1 /* SPIFFS Image Generation on Build Example
2
3 This example code is in the Public Domain (or CC0 licensed, at your option.)
4
5 Unless required by applicable law or agreed to in writing, this
6 software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
7 CONDITIONS OF ANY KIND, either express or implied.
8 */
9
10 #include <stdio.h>
11 #include <string.h>
12 #include <sys/unistd.h>
13 #include <sys/stat.h>
14 #include "esp_err.h"
15 #include "esp_log.h"
16 #include "esp_spiffs.h"
17 #include "mbedtls/md5.h"
18
19 static const char *TAG = "example";
20
read_hello_txt(void)21 static void read_hello_txt(void)
22 {
23 ESP_LOGI(TAG, "Reading hello.txt");
24
25 // Open for reading hello.txt
26 FILE* f = fopen("/spiffs/hello.txt", "r");
27 if (f == NULL) {
28 ESP_LOGE(TAG, "Failed to open hello.txt");
29 return;
30 }
31
32 char buf[64];
33 memset(buf, 0, sizeof(buf));
34 fread(buf, 1, sizeof(buf), f);
35 fclose(f);
36
37 // Display the read contents from the file
38 ESP_LOGI(TAG, "Read from hello.txt: %s", buf);
39 }
40
compute_alice_txt_md5(void)41 static void compute_alice_txt_md5(void)
42 {
43 ESP_LOGI(TAG, "Computing alice.txt MD5 hash");
44
45 // The file alice.txt lives under a subdirectory, though SPIFFS itself is flat
46 FILE* f = fopen("/spiffs/sub/alice.txt", "r");
47 if (f == NULL) {
48 ESP_LOGE(TAG, "Failed to open alice.txt");
49 return;
50 }
51
52 // Read file and compute the digest chunk by chunk
53 #define MD5_MAX_LEN 16
54
55 char buf[64];
56 mbedtls_md5_context ctx;
57 unsigned char digest[MD5_MAX_LEN];
58
59 mbedtls_md5_init(&ctx);
60 mbedtls_md5_starts_ret(&ctx);
61
62 size_t read;
63
64 do {
65 read = fread((void*) buf, 1, sizeof(buf), f);
66 mbedtls_md5_update_ret(&ctx, (unsigned const char*) buf, read);
67 } while(read == sizeof(buf));
68
69 mbedtls_md5_finish_ret(&ctx, digest);
70
71 // Create a string of the digest
72 char digest_str[MD5_MAX_LEN * 2];
73
74 for (int i = 0; i < MD5_MAX_LEN; i++) {
75 sprintf(&digest_str[i * 2], "%02x", (unsigned int)digest[i]);
76 }
77
78 // For reference, MD5 should be deeb71f585cbb3ae5f7976d5127faf2a
79 ESP_LOGI(TAG, "Computed MD5 hash of alice.txt: %s", digest_str);
80
81 fclose(f);
82 }
83
app_main(void)84 void app_main(void)
85 {
86 ESP_LOGI(TAG, "Initializing SPIFFS");
87
88 esp_vfs_spiffs_conf_t conf = {
89 .base_path = "/spiffs",
90 .partition_label = NULL,
91 .max_files = 5,
92 .format_if_mount_failed = false
93 };
94
95 // Use settings defined above to initialize and mount SPIFFS filesystem.
96 // Note: esp_vfs_spiffs_register is an all-in-one convenience function.
97 esp_err_t ret = esp_vfs_spiffs_register(&conf);
98
99 if (ret != ESP_OK) {
100 if (ret == ESP_FAIL) {
101 ESP_LOGE(TAG, "Failed to mount or format filesystem");
102 } else if (ret == ESP_ERR_NOT_FOUND) {
103 ESP_LOGE(TAG, "Failed to find SPIFFS partition");
104 } else {
105 ESP_LOGE(TAG, "Failed to initialize SPIFFS (%s)", esp_err_to_name(ret));
106 }
107 return;
108 }
109
110 size_t total = 0, used = 0;
111 ret = esp_spiffs_info(NULL, &total, &used);
112 if (ret != ESP_OK) {
113 ESP_LOGE(TAG, "Failed to get SPIFFS partition information (%s)", esp_err_to_name(ret));
114 } else {
115 ESP_LOGI(TAG, "Partition size: total: %d, used: %d", total, used);
116 }
117
118 /* The following calls demonstrate reading files from the generated SPIFFS
119 * image. The images should contain the same files and contents as the spiffs_image directory.
120 */
121
122 // Read and display the contents of a small text file (hello.txt)
123 read_hello_txt();
124
125 // Compute and display the MD5 hash of a large text file (alice.txt)
126 compute_alice_txt_md5();
127
128 // All done, unmount partition and disable SPIFFS
129 esp_vfs_spiffs_unregister(NULL);
130 ESP_LOGI(TAG, "SPIFFS unmounted");
131 }
132
