Initial revision

1 files changed, 464 insertions, 0 deletions

diff --git a/bfd/coff-stgo32.c b/bfd/coff-stgo32.c
new file mode 100644
index 0000000000..21724fec0d
--- /dev/null
+++ b/bfd/coff-stgo32.c
@@ -0,0 +1,464 @@
+/* BFD back-end for Intel 386 COFF files (go32 variant with a stub).
+   Copyright 1997, 1998 Free Software Foundation, Inc.
+   Written by Robert Hoehne.
+
+   This file is part of BFD, the Binary File Descriptor library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/* This file handles now also stubbed coff images. The stub is a small
+   DOS executable program before the coff image to load it in memory
+   and execute it. This is needed, because DOS cannot run coff files.
+
+   All the functions below are called by the corresponding functions
+   from coffswap.h.
+   The only thing what they do is to adjust the information stored in
+   the COFF file which are offset into the file.
+   This is needed, because DJGPP uses a very special way to load and run
+   the coff image. It loads the image in memory and assumes then, that the
+   image had no stub by using the filepointers as pointers in the coff
+   image and NOT in the file.
+
+   To be compatible with any existing executables I have fixed this
+   here and NOT in the DJGPP startup code.
+ */
+
+#define TARGET_SYM		go32stubbedcoff_vec
+#define TARGET_NAME		"coff-go32-exe"
+#define TARGET_UNDERSCORE	'_'
+#define COFF_GO32_EXE
+
+#include "bfd.h"
+
+/* At first the prototypes */
+
+static void
+adjust_filehdr_in_post PARAMS ((bfd * abfd, PTR src, PTR dst));
+static void
+adjust_filehdr_out_pre PARAMS ((bfd * abfd, PTR in, PTR out));
+static void
+adjust_filehdr_out_post PARAMS ((bfd * abfd, PTR in, PTR out));
+
+static void
+adjust_scnhdr_in_post PARAMS ((bfd * abfd, PTR ext, PTR in));
+static void
+adjust_scnhdr_out_pre PARAMS ((bfd * abfd, PTR in, PTR out));
+static void
+adjust_scnhdr_out_post PARAMS ((bfd * abfd, PTR in, PTR out));
+
+static void
+adjust_aux_in_post PARAMS ((bfd * abfd, PTR ext1, int type, int class, int indx,
+			    int numaux, PTR in1));
+static void
+adjust_aux_out_pre PARAMS ((bfd * abfd, PTR inp, int type, int class, int indx,
+			    int numaux, PTR extp));
+static void
+adjust_aux_out_post PARAMS ((bfd * abfd, PTR inp, int type, int class, int indx,
+			     int numaux, PTR extp));
+
+static void
+create_go32_stub PARAMS ((bfd * abfd));
+
+/*
+   All that ..._PRE and ...POST functions are called from the corresponding
+   coff_swap... functions. The ...PRE functions are called at the beginning
+   of the function and the ...POST functions at the end of the swap routines.
+ */
+
+#define COFF_ADJUST_FILEHDR_IN_POST adjust_filehdr_in_post
+#define COFF_ADJUST_FILEHDR_OUT_PRE adjust_filehdr_out_pre
+#define COFF_ADJUST_FILEHDR_OUT_POST adjust_filehdr_out_post
+
+#define COFF_ADJUST_SCNHDR_IN_POST adjust_scnhdr_in_post
+#define COFF_ADJUST_SCNHDR_OUT_PRE adjust_scnhdr_out_pre
+#define COFF_ADJUST_SCNHDR_OUT_POST adjust_scnhdr_out_post
+
+#define COFF_ADJUST_AUX_IN_POST adjust_aux_in_post
+#define COFF_ADJUST_AUX_OUT_PRE adjust_aux_out_pre
+#define COFF_ADJUST_AUX_OUT_POST adjust_aux_out_post
+
+static boolean
+  go32_stubbed_coff_bfd_copy_private_bfd_data PARAMS ((bfd * ibfd, bfd * obfd));
+
+#define coff_bfd_copy_private_bfd_data go32_stubbed_coff_bfd_copy_private_bfd_data
+
+#include "coff-i386.c"
+
+/* I hold in the usrdata the stub */
+#define bfd_coff_go32stub bfd_usrdata
+
+/* This macro is used, because I cannot assume the endianess of the
+   host system */
+#define _H(index) (bfd_h_get_16(abfd, (bfd_byte *)(header+index*2)))
+
+/* This function checks if the bfd is a stubbed coff image */
+static const bfd_target *
+go32_stubbed_coff_object_p (abfd)
+     bfd *abfd;
+{
+  unsigned char header[10];
+  char magic[8];
+  unsigned long coff_start, exe_start;
+
+  if (bfd_read (&header, 1, sizeof (header), abfd) != sizeof (header))
+    {
+      if (bfd_get_error () != bfd_error_system_call)
+	bfd_set_error (bfd_error_wrong_format);
+      return 0;
+    }
+  if (_H (0) != 0x5a4d)		/* it is not an exe file. maybe a coff-image */
+    {
+      if (bfd_get_error () != bfd_error_system_call)
+	bfd_set_error (bfd_error_wrong_format);
+      return 0;
+    }
+  coff_start = (long) _H (2) * 512L;
+  if (_H (1))
+    coff_start += (long) _H (1) - 512L;
+
+  /* We can handle only a stub with a length of STUBSIZE */
+  if (coff_start != STUBSIZE)
+    {
+      bfd_set_error (bfd_error_wrong_format);
+      return 0;
+    }
+  exe_start = _H (4) * 16;
+  if (bfd_seek (abfd, exe_start, SEEK_SET) != 0)
+    return 0;
+  if (bfd_read (&magic, 1, 8, abfd) != 8)
+    {
+      if (bfd_get_error () != bfd_error_system_call)
+	bfd_set_error (bfd_error_wrong_format);
+      return 0;
+    }
+  if (memcmp (magic, "go32stub", 8) != 0)
+    {
+      bfd_set_error (bfd_error_wrong_format);
+      return 0;
+    }
+  if (bfd_seek (abfd, 0, SEEK_SET) != 0)
+    return 0;
+
+  /* Call the normal COFF detection routine */
+  return coff_object_p (abfd);
+}
+
+/* These bytes are a 2048-byte DOS executable, which loads the COFF
+   image into memory and then runs it. It is called 'stub' */
+
+static unsigned char stub_bytes[STUBSIZE] =
+{
+#include "go32stub.h"
+};
+
+/*
+   I have not commented each swap function below, because the
+   technique is in any function the same. For the ...in function,
+   all the pointers are adjusted by adding STUBSIZE and for the
+   ...out function, it is subtracted first and after calling the
+   standard swap function it is reset to the old value */
+
+/* This macro is used for adjusting the filepointers, which
+   is done only, if the pointer is nonzero */
+
+#define ADJUST_VAL(val,diff) \
+  if (val != 0) val += diff
+
+static void
+adjust_filehdr_in_post  (abfd, src, dst)
+     bfd *abfd;
+     PTR src;
+     PTR dst;
+{
+  FILHDR *filehdr_src = (FILHDR *) src;
+  struct internal_filehdr *filehdr_dst = (struct internal_filehdr *) dst;
+
+  ADJUST_VAL (filehdr_dst->f_symptr, STUBSIZE);
+
+  /* Save now the stub to be used later */
+  bfd_coff_go32stub (abfd) = (PTR) bfd_alloc (abfd, STUBSIZE);
+
+  /* Since this function returns no status, I do not set here
+     any bfd_error_...
+     That means, before the use of bfd_coff_go32stub (), this value
+     should be checked if it is != NULL */
+  if (bfd_coff_go32stub (abfd) == NULL)
+    return;
+  memcpy (bfd_coff_go32stub (abfd), filehdr_src->stub, STUBSIZE);
+}
+
+static void
+adjust_filehdr_out_pre  (abfd, in, out)
+     bfd *abfd;
+     PTR in;
+     PTR out;
+{
+  struct internal_filehdr *filehdr_in = (struct internal_filehdr *) in;
+  FILHDR *filehdr_out = (FILHDR *) out;
+
+  /* Generate the stub */
+  create_go32_stub (abfd);
+
+  /* Copy the stub to the file header */
+  if (bfd_coff_go32stub (abfd) != NULL)
+    memcpy (filehdr_out->stub, bfd_coff_go32stub (abfd), STUBSIZE);
+  else
+    /* use the default */
+    memcpy (filehdr_out->stub, stub_bytes, STUBSIZE);
+
+  ADJUST_VAL (filehdr_in->f_symptr, -STUBSIZE);
+}
+
+static void
+adjust_filehdr_out_post  (abfd, in, out)
+     bfd *abfd;
+     PTR in;
+     PTR out;
+{
+  struct internal_filehdr *filehdr_in = (struct internal_filehdr *) in;
+  /* undo the above change */
+  ADJUST_VAL (filehdr_in->f_symptr, STUBSIZE);
+}
+
+static void
+adjust_scnhdr_in_post  (abfd, ext, in)
+     bfd *abfd;
+     PTR ext;
+     PTR in;
+{
+  struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
+
+  ADJUST_VAL (scnhdr_int->s_scnptr, STUBSIZE);
+  ADJUST_VAL (scnhdr_int->s_relptr, STUBSIZE);
+  ADJUST_VAL (scnhdr_int->s_lnnoptr, STUBSIZE);
+}
+
+static void
+adjust_scnhdr_out_pre  (abfd, in, out)
+     bfd *abfd;
+     PTR in;
+     PTR out;
+{
+  struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
+
+  ADJUST_VAL (scnhdr_int->s_scnptr, -STUBSIZE);
+  ADJUST_VAL (scnhdr_int->s_relptr, -STUBSIZE);
+  ADJUST_VAL (scnhdr_int->s_lnnoptr, -STUBSIZE);
+}
+
+static void
+adjust_scnhdr_out_post (abfd, in, out)
+     bfd *abfd;
+     PTR in;
+     PTR out;
+{
+  struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
+
+  ADJUST_VAL (scnhdr_int->s_scnptr, STUBSIZE);
+  ADJUST_VAL (scnhdr_int->s_relptr, STUBSIZE);
+  ADJUST_VAL (scnhdr_int->s_lnnoptr, STUBSIZE);
+}
+
+static void
+adjust_aux_in_post  (abfd, ext1, type, class, indx, numaux, in1)
+     bfd *abfd;
+     PTR ext1;
+     int type;
+     int class;
+     int indx;
+     int numaux;
+     PTR in1;
+{
+  union internal_auxent *in = (union internal_auxent *) in1;
+
+  if (class == C_BLOCK || class == C_FCN || ISFCN (type) || ISTAG (class))
+    {
+      ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, STUBSIZE);
+    }
+}
+
+static void
+adjust_aux_out_pre  (abfd, inp, type, class, indx, numaux, extp)
+     bfd *abfd;
+     PTR inp;
+     int type;
+     int class;
+     int indx;
+     int numaux;
+     PTR extp;
+{
+  union internal_auxent *in = (union internal_auxent *) inp;
+
+  if (class == C_BLOCK || class == C_FCN || ISFCN (type) || ISTAG (class))
+    {
+      ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, -STUBSIZE);
+    }
+}
+
+static void
+adjust_aux_out_post (abfd, inp, type, class, indx, numaux, extp)
+     bfd *abfd;
+     PTR inp;
+     int type;
+     int class;
+     int indx;
+     int numaux;
+     PTR extp;
+{
+  union internal_auxent *in = (union internal_auxent *) inp;
+
+  if (class == C_BLOCK || class == C_FCN || ISFCN (type) || ISTAG (class))
+    {
+      ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, STUBSIZE);
+    }
+}
+
+/*
+   That's the function, which creates the stub. There are
+   different cases from where the stub is taken.
+   At first the environment variable $(GO32STUB) is checked and then
+   $(STUB) if it was not set.
+   If it exists and points to a valid stub the stub is taken from
+   that file. This file can be also a whole executable file, because
+   the stub is computed from the exe information at the start of that
+   file.
+
+   If there was any error, the standard stub (compiled in this file)
+   is taken.
+ */
+
+static void
+create_go32_stub (abfd)
+     bfd *abfd;
+{
+  /* Do it only once */
+  if (bfd_coff_go32stub (abfd) == NULL)
+    {
+      char *stub;
+      struct stat st;
+      int f;
+      unsigned char header[10];
+      char magic[8];
+      unsigned long coff_start, exe_start;
+
+      /* Check at first the environment variable $(GO32STUB) */
+      stub = getenv ("GO32STUB");
+      /* Now check the environment variable $(STUB) */
+      if (stub == NULL)
+	stub = getenv ("STUB");
+      if (stub == NULL)
+	goto stub_end;
+      if (stat (stub, &st) != 0)
+	goto stub_end;
+#ifdef O_BINARY
+      f = open (stub, O_RDONLY | O_BINARY);
+#else
+      f = open (stub, O_RDONLY);
+#endif
+      if (f < 0)
+	goto stub_end;
+      if (read (f, &header, sizeof (header)) < 0)
+	{
+	  close (f);
+	  goto stub_end;
+	}
+      if (_H (0) != 0x5a4d)	/* it is not an exe file */
+	{
+	  close (f);
+	  goto stub_end;
+	}
+      /* Compute the size of the stub (it is every thing up
+         to the beginning of the coff image) */
+      coff_start = (long) _H (2) * 512L;
+      if (_H (1))
+	coff_start += (long) _H (1) - 512L;
+
+      /* Currently there is only a fixed stub size of 2048 bytes
+         supported */
+      if (coff_start != 2048)
+	{
+	  close (f);
+	  goto stub_end;
+	}
+      exe_start = _H (4) * 16;
+      if ((unsigned long) lseek (f, exe_start, SEEK_SET) != exe_start)
+	{
+	  close (f);
+	  goto stub_end;
+	}
+      if (read (f, &magic, 8) != 8)
+	{
+	  close (f);
+	  goto stub_end;
+	}
+      if (memcmp (magic, "go32stub", 8) != 0)
+	{
+	  close (f);
+	  goto stub_end;
+	}
+      /* Now we found a correct stub (hopefully) */
+      bfd_coff_go32stub (abfd) = (PTR) bfd_alloc (abfd, coff_start);
+      if (bfd_coff_go32stub (abfd) == NULL)
+	{
+	  close (f);
+	  return;
+	}
+      lseek (f, 0L, SEEK_SET);
+      if ((unsigned long) read (f, bfd_coff_go32stub (abfd), coff_start)
+	  != coff_start)
+	{
+	  bfd_release (abfd, bfd_coff_go32stub (abfd));
+	  bfd_coff_go32stub (abfd) = NULL;
+	}
+      close (f);
+    }
+stub_end:
+  /* There was something wrong above, so use now the standard builtin
+     stub */
+  if (bfd_coff_go32stub (abfd) == NULL)
+    {
+      bfd_coff_go32stub (abfd) = (PTR) bfd_alloc (abfd, STUBSIZE);
+      if (bfd_coff_go32stub (abfd) == NULL)
+	{
+	  return;
+	}
+
+      memcpy (bfd_coff_go32stub (abfd), stub_bytes, STUBSIZE);
+    }
+}
+
+/* If ibfd was a stubbed coff image, copy the stub from that bfd
+   to the new obfd.
+ */
+
+static boolean
+go32_stubbed_coff_bfd_copy_private_bfd_data  (ibfd, obfd)
+     bfd *ibfd;
+     bfd *obfd;
+{
+  /* check if both are the same targets */
+  if (ibfd->xvec != obfd->xvec)
+    return true;
+
+  /* check if both have a valid stub */
+  if (bfd_coff_go32stub (ibfd) == NULL
+      || bfd_coff_go32stub (obfd) == NULL)
+    return true;
+
+  /* Now copy the stub */
+  memcpy (bfd_coff_go32stub (obfd), bfd_coff_go32stub (ibfd), STUBSIZE);
+
+  return true;
+}