1 files changed, 82 insertions, 0 deletions
diff --git a/bs/cross-arch.sh b/bs/cross-arch.sh
new file mode 100755
index 000000000..c520433a5
--- /dev/null
+++ b/bs/cross-arch.sh
@@ -0,0 +1,82 @@
+#!/bin/sh
+# many parts of this blatantly ripped from GNU Autoconf macros
+# Use this for cross-compiling, as we can't run cross-compiled binaries
+# on our host.
+if test -z "$O" || ! cd "$O"; then
+	echo '$O= not defined or not a directory' >&2
+	exit 1
+fi
+
+echo '/* architecture-specific settings (auto-detected): */'
+# check sizes of various types we care for
+# this is slightly slower but much easier to read and follow than the
+# bisecting autoconf version
+for t in short int long 'long long'; do
+	> out
+	for s in 2 4 6 8 12 1 16 24 32 0; do
+		cat > t.c <<EOF
+int main(void)
+{
+	static int x[(long int)(sizeof($t)) == $s ? 1 : -1];
+	x[0] = 0;
+	return 0;
+}
+EOF
+		echo "trying sizeof($t) == $s" >> out
+		$CC -o t.o $CFLAGS $CPPFLAGS t.c \
+			>> out 2>&1 && break
+	done
+	if test $s -eq 0; then
+		echo "Unable to calculate sizeof($t) for cross-compiling" >&2
+		cat out >&2
+		exit 1
+	fi
+	t=`echo $t | tr a-z A-Z | tr ' ' _`
+	echo "#define SIZEOF_$t $s"
+	echo "SIZEOF_$t := $s" >> config_detected.mk
+done
+
+# check endian-ness
+cat > t.c <<EOF
+short ascii_mm[] = { 0x4249, 0x4765, 0x6E44, 0x6961, 0x6E53, 0x7953, 0 };
+short ascii_ii[] = { 0x694C, 0x5454, 0x656C, 0x6E45, 0x6944, 0x6E61, 0 };
+void _ascii(void)
+{
+	char *s = (char *)ascii_mm;
+	s = (char *)ascii_ii;
+}
+
+short ebcdic_ii[] = { 0x89D3, 0xE3E3, 0x8593, 0x95C5, 0x89C4, 0x9581, 0 };
+short ebcdic_mm[] = { 0xC2C9, 0xC785, 0x95C4, 0x8981, 0x95E2, 0xA8E2, 0 };
+void _ebcdic(void)
+{
+	char *s = (char *)ebcdic_mm;
+	s = (char *)ebcdic_ii;
+}
+
+int main(void)
+{
+	_ascii();
+	_ebcdic();
+
+	return 0;
+}
+EOF
+
+echo "compiling endian test" > out
+$CC -o t.o $CFLAGS $CPPFLAGS t.c >> out 2>&1
+if grep BIGenDianSyS t.o >/dev/null 2>&1; then
+	echo "#define WORDS_BIGENDIAN 1"
+	echo "WORDS_BIGENDIAN := 1" >> config_detected.mk
+elif grep LiTTleEnDian t.o >/dev/null 2>&1; then
+	echo "/* #undef WORDS_BIGENDIAN */"
+	echo "# WORDS_BIGENDIAN :=" >> config_detected.mk
+else
+	echo "Unable to determine endian-ness for cross compiling" >&2
+	cat out >&2
+	exit 1
+fi
+
+echo ''
+
+exec rm -f t.o out t.c