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-rw-r--r--rdoff/ldrdf1.c728
1 files changed, 728 insertions, 0 deletions
diff --git a/rdoff/ldrdf1.c b/rdoff/ldrdf1.c
new file mode 100644
index 00000000..9e4a215d
--- /dev/null
+++ b/rdoff/ldrdf1.c
@@ -0,0 +1,728 @@
+/* ldrdf.c RDOFF Object File linker/loader main program
+ *
+ * The Netwide Assembler is copyright (C) 1996 Simon Tatham and
+ * Julian Hall. All rights reserved. The software is
+ * redistributable under the licence given in the file "Licence"
+ * distributed in the NASM archive.
+ */
+
+/* TODO: Make the system skip a module (other than the first) if none
+ * of the other specified modules contain a reference to it.
+ * May require the system to make an extra pass of the modules to be
+ * loaded eliminating those that aren't required.
+ *
+ * Support all the existing documented options...
+ *
+ * Support libaries (.a files - requires a 'ranlib' type utility)
+ * (I think I've got this working, so I've upped the version)
+ *
+ * -s option to strip resolved symbols from exports. (Could make this an
+ * external utility)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "rdoff.h"
+#include "nasmlib.h"
+#include "symtab.h"
+#include "collectn.h"
+#include "rdlib.h"
+
+#define LDRDF_VERSION "0.30"
+
+/* global variables - those to set options: */
+
+int verbose = 0; /* reflects setting of command line switch */
+int align = 16;
+int errors = 0; /* set by functions to cause halt after current
+ stage of processing */
+
+/* the linked list of modules that must be loaded & linked */
+
+struct modulenode {
+ rdffile f; /* the file */
+ long coderel; /* module's code relocation factor */
+ long datarel; /* module's data relocation factor */
+ long bssrel; /* module's bss data reloc. factor */
+ void * header; /* header location, if loaded */
+ char * name; /* filename */
+ struct modulenode *next;
+};
+
+#define newstr(str) strcpy(malloc(strlen(str) + 1),str)
+#define newstrcat(s1,s2) strcat(strcpy(malloc(strlen(s1)+strlen(s2)+1),s1),s2)
+
+
+struct modulenode *modules = NULL,*lastmodule = NULL;
+
+/* the linked list of libraries to be searched for missing imported
+ symbols */
+
+struct librarynode * libraries = NULL, * lastlib = NULL;
+
+void *symtab; /* The symbol table */
+
+rdf_headerbuf * newheader ; /* New header to be written to output */
+
+/* loadmodule - find the characteristics of a module and add it to the
+ * list of those being linked together */
+
+void loadmodule(char *filename)
+{
+ struct modulenode *prev;
+ if (! modules) {
+ modules = malloc(sizeof(struct modulenode));
+ lastmodule = modules;
+ prev = NULL;
+ }
+ else {
+ lastmodule->next = malloc(sizeof(struct modulenode));
+ prev = lastmodule;
+ lastmodule = lastmodule->next;
+ }
+
+ if (! lastmodule) {
+ fputs("ldrdf: not enough memory\n",stderr);
+ exit(1);
+ }
+
+ if (rdfopen(&lastmodule->f,filename)) {
+ rdfperror("ldrdf",filename);
+ exit(1);
+ }
+
+ lastmodule->header = NULL; /* header hasn't been loaded */
+ lastmodule->name = filename;
+ lastmodule->next = NULL;
+
+ if (prev) {
+ lastmodule->coderel = prev->coderel + prev->f.code_len;
+ if (lastmodule->coderel % align != 0)
+ lastmodule->coderel += align - (lastmodule->coderel % align);
+ lastmodule->datarel = prev->datarel + prev->f.data_len;
+ if (lastmodule->datarel % align != 0)
+ lastmodule->datarel += align - (lastmodule->datarel % align);
+ }
+ else {
+ lastmodule->coderel = 0;
+ lastmodule->datarel = 0;
+ }
+
+ if (verbose)
+ printf("%s code = %08lx (+%04lx), data = %08lx (+%04lx)\n",filename,
+ lastmodule->coderel,lastmodule->f.code_len,
+ lastmodule->datarel,lastmodule->f.data_len);
+
+ lastmodule->header = malloc(lastmodule->f.header_len);
+ if (!lastmodule->header) {
+ fprintf(stderr,"ldrdf: out of memory\n");
+ exit(1);
+ }
+
+ if (rdfloadseg(&lastmodule->f,RDOFF_HEADER,lastmodule->header))
+ {
+ rdfperror("ldrdf",filename);
+ exit(1);
+ }
+}
+
+/* load_library add a library to list of libraries to search
+ * for undefined symbols
+ */
+
+void load_library(char * name)
+{
+ if (verbose)
+ printf("adding library %s to search path\n",name);
+
+ if (! lastlib) {
+ lastlib = libraries = malloc(sizeof(struct librarynode));
+ }
+ else
+ {
+ lastlib->next = malloc(sizeof(struct librarynode));
+ lastlib = lastlib->next;
+ }
+
+ if (! lastlib) {
+ fprintf(stderr, "ldrdf: out of memory\n");
+ exit(1);
+ }
+ strcpy (lastlib->name = malloc (1+strlen(name)), name);
+ lastlib->fp = NULL;
+ lastlib->referenced = 0;
+ lastlib->next = NULL;
+}
+
+
+/* build_symbols() step through each module's header, and locate
+ * exported symbols, placing them in a global table
+ */
+
+long bsslength;
+
+void mod_addsymbols(struct modulenode * mod)
+{
+ rdfheaderrec *r;
+ symtabEnt e;
+ long cbBss;
+
+ mod->bssrel = bsslength;
+ cbBss = 0;
+ rdfheaderrewind(&mod->f);
+ while ((r = rdfgetheaderrec(&mod->f)))
+ {
+
+ if (r->type == 5) /* Allocate BSS */
+ cbBss += r->b.amount;
+
+ if (r->type != 3) continue; /* ignore all but export recs */
+
+ e.segment = r->e.segment;
+ e.offset = r->e.offset +
+ (e.segment == 0 ? mod->coderel : /* 0 -> code */
+ e.segment == 1 ? mod->datarel : /* 1 -> data */
+ mod->bssrel) ; /* 2 -> bss */
+
+ e.flags = 0;
+ e.name = malloc(strlen(r->e.label) + 1);
+ if (! e.name)
+ {
+ fprintf(stderr,"ldrdf: out of memory\n");
+ exit(1);
+ }
+ strcpy(e.name,r->e.label);
+ symtabInsert(symtab,&e);
+ }
+ bsslength += cbBss;
+}
+
+void build_symbols()
+{
+ struct modulenode *mod;
+
+ if (verbose) printf("building global symbol table:\n");
+ newheader = rdfnewheader();
+
+ symtab = symtabNew();
+ bsslength = 0; /* keep track of location of BSS symbols */
+
+ for (mod = modules; mod; mod = mod->next)
+ {
+ mod_addsymbols( mod );
+ }
+ if (verbose)
+ {
+ symtabDump(symtab,stdout);
+ printf("BSS length = %ld bytes\n\n",bsslength);
+ }
+}
+
+
+/* scan_libraries() search through headers of modules for undefined
+ * symbols, and scan libraries for those symbols,
+ * adding library modules found to list of modules
+ * to load. */
+
+void scan_libraries(void)
+{
+ struct modulenode * mod, * nm;
+ struct librarynode * lib;
+ rdfheaderrec * r;
+ int found;
+ char * tmp;
+
+ if (verbose) printf("Scanning libraries for unresolved symbols...\n");
+
+ mod = modules;
+
+ while (mod)
+ {
+ rdfheaderrewind(&mod->f);
+
+ while ((r = rdfgetheaderrec(&mod->f)))
+ {
+ if (r->type != 2) continue; /* not an import record */
+ if ( symtabFind (symtab,r->i.label) )
+ continue; /* symbol already defined */
+
+ /* okay, we have an undefined symbol... step through
+ the libraries now */
+ if (verbose >= 2) {
+ printf("undefined symbol '%s'...",r->i.label);
+ fflush(stdout);
+ }
+
+ lib = libraries;
+ found = 0;
+
+ tmp = newstr(r->i.label);
+ while (! found && lib)
+ {
+ /* move this to an outer loop...! */
+ nm = malloc(sizeof(struct modulenode));
+
+ if (rdl_searchlib(lib,tmp,&nm->f))
+ { /* found a module in the library */
+
+ /* create a modulenode for it */
+
+ if (! nm) {
+ fprintf(stderr,"ldrdf: out of memory\n");
+ exit(1);
+ }
+
+ nm->name = newstrcat(lib->name,nm->f.name);
+ if (verbose >= 2) printf("found in '%s'\n",nm->name);
+
+ nm->coderel = lastmodule->coderel + lastmodule->f.code_len;
+ if (nm->coderel % align != 0)
+ nm->coderel += align - (nm->coderel % align);
+
+ nm->datarel = lastmodule->datarel + lastmodule->f.data_len;
+ if (nm->datarel % align != 0)
+ nm->datarel += align - (nm->datarel % align);
+
+ nm->header = malloc(nm->f.header_len);
+ if (! nm->header)
+ {
+ fprintf(stderr,"ldrdf: out of memory\n");
+ exit(1);
+ }
+
+ if (rdfloadseg(&nm->f,RDOFF_HEADER,nm->header))
+ {
+ rdfperror("ldrdf",nm->name);
+ exit(1);
+ }
+
+ nm->next = NULL;
+ found = 1;
+ lastmodule->next = nm;
+ lastmodule = nm;
+
+ if (verbose)
+ printf("%s code = %08lx (+%04lx), data = %08lx "
+ "(+%04lx)\n",lastmodule->name,
+ lastmodule->coderel,lastmodule->f.code_len,
+ lastmodule->datarel,lastmodule->f.data_len);
+
+ /* add the module's info to the symbol table */
+ mod_addsymbols(nm);
+ }
+ else
+ {
+ if (rdl_error) {
+ rdl_perror("ldrdf",lib->name);
+ exit(1);
+ }
+ free(nm);
+ }
+ lib = lib->next;
+ }
+ free(tmp);
+ if (!found && verbose >= 2) printf("not found\n");
+ }
+ mod = mod->next;
+ }
+}
+
+/* load_segments() allocates memory for & loads the code & data segs
+ * from the RDF modules
+ */
+
+char *text,*data;
+long textlength,datalength;
+
+void load_segments(void)
+{
+ struct modulenode *mod;
+
+ if (!modules) {
+ fprintf(stderr,"ldrdf: nothing to do\n");
+ exit(0);
+ }
+ if (!lastmodule) {
+ fprintf(stderr,"ldrdf: panic: module list exists, but lastmodule=NULL\n");
+ exit(3);
+ }
+
+ if (verbose)
+ printf("loading modules into memory\n");
+
+ /* The following stops 16 bit DOS from crashing whilst attempting to
+ work using segments > 64K */
+ if (sizeof(int) == 2) { /* expect a 'code has no effect' warning on 32 bit
+ platforms... */
+ if (lastmodule->coderel + lastmodule->f.code_len > 65535 ||
+ lastmodule->datarel + lastmodule->f.data_len > 65535) {
+ fprintf(stderr,"ldrdf: segment length has exceeded 64K; use a 32 bit "
+ "version.\nldrdf: code size = %05lx, data size = %05lx\n",
+ lastmodule->coderel + lastmodule->f.code_len,
+ lastmodule->datarel + lastmodule->f.data_len);
+ exit(1);
+ }
+ }
+
+ text = malloc(textlength = lastmodule->coderel + lastmodule->f.code_len);
+ data = malloc(datalength = lastmodule->datarel + lastmodule->f.data_len);
+
+ if (!text || !data) {
+ fprintf(stderr,"ldrdf: out of memory\n");
+ exit(1);
+ }
+
+ mod = modules;
+ while (mod) { /* load the segments for each module */
+ if (verbose >= 2) printf(" loading %s\n",mod->name);
+ if (rdfloadseg(&mod->f,RDOFF_CODE,&text[mod->coderel]) ||
+ rdfloadseg(&mod->f,RDOFF_DATA,&data[mod->datarel])) {
+ rdfperror("ldrdf",mod->name);
+ exit(1);
+ }
+ rdfclose(&mod->f); /* close file; segments remain */
+ mod = mod->next;
+ }
+}
+
+/* link_segments() step through relocation records in each module's
+ * header, fixing up references.
+ */
+
+void link_segments(void)
+{
+ struct modulenode *mod;
+ Collection imports;
+ symtabEnt *s;
+ long rel,relto;
+ char *seg;
+ rdfheaderrec *r;
+ int bRelative;
+
+ if (verbose) printf("linking segments\n");
+
+ collection_init(&imports);
+
+ for (mod = modules; mod; mod = mod->next) {
+ if (verbose >= 2) printf("* processing %s\n",mod->name);
+ rdfheaderrewind(&mod->f);
+ while((r = rdfgetheaderrec(&mod->f))) {
+ if (verbose >= 3) printf("record type: %d\n",r->type);
+ switch(r->type) {
+ case 1: /* relocation record */
+ if (r->r.segment >= 64) { /* Relative relocation; */
+ bRelative = 1; /* need to find location relative */
+ r->r.segment -= 64; /* to start of this segment */
+ relto = r->r.segment == 0 ? mod->coderel : mod->datarel;
+ }
+ else
+ {
+ bRelative = 0; /* non-relative - need to relocate
+ * at load time */
+ relto = 0; /* placate optimiser warnings */
+ }
+
+ /* calculate absolute offset of reference, not rel to beginning of
+ segment */
+ r->r.offset += r->r.segment == 0 ? mod->coderel : mod->datarel;
+
+ /* calculate the relocation factor to apply to the operand -
+ the base address of one of this modules segments if referred
+ segment is 0 - 2, or the address of an imported symbol
+ otherwise. */
+
+ if (r->r.refseg == 0) rel = mod->coderel;
+ else if (r->r.refseg == 1) rel = mod->datarel;
+ else if (r->r.refseg == 2) rel = mod->bssrel;
+ else { /* cross module link - find reference */
+ s = *colln(&imports,r->r.refseg - 2);
+ if (!s) {
+ fprintf(stderr,"ldrdf: link to undefined segment %04x in"
+ " %s:%d\n", r->r.refseg,mod->name,r->r.segment);
+ errors = 1;
+ break;
+ }
+ rel = s->offset;
+
+ r->r.refseg = s->segment; /* change referred segment,
+ so that new header is
+ correct */
+ }
+
+ if (bRelative) /* Relative - subtract current segment start */
+ rel -= relto;
+ else
+ { /* Add new relocation header */
+ rdfaddheader(newheader,r);
+ }
+
+ /* Work out which segment we're making changes to ... */
+ if (r->r.segment == 0) seg = text;
+ else if (r->r.segment == 1) seg = data;
+ else {
+ fprintf(stderr,"ldrdf: relocation in unknown segment %d in "
+ "%s\n", r->r.segment,mod->name);
+ errors = 1;
+ break;
+ }
+
+ /* Add the relocation factor to the datum specified: */
+
+ if (verbose >= 3)
+ printf(" - relocating %d:%08lx by %08lx\n",r->r.segment,
+ r->r.offset,rel);
+
+ /**** The following code is non-portable. Rewrite it... ****/
+ switch(r->r.length) {
+ case 1:
+ seg[r->r.offset] += (char) rel;
+ break;
+ case 2:
+ *(int16 *)(seg + r->r.offset) += (int16) rel;
+ break;
+ case 4:
+ *(long *)(seg + r->r.offset) += rel;
+ break;
+ }
+ break;
+
+ case 2: /* import record */
+ s = symtabFind(symtab, r->i.label);
+ if (s == NULL) {
+ /* Need to add support for dynamic linkage */
+ fprintf(stderr,"ldrdf: undefined symbol %s in module %s\n",
+ r->i.label,mod->name);
+ errors = 1;
+ }
+ else
+ {
+ *colln(&imports,r->i.segment - 2) = s;
+ if (verbose >= 2)
+ printf("imported %s as %04x\n", r->i.label, r->i.segment);
+ }
+ break;
+
+ case 3: /* export; dump to output new version */
+ s = symtabFind(symtab, r->e.label);
+ if (! s) {
+ fprintf(stderr,"ldrdf: internal error - undefined symbol %s "
+ "exported in header of '%s'\n",r->e.label,mod->name);
+ continue;
+ }
+ r->e.offset = s->offset;
+ rdfaddheader(newheader,r);
+ break;
+
+ case 4: /* DLL record */
+ rdfaddheader(newheader,r); /* copy straight to output */
+ break;
+ }
+ }
+ if (rdf_errno != 0) {
+ rdfperror("ldrdf",mod->name);
+ exit(1);
+ }
+ collection_reset(&imports);
+ }
+}
+
+/* write_output() write linked program out to a file */
+
+void write_output(char *filename)
+{
+ FILE * fp;
+ rdfheaderrec r;
+
+ if (verbose) printf("writing output to '%s'\n",filename);
+
+ fp = fopen(filename,"wb");
+ if (! fp)
+ {
+ fprintf(stderr,"ldrdf: could not open '%s' for writing\n",filename);
+ exit(1);
+ }
+
+
+ /* add BSS length count to header... */
+ if (bsslength)
+ {
+ r.type = 5;
+ r.b.amount = bsslength;
+ rdfaddheader(newheader,&r);
+ }
+
+ /* Write header */
+ rdfwriteheader(fp,newheader);
+ rdfdoneheader(newheader);
+ newheader = NULL;
+
+ /* Write text */
+ if (fwrite(&textlength,1,4,fp) != 4
+ || fwrite(text,1,textlength,fp) !=textlength)
+ {
+ fprintf(stderr,"ldrdf: error writing %s\n",filename);
+ exit(1);
+ }
+
+ /* Write data */
+ if (fwrite(&datalength,1,4,fp) != 4 ||
+ fwrite(data,1,datalength,fp) != datalength)
+ {
+ fprintf (stderr,"ldrdf: error writing %s\n", filename);
+ exit(1);
+ }
+ fclose(fp);
+}
+
+
+/* main program: interpret command line, and pass parameters on to
+ * individual module loaders & the linker
+ *
+ * Command line format:
+ * ldrdf [-o outfile | -x] [-r xxxx] [-v] [--] infile [infile ...]
+ *
+ * Default action is to output a file named 'aout.rdx'. -x specifies
+ * that the linked object program should be executed, rather than
+ * written to a file. -r specifies that the object program should
+ * be prelocated at address 'xxxx'. This option cannot be used
+ * in conjunction with -x.
+ */
+
+const char *usagemsg = "usage:\n"
+" ldrdf [-o outfile | -x] [-a x] [-v] [-p x] [--] infile [infile ...]\n"
+" [-l<libname> ...]\n\n"
+" ldrdf -h displays this message\n"
+" ldrdf -r displays version information\n\n"
+" -o selects output filename (default is aout.rdx)\n"
+" -x causes ldrdx to link & execute rather than write to file\n"
+" -a x causes object program to be statically relocated to address 'x'\n"
+" -v turns on verbose mode\n"
+" -p x causes segments to be aligned (padded) to x byte boundaries\n"
+" (default is 16 bytes)\n"
+" -l<name> causes 'name' to be linked in as a library. Note no search is\n"
+" performed - the entire pathname MUST be specified.\n";
+
+void usage(void)
+{
+ fputs(usagemsg,stderr);
+}
+
+int main(int argc,char **argv)
+{
+ char *ofilename = "aout.rdx";
+ long relocateaddr = -1; /* -1 if no relocation is to occur */
+ int execute = 0; /* 1 to execute after linking, 0 otherwise */
+ int procsw = 1; /* set to 0 by '--' */
+ int tmp;
+
+ if (argc == 1) {
+ usage();
+ exit(1);
+ }
+
+ /* process command line switches, and add modules specified to linked list
+ of modules, keeping track of total memory required to load them */
+
+ while(argv++,--argc) {
+ if (procsw && !strcmp(*argv,"-h")) { /* Help command */
+ usage(); exit(1);
+ }
+ else if (procsw && !strcmp(*argv,"-r")) {
+ printf("ldrdf version %s (%s) (%s)\n",LDRDF_VERSION,_RDOFF_H,
+ sizeof(int) == 2 ? "16 bit" : "32 bit");
+ exit(1);
+ }
+ else if (procsw && !strcmp(*argv,"-o")) {
+ ofilename = *++argv;
+ --argc;
+ if (execute) {
+ fprintf(stderr,"ldrdf: -o and -x switches incompatible\n");
+ exit(1);
+ }
+ if (verbose > 1) printf("output filename set to '%s'\n",ofilename);
+ }
+ else if (procsw && !strcmp(*argv,"-x")) {
+ execute++;
+ if (verbose > 1) printf("will execute linked object\n");
+ }
+ else if (procsw && !strcmp(*argv,"-a")) {
+ relocateaddr = readnum(*++argv,&tmp);
+ --argc;
+ if (tmp) {
+ fprintf(stderr,"ldrdf: error in parameter to '-a' switch: '%s'\n",
+ *argv);
+ exit(1);
+ }
+ if (execute) {
+ fprintf(stderr,"ldrdf: -a and -x switches incompatible\n");
+ exit(1);
+ }
+ if (verbose) printf("will relocate to %08lx\n",relocateaddr);
+ }
+ else if (procsw && !strcmp(*argv,"-v")) {
+ verbose++;
+ if (verbose == 1) printf("verbose mode selected\n");
+ }
+ else if (procsw && !strcmp(*argv,"-p")) {
+ align = readnum(*++argv,&tmp);
+ --argc;
+ if (tmp) {
+ fprintf(stderr,"ldrdf: error in parameter to '-p' switch: '%s'\n",
+ *argv);
+ exit(1);
+ }
+ if (align != 1 && align != 2 && align != 4 && align != 8 && align != 16
+ && align != 32 && align != 256) {
+ fprintf(stderr,"ldrdf: %d is an invalid alignment factor - must be"
+ "1,2,4,8,16 or 256\n",align);
+ exit(1);
+ }
+ if (verbose > 1) printf("alignment %d selected\n",align);
+ }
+ else if (procsw && !strncmp(*argv,"-l",2)) {
+ load_library(*argv + 2);
+ }
+ else if (procsw && !strcmp(*argv,"--")) {
+ procsw = 0;
+ }
+ else { /* is a filename */
+ if (verbose > 1) printf("processing module %s\n",*argv);
+ loadmodule(*argv);
+ }
+ }
+
+ /* we should be scanning for unresolved references, and removing
+ unreferenced modules from the list of modules here, so that
+ we know about the final size once libraries have been linked in */
+
+ build_symbols(); /* build a global symbol table... */
+
+ scan_libraries(); /* check for imported symbols not in table,
+ and ensure the relevant library modules
+ are loaded */
+
+ load_segments(); /* having calculated size of reqd segments, load
+ each rdoff module's segments into memory */
+
+ link_segments(); /* step through each module's header, and resolve
+ references to the global symbol table.
+ This also does local address fixups. */
+
+ if (errors) {
+ fprintf(stderr,"ldrdf: there were errors - aborted\n");
+ exit(errors);
+ }
+ if (execute) {
+ fprintf(stderr,"ldrdf: module execution not yet supported\n");
+ exit(1);
+ }
+ if (relocateaddr != -1) {
+ fprintf(stderr,"ldrdf: static relocation not yet supported\n");
+ exit(1);
+ }
+
+ write_output(ofilename);
+ return 0;
+}