[PATCH] add --reverse option to objcopy
Nathan Froyd
froydnj@codesourcery.com
Fri Apr 20 17:19:00 GMT 2007
On Fri, Apr 20, 2007 at 02:32:56PM +0100, Nick Clifton wrote:
> * H.J. pointed out that the name of the switch is slightly confusing.
> --reverse-endian or --reverse-bytes might be a more reasonable
> name.
I have changed the option to --reverse-bytes in the code and the
documentation.
> * I think that this paragraph in the documentation is rather
> confusing:
>
> +By using @samp{--reverse=2} followed by @samp{--reverse=4}, then bytes
> +ordered @code{34127856} would be generated.
>
> To me this implied that you can use the --reverse switch twice on
> the same command line in order to achieve the effect you describe. If I
> have read the code correctly however, only the last instance of the
> switch on the command line will be honored, and so you need to run the
> objcopy command *twice* in order to achieve the desired effect.
Yes, that's not particularly clear. I have altered the paragraph to
make it more obvious that you need to run the command twice.
> * The code should check to see if --reverse if issued more than once
> on the command line and (if they have different values) warn the user
> that the earlier value(s) are being ignored.
Done.
OK?
-Nathan
-------------- next part --------------
binutils/
2007-04-20 Nathan Froyd <froydnj@codesourcery.com>
Phil Edwards <phil@codesourcery.com>
Thomas de Lellis <tdel@windriver.com>
* objcopy.c (reverse_bytes): New variable.
(command_line_switch, copy_main): Add OPTION_REVERSE_ENDIAN.
(copy_options, copy_usage): Add "reverse-bytes" entry.
(copy_section): Reverse bytes within output sections.
* doc/binutils.texi: Document new objcopy option.
binutils/testsuite/
2007-04-20 Nathan Froyd <froydnj@codesourcery.com>
Phil Edwards <phil@codesourcery.com>
Thomas de Lellis <tdel@windriver.com>
* binutils-all/objcopy.exp: Add test for --reverse-bytes.
Index: binutils/objcopy.c
===================================================================
RCS file: /cvs/src/src/binutils/objcopy.c,v
retrieving revision 1.107
diff -u -r1.107 objcopy.c
--- binutils/objcopy.c 12 Apr 2007 19:20:46 -0000 1.107
+++ binutils/objcopy.c 20 Apr 2007 16:58:18 -0000
@@ -218,6 +218,11 @@
/* True if --extract-symbol was passed on the command line. */
static bfd_boolean extract_symbol = FALSE;
+/* If `reverse_bytes' is nonzero, then reverse the order of every chunk
+ of <reverse_bytes> bytes within each output section. */
+static int reverse_bytes = 0;
+
+
/* 150 isn't special; it's just an arbitrary non-ASCII char value. */
enum command_line_switch
{
@@ -265,7 +270,8 @@
OPTION_WRITABLE_TEXT,
OPTION_PURE,
OPTION_IMPURE,
- OPTION_EXTRACT_SYMBOL
+ OPTION_EXTRACT_SYMBOL,
+ OPTION_REVERSE_BYTES
};
/* Options to handle if running as "strip". */
@@ -358,6 +364,7 @@
{"remove-leading-char", no_argument, 0, OPTION_REMOVE_LEADING_CHAR},
{"remove-section", required_argument, 0, 'R'},
{"rename-section", required_argument, 0, OPTION_RENAME_SECTION},
+ {"reverse-bytes", required_argument, 0, OPTION_REVERSE_BYTES},
{"set-section-flags", required_argument, 0, OPTION_SET_SECTION_FLAGS},
{"set-start", required_argument, 0, OPTION_SET_START},
{"srec-len", required_argument, 0, OPTION_SREC_LEN},
@@ -471,6 +478,7 @@
--rename-section <old>=<new>[,<flags>] Rename section <old> to <new>\n\
--change-leading-char Force output format's leading character style\n\
--remove-leading-char Remove leading character from global symbols\n\
+ --reverse-bytes=<num> Reverse <num> bytes at a time, in output sections with content\n\
--redefine-sym <old>=<new> Redefine symbol name <old> to <new>\n\
--redefine-syms <file> --redefine-sym for all symbol pairs \n\
listed in <file>\n\
@@ -2383,6 +2391,32 @@
if (!bfd_get_section_contents (ibfd, isection, memhunk, 0, size))
RETURN_NONFATAL (bfd_get_filename (ibfd));
+ if (reverse_bytes)
+ {
+ /* We don't handle leftover bytes (too many possible behaviors,
+ and we don't know what the user wants). The section length
+ must be a multiple of the number of bytes to swap. */
+ if ((size % reverse_bytes) == 0)
+ {
+ unsigned long i, j;
+ bfd_byte b;
+
+ for (i = 0; i < size; i += reverse_bytes)
+ for (j = 0; j < (unsigned long)(reverse_bytes / 2); j++)
+ {
+ bfd_byte *m = (bfd_byte*)memhunk;
+
+ b = m[i + j];
+ m[i + j] = m[(i + reverse_bytes) - (j + 1)];
+ m[(i + reverse_bytes) - (j + 1)] = b;
+ }
+ }
+ else
+ /* User must pad the section up in order to do this. */
+ fatal (_("cannot reverse bytes: length of section %s must be evenly divisible by %d"),
+ bfd_section_name (ibfd, isection), reverse_bytes);
+ }
+
if (copy_byte >= 0)
{
/* Keep only every `copy_byte'th byte in MEMHUNK. */
@@ -3256,6 +3290,20 @@
extract_symbol = TRUE;
break;
+ case OPTION_REVERSE_BYTES:
+ {
+ int prev = reverse_bytes;
+
+ reverse_bytes = atoi (optarg);
+ if ((reverse_bytes <= 0) || ((reverse_bytes % 2) != 0))
+ fatal (_("number of bytes to reverse must be positive and even"));
+ break;
+
+ if (prev && prev != reverse_bytes)
+ non_fatal (_("Warning: ignoring previous --reverse-bytes value of %d"),
+ prev);
+ }
+
case 0:
/* We've been given a long option. */
break;
Index: binutils/doc/binutils.texi
===================================================================
RCS file: /cvs/src/src/binutils/doc/binutils.texi,v
retrieving revision 1.104
diff -u -r1.104 binutils.texi
--- binutils/doc/binutils.texi 28 Mar 2007 09:08:53 -0000 1.104
+++ binutils/doc/binutils.texi 20 Apr 2007 16:58:18 -0000
@@ -987,6 +987,7 @@
[@option{--add-section} @var{sectionname}=@var{filename}]
[@option{--rename-section} @var{oldname}=@var{newname}[,@var{flags}]]
[@option{--change-leading-char}] [@option{--remove-leading-char}]
+ [@option{--reverse-bytes=}@var{num}]
[@option{--srec-len=}@var{ival}] [@option{--srec-forceS3}]
[@option{--redefine-sym} @var{old}=@var{new}]
[@option{--redefine-syms=}@var{filename}]
@@ -1052,6 +1053,7 @@
files. If the input format has an endianness (some formats do not),
@command{objcopy} can only copy the inputs into file formats that have the
same endianness or which have no endianness (e.g., @samp{srec}).
+(However, see the @option{--reverse-bytes} option.)
@c man end
@@ -1342,6 +1344,30 @@
when appropriate, regardless of the object file format of the output
file.
+@item --reverse-bytes=@var{num}
+Reverse the bytes in a section with output contents. A section length must
+be evenly divisible by the value given in order for the swap to be able to
+take place. Reversing takes place before the interleaving is performed.
+
+This option is used typically in generating ROM images for problematic
+target systems. For example, on some target boards, the 32-bit words
+fetched from 8-bit ROMs are re-assembled in little-endian byte order
+regardless of the CPU byte order. Depending on the programming model, the
+endianness of the ROM may need to be modified.
+
+Consider a simple file with a section containing the following eight
+bytes: @code{12345678}.
+
+Using @samp{--reverse-bytes=2} for the above example, the bytes in the
+output file would be ordered @code{21436587}.
+
+Using @samp{--reverse-bytes=4} for the above example, the bytes in the
+output file would be ordered @code{43218765}.
+
+By using @samp{--reverse-bytes=2} for the above example, followed by
+@samp{--reverse-bytes=4} on the output file, the bytes in the second
+output file would be ordered @code{34127856}.
+
@item --srec-len=@var{ival}
Meaningful only for srec output. Set the maximum length of the Srecords
being produced to @var{ival}. This length covers both address, data and
Index: binutils/testsuite/binutils-all/objcopy.exp
===================================================================
RCS file: /cvs/src/src/binutils/testsuite/binutils-all/objcopy.exp,v
retrieving revision 1.41
diff -u -r1.41 objcopy.exp
--- binutils/testsuite/binutils-all/objcopy.exp 12 Apr 2007 19:20:46 -0000 1.41
+++ binutils/testsuite/binutils-all/objcopy.exp 20 Apr 2007 16:58:18 -0000
@@ -113,5 +113,39 @@
objcopy_test "simple copy" bintest.s
+# Test reversing bytes in a section.
+
+set reversed ${tempfile}-reversed
+set got [binutils_run $OBJCOPY "$OBJCOPYFLAGS -j .data --reverse-bytes=4 $tempfile $reversed"]
+
+if ![string match "" $got] then {
+ fail "objcopy --reverse-bytes"
+} else {
+ if [is_remote host] {
+ remote_upload host ${reversed} tmpdir/copy-reversed.o
+ set reversed tmpdir/copy-reversed.o
+ }
+
+ set origdata [binutils_run $OBJDUMP "$OBJDUMPFLAGS -s -j .data $tempfile"]
+ set revdata [binutils_run $OBJDUMP "$OBJDUMPFLAGS -s -j .data $reversed"]
+
+ set want "^ \[0-9\]+ (\[0-9\]+)"
+ set found_orig [regexp -lineanchor $want $origdata -> origdata]
+ set found_rev [regexp -lineanchor $want $revdata -> revdata]
+
+ if {$found_orig == 0 || $found_rev == 0} then {
+ fail "objcopy --reverse-bytes"
+ } else {
+ scan $origdata "%2x%2x%2x%2x" b1 b2 b3 b4
+ scan $revdata "%2x%2x%2x%2x" c4 c3 c2 c1
+
+ if {$b1 == $c1 && $b2 == $c2 && $b3 == $c3 && $b4 == $c4} then {
+ pass "objcopy --reverse-bytes"
+ } else {
+ fail "objcopy --reverse-bytes"
+ }
+ }
+}
+
# Test generating S records.
# We make the srec filename 8.3 compatible. Note that the header string
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