futility: add load_fmap command, useful for tests

This adds a "load_fmap" command, which is pretty much the
opposite of the "dump_fmap -x" command. It allows you to
replace the content of any FMAP areas with new stuff, without
mucking around with dd. There's a test for it, too.

BUG=chromium:224734
BRANCH=ToT
TEST=make runtests

Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Change-Id: I5a9ab249c9e63a9bb1a9b26feeb3ed757cd294f1
Reviewed-on: https://chromium-review.googlesource.com/216228
Reviewed-by: Randall Spangler <rspangler@chromium.org>

4 files changed, 247 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index 9782b826..783190b1 100644
--- a/Makefile
+++ b/Makefile
@@ -542,6 +542,7 @@ FUTIL_SRCS = \
 	$(FUTIL_STATIC_SRCS) \
 	futility/cmd_dev_sign_file.c \
 	futility/cmd_dump_kernel_config.c \
+	futility/cmd_load_fmap.c \
 	futility/cmd_vbutil_firmware.c \
 	futility/cmd_vbutil_kernel.c \
 	futility/cmd_vbutil_key.c \
diff --git a/futility/cmd_load_fmap.c b/futility/cmd_load_fmap.c
new file mode 100644
index 00000000..3b10aa9f
--- /dev/null
+++ b/futility/cmd_load_fmap.c
@@ -0,0 +1,202 @@
+/*
+ * Copyright 2014 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "fmap.h"
+#include "futility.h"
+
+
+static const char usage[] = "\n"
+	"Usage:  " MYNAME " %s [OPTIONS] FILE AREA:file [AREA:file ...]\n"
+	"\n"
+	"Replace the contents of specific FMAP areas. This is the complement\n"
+	"of " MYNAME " dump_fmap -x FILE AREA [AREA ...]\n"
+	"\n"
+	"Options:\n"
+	"  -o OUTFILE     Write the result to this file, instead of modifying\n"
+	"                   the input file. This is safer, since there are no\n"
+	"                   safeguards against doing something stupid.\n"
+	"\n"
+	"Example:\n"
+	"\n"
+	"  This will clear the RO_VPD area, and scramble VBLOCK_B:\n"
+	"\n"
+	"  " MYNAME " %s bios.bin RO_VPD:/dev/zero VBLOCK_B:/dev/urandom\n"
+	"\n";
+
+static void help_and_quit(const char *prog)
+{
+	fprintf(stderr, usage, prog, prog);
+	exit(1);
+}
+
+static const struct option long_opts[] = {
+	/* name    hasarg *flag  val */
+	{NULL,          0, NULL, 0},
+};
+static char *short_opts = ":o:";
+
+
+static int copy_to_area(char *file, uint8_t *buf, uint32_t len, char *area)
+{
+	FILE *fp;
+	int retval = 0;
+	int n;
+
+	fp = fopen(file, "r");
+	if (!fp) {
+		fprintf(stderr, "area %s: can't open %s for reading: %s\n",
+			area, file, strerror(errno));
+		return 1;
+	}
+
+	n = fread(buf, 1, len, fp);
+	if (n == 0) {
+		if (feof(fp))
+			fprintf(stderr, "area %s: unexpected EOF on %s\n",
+				area, file);
+		if (ferror(fp))
+			fprintf(stderr, "area %s: can't read from %s: %s\n",
+				area, file, strerror(errno));
+		retval = 1;
+	} else if (n < len) {
+		fprintf(stderr, "Warning on area %s: only read %d "
+			"(not %d) from %s\n", area, n, len, file);
+	}
+
+	if (0 != fclose(fp)) {
+		fprintf(stderr, "area %s: error closing %s: %s\n",
+			area, file, strerror(errno));
+		retval = 1;
+	}
+
+	return retval;
+}
+
+
+static int do_load_fmap(int argc, char *argv[])
+{
+	char *infile = 0;
+	char *outfile = 0;
+	void *mmap_ptr = 0;
+	uint8_t *buf;
+	uint32_t len;
+	FmapHeader *fmap;
+	FmapAreaHeader *ah;
+	int errorcnt = 0;
+	int fd, i;
+
+	opterr = 0;		/* quiet, you */
+	while ((i = getopt_long(argc, argv, short_opts, long_opts, 0)) != -1) {
+		switch (i) {
+		case 'o':
+			outfile = optarg;
+			break;
+		case '?':
+			if (optopt)
+				fprintf(stderr, "Unrecognized option: -%c\n",
+					optopt);
+			else
+				fprintf(stderr, "Unrecognized option\n");
+			errorcnt++;
+			break;
+		case ':':
+			fprintf(stderr, "Missing argument to -%c\n", optopt);
+			errorcnt++;
+			break;
+		default:
+			DIE;
+		}
+	}
+
+	if (errorcnt)
+		help_and_quit(argv[0]);
+
+	if (argc - optind < 2) {
+		fprintf(stderr,
+			"You must specify an input file"
+			" and at least one AREA:file argument\n");
+		help_and_quit(argv[0]);
+	}
+
+	infile = argv[optind++];
+
+	/* okay, let's do it ... */
+	if (outfile)
+		copy_file_or_die(infile, outfile);
+	else
+		outfile = infile;
+
+	fd = open(outfile, O_RDWR);
+	if (fd < 0) {
+		fprintf(stderr, "Can't open %s: %s\n",
+			outfile, strerror(errno));
+		return 1;
+	}
+
+	errorcnt |= map_it(fd, 1, &mmap_ptr, &len);
+	if (errorcnt)
+		goto done_file;
+	buf = (uint8_t *)mmap_ptr;
+
+	fmap = fmap_find(buf, len);
+	if (!fmap) {
+		fprintf(stderr, "Can't find an FMAP in %s\n", infile);
+		errorcnt++;
+		goto done_map;
+	}
+
+	for (i = optind; i < argc; i++) {
+		char *a = argv[i];
+		char *f = strchr(a, ':');
+
+		if (!f || a == f || *(f+1) == '\0') {
+			fprintf(stderr, "argument \"%s\" is bogus\n", a);
+			errorcnt++;
+			break;
+		}
+		*f++ = '\0';
+		uint8_t *area_buf = fmap_find_by_name(buf, len, fmap, a, &ah);
+		if (!area_buf) {
+			fprintf(stderr, "Can't find area \"%s\" in FMAP\n", a);
+			errorcnt++;
+			break;
+		}
+
+		if (0 != copy_to_area(f, area_buf, ah->area_size, a)) {
+			errorcnt++;
+			break;
+		}
+	}
+
+done_map:
+	errorcnt |= unmap_it(fd, 1, mmap_ptr, len);
+
+done_file:
+
+	if (0 != close(fd)) {
+		fprintf(stderr, "Error closing %s: %s\n",
+			outfile, strerror(errno));
+		errorcnt++;
+	}
+
+	return !!errorcnt;
+}
+
+DECLARE_FUTIL_COMMAND(load_fmap, do_load_fmap,
+		      "Replace the contents of specified FMAP areas");
diff --git a/tests/futility/run_test_scripts.sh b/tests/futility/run_test_scripts.sh
index 3369bedf..a1aa24cb 100755
--- a/tests/futility/run_test_scripts.sh
+++ b/tests/futility/run_test_scripts.sh
@@ -42,6 +42,7 @@ export OUTDIR
 TESTS="
 ${SCRIPTDIR}/test_main.sh
 ${SCRIPTDIR}/test_dump_fmap.sh
+${SCRIPTDIR}/test_load_fmap.sh
 ${SCRIPTDIR}/test_gbb_utility.sh
 ${SCRIPTDIR}/test_resign_firmware.sh
 "
diff --git a/tests/futility/test_load_fmap.sh b/tests/futility/test_load_fmap.sh
new file mode 100755
index 00000000..c5e61633
--- /dev/null
+++ b/tests/futility/test_load_fmap.sh
@@ -0,0 +1,43 @@
+#!/bin/bash -eux
+# Copyright 2014 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+me=${0##*/}
+TMP="$me.tmp"
+
+# Work in scratch directory
+cd "$OUTDIR"
+
+
+IN=${SCRIPTDIR}/data/bios_link_mp.bin
+BIOS=${TMP}.bios.bin
+
+cp ${IN} ${BIOS}
+
+AREAS="RW_SECTION_A VBLOCK_B BOOT_STUB"
+
+# Extract good blobs first
+${FUTILITY} dump_fmap -x ${BIOS} ${AREAS}
+
+# Save the good blobs, make same-size random blobs, create command
+CMDS=""
+for a in ${AREAS}; do
+  size=$(stat -c '%s' $a)
+  mv $a $a.good
+  dd if=/dev/urandom of=$a.rand bs=$size count=1
+  CMDS="$CMDS $a:$a.rand"
+done
+
+# Poke the new blobs in
+${FUTILITY} load_fmap ${BIOS} ${CMDS}
+
+# Pull them back out and see if they match
+${FUTILITY} dump_fmap -x ${BIOS} ${AREAS}
+for a in ${AREAS}; do
+  cmp $a $a.rand
+done
+
+# cleanup
+rm -f ${TMP}* ${AREAS} *.rand *.good
+exit 0