[M] Change in flashrom[master]: flashrom.c: Factor out setup_curcontents() from flashrom_image_write()

[Edward O'Callaghan (Code Review)]

Edward O'Callaghan has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/70025 )

Change subject: flashrom.c: Factor out setup_curcontents() from flashrom_image_write()
......................................................................

flashrom.c: Factor out setup_curcontents() from flashrom_image_write()

The CrOS tree factored this functionality into its
own function, seems reasonable.

Change-Id: I4baf09700d7efcbca3a6ba0cfda3231837e0a34a
Signed-off-by: Edward O'Callaghan 
---
M flashrom.c
1 file changed, 54 insertions(+), 25 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/25/70025/1

diff --git a/flashrom.c b/flashrom.c
index 51a6b64..48ac687 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -1800,6 +1800,44 @@
    memcpy(newcontents + start, oldcontents + start, copy_len);
 }

+static int setup_curcontents(struct flashctx *const flashctx,
+		void *curcontents, const void *const refcontents)
+{
+	const size_t flash_size = flashctx->chip->total_size * 1024;
+	const bool verify_all = flashctx->flags.verify_whole_chip;
+
+	memset(curcontents, UNERASED_VALUE(flashctx), flash_size);
+
+	/* If given, assume flash chip contains same data as `refcontents`. */
+	if (refcontents) {
+		msg_cinfo("Assuming old flash chip contents as ref-file...\n");
+		memcpy(curcontents, refcontents, flash_size);
+	} else {
+		/*
+		 * Read the whole chip to be able to check whether regions need to be
+		 * erased and to give better diagnostics in case write fails.
+		 * The alternative is to read only the regions which are to be
+		 * preserved, but in that case we might perform unneeded erase which
+		 * takes time as well.
+		 */
+		msg_cinfo("Reading old flash chip contents... ");
+		if (verify_all) {
+			if (read_flash(flashctx, curcontents, 0, flash_size)) {
+				msg_cinfo("FAILED.\n");
+				return -1;
+			}
+		} else {
+			if (read_by_layout(flashctx, curcontents)) {
+				msg_cinfo("FAILED.\n");
+				return -1;
+			}
+		}
+		msg_cinfo("done.\n");
+	}
+
+	return 0;
+}
+
 int flashrom_image_write(struct flashctx *const flashctx, void *const buffer, const size_t buffer_len,
                          const void *const refbuffer)
 {
@@ -1840,34 +1878,12 @@
    if (prepare_flash_access(flashctx, false, true, false, verify))
    	goto _free_ret;

-	/* If given, assume flash chip contains same data as `refcontents`. */
+	if (setup_curcontents(flashctx, curcontents, refcontents) < 0)
+                goto _finalize_ret;
+
    if (refcontents) {
-		msg_cinfo("Assuming old flash chip contents as ref-file...\n");
-		memcpy(curcontents, refcontents, flash_size);
    	if (oldcontents)
    		memcpy(oldcontents, refcontents, flash_size);
-	} else {
-		/*
-		 * Read the whole chip to be able to check whether regions need to be
-		 * erased and to give better diagnostics in case write fails.
-		 * The alternative is to read only the regions which are to be
-		 * preserved, but in that case we might perform unneeded erase which
-		 * takes time as well.
-		 */
-		msg_cinfo("Reading old flash chip contents... ");
-		if (verify_all) {
-			if (read_flash(flashctx, oldcontents, 0, flash_size)) {
-				msg_cinfo("FAILED.\n");
-				goto _finalize_ret;
-			}
-			memcpy(curcontents, oldcontents, flash_size);
-		} else {
-			if (read_by_layout(flashctx, curcontents)) {
-				msg_cinfo("FAILED.\n");
-				goto _finalize_ret;
-			}
-		}
-		msg_cinfo("done.\n");
    }

if (write_by_layout(flashctx, curcontents, newcontents)) {