[Qemu-devel] [PATCH 4/4] Multiboot build system

[Alexander Graf <agraf@suse.de>]

In order to build the multiboot option rom, we need a Makefile and a tool
to sign the rom with.

Both are provided by this patch and mostly taken from the extboot source,
written by Anthony Liguori.

Once built, please copy the multiboot.bin file to your pc-bios directory
to actually be able to use the option rom.

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 pc-bios/multiboot/Makefile  |   41 ++++++++++++++++++++++
 pc-bios/multiboot/signrom.c |   79 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 120 insertions(+), 0 deletions(-)
 create mode 100644 pc-bios/multiboot/Makefile
 create mode 100644 pc-bios/multiboot/signrom.c

diff --git a/pc-bios/multiboot/Makefile b/pc-bios/multiboot/Makefile
new file mode 100644
index 0000000..0e7a764
--- /dev/null
+++ b/pc-bios/multiboot/Makefile
@@ -0,0 +1,41 @@
+OBJCOPY=objcopy
+
+# from kernel sources - scripts/Kbuild.include
+# try-run
+# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
+# Exit code chooses option. "$$TMP" is can be used as temporary file and
+# is automatically cleaned up.
+try-run = $(shell set -e;		\
+	TMP="$(TMPOUT).$$$$.tmp";	\
+	if ($(1)) >/dev/null 2>&1;	\
+	then echo "$(2)";		\
+	else echo "$(3)";		\
+	fi;				\
+	rm -f "$$TMP")
+
+# cc-option-yn
+# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
+cc-option-yn = $(call try-run,\
+	$(CC) $(KBUILD_CFLAGS) $(1) -S -xc /dev/null -o "$$TMP",y,n)
+
+CFLAGS = -Wall -Wstrict-prototypes -Werror -fomit-frame-pointer -fno-builtin
+ifeq ($(call cc-option-yn,-fno-stack-protector),y)
+CFLAGS += -fno-stack-protector
+endif
+
+all: multiboot.bin
+
+%.o: %.S
+	$(CC) $(CFLAGS) -o $@ -c $<
+
+multiboot.img: multiboot.o
+	$(LD) --oformat binary -Ttext 0 -o $@ $<
+
+multiboot.bin: multiboot.img signrom
+	./signrom multiboot.img multiboot.bin
+
+signrom: signrom.c
+	$(CC) -o $@ -g -Wall $^
+
+clean:
+	$(RM) *.o *.img *.bin signrom *~
diff --git a/pc-bios/multiboot/signrom.c b/pc-bios/multiboot/signrom.c
new file mode 100644
index 0000000..fe8d677
--- /dev/null
+++ b/pc-bios/multiboot/signrom.c
@@ -0,0 +1,79 @@
+/*
+ * Extended Boot Option ROM
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Copyright IBM Corporation, 2007
+ *   Authors: Anthony Liguori <aliguori@us.ibm.com>
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+int main(int argc, char **argv)
+{
+	FILE *fin, *fout;
+	char buffer[512], oldbuffer[512];
+	int i, size, lag = 0;
+	uint8_t sum = 0;
+
+	if (argc != 3) {
+		printf("Usage: %s ROM OUTPUT\n", argv[0]);
+		return 1;
+	}
+
+	fin = fopen(argv[1], "rb");
+	fout = fopen(argv[2], "wb");
+
+	if (fin == NULL || fout == NULL) {
+		fprintf(stderr, "Could not open input/output files\n");
+		return 1;
+	}
+
+	do {
+		size = fread(buffer, 512, 1, fin);
+		if (size == 1) {
+			for (i = 0; i < 512; i++)
+				sum += buffer[i];
+
+			if (lag) {
+				if (fwrite(oldbuffer, 512, 1, fout) != 1) {
+					fprintf(stderr, "Write failed\n");
+					return 1;
+				}
+			}
+			lag = 1;
+			memcpy(oldbuffer, buffer, 512);
+		}
+	} while (size == 1);
+
+	if (size != 0) {
+		fprintf(stderr, "Failed to read from input file\n");
+		return 1;
+	}
+
+	oldbuffer[511] = -sum;
+
+	if (fwrite(oldbuffer, 512, 1, fout) != 1) {
+		fprintf(stderr, "Failed to write to output file\n");
+		return 1;
+	}
+
+	fclose(fin);
+	fclose(fout);
+
+	return 0;
+}
-- 
1.6.0.2