NASM 0.98enasm-0.98ebranch-0_98e

5 files changed, 742 insertions, 14 deletions

diff --git a/doc/nasmdoc.src b/doc/nasmdoc.src
index 66825ed8..53e4b70a 100644
--- a/doc/nasmdoc.src
+++ b/doc/nasmdoc.src
@@ -7920,8 +7920,8 @@ destination (first) operand.
 \c MOVSW                         ; o16 A5               [8086]
 \c MOVSD                         ; o32 A5               [386]
 
-\c{MOVSB} copies the byte at \c{[ES:DI]} or \c{[ES:EDI]} to
-\c{[DS:SI]} or \c{[DS:ESI]}. It then increments or decrements
+\c{MOVSB} copies the byte at \c{[DS:SI]} or \c{[DS:ESI]} to
+\c{[ES:DI]} or \c{[ES:EDI]}. It then increments or decrements
 (depending on the direction flag: increments if the flag is clear,
 decrements if it is set) \c{SI} and \c{DI} (or \c{ESI} and \c{EDI}).
 
diff --git a/nasm.h b/nasm.h
index 0d0fa5ba..89705c6f 100644
--- a/nasm.h
+++ b/nasm.h
@@ -13,7 +13,7 @@
 
 #define NASM_MAJOR_VER 0
 #define NASM_MINOR_VER 98
-#define NASM_VER "0.98.16"
+#define NASM_VER "0.98.17"
 
 #ifndef NULL
 #define NULL 0
diff --git a/ndisasm.c b/ndisasm.c
index 227dde7f..71d07df3 100644
--- a/ndisasm.c
+++ b/ndisasm.c
@@ -235,7 +235,7 @@ int main(int argc, char **argv)
 	p += lenread;
 	if ((unsigned long)offset == nextsync) {
 	    if (synclen) {
-		printf("%08lX  skipping 0x%lX bytes\n", offset, synclen);
+		fprintf(stdout, "%08lX  skipping 0x%lX bytes\n", offset, synclen);
 		offset += synclen;
 		skip (synclen, fp);
 	    }
@@ -271,26 +271,26 @@ static void output_ins (unsigned long offset, unsigned char *data,
 			int datalen, char *insn) 
 {
     int bytes;
-    printf("%08lX  ", offset);
+    fprintf(stdout, "%08lX  ", offset);
 
     bytes = 0;
     while (datalen > 0 && bytes < BPL) {
-	printf("%02X", *data++);
+	fprintf(stdout, "%02X", *data++);
 	bytes++;
 	datalen--;
     }
 
-    printf("%*s%s\n", (BPL+1-bytes)*2, "", insn);
+    fprintf(stdout, "%*s%s\n", (BPL+1-bytes)*2, "", insn);
 
     while (datalen > 0) {
-	printf("         -");
+	fprintf(stdout, "         -");
 	bytes = 0;
 	while (datalen > 0 && bytes < BPL) {
-	    printf("%02X", *data++);
+	    fprintf(stdout, "%02X", *data++);
 	    bytes++;
 	    datalen--;
 	}
-	printf("\n");
+	fprintf(stdout, "\n");
     }
 }
 
diff --git a/outelf.c b/outelf.c
index 38f4a563..50cd36ba 100644
--- a/outelf.c
+++ b/outelf.c
@@ -554,7 +554,7 @@ static void elf_add_reloc (struct Section *sect, long segment,
 	r->symbol = 0;
 	for (i=0; i<nsects; i++)
 	    if (segment == sects[i]->index)
-		r->symbol = i+3;
+		r->symbol = i+2;
 	if (!r->symbol)
 	    r->symbol = GLOBAL_TEMP_BASE + raa_read(bsym, segment);
     }
@@ -928,13 +928,13 @@ static struct SAA *elf_build_symtab (long *len, long *local)
      * Now some standard symbols defining the segments, for relocation
      * purposes.
      */
-    for (i = 1; i <= nsects+1; i++) {
+    for (i = 1; i <= nsects; i++) {
 	p = entry;
 	WRITELONG (p, 0);	       /* no symbol name */
 	WRITELONG (p, 0);	       /* offset zero */
 	WRITELONG (p, 0);	       /* size zero */
 	WRITESHORT (p, 3);	       /* local section-type thing */
-	WRITESHORT (p, (i==1 ? SHN_ABS : i-1));   /* the section id */
+	WRITESHORT (p, i);             /* the section id */
 	saa_wbytes (s, entry, 16L);
 	*len += 16;
 	(*local)++;
@@ -992,7 +992,7 @@ static struct SAA *elf_build_reltab (long *len, struct Reloc *r) {
 	long sym = r->symbol;
 
 	if (sym >= GLOBAL_TEMP_BASE)
-	    sym += -GLOBAL_TEMP_BASE + (nsects+3) + nlocals;
+	    sym += -GLOBAL_TEMP_BASE + (nsects+2) + nlocals;
 
 	p = entry;
 	WRITELONG (p, r->address);
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;
+}