Use a template assembly file for firmware object files.

Similar to r366897, this uses the .incbin directive to pull in a
firmware file's contents into a .fwo file.  The same scheme for
computing symbol names from the filename is used as before to maximize
compatiblity and not require rebuilding existing .fwo files for
NO_CLEAN builds.  Using ld -o binary requires extra hacks in linkers
to either specify ABI options (e.g. soft- vs hard-float) or to ignore
ABI incompatiblities when linking certain objects (e.g.  object files
with only data).  Using the compiler driver avoids the need for these
hacks as the compiler driver is able to set all the appropriate ABI
options.

Reviewed by:	imp, markj
Obtained from:	CheriBSD
Sponsored by:	DARPA
Differential Revision:	https://reviews.freebsd.org/D27579

4 files changed, 60 insertions, 16 deletions

diff --git a/sys/conf/kern.pre.mk b/sys/conf/kern.pre.mk
index e13af7cea00b..cb1703097836 100644
--- a/sys/conf/kern.pre.mk
+++ b/sys/conf/kern.pre.mk
@@ -184,8 +184,9 @@ NORMAL_M= ${AWK} -f $S/tools/makeobjops.awk ${.IMPSRC} -c ; \
 	  ${CC} -c ${CFLAGS} ${WERROR} ${PROF} ${.PREFIX}.c
 
 NORMAL_FW= uudecode -o ${.TARGET} ${.ALLSRC}
-NORMAL_FWO= ${LD} -b binary --no-warn-mismatch -d -warn-common -r \
-	-m ${LD_EMULATION} -o ${.TARGET} ${.ALLSRC:M*.fw}
+NORMAL_FWO= ${CC:N${CCACHE_BIN}} -c ${ASM_CFLAGS} ${WERROR} -o ${.TARGET} \
+	$S/kern/firmw.S -DFIRMW_FILE="${.ALLSRC:M*.fw}" \
+	-DFIRMW_SYMBOL="${.ALLSRC:M*.fw:C/[-.\/]/_/g}"
 
 # for ZSTD in the kernel (include zstd/lib/freebsd before other CFLAGS)
 ZSTD_C= ${CC} -c -DZSTD_HEAPMODE=1 -I$S/contrib/zstd/lib/freebsd ${CFLAGS} -I$S/contrib/zstd/lib -I$S/contrib/zstd/lib/common ${WERROR} -Wno-inline -Wno-missing-prototypes ${PROF} -U__BMI__ ${.IMPSRC}
diff --git a/sys/conf/kmod.mk b/sys/conf/kmod.mk
index b19d911604c3..54ecbdf69c88 100644
--- a/sys/conf/kmod.mk
+++ b/sys/conf/kmod.mk
@@ -187,19 +187,13 @@ SRCS+=	${KMOD:S/$/.c/}
 CLEANFILES+=	${KMOD:S/$/.c/}
 
 .for _firmw in ${FIRMWS}
-${_firmw:C/\:.*$/.fwo/:T}:	${_firmw:C/\:.*$//}
+${_firmw:C/\:.*$/.fwo/:T}:	${_firmw:C/\:.*$//} ${SYSDIR}/kern/firmw.S
 	@${ECHO} ${_firmw:C/\:.*$//} ${.ALLSRC:M*${_firmw:C/\:.*$//}}
-	@if [ -e ${_firmw:C/\:.*$//} ]; then			\
-		${LD} -b binary --no-warn-mismatch ${_LDFLAGS}	\
-		    -m ${LD_EMULATION} -r -d			\
-		    -o ${.TARGET} ${_firmw:C/\:.*$//};		\
-	else							\
-		ln -s ${.ALLSRC:M*${_firmw:C/\:.*$//}} ${_firmw:C/\:.*$//}; \
-		${LD} -b binary --no-warn-mismatch ${_LDFLAGS}	\
-		    -m ${LD_EMULATION} -r -d			\
-		    -o ${.TARGET} ${_firmw:C/\:.*$//};		\
-		rm ${_firmw:C/\:.*$//};				\
-	fi
+	${CC:N${CCACHE_BIN}} -c -x assembler-with-cpp -DLOCORE 	\
+	    ${CFLAGS} ${WERROR} 				\
+	    -DFIRMW_FILE="${.ALLSRC:M*${_firmw:C/\:.*$//}}" 	\
+	    -DFIRMW_SYMBOL="${_firmw:C/\:.*$//:C/[-.\/]/_/g}"	\
+	    ${SYSDIR}/kern/firmw.S -o ${.TARGET}
 
 OBJS+=	${_firmw:C/\:.*$/.fwo/:T}
 .endfor
diff --git a/sys/kern/firmw.S b/sys/kern/firmw.S
new file mode 100644
index 000000000000..7a4ca1e45808
--- /dev/null
+++ b/sys/kern/firmw.S
@@ -0,0 +1,49 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2020 John Baldwin <jhb@FreeBSD.org>
+ *
+ * This software was developed by SRI International and the University of
+ * Cambridge Computer Laboratory (Department of Computer Science and
+ * Technology) under DARPA contract HR0011-18-C-0016 ("ECATS"), as part of the
+ * DARPA SSITH research programme.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/cdefs.h>
+
+#define	FIRMW_START(S)	__CONCAT(_binary_, __CONCAT(S, _start))
+#define	FIRMW_END(S)	__CONCAT(_binary_, __CONCAT(S, _end))
+
+	.section rodata, "a", %progbits
+	.globl	FIRMW_START(FIRMW_SYMBOL)
+	.type	FIRMW_START(FIRMW_SYMBOL), %object
+FIRMW_START(FIRMW_SYMBOL):
+	.incbin	__XSTRING(FIRMW_FILE)
+	.size	FIRMW_START(FIRMW_SYMBOL), . - FIRMW_START(FIRMW_SYMBOL)
+	.globl	FIRMW_END(FIRMW_SYMBOL)
+	.type	FIRMW_END(FIRMW_SYMBOL), %object
+FIRMW_END(FIRMW_SYMBOL):
+	.size	FIRMW_END(FIRMW_SYMBOL), . - FIRMW_END(FIRMW_SYMBOL)
diff --git a/sys/tools/fw_stub.awk b/sys/tools/fw_stub.awk
index ea9f6ab8cd9b..807c51b6190b 100644
--- a/sys/tools/fw_stub.awk
+++ b/sys/tools/fw_stub.awk
@@ -143,7 +143,7 @@ if (opt_l) {
 
 for (file_i = 0; file_i < num_files; file_i++) {
 	symb = filenames[file_i];
-	# '-', '.' and '/' are converted to '_' by ld/objcopy
+	# '-', '.' and '/' are converted to '_'
 	gsub(/-|\.|\//, "_", symb);
 	printc("extern char _binary_" symb "_start[], _binary_" symb "_end[];");
 }
@@ -170,7 +170,7 @@ for (file_i = 0; file_i < num_files; file_i++) {
 	short = shortnames[file_i];
 	symb = filenames[file_i];
 	version = versions[file_i];
-	# '-', '.' and '/' are converted to '_' by ld/objcopy
+	# '-', '.' and '/' are converted to '_'
 	gsub(/-|\.|\//, "_", symb);
 
 	reg = "\t\tfp = ";