vboot_reference/futility: Port W path to using libflashrom

Use libflashrom API over sub-processing the flashrom CLI.

Squash in,
  vboot_reference/futility: Use image layout as fallback

  Use the layout encoding within the image as the fallback if
  we cannot read it from ROM. Also cleanup error paths while
  here.

BUG=b:203715651
BRANCH=none
TEST=cros deploy to nocturne and ran:
 `/usr/sbin/chromeos-firmwareupdate --mode=recovery --wp=1`.
&& `$ cros_run_unit_tests --board nocturne --packages vboot_reference`.

Cq-Depend: chromium:3249690, chromium:3281062, chromium:3288610
Signed-off-by: Edward O'Callaghan <quasisec@google.com>
Change-Id: I892aec510d8023abd42a07cbb036be79bc8b4498
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3247852
Tested-by: Edward O'Callaghan <quasisec@chromium.org>
Auto-Submit: Edward O'Callaghan <quasisec@chromium.org>
Commit-Queue: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-by: Sam McNally <sammc@chromium.org>

2 files changed, 121 insertions, 30 deletions

diff --git a/Makefile b/Makefile
index 7d074b42..0435936c 100644
--- a/Makefile
+++ b/Makefile
@@ -305,6 +305,8 @@ ifneq (${HAVE_LIBZIP},)
   LIBZIP_LIBS := $(shell ${PKG_CONFIG} --libs libzip)
 endif
 
+FLASHROM_LIBS := $(shell ${PKG_CONFIG} --libs flashrom)
+
 # Determine QEMU architecture needed, if any
 ifeq (${ARCH},${HOST_ARCH})
   # Same architecture; no need for QEMU
@@ -1044,7 +1046,7 @@ signing_install: $(if ${SDK_BUILD},\
 futil: ${FUTIL_BIN}
 
 # FUTIL_LIBS is shared by FUTIL_BIN and TEST_FUTIL_BINS.
-FUTIL_LIBS = ${CRYPTO_LIBS} ${LIBZIP_LIBS}
+FUTIL_LIBS = ${CRYPTO_LIBS} ${LIBZIP_LIBS} ${FLASHROM_LIBS}
 
 ${FUTIL_BIN}: LDLIBS += ${FUTIL_LIBS}
 ${FUTIL_BIN}: ${FUTIL_OBJS} ${UTILLIB} ${FWLIB}
diff --git a/futility/updater_utils.c b/futility/updater_utils.c
index 51936a52..039788a2 100644
--- a/futility/updater_utils.c
+++ b/futility/updater_utils.c
@@ -9,11 +9,14 @@
 #include <limits.h>
 #include <sys/stat.h>
 #include <sys/types.h>
+#include <string.h>
 #include <unistd.h>
 #if defined (__FreeBSD__) || defined(__OpenBSD__)
 #include <sys/wait.h>
 #endif
 
+#include <libflashrom.h>
+
 #include "2common.h"
 #include "crossystem.h"
 #include "host_misc.h"
@@ -25,7 +28,6 @@
 
 enum flashrom_ops {
 	FLASHROM_READ,
-	FLASHROM_WRITE,
 	FLASHROM_WP_STATUS,
 };
 
@@ -565,11 +567,6 @@ static int host_flashrom(enum flashrom_ops op, const char *image_path,
 		assert(image_path);
 		break;
 
-	case FLASHROM_WRITE:
-		op_cmd = "-w";
-		assert(image_path);
-		break;
-
 	case FLASHROM_WP_STATUS:
 		op_cmd = "--wp-status";
 		assert(image_path == NULL);
@@ -587,7 +584,7 @@ static int host_flashrom(enum flashrom_ops op, const char *image_path,
 	if (!extra)
 		extra = "";
 
-	/* TODO(hungte) In future we should link with flashrom directly. */
+	/* TODO(b/203715651): link with flashrom directly. */
 	ASPRINTF(&command, "flashrom %s %s -p %s %s %s %s %s", op_cmd,
 		 image_path, programmer, dash_i, section_name, extra,
 		 postfix);
@@ -618,6 +615,119 @@ static int host_flashrom(enum flashrom_ops op, const char *image_path,
 	return r;
 }
 
+static int flashrom_print_cb(enum flashrom_log_level level, const char *fmt,
+			     va_list ap)
+{
+	int ret = 0;
+	enum flashrom_log_level verbose_screen = FLASHROM_MSG_INFO;
+	FILE *output_type = (level < verbose_screen) ? stderr : stdout;
+
+	if (level > verbose_screen)
+		return ret;
+
+#define COLOUR_RESET "\033[0;m"
+#define MAGENTA_TEXT "\033[35;1m"
+
+	if (level != FLASHROM_MSG_SPEW)
+		fprintf(output_type, MAGENTA_TEXT);
+
+	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) {
+		fprintf(output_type, COLOUR_RESET);
+		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_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_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)
 {
@@ -673,28 +783,7 @@ int write_system_firmware(const struct firmware_image *image,
 			  struct tempfile *tempfiles,
 			  int verbosity)
 {
-	const char *tmp_path = get_firmware_image_temp_file(image, tempfiles);
-	const char *tmp_diff = NULL;
-
-	const char *programmer = image->programmer;
-	char *extra = NULL;
-	int r;
-
-	if (!tmp_path)
-		return -1;
-
-	if (diff_image) {
-		tmp_diff = get_firmware_image_temp_file(
-				diff_image, tempfiles);
-		if (!tmp_diff)
-			return -1;
-		ASPRINTF(&extra, "--noverify --flash-contents=%s", tmp_diff);
-	}
-
-	r = host_flashrom(FLASHROM_WRITE, tmp_path, programmer, verbosity,
-			  section_name, extra);
-	free(extra);
-	return r;
+	return host_flashrom_write(image, section_name, diff_image);
 }
 
 /* Helper function to configure all properties. */