From cf85ca788a53c3a45b383edeabd843e319706de3 Mon Sep 17 00:00:00 2001
From: Imbus <aa>
Date: Sat, 7 Feb 2026 13:23:53 +0100
Subject: [PATCH] Verification logic now verifies both by-block and crc32

---
 writeimg.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/writeimg.c b/writeimg.c
index c83ce29..538f480 100644
--- a/writeimg.c
+++ b/writeimg.c
@@ -1,3 +1,4 @@
+#include "crc32.h"
 #include <assert.h>
 #include <fcntl.h>
 #include <getopt.h>
@@ -73,10 +74,13 @@ int perform_write(write_job_t *job) {
     /* TODO: Checks */
     assert(job->bufsize >= job->block_size);
 
+    int crc = crc32_init();
+
     while (!job->verify_only) {
         ssize_t read_bytes = read(file_fd, job->buffer, job->block_size);
         if (read_bytes == 0) {
             fsync(block_fd);
+            crc = crc32_finalize(crc);
             break; /* Finished */
         }
 
@@ -86,6 +90,8 @@ int perform_write(write_job_t *job) {
             exit(EXIT_FAILURE);
         }
 
+        crc = crc32_update(crc, job->buffer, read_bytes);
+
         ssize_t written_bytes = write(block_fd, job->buffer, read_bytes);
         if (written_bytes < 0) {
             fprintf(stderr, "%s: Write error\n", job->dev_name);
@@ -100,6 +106,8 @@ int perform_write(write_job_t *job) {
     memset(job->buffer, 0, BLOCKSIZE);
     memset(job->buffer2, 0, BLOCKSIZE);
 
+    int crc_back = crc32_init();
+
     while (1) {
         ssize_t read_file = read(file_fd, job->buffer2, job->block_size);
         ssize_t read_block = read(block_fd, job->buffer, read_file);
@@ -108,8 +116,13 @@ int perform_write(write_job_t *job) {
         assert(read_block >= 0);
         assert(read_file >= 0);
 
-        if (read_file == 0)
+        if (read_file == 0) {
+            crc_back = crc32_finalize(crc_back);
+            assert(crc_back == crc);
             break;
+        }
+
+        crc_back = crc32_update(crc_back, job->buffer, read_file);
 
         int cmp = memcmp((const void *)job->buffer2, (const void *)job->buffer, (size_t)read_file);
         if (0 != cmp) {