1 files changed, 143 insertions, 0 deletions
diff --git a/util/cbfstool/flashrom.c b/util/cbfstool/flashrom.c
new file mode 100644
index 0000000000..64f73e420b
--- /dev/null
+++ b/util/cbfstool/flashrom.c
@@ -0,0 +1,143 @@
+/* Copyright 2020 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.
+ */
+
+/* For strdup */
+#define _POSIX_C_SOURCE 200809L
+#include <fcntl.h>
+#include <limits.h>
+#include <stdbool.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 "common.h" /* from cbfstool for buffer API. */
+#include "subprocess.h" /* from vboot_reference */
+#include "flashrom.h"
+
+#define FLASHROM_EXEC_NAME "flashrom"
+#define FLASHROM_PROGRAMMER_INTERNAL_AP "host"
+
+/**
+ * Helper to create a temporary file.
+ *
+ * @param path_out	An output pointer for the filename. Caller should free.
+ *
+ * @return 0 on success, -1 for file open error, or -2 for write error.
+ */
+static int create_temp_file(char **path_out)
+{
+	int fd;
+	int rv;
+	char *path;
+	mode_t umask_save;
+
+#if defined(__FreeBSD__)
+#define P_tmpdir "/tmp"
+#endif
+	*path_out = NULL;
+	path = strdup(P_tmpdir "/flashrom.XXXXXX");
+	/* Set the umask before mkstemp for security considerations. */
+	umask_save = umask(077);
+	fd = mkstemp(path);
+	umask(umask_save);
+	if (fd < 0) {
+		rv = -1;
+		goto fail;
+	}
+
+	close(fd);
+	*path_out = path;
+
+	return 0;
+fail:
+	free(path);
+	return rv;
+}
+
+static int run_flashrom(const char *const argv[])
+{
+	int status = subprocess_run(argv, &subprocess_null, &subprocess_null,
+				    &subprocess_null);
+	if (status) {
+		fprintf(stderr, "Flashrom invocation failed (exit status %d):",
+			status);
+		for (const char *const *argp = argv; *argp; argp++)
+			fprintf(stderr, " %s", *argp);
+		fprintf(stderr, "\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+int flashrom_host_read(struct buffer *buffer, const char *region)
+{
+	char *tmpfile;
+	char region_param[PATH_MAX];
+	int rv;
+
+	if (create_temp_file(&tmpfile) != 0)
+		return -1;
+	if (region)
+		snprintf(region_param, sizeof(region_param), "%s:%s", region,
+			 tmpfile);
+	const char *const argv[] = {
+		FLASHROM_EXEC_NAME,
+		"-p",
+		FLASHROM_PROGRAMMER_INTERNAL_AP,
+		"-r",
+		region ? "-i" : tmpfile,
+		region ? region_param : NULL,
+		NULL,
+	};
+	rv = run_flashrom(argv);
+	if (!rv)
+		rv = buffer_from_file(buffer, tmpfile);
+
+	unlink(tmpfile);
+	free(tmpfile);
+
+	return rv;
+}
+
+int flashrom_host_write(struct buffer *buffer, const char *region)
+{
+	char *tmpfile;
+	char region_param[PATH_MAX];
+	int rv;
+
+	if (create_temp_file(&tmpfile) != 0)
+		return -1;
+	if (buffer_write_file(buffer, tmpfile) != 0) {
+		rv = -2;
+		goto fail;
+	}
+
+	if (region)
+		snprintf(region_param, sizeof(region_param), "%s:%s", region,
+			 tmpfile);
+	const char *const argv[] = {
+		FLASHROM_EXEC_NAME,
+		"-p",
+		FLASHROM_PROGRAMMER_INTERNAL_AP,
+		"--noverify-all",
+		"-w",
+		region ? "-i" : tmpfile,
+		region ? region_param : NULL,
+		NULL,
+	};
+
+	rv = run_flashrom(argv);
+
+fail:
+	unlink(tmpfile);
+	free(tmpfile);
+
+	return rv;
+}