vboot_ref/futility: Extract out flashrom call logic

Separate out all the flashrom worker code used in futility
to allow for later building a futility without flashrom
support.

BUG=b:203715651,b:209702505
BRANCH=none
TEST=builds

Signed-off-by: Edward O'Callaghan <quasisec@google.com>
Change-Id: I938141056424f8f93a598bbb288ee7c8770edc95
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3350298
Tested-by: Edward O'Callaghan <quasisec@chromium.org>
Auto-Submit: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Commit-Queue: Edward O'Callaghan <quasisec@chromium.org>

5 files changed, 216 insertions, 191 deletions

diff --git a/Makefile b/Makefile
index 25539c73..8fc602ed 100644
--- a/Makefile
+++ b/Makefile
@@ -665,7 +665,8 @@ FUTIL_SRCS = \
 	futility/updater_quirks.c \
 	futility/updater_utils.c \
 	futility/vb1_helper.c \
-	futility/vb2_helper.c
+	futility/vb2_helper.c \
+	futility/flashrom_drv.c
 
 # List of commands built in futility.
 FUTIL_CMD_LIST = ${BUILD}/gen/futility_cmds.c
diff --git a/futility/flashrom_drv.c b/futility/flashrom_drv.c
new file mode 100644
index 00000000..5ebe4468
--- /dev/null
+++ b/futility/flashrom_drv.c
@@ -0,0 +1,197 @@
+/* Copyright 2021 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.
+ *
+ * The utility functions for firmware updater.
+ */
+
+#include <libflashrom.h>
+
+#include "2common.h"
+#include "crossystem.h"
+#include "host_misc.h"
+#include "util_misc.h"
+#include "updater.h"
+
+#define FLASHROM_OUTPUT_WP_PATTERN "write protect is "
+
+/* System environment values. */
+static const char * const FLASHROM_OUTPUT_WP_ENABLED =
+			  FLASHROM_OUTPUT_WP_PATTERN "enabled",
+		  * const FLASHROM_OUTPUT_WP_DISABLED =
+			  FLASHROM_OUTPUT_WP_PATTERN "disabled";
+
+// global to allow verbosity level to be injected into callback.
+static enum flashrom_log_level g_verbose_screen = FLASHROM_MSG_INFO;
+
+static int flashrom_print_cb(enum flashrom_log_level level, const char *fmt,
+			     va_list ap)
+{
+	int ret = 0;
+	FILE *output_type = (level < FLASHROM_MSG_INFO) ? stderr : stdout;
+
+	if (level > g_verbose_screen)
+		return ret;
+
+	ret = vfprintf(output_type, fmt, ap);
+	/* msg_*spew often happens inside chip accessors
+	 * in possibly time-critical operations.
+	 * Don't slow them down by flushing.
+	 */
+	if (level != FLASHROM_MSG_SPEW)
+		fflush(output_type);
+
+	return ret;
+}
+
+static char *flashrom_extract_params(const char *str, char **prog, char **params)
+{
+	char *tmp = strdup(str);
+	*prog = strtok(tmp, ":");
+	*params = strtok(NULL, "");
+	return tmp;
+}
+
+int flashrom_read_image(struct firmware_image *image, int verbosity)
+{
+	int r = 0;
+	size_t len = 0;
+
+	g_verbose_screen = verbosity;
+
+	char *programmer, *params;
+	char *tmp = flashrom_extract_params(image->programmer, &programmer, &params);
+
+	struct flashrom_programmer *prog = NULL;
+	struct flashrom_flashctx *flashctx = NULL;
+
+	flashrom_set_log_callback((flashrom_log_callback *)&flashrom_print_cb);
+
+	r |= flashrom_init(1);
+	r |= flashrom_programmer_init(&prog, programmer, params);
+	r |= flashrom_flash_probe(&flashctx, prog, NULL);
+
+	len = flashrom_flash_getsize(flashctx);
+	image->data = calloc(1, len);
+	image->size = len;
+	image->file_name = strdup("<none>");
+
+	r |= flashrom_image_read(flashctx, image->data, len);
+
+	r |= flashrom_programmer_shutdown(prog);
+	flashrom_flash_release(flashctx);
+	free(tmp);
+
+	return r;
+}
+
+int flashrom_write_image(const struct firmware_image *image,
+			const char *region,
+			const struct firmware_image *diff_image,
+			int verbosity)
+{
+	int r = 0;
+	size_t len = 0;
+
+	g_verbose_screen = verbosity;
+
+	char *programmer, *params;
+	char *tmp = flashrom_extract_params(image->programmer, &programmer, &params);
+
+	struct flashrom_programmer *prog = NULL;
+	struct flashrom_flashctx *flashctx = NULL;
+	struct flashrom_layout *layout = NULL;
+
+	flashrom_set_log_callback((flashrom_log_callback *)&flashrom_print_cb);
+
+	r |= flashrom_init(1);
+	r |= flashrom_programmer_init(&prog, programmer, params);
+	r |= flashrom_flash_probe(&flashctx, prog, NULL);
+
+	len = flashrom_flash_getsize(flashctx);
+	if (len == 0) {
+		ERROR("zero sized flash detected\n");
+		r = -1;
+		goto err_cleanup;
+	}
+
+	if (diff_image) {
+		if (diff_image->size != image->size) {
+			ERROR("diff_image->size != image->size");
+			r = -1;
+			goto err_cleanup;
+		}
+	}
+
+	if (region) {
+		r = flashrom_layout_read_fmap_from_buffer(
+			&layout, flashctx, (const uint8_t *)image->data,
+			image->size);
+		if (r > 0) {
+			WARN("could not read fmap from image, r=%d, "
+				"falling back to read from rom\n", r);
+			r = flashrom_layout_read_fmap_from_rom(
+				&layout, flashctx, 0, len);
+			if (r > 0) {
+				ERROR("could not read fmap from rom, r=%d\n", r);
+				r = -1;
+				goto err_cleanup;
+			}
+		}
+		// empty region causes seg fault in API.
+		r |= flashrom_layout_include_region(layout, region);
+		if (r > 0) {
+			ERROR("could not include region = '%s'\n", region);
+			r = -1;
+			goto err_cleanup;
+		}
+		flashrom_layout_set(flashctx, layout);
+	}
+
+	flashrom_flag_set(flashctx, FLASHROM_FLAG_VERIFY_WHOLE_CHIP, true);
+	flashrom_flag_set(flashctx, FLASHROM_FLAG_VERIFY_AFTER_WRITE, true);
+	if (diff_image) /* equiv --noverify --flash-contents=diff_image at cli */
+		flashrom_flag_set(flashctx, FLASHROM_FLAG_VERIFY_AFTER_WRITE, false);
+
+	r |= flashrom_image_write(flashctx, image->data, image->size,
+				  diff_image ? diff_image->data : NULL);
+
+err_cleanup:
+	r |= flashrom_programmer_shutdown(prog);
+	flashrom_layout_release(layout);
+	flashrom_flash_release(flashctx);
+	free(tmp);
+
+	return r;
+}
+
+/* Helper function to return write protection status via given programmer. */
+enum wp_state flashrom_get_wp(const char *programmer)
+{
+	char *command, *result;
+	const char *postfix;
+	int r;
+
+	/* grep is needed because host_shell only returns 1 line. */
+	postfix = " 2>/dev/null | grep \"" FLASHROM_OUTPUT_WP_PATTERN "\"";
+
+
+	/* TODO(b/203715651): link with flashrom directly. */
+	ASPRINTF(&command, "flashrom --wp-status -p %s %s", programmer, postfix);
+
+	/* invokes flashrom(8) with non-zero result if error. */
+	result = host_shell(command);
+	strip_string(result, NULL);
+	free(command);
+	VB2_DEBUG("wp-status: %s\n", result);
+
+	if (strstr(result, FLASHROM_OUTPUT_WP_ENABLED))
+		r = WP_ENABLED;
+	else if (strstr(result, FLASHROM_OUTPUT_WP_DISABLED))
+		r = WP_DISABLED;
+	else
+		r = WP_ERROR;
+	free(result);
+
+	return r;
+}
diff --git a/futility/updater.c b/futility/updater.c
index 8b1c1555..b550b33c 100644
--- a/futility/updater.c
+++ b/futility/updater.c
@@ -458,7 +458,7 @@ static int write_optional_firmware(struct updater_config *cfg,
 	 */
 	if (check_programmer_wp &&
 	    get_system_property(SYS_PROP_WP_HW, cfg) == WP_ENABLED &&
-	    host_get_wp(image->programmer) == WP_ENABLED) {
+	    flashrom_get_wp(image->programmer) == WP_ENABLED) {
 		ERROR("Target %s is write protected, skip updating.\n",
 		      image->programmer);
 		return 0;
diff --git a/futility/updater_utils.c b/futility/updater_utils.c
index 503747ac..936abaf3 100644
--- a/futility/updater_utils.c
+++ b/futility/updater_utils.c
@@ -15,8 +15,6 @@
 #include <sys/wait.h>
 #endif
 
-#include <libflashrom.h>
-
 #include "2common.h"
 #include "crossystem.h"
 #include "host_misc.h"
@@ -24,14 +22,9 @@
 #include "updater.h"
 
 #define COMMAND_BUFFER_SIZE 256
-#define FLASHROM_OUTPUT_WP_PATTERN "write protect is "
 
 /* System environment values. */
-static const char * const STR_REV = "rev",
-		  * const FLASHROM_OUTPUT_WP_ENABLED =
-			  FLASHROM_OUTPUT_WP_PATTERN "enabled",
-		  * const FLASHROM_OUTPUT_WP_DISABLED =
-			  FLASHROM_OUTPUT_WP_PATTERN "disabled";
+static const char * const STR_REV = "rev";
 
 /*
  * Strips a string (usually from shell execution output) by removing all the
@@ -522,182 +515,6 @@ char *host_detect_servo(int *need_prepare_ptr)
 	return ret;
 }
 
-// global to allow verbosity level to be injected into callback.
-static enum flashrom_log_level g_verbose_screen = FLASHROM_MSG_INFO;
-
-static int flashrom_print_cb(enum flashrom_log_level level, const char *fmt,
-			     va_list ap)
-{
-	int ret = 0;
-	FILE *output_type = (level < FLASHROM_MSG_INFO) ? stderr : stdout;
-
-	if (level > g_verbose_screen)
-		return ret;
-
-	ret = vfprintf(output_type, fmt, ap);
-	/* msg_*spew often happens inside chip accessors
-	 * in possibly time-critical operations.
-	 * Don't slow them down by flushing.
-	 */
-	if (level != FLASHROM_MSG_SPEW)
-		fflush(output_type);
-
-	return ret;
-}
-
-static char *flashrom_extract_params(const char *str, char **prog, char **params)
-{
-	char *tmp = strdup(str);
-	*prog = strtok(tmp, ":");
-	*params = strtok(NULL, "");
-	return tmp;
-}
-
-static int host_flashrom_read(struct firmware_image *image)
-{
-	int r = 0;
-	size_t len = 0;
-
-	char *programmer, *params;
-	char *tmp = flashrom_extract_params(image->programmer, &programmer, &params);
-
-	struct flashrom_programmer *prog = NULL;
-	struct flashrom_flashctx *flashctx = NULL;
-
-	flashrom_set_log_callback((flashrom_log_callback *)&flashrom_print_cb);
-
-	r |= flashrom_init(1);
-	r |= flashrom_programmer_init(&prog, programmer, params);
-	r |= flashrom_flash_probe(&flashctx, prog, NULL);
-
-	len = flashrom_flash_getsize(flashctx);
-	image->data = calloc(1, len);
-	image->size = len;
-	image->file_name = strdup("<none>");
-
-	r |= flashrom_image_read(flashctx, image->data, len);
-
-	r |= flashrom_programmer_shutdown(prog);
-	flashrom_flash_release(flashctx);
-	free(tmp);
-
-	return r;
-}
-
-static int host_flashrom_write(const struct firmware_image *image,
-			       const char *region,
-			       const struct firmware_image *diff_image)
-{
-	int r = 0;
-	size_t len = 0;
-
-	char *programmer, *params;
-	char *tmp = flashrom_extract_params(image->programmer, &programmer, &params);
-
-	struct flashrom_programmer *prog = NULL;
-	struct flashrom_flashctx *flashctx = NULL;
-	struct flashrom_layout *layout = NULL;
-
-	flashrom_set_log_callback((flashrom_log_callback *)&flashrom_print_cb);
-
-	r |= flashrom_init(1);
-	r |= flashrom_programmer_init(&prog, programmer, params);
-	r |= flashrom_flash_probe(&flashctx, prog, NULL);
-
-	len = flashrom_flash_getsize(flashctx);
-	if (len == 0) {
-		ERROR("zero sized flash detected\n");
-		r = -1;
-		goto err_cleanup;
-	}
-
-	if (diff_image) {
-		if (diff_image->size != image->size) {
-			ERROR("diff_image->size != image->size");
-			r = -1;
-			goto err_cleanup;
-		}
-	}
-
-	if (region) {
-		r = flashrom_layout_read_fmap_from_buffer(
-			&layout, flashctx, (const uint8_t *)image->data,
-			image->size);
-		if (r > 0) {
-			WARN("could not read fmap from image, r=%d, "
-				"falling back to read from rom\n", r);
-			r = flashrom_layout_read_fmap_from_rom(
-				&layout, flashctx, 0, len);
-			if (r > 0) {
-				ERROR("could not read fmap from rom, r=%d\n", r);
-				r = -1;
-				goto err_cleanup;
-			}
-		}
-		// empty region causes seg fault in API.
-		r |= flashrom_layout_include_region(layout, region);
-		if (r > 0) {
-			ERROR("could not include region = '%s'\n", region);
-			r = -1;
-			goto err_cleanup;
-		}
-		flashrom_layout_set(flashctx, layout);
-	}
-
-	flashrom_flag_set(flashctx, FLASHROM_FLAG_VERIFY_WHOLE_CHIP, true);
-	flashrom_flag_set(flashctx, FLASHROM_FLAG_VERIFY_AFTER_WRITE, true);
-	if (diff_image) /* equiv --noverify --flash-contents=diff_image at cli */
-		flashrom_flag_set(flashctx, FLASHROM_FLAG_VERIFY_AFTER_WRITE, false);
-
-	r |= flashrom_image_write(flashctx, image->data, image->size,
-				  diff_image ? diff_image->data : NULL);
-
-err_cleanup:
-	r |= flashrom_programmer_shutdown(prog);
-	flashrom_layout_release(layout);
-	flashrom_flash_release(flashctx);
-	free(tmp);
-
-	return r;
-}
-
-/* Helper function to return write protection status via given programmer. */
-enum wp_state host_get_wp(const char *programmer)
-{
-	char *command, *result;
-	const char *postfix;
-	int r;
-
-	/* grep is needed because host_shell only returns 1 line. */
-	postfix = " 2>/dev/null | grep \"" FLASHROM_OUTPUT_WP_PATTERN "\"";
-
-
-	/* TODO(b/203715651): link with flashrom directly. */
-	ASPRINTF(&command, "flashrom --wp-status -p %s %s", programmer, postfix);
-
-	/* invokes flashrom(8) with non-zero result if error. */
-	result = host_shell(command);
-	strip_string(result, NULL);
-	free(command);
-	VB2_DEBUG("wp-status: %s\n", result);
-
-	if (strstr(result, FLASHROM_OUTPUT_WP_ENABLED))
-		r = WP_ENABLED;
-	else if (strstr(result, FLASHROM_OUTPUT_WP_DISABLED))
-		r = WP_DISABLED;
-	else
-		r = WP_ERROR;
-	free(result);
-
-	return r;
-}
-
-/* Helper function to return host software write protection status. */
-static int host_get_wp_sw(void)
-{
-	return host_get_wp(PROG_HOST);
-}
-
 /*
  * Loads the active system firmware image (usually from SPI flash chip).
  * Returns 0 if success, non-zero if error.
@@ -707,8 +524,7 @@ int load_system_firmware(struct firmware_image *image,
 {
 	int r;
 
-	g_verbose_screen = verbosity + 1;
-	r = host_flashrom_read(image);
+	r = flashrom_read_image(image, (verbosity + 1));
 	if (!r)
 		r = parse_firmware_image(image);
 	return r;
@@ -725,8 +541,13 @@ int write_system_firmware(const struct firmware_image *image,
 			  struct tempfile *tempfiles,
 			  int verbosity)
 {
-	g_verbose_screen = verbosity + 1;
-	return host_flashrom_write(image, section_name, diff_image);
+	return flashrom_write_image(image, section_name, diff_image, (verbosity + 1));
+}
+
+/* Helper function to return host software write protection status. */
+static int host_get_wp_sw(void)
+{
+	return flashrom_get_wp(PROG_HOST);
 }
 
 /* Helper function to configure all properties. */
diff --git a/futility/updater_utils.h b/futility/updater_utils.h
index 25316757..2d64c295 100644
--- a/futility/updater_utils.h
+++ b/futility/updater_utils.h
@@ -175,7 +175,7 @@ enum wp_state {
 };
 
 /* Helper function to return write protection status via given programmer. */
-enum wp_state host_get_wp(const char *programmer);
+enum wp_state flashrom_get_wp(const char *programmer);
 
 /* The environment variable name for setting servod port. */
 #define ENV_SERVOD_PORT	"SERVOD_PORT"
@@ -228,4 +228,10 @@ void init_system_properties(struct system_property *props, int num);
  */
 const char *get_firmware_rootkey_hash(const struct firmware_image *image);
 
+int flashrom_read_image(struct firmware_image *image, int verbosity);
+int flashrom_write_image(const struct firmware_image *image,
+			const char *region,
+			const struct firmware_image *diff_image,
+			int verbosity);
+
 #endif  /* VBOOT_REFERENCE_FUTILITY_UPDATER_UTILS_H_ */