes to check EXE signature */
- if (finfo.size()<=2)
- {
- fatalError(CANNOT_READ, fname);
- }
- ComLoader com_loader;
- ExeLoader exe_loader;
- if(exe_loader.canLoad(finfo)) {
- prog.fCOM = false;
- return exe_loader.load(prog,finfo);
- }
- if(com_loader.canLoad(finfo)) {
- prog.fCOM = true;
- return com_loader.load(prog,finfo);
- }
- return false;
- }
- uint32_t SynthLab;
- /* Parses the program, builds the call graph, and returns the list of
- * procedures found */
- void DccFrontend::parse(Project &proj)
- {
- PROG &prog(proj.prog);
- STATE state;
- /* Set initial state */
- state.setState(rES, 0); /* PSP segment */
- state.setState(rDS, 0);
- state.setState(rCS, prog.initCS);
- state.setState(rSS, prog.initSS);
- state.setState(rSP, prog.initSP);
- state.IP = ((uint32_t)prog.initCS << 4) + prog.initIP;
- SynthLab = SYNTHESIZED_MIN;
- /* Check for special settings of initial state, based on idioms of the
- startup code */
- state.checkStartup();
- Function *start_proc;
- /* Make a struct for the initial procedure */
- if (prog.offMain != -1)
- {
- start_proc = proj.createFunction(0,"main");
- start_proc->retVal.loc = REG_FRAME;
- start_proc->retVal.type = TYPE_WORD_SIGN;
- start_proc->retVal.id.regi = rAX;
- /* We know where main() is. Start the flow of control from there */
- start_proc->procEntry = prog.offMain;
- /* In medium and large models, the segment of main may (will?) not be
- the same as the initial CS segment (of the startup code) */
- state.setState(rCS, prog.segMain);
- state.IP = prog.offMain;
- }
- else
- {
- start_proc = proj.createFunction(0,"start");
- /* Create initial procedure at program start address */
- start_proc->procEntry = (uint32_t)state.IP;
- }
- /* The state info is for the first procedure */
- start_proc->state = state;
- /* Set up call graph initial node */
- proj.callGraph = new CALL_GRAPH;
- proj.callGraph->proc = start_proc;
- /* This proc needs to be called to set things up for LibCheck(), which
- checks a proc to see if it is a know C (etc) library */
- SetupLibCheck();
- //BUG: proj and g_proj are 'live' at this point !
- /* Recursively build entire procedure list */
- start_proc->FollowCtrl(proj.callGraph, &state);
- /* This proc needs to be called to clean things up from SetupLibCheck() */
- CleanupLibCheck();
- }
|