NASM 0.91

1 files changed, 540 insertions, 0 deletions

diff --git a/rdoff/ldrdf.c b/rdoff/ldrdf.c
new file mode 100644
index 0000000..ce86b7e
--- /dev/null
+++ b/rdoff/ldrdf.c
@@ -0,0 +1,540 @@
+/* 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 libaries (.a files - requires a 'ranlib' type utility)
+ *
+ * -s option to strip resolved symbols from exports.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "nasm.h"
+#include "rdoff.h"
+#include "nasmlib.h"
+#include "symtab.h"
+#include "collectn.h"
+
+#define LDRDF_VERSION "0.11"
+
+/* 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;
+};
+
+struct modulenode *modules = NULL,*lastmodule = 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);
+
+}
+
+/* load_segments()	allocates memory for & loads the code & data segs
+ *			from the RDF modules
+ */
+
+char *text,*data;
+long textlength,datalength,bsslength;
+
+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 */
+    mod->header = malloc(mod->f.header_len);
+    if (!mod->header) {
+      fprintf(stderr,"ldrdf: out of memory\n");
+      exit(1);
+    }
+    if (rdfloadseg(&mod->f,RDOFF_HEADER,mod->header) ||
+	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;
+  }
+}
+
+/* build_symbols()	step through each module's header, and locate
+ *			exported symbols, placing them in a global table
+ */
+
+void build_symbols()
+{
+  struct modulenode *mod;
+  rdfheaderrec *r;
+  symtabEnt e;
+  long bssloc,cbBss;
+
+  if (verbose) printf("building global symbol table:\n");
+  newheader = rdfnewheader();
+
+  symtab = symtabNew();
+  bssloc = 0;			/* keep track of location of BSS symbols */
+
+  for (mod = modules; mod; mod = mod->next)
+  {
+      mod->bssrel = bssloc;
+      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);
+      }
+      bssloc += cbBss;
+  }
+  if (verbose)
+  {
+      symtabDump(symtab,stdout);
+      printf("BSS length = %ld bytes\n\n",bssloc);
+  }
+  bsslength = bssloc;
+}
+
+/* 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 = 0; /* placate gcc */
+  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))) {
+	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			*/
+
+	    /* 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) continue;	/* eh? probably doesn't matter... */
+
+	    r->e.offset = s->offset;
+	    rdfaddheader(newheader,r);
+	    break;
+
+	case 4:		/* DLL record */
+	    rdfaddheader(newheader,r);		/* copy straight to output */
+	    break;
+	}
+    }
+    collection_reset(&imports);
+  }
+}
+
+/* write_output()	write linked program out to a file */
+
+void write_output(char *filename)
+{
+    FILE		* fp;
+    rdfheaderrec	r;
+
+    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\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";
+
+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 && !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 */
+
+  load_segments();	/* having calculated size of reqd segments, load
+			   each rdoff module's segments into memory */
+
+  build_symbols();	/* build a global symbol table...
+			   perhaps this should be done before load_segs? */
+
+  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;
+}