It may not be OS-dev specific, but it's an extremely simple format to implement. I figured some people may find it useful as a temporary stand-in in their projects.
Below is the shell script that does the conversion:
Code: Select all
#!/bin/sh
# Display the usage information.
usage ()
{
cat << EOF
Usage: $0 [options] file...
Options:
-h Show this message
-o FILE Place output into FILE
-T FILE Use FILE as linker script
EOF
}
OPTIND=1
while getopts "ho:" OPTION
do
case $OPTION in
h)
usage
exit 1
;;
o)
export OUTPUT="$OPTARG"
;;
T)
export LDSCRIPT="$OPTARG"
;;
esac
done
if [ "$OUTPUT" = "" ]
then
echo "$0: no output file specified" >&2
echo "$0: use the -h option for usage information" >&2
exit 1
else
export LDOUT="`echo "$OUTPUT" | sed 's/\.actor/.o/'`"
fi
if [ "$LDSCRIPT" = "" ]
then
export LDSCRIPT="actor.x"
fi
shift $((OPTIND - 1))
# Compile and link the code for the actor.
cc -c -o "$LDOUT.1" $* \
-fno-exceptions -fno-unwind-tables -fno-asynchronous-unwind-tables
ld -r -o "$LDOUT" -T $LDSCRIPT "$LDOUT.1"
# Remove the old file for the actor if it exists and create a blank file.
rm -f "$OUTPUT" "$LDOUT.1"
touch "$OUTPUT"
# Dump the .text, .data, and .rodata sections into the actor.
objdump -s -j ".text" "$LDOUT" |
grep '^ [0-9]' | # Grab only hex dump lines.
sed -r 's/^ +[0-9a-f]+ +//;s/ .*//' | # Remove offsets and ASCII.
sed ':a;N;$!ba;s/\n/ /g;s/ //g' | # Remove whitespace.
xxd -r -p - >> "$OUTPUT" # Convert to binary code.
export TEXTSIZE="`stat -c%s \"$OUTPUT\"`"
objdump -s -j ".data" "$LDOUT" |
grep '^ [0-9]' | # Grab only hex dump lines.
sed -r 's/^ +[0-9a-f]+ +//;s/ .*//' | # Remove offsets and ASCII.
sed ':a;N;$!ba;s/\n/ /g;s/ //g' | # Remove whitespace.
xxd -r -p - >> "$OUTPUT" # Convert to binary code.
export DATASIZE="`stat -c%s \"$OUTPUT\"`"
export DATASIZE="`expr $DATASIZE - $TEXTSIZE`"
objdump -s -j ".rodata" "$LDOUT" |
grep '^ [0-9]' | # Grab only hex dump lines.
sed -r 's/^ +[0-9a-f]+ +//;s/ .*//' | # Remove offsets and ASCII.
sed ':a;N;$!ba;s/\n/ /g;s/ //g' | # Remove whitespace.
xxd -r -p - >> "$OUTPUT" # Convert to binary code.
export TABLEOFFSET="`stat -c%s \"$OUTPUT\"`"
export RODATASIZE="`expr $TABLEOFFSET - $DATASIZE - $TEXTSIZE`"
# Get the size of the .bss section and write the size table to memory.
export BSSSIZE="`size -A \"$LDOUT\" |
grep .bss | sed -r 's/\.bss *//;s/ [0-9]+//'`"
printf "%08x%08x%08x%08x" $TEXTSIZE $DATASIZE $RODATASIZE $BSSSIZE |
xxd -r -p - >> "$OUTPUT"
# Write the number of relocations
export TEXTRC="`objdump -r -j \".text\" \"$LDOUT\" |
grep '^[0-9]' | wc -l`"
export DATARC="`objdump -r -j \".data\" \"$LDOUT\" |
grep '^[0-9]' | wc -l`"
export RODATARC="`objdump -r -j \".rodata\" \"$LDOUT\" |
grep '^[0-9]' | wc -l`"
export BSSRC="`objdump -r -j \".bss\" \"$LDOUT\" |
grep '^[0-9]' | wc -l`"
printf "%08x" `expr $TEXTRC + $DATARC + $RODATARC + $BSSRC` |
xxd -r -p - >> "$OUTPUT"
# ---
# Eventually, I'll need to canonicalize the relocations and insert them
# the file here; note: this is done with 'objdump -r'.
# ---
# Write a relative pointer to the size table at the end of the file.
export ENDOFFSET="`stat -c%s \"$OUTPUT\"`"
export RELATIVEOFFSET="`expr $ENDOFFSET - $TABLEOFFSET + 4`"
printf "%08x" $RELATIVEOFFSET | xxd -r -p - >> "$OUTPUT"
# Print the location of the symbol for the actor data.
echo `nm -g "$LDOUT" | grep '\s*actor_data$'`
