/* BFD back-end for Intel 386 COFF files (DJGPP variant with a stub).
- Copyright (C) 1997-2014 Free Software Foundation, Inc.
+ Copyright (C) 1997-2023 Free Software Foundation, Inc.
Written by Robert Hoehne.
This file is part of BFD, the Binary File Descriptor library.
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. */
+ The COFF image is loaded in memory without the stub attached, so
+ all offsets are relative to the beginning of the image, not the
+ actual file. We handle this in bfd by setting bfd->origin to where
+ the COFF image starts. */
#define TARGET_SYM i386_coff_go32stubbed_vec
#define TARGET_NAME "coff-go32-exe"
{ COFF_SECTION_NAME_PARTIAL_MATCH (".gnu.linkonce.wi"), \
COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 0 }
+/* Section contains extended relocations. */
+#define IMAGE_SCN_LNK_NRELOC_OVFL (0x01000000)
+
#include "sysdep.h"
#include "bfd.h"
+#include "coff/msdos.h"
-/* 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. */
-
-static void
-adjust_filehdr_in_post (bfd *, void *, void *);
-static void
-adjust_filehdr_out_pre (bfd *, void *, void *);
-static void
-adjust_filehdr_out_post (bfd *, void *, void *);
-static void
-adjust_scnhdr_in_post (bfd *, void *, void *);
-static void
-adjust_scnhdr_out_pre (bfd *, void *, void *);
-static void
-adjust_scnhdr_out_post (bfd *, void *, void *);
-static void
-adjust_aux_in_post (bfd *, void *, int, int, int, int, void *);
-static void
-adjust_aux_out_pre (bfd *, void *, int, int, int, int, void *);
-static void
-adjust_aux_out_post (bfd *, void *, int, int, int, int, void *);
-static void
-create_go32_stub (bfd *);
-
-#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
+static bfd_cleanup go32exe_check_format (bfd *);
+static bool go32exe_write_object_contents (bfd *);
+static bool go32exe_mkobject (bfd *);
+static bool go32exe_copy_private_bfd_data (bfd *, bfd *);
-#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
+/* Defined in coff-go32.c. */
+bool _bfd_go32_mkobject (bfd *);
+void _bfd_go32_swap_scnhdr_in (bfd *, void *, void *);
+unsigned int _bfd_go32_swap_scnhdr_out (bfd *, void *, void *);
-#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 const bfd_target *go32_check_format (bfd *);
-
-#define COFF_CHECK_FORMAT go32_check_format
-
-static bfd_boolean
- go32_stubbed_coff_bfd_copy_private_bfd_data (bfd *, bfd *);
-
-#define coff_bfd_copy_private_bfd_data go32_stubbed_coff_bfd_copy_private_bfd_data
+#define COFF_CHECK_FORMAT go32exe_check_format
+#define COFF_WRITE_CONTENTS go32exe_write_object_contents
+#define coff_mkobject go32exe_mkobject
+#define coff_bfd_copy_private_bfd_data go32exe_copy_private_bfd_data
+#define coff_SWAP_scnhdr_in _bfd_go32_swap_scnhdr_in
+#define coff_SWAP_scnhdr_out _bfd_go32_swap_scnhdr_out
#include "coff-i386.c"
/* These bytes are a 2048-byte DOS executable, which loads the COFF
image into memory and then runs it. It is called 'stub'. */
-
-static const unsigned char stub_bytes[GO32_STUBSIZE] =
+#define GO32EXE_DEFAULT_STUB_SIZE 2048
+static const unsigned char go32exe_default_stub[GO32EXE_DEFAULT_STUB_SIZE] =
{
#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 GO32_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 (bfd * abfd ATTRIBUTE_UNUSED,
- void * src,
- void * dst)
-{
- FILHDR *filehdr_src = (FILHDR *) src;
- struct internal_filehdr *filehdr_dst = (struct internal_filehdr *) dst;
-
- ADJUST_VAL (filehdr_dst->f_symptr, GO32_STUBSIZE);
-
- /* Save now the stub to be used later. Put the stub data to FILEHDR_DST
- first as coff_data (abfd) still does not exist. It may not even be ever
- created as we are just checking the file format of ABFD. */
- memcpy (filehdr_dst->go32stub, filehdr_src->stub, GO32_STUBSIZE);
- filehdr_dst->f_flags |= F_GO32STUB;
-}
-
-static void
-adjust_filehdr_out_pre (bfd * abfd, void * in, void * 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 (coff_data (abfd)->go32stub != NULL)
- memcpy (filehdr_out->stub, coff_data (abfd)->go32stub, GO32_STUBSIZE);
- else
- /* Use the default. */
- memcpy (filehdr_out->stub, stub_bytes, GO32_STUBSIZE);
-
- ADJUST_VAL (filehdr_in->f_symptr, -GO32_STUBSIZE);
-}
-
-static void
-adjust_filehdr_out_post (bfd * abfd ATTRIBUTE_UNUSED,
- void * in,
- void * out ATTRIBUTE_UNUSED)
-{
- struct internal_filehdr *filehdr_in = (struct internal_filehdr *) in;
- /* Undo the above change. */
- ADJUST_VAL (filehdr_in->f_symptr, GO32_STUBSIZE);
-}
-
-static void
-adjust_scnhdr_in_post (bfd * abfd ATTRIBUTE_UNUSED,
- void * ext ATTRIBUTE_UNUSED,
- void * in)
-{
- struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
-
- ADJUST_VAL (scnhdr_int->s_scnptr, GO32_STUBSIZE);
- ADJUST_VAL (scnhdr_int->s_relptr, GO32_STUBSIZE);
- ADJUST_VAL (scnhdr_int->s_lnnoptr, GO32_STUBSIZE);
-}
-
-static void
-adjust_scnhdr_out_pre (bfd * abfd ATTRIBUTE_UNUSED,
- void * in,
- void * out ATTRIBUTE_UNUSED)
-{
- struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
-
- ADJUST_VAL (scnhdr_int->s_scnptr, -GO32_STUBSIZE);
- ADJUST_VAL (scnhdr_int->s_relptr, -GO32_STUBSIZE);
- ADJUST_VAL (scnhdr_int->s_lnnoptr, -GO32_STUBSIZE);
-}
-
-static void
-adjust_scnhdr_out_post (bfd * abfd ATTRIBUTE_UNUSED,
- void * in,
- void * out ATTRIBUTE_UNUSED)
-{
- struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
-
- ADJUST_VAL (scnhdr_int->s_scnptr, GO32_STUBSIZE);
- ADJUST_VAL (scnhdr_int->s_relptr, GO32_STUBSIZE);
- ADJUST_VAL (scnhdr_int->s_lnnoptr, GO32_STUBSIZE);
-}
-
-static void
-adjust_aux_in_post (bfd * abfd ATTRIBUTE_UNUSED,
- void * ext1 ATTRIBUTE_UNUSED,
- int type,
- int in_class,
- int indx ATTRIBUTE_UNUSED,
- int numaux ATTRIBUTE_UNUSED,
- void * in1)
-{
- union internal_auxent *in = (union internal_auxent *) in1;
-
- if (in_class == C_BLOCK || in_class == C_FCN || ISFCN (type)
- || ISTAG (in_class))
- {
- ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, GO32_STUBSIZE);
- }
-}
-
-static void
-adjust_aux_out_pre (bfd *abfd ATTRIBUTE_UNUSED,
- void * inp,
- int type,
- int in_class,
- int indx ATTRIBUTE_UNUSED,
- int numaux ATTRIBUTE_UNUSED,
- void * extp ATTRIBUTE_UNUSED)
-{
- union internal_auxent *in = (union internal_auxent *) inp;
-
- if (in_class == C_BLOCK || in_class == C_FCN || ISFCN (type)
- || ISTAG (in_class))
- {
- ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, -GO32_STUBSIZE);
- }
-}
-
-static void
-adjust_aux_out_post (bfd *abfd ATTRIBUTE_UNUSED,
- void * inp,
- int type,
- int in_class,
- int indx ATTRIBUTE_UNUSED,
- int numaux ATTRIBUTE_UNUSED,
- void * extp ATTRIBUTE_UNUSED)
-{
- union internal_auxent *in = (union internal_auxent *) inp;
-
- if (in_class == C_BLOCK || in_class == C_FCN || ISFCN (type)
- || ISTAG (in_class))
- {
- ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, GO32_STUBSIZE);
- }
-}
+/* Temporary location for stub read from input file. */
+static char * go32exe_temp_stub = NULL;
+static bfd_size_type go32exe_temp_stub_size = 0;
/* That's the function, which creates the stub. There are
different cases from where the stub is taken.
file.
If there was any error, the standard stub (compiled in this file)
- is taken. */
+ is taken.
+
+ Ideally this function should exec '$(TARGET)-stubify' to generate
+ a stub, like gcc does. */
static void
-create_go32_stub (bfd *abfd)
+go32exe_create_stub (bfd *abfd)
{
/* Do it only once. */
- if (coff_data (abfd)->go32stub == NULL)
+ if (coff_data (abfd)->stub == NULL)
{
char *stub;
struct stat st;
unsigned long coff_start;
long exe_start;
+ /* If we read a stub from an input file, use that one. */
+ if (go32exe_temp_stub != NULL)
+ {
+ coff_data (abfd)->stub = bfd_alloc (abfd,
+ go32exe_temp_stub_size);
+ if (coff_data (abfd)->stub == NULL)
+ return;
+ memcpy (coff_data (abfd)->stub, go32exe_temp_stub,
+ go32exe_temp_stub_size);
+ coff_data (abfd)->stub_size = go32exe_temp_stub_size;
+ free (go32exe_temp_stub);
+ go32exe_temp_stub = NULL;
+ go32exe_temp_stub_size = 0;
+ return;
+ }
+
/* Check at first the environment variable $(GO32STUB). */
stub = getenv ("GO32STUB");
/* Now check the environment variable $(STUB). */
goto stub_end;
}
/* Compute the size of the stub (it is every thing up
- to the beginning of the coff image). */
+ 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 ((long) lseek (f, exe_start, SEEK_SET) != exe_start)
{
close (f);
goto stub_end;
}
- if (! CONST_STRNEQ (magic, "go32stub"))
+ if (! startswith (magic, "go32stub"))
{
close (f);
goto stub_end;
}
/* Now we found a correct stub (hopefully). */
- coff_data (abfd)->go32stub = bfd_alloc (abfd, (bfd_size_type) coff_start);
- if (coff_data (abfd)->go32stub == NULL)
+ coff_data (abfd)->stub = bfd_alloc (abfd, (bfd_size_type) coff_start);
+ if (coff_data (abfd)->stub == NULL)
{
close (f);
return;
}
lseek (f, 0L, SEEK_SET);
- if ((unsigned long) read (f, coff_data (abfd)->go32stub, coff_start)
+ if ((unsigned long) read (f, coff_data (abfd)->stub, coff_start)
!= coff_start)
{
- bfd_release (abfd, coff_data (abfd)->go32stub);
- coff_data (abfd)->go32stub = NULL;
+ bfd_release (abfd, coff_data (abfd)->stub);
+ coff_data (abfd)->stub = NULL;
}
+ else
+ coff_data (abfd)->stub_size = coff_start;
close (f);
}
-stub_end:
+ stub_end:
/* There was something wrong above, so use now the standard builtin
stub. */
- if (coff_data (abfd)->go32stub == NULL)
+ if (coff_data (abfd)->stub == NULL)
{
- coff_data (abfd)->go32stub
- = bfd_alloc (abfd, (bfd_size_type) GO32_STUBSIZE);
- if (coff_data (abfd)->go32stub == NULL)
+ coff_data (abfd)->stub
+ = bfd_alloc (abfd, (bfd_size_type) GO32EXE_DEFAULT_STUB_SIZE);
+ if (coff_data (abfd)->stub == NULL)
return;
- memcpy (coff_data (abfd)->go32stub, stub_bytes, GO32_STUBSIZE);
+ memcpy (coff_data (abfd)->stub, go32exe_default_stub,
+ GO32EXE_DEFAULT_STUB_SIZE);
+ coff_data (abfd)->stub_size = GO32EXE_DEFAULT_STUB_SIZE;
}
}
/* If ibfd was a stubbed coff image, copy the stub from that bfd
to the new obfd. */
-static bfd_boolean
-go32_stubbed_coff_bfd_copy_private_bfd_data (bfd *ibfd, bfd *obfd)
+static bool
+go32exe_copy_private_bfd_data (bfd *ibfd, bfd *obfd)
{
/* Check if both are the same targets. */
if (ibfd->xvec != obfd->xvec)
- return TRUE;
+ return true;
- /* Check if we have a source stub. */
- if (coff_data (ibfd)->go32stub == NULL)
- return TRUE;
+ /* Make sure we have a source stub. */
+ BFD_ASSERT (coff_data (ibfd)->stub != NULL);
- /* As adjust_filehdr_out_pre may get called only after this function,
- optionally allocate the output stub. */
- if (coff_data (obfd)->go32stub == NULL)
- coff_data (obfd)->go32stub = bfd_alloc (obfd,
- (bfd_size_type) GO32_STUBSIZE);
+ /* Reallocate the output stub if necessary. */
+ if (coff_data (ibfd)->stub_size > coff_data (obfd)->stub_size)
+ coff_data (obfd)->stub = bfd_alloc (obfd, coff_data (ibfd)->stub_size);
+ if (coff_data (obfd)->stub == NULL)
+ return false;
/* Now copy the stub. */
- if (coff_data (obfd)->go32stub != NULL)
- memcpy (coff_data (obfd)->go32stub, coff_data (ibfd)->go32stub,
- GO32_STUBSIZE);
+ memcpy (coff_data (obfd)->stub, coff_data (ibfd)->stub,
+ coff_data (ibfd)->stub_size);
+ coff_data (obfd)->stub_size = coff_data (ibfd)->stub_size;
+ obfd->origin = coff_data (obfd)->stub_size;
- return TRUE;
+ return true;
}
-/* coff_object_p only checks 2 bytes F_MAGIC at GO32_STUBSIZE inside the file
- which is too fragile. */
+/* Cleanup function, returned from check_format hook. */
-static const bfd_target *
-go32_check_format (bfd *abfd)
+static void
+go32exe_cleanup (bfd *abfd)
{
- char mz[2];
+ abfd->origin = 0;
+
+ free (go32exe_temp_stub);
+ go32exe_temp_stub = NULL;
+ go32exe_temp_stub_size = 0;
+}
+
+/* Check that there is a GO32 stub and read it to go32exe_temp_stub.
+ Then set abfd->origin so that the COFF image is read at the correct
+ file offset. */
- if (bfd_bread (mz, 2, abfd) != 2 || mz[0] != 'M' || mz[1] != 'Z')
+static bfd_cleanup
+go32exe_check_format (bfd *abfd)
+{
+ struct external_DOS_hdr filehdr_dos;
+ uint16_t num_pages;
+ uint16_t last_page_size;
+ uint32_t header_end;
+ bfd_size_type stubsize;
+
+ /* This format can not appear in an archive. */
+ if (abfd->origin != 0)
{
bfd_set_error (bfd_error_wrong_format);
return NULL;
}
+ bfd_set_error (bfd_error_system_call);
+
+ /* Read in the stub file header, which is a DOS MZ executable. */
+ if (bfd_bread (&filehdr_dos, DOS_HDR_SIZE, abfd) != DOS_HDR_SIZE)
+ goto fail;
+
+ /* Make sure that this is an MZ executable. */
+ if (H_GET_16 (abfd, filehdr_dos.e_magic) != IMAGE_DOS_SIGNATURE)
+ goto fail_format;
+
+ /* Determine the size of the stub */
+ num_pages = H_GET_16 (abfd, filehdr_dos.e_cp);
+ last_page_size = H_GET_16 (abfd, filehdr_dos.e_cblp);
+ stubsize = num_pages * 512;
+ if (last_page_size != 0)
+ stubsize += last_page_size - 512;
+
+ ufile_ptr filesize = bfd_get_file_size (abfd);
+ if (filesize != 0 && stubsize > filesize)
+ goto fail_format;
+
+ /* Save now the stub to be used later. Put the stub data to a temporary
+ location first as tdata still does not exist. It may not even
+ be ever created if we are just checking the file format of ABFD. */
+ bfd_seek (abfd, 0, SEEK_SET);
+ go32exe_temp_stub = bfd_malloc (stubsize);
+ if (go32exe_temp_stub == NULL)
+ goto fail;
+ if (bfd_bread (go32exe_temp_stub, stubsize, abfd) != stubsize)
+ goto fail;
+ go32exe_temp_stub_size = stubsize;
+
+ /* Confirm that this is a go32stub. */
+ header_end = H_GET_16 (abfd, filehdr_dos.e_cparhdr) * 16UL;
+ if (go32exe_temp_stub_size < header_end
+ || go32exe_temp_stub_size - header_end < sizeof "go32stub" - 1
+ || !startswith (go32exe_temp_stub + header_end, "go32stub"))
+ goto fail_format;
+
+ /* Set origin to where the COFF header starts and seek there. */
+ abfd->origin = stubsize;
+ if (bfd_seek (abfd, 0, SEEK_SET) != 0)
+ goto fail;
+
+ /* Call coff_object_p to read the COFF image. If this fails then the file
+ must be just a stub with no COFF data attached. */
+ bfd_cleanup cleanup = coff_object_p (abfd);
+ if (cleanup == NULL)
+ goto fail;
+ BFD_ASSERT (cleanup == _bfd_no_cleanup);
+
+ return go32exe_cleanup;
+
+ fail_format:
+ bfd_set_error (bfd_error_wrong_format);
+ fail:
+ go32exe_cleanup (abfd);
+ return NULL;
+}
+
+/* Write the stub to the output file, then call coff_write_object_contents. */
+
+static bool
+go32exe_write_object_contents (bfd *abfd)
+{
+ const bfd_size_type pos = bfd_tell (abfd);
+ const bfd_size_type stubsize = coff_data (abfd)->stub_size;
+
+ BFD_ASSERT (stubsize != 0);
+
+ bfd_set_error (bfd_error_system_call);
+
+ /* Write the stub. */
+ abfd->origin = 0;
if (bfd_seek (abfd, 0, SEEK_SET) != 0)
- return NULL;
+ return false;
+ if (bfd_bwrite (coff_data (abfd)->stub, stubsize, abfd) != stubsize)
+ return false;
+
+ /* Seek back to where we were. */
+ abfd->origin = stubsize;
+ if (bfd_seek (abfd, pos, SEEK_SET) != 0)
+ return false;
+
+ return coff_write_object_contents (abfd);
+}
+
+/* mkobject hook. Called directly through bfd_set_format or via
+ coff_mkobject_hook etc from bfd_check_format. */
+
+static bool
+go32exe_mkobject (bfd *abfd)
+{
+ /* Don't output to an archive. */
+ if (abfd->my_archive != NULL)
+ return false;
+
+ if (!_bfd_go32_mkobject (abfd))
+ return false;
+
+ go32exe_create_stub (abfd);
+ if (coff_data (abfd)->stub == NULL)
+ {
+ bfd_release (abfd, coff_data (abfd));
+ return false;
+ }
+ abfd->origin = coff_data (abfd)->stub_size;
- return coff_object_p (abfd);
+ return true;
}