mbed-os-examples / Mbed OS mbed-os-example-mbed5-filesystem

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main.cpp@28:bc8560ba955d, 2019-01-17 (annotated)

Committer:
mbed_official
Date:
Thu Jan 17 13:15:29 2019 +0000
Revision:
28:bc8560ba955d
Parent:
26:06d3aa3eff55
Child:
29:d28cf713107b
Enhance documentation for the following:



- Explain how to use FAT FS vs. LittleFS

- Explain how to use your own block device



.

Commit copied from https://github.com/ARMmbed/mbed-os-example-filesystem

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 0:8e251d9511b8 1 /* mbed Microcontroller Library
mbed_official 0:8e251d9511b8 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 0:8e251d9511b8 3 *
mbed_official 0:8e251d9511b8 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 0:8e251d9511b8 5 * you may not use this file except in compliance with the License.
mbed_official 0:8e251d9511b8 6 * You may obtain a copy of the License at
mbed_official 0:8e251d9511b8 7 *
mbed_official 0:8e251d9511b8 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 0:8e251d9511b8 9 *
mbed_official 0:8e251d9511b8 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 0:8e251d9511b8 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 0:8e251d9511b8 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 0:8e251d9511b8 13 * See the License for the specific language governing permissions and
mbed_official 0:8e251d9511b8 14 * limitations under the License.
mbed_official 0:8e251d9511b8 15 */
mbed_official 0:8e251d9511b8 16 #include "mbed.h"
mbed_official 0:8e251d9511b8 17 #include <stdio.h>
mbed_official 0:8e251d9511b8 18 #include <errno.h>
mbed_official 0:8e251d9511b8 19
mbed_official 26:06d3aa3eff55 20 #include "BlockDevice.h"
mbed_official 0:8e251d9511b8 21
mbed_official 28:bc8560ba955d 22 // This will take the system's default block device
mbed_official 28:bc8560ba955d 23 BlockDevice *bd = BlockDevice::get_default_instance();
mbed_official 28:bc8560ba955d 24
mbed_official 28:bc8560ba955d 25 // Instead of the default block device, you can define your own block device.
mbed_official 28:bc8560ba955d 26 // For example: HeapBlockDevice with size of 2048 bytes, read size 1, write size 1 and erase size 512.
mbed_official 28:bc8560ba955d 27 // #include "HeapBlockDevice.h"
mbed_official 28:bc8560ba955d 28 // BlockDevice *bd = new HeapBlockDevice(2048, 1, 1, 512);
mbed_official 0:8e251d9511b8 29
mbed_official 0:8e251d9511b8 30
mbed_official 28:bc8560ba955d 31 // This example uses LittleFileSystem as the default file system
mbed_official 28:bc8560ba955d 32 #include "LittleFileSystem.h"
mbed_official 28:bc8560ba955d 33 LittleFileSystem fs("fs");
mbed_official 0:8e251d9511b8 34
mbed_official 28:bc8560ba955d 35 // Uncomment the following two lines and comment the previous two to use FAT file system.
mbed_official 28:bc8560ba955d 36 // #include "FATFileSystem.h"
mbed_official 28:bc8560ba955d 37 // FATFileSystem fs("fs");
mbed_official 0:8e251d9511b8 38
mbed_official 0:8e251d9511b8 39
mbed_official 0:8e251d9511b8 40 // Set up the button to trigger an erase
mbed_official 0:8e251d9511b8 41 InterruptIn irq(BUTTON1);
mbed_official 0:8e251d9511b8 42 void erase() {
mbed_official 0:8e251d9511b8 43 printf("Initializing the block device... ");
mbed_official 0:8e251d9511b8 44 fflush(stdout);
mbed_official 26:06d3aa3eff55 45 int err = bd->init();
mbed_official 0:8e251d9511b8 46 printf("%s\n", (err ? "Fail :(" : "OK"));
mbed_official 0:8e251d9511b8 47 if (err) {
mbed_official 0:8e251d9511b8 48 error("error: %s (%d)\n", strerror(-err), err);
mbed_official 0:8e251d9511b8 49 }
mbed_official 0:8e251d9511b8 50
mbed_official 0:8e251d9511b8 51 printf("Erasing the block device... ");
mbed_official 0:8e251d9511b8 52 fflush(stdout);
mbed_official 26:06d3aa3eff55 53 err = bd->erase(0, bd->size());
mbed_official 0:8e251d9511b8 54 printf("%s\n", (err ? "Fail :(" : "OK"));
mbed_official 0:8e251d9511b8 55 if (err) {
mbed_official 0:8e251d9511b8 56 error("error: %s (%d)\n", strerror(-err), err);
mbed_official 0:8e251d9511b8 57 }
mbed_official 0:8e251d9511b8 58
mbed_official 0:8e251d9511b8 59 printf("Deinitializing the block device... ");
mbed_official 0:8e251d9511b8 60 fflush(stdout);
mbed_official 26:06d3aa3eff55 61 err = bd->deinit();
mbed_official 0:8e251d9511b8 62 printf("%s\n", (err ? "Fail :(" : "OK"));
mbed_official 0:8e251d9511b8 63 if (err) {
mbed_official 0:8e251d9511b8 64 error("error: %s (%d)\n", strerror(-err), err);
mbed_official 0:8e251d9511b8 65 }
mbed_official 0:8e251d9511b8 66 }
mbed_official 0:8e251d9511b8 67
mbed_official 0:8e251d9511b8 68
mbed_official 0:8e251d9511b8 69 // Entry point for the example
mbed_official 0:8e251d9511b8 70 int main() {
mbed_official 0:8e251d9511b8 71 printf("--- Mbed OS filesystem example ---\n");
mbed_official 0:8e251d9511b8 72
mbed_official 12:a07d0af60cc6 73 // Setup the erase event on button press, use the event queue
mbed_official 12:a07d0af60cc6 74 // to avoid running in interrupt context
mbed_official 12:a07d0af60cc6 75 irq.fall(mbed_event_queue()->event(erase));
mbed_official 0:8e251d9511b8 76
mbed_official 0:8e251d9511b8 77 // Try to mount the filesystem
mbed_official 0:8e251d9511b8 78 printf("Mounting the filesystem... ");
mbed_official 0:8e251d9511b8 79 fflush(stdout);
mbed_official 26:06d3aa3eff55 80 int err = fs.mount(bd);
mbed_official 0:8e251d9511b8 81 printf("%s\n", (err ? "Fail :(" : "OK"));
mbed_official 0:8e251d9511b8 82 if (err) {
mbed_official 0:8e251d9511b8 83 // Reformat if we can't mount the filesystem
mbed_official 0:8e251d9511b8 84 // this should only happen on the first boot
mbed_official 0:8e251d9511b8 85 printf("No filesystem found, formatting... ");
mbed_official 0:8e251d9511b8 86 fflush(stdout);
mbed_official 26:06d3aa3eff55 87 err = fs.reformat(bd);
mbed_official 0:8e251d9511b8 88 printf("%s\n", (err ? "Fail :(" : "OK"));
mbed_official 0:8e251d9511b8 89 if (err) {
mbed_official 0:8e251d9511b8 90 error("error: %s (%d)\n", strerror(-err), err);
mbed_official 0:8e251d9511b8 91 }
mbed_official 0:8e251d9511b8 92 }
mbed_official 0:8e251d9511b8 93
mbed_official 0:8e251d9511b8 94 // Open the numbers file
mbed_official 0:8e251d9511b8 95 printf("Opening \"/fs/numbers.txt\"... ");
mbed_official 0:8e251d9511b8 96 fflush(stdout);
mbed_official 0:8e251d9511b8 97 FILE *f = fopen("/fs/numbers.txt", "r+");
mbed_official 0:8e251d9511b8 98 printf("%s\n", (!f ? "Fail :(" : "OK"));
mbed_official 0:8e251d9511b8 99 if (!f) {
mbed_official 0:8e251d9511b8 100 // Create the numbers file if it doesn't exist
mbed_official 0:8e251d9511b8 101 printf("No file found, creating a new file... ");
mbed_official 0:8e251d9511b8 102 fflush(stdout);
mbed_official 0:8e251d9511b8 103 f = fopen("/fs/numbers.txt", "w+");
mbed_official 0:8e251d9511b8 104 printf("%s\n", (!f ? "Fail :(" : "OK"));
mbed_official 0:8e251d9511b8 105 if (!f) {
mbed_official 0:8e251d9511b8 106 error("error: %s (%d)\n", strerror(errno), -errno);
mbed_official 0:8e251d9511b8 107 }
mbed_official 0:8e251d9511b8 108
mbed_official 0:8e251d9511b8 109 for (int i = 0; i < 10; i++) {
mbed_official 0:8e251d9511b8 110 printf("\rWriting numbers (%d/%d)... ", i, 10);
mbed_official 0:8e251d9511b8 111 fflush(stdout);
mbed_official 0:8e251d9511b8 112 err = fprintf(f, " %d\n", i);
mbed_official 0:8e251d9511b8 113 if (err < 0) {
mbed_official 0:8e251d9511b8 114 printf("Fail :(\n");
mbed_official 0:8e251d9511b8 115 error("error: %s (%d)\n", strerror(errno), -errno);
mbed_official 0:8e251d9511b8 116 }
mbed_official 0:8e251d9511b8 117 }
mbed_official 0:8e251d9511b8 118 printf("\rWriting numbers (%d/%d)... OK\n", 10, 10);
mbed_official 0:8e251d9511b8 119
mbed_official 0:8e251d9511b8 120 printf("Seeking file... ");
mbed_official 0:8e251d9511b8 121 fflush(stdout);
mbed_official 0:8e251d9511b8 122 err = fseek(f, 0, SEEK_SET);
mbed_official 0:8e251d9511b8 123 printf("%s\n", (err < 0 ? "Fail :(" : "OK"));
mbed_official 0:8e251d9511b8 124 if (err < 0) {
mbed_official 0:8e251d9511b8 125 error("error: %s (%d)\n", strerror(errno), -errno);
mbed_official 0:8e251d9511b8 126 }
mbed_official 0:8e251d9511b8 127 }
mbed_official 0:8e251d9511b8 128
mbed_official 0:8e251d9511b8 129 // Go through and increment the numbers
mbed_official 0:8e251d9511b8 130 for (int i = 0; i < 10; i++) {
mbed_official 0:8e251d9511b8 131 printf("\rIncrementing numbers (%d/%d)... ", i, 10);
mbed_official 0:8e251d9511b8 132 fflush(stdout);
mbed_official 0:8e251d9511b8 133
mbed_official 0:8e251d9511b8 134 // Get current stream position
mbed_official 0:8e251d9511b8 135 long pos = ftell(f);
mbed_official 0:8e251d9511b8 136
mbed_official 0:8e251d9511b8 137 // Parse out the number and increment
mbed_official 0:8e251d9511b8 138 int32_t number;
mbed_official 0:8e251d9511b8 139 fscanf(f, "%d", &number);
mbed_official 0:8e251d9511b8 140 number += 1;
mbed_official 0:8e251d9511b8 141
mbed_official 0:8e251d9511b8 142 // Seek to beginning of number
mbed_official 0:8e251d9511b8 143 fseek(f, pos, SEEK_SET);
mbed_official 0:8e251d9511b8 144
mbed_official 0:8e251d9511b8 145 // Store number
mbed_official 0:8e251d9511b8 146 fprintf(f, " %d\n", number);
mbed_official 10:38d6b74b0eb7 147
mbed_official 10:38d6b74b0eb7 148 // Flush between write and read on same file
mbed_official 10:38d6b74b0eb7 149 fflush(f);
mbed_official 0:8e251d9511b8 150 }
mbed_official 0:8e251d9511b8 151 printf("\rIncrementing numbers (%d/%d)... OK\n", 10, 10);
mbed_official 0:8e251d9511b8 152
mbed_official 0:8e251d9511b8 153 // Close the file which also flushes any cached writes
mbed_official 0:8e251d9511b8 154 printf("Closing \"/fs/numbers.txt\"... ");
mbed_official 0:8e251d9511b8 155 fflush(stdout);
mbed_official 0:8e251d9511b8 156 err = fclose(f);
mbed_official 0:8e251d9511b8 157 printf("%s\n", (err < 0 ? "Fail :(" : "OK"));
mbed_official 0:8e251d9511b8 158 if (err < 0) {
mbed_official 0:8e251d9511b8 159 error("error: %s (%d)\n", strerror(errno), -errno);
mbed_official 0:8e251d9511b8 160 }
mbed_official 0:8e251d9511b8 161
mbed_official 0:8e251d9511b8 162 // Display the root directory
mbed_official 0:8e251d9511b8 163 printf("Opening the root directory... ");
mbed_official 0:8e251d9511b8 164 fflush(stdout);
mbed_official 0:8e251d9511b8 165 DIR *d = opendir("/fs/");
mbed_official 0:8e251d9511b8 166 printf("%s\n", (!d ? "Fail :(" : "OK"));
mbed_official 0:8e251d9511b8 167 if (!d) {
mbed_official 0:8e251d9511b8 168 error("error: %s (%d)\n", strerror(errno), -errno);
mbed_official 0:8e251d9511b8 169 }
mbed_official 0:8e251d9511b8 170
mbed_official 0:8e251d9511b8 171 printf("root directory:\n");
mbed_official 0:8e251d9511b8 172 while (true) {
mbed_official 0:8e251d9511b8 173 struct dirent *e = readdir(d);
mbed_official 0:8e251d9511b8 174 if (!e) {
mbed_official 0:8e251d9511b8 175 break;
mbed_official 0:8e251d9511b8 176 }
mbed_official 0:8e251d9511b8 177
mbed_official 0:8e251d9511b8 178 printf(" %s\n", e->d_name);
mbed_official 0:8e251d9511b8 179 }
mbed_official 0:8e251d9511b8 180
mbed_official 0:8e251d9511b8 181 printf("Closing the root directory... ");
mbed_official 0:8e251d9511b8 182 fflush(stdout);
mbed_official 0:8e251d9511b8 183 err = closedir(d);
mbed_official 0:8e251d9511b8 184 printf("%s\n", (err < 0 ? "Fail :(" : "OK"));
mbed_official 0:8e251d9511b8 185 if (err < 0) {
mbed_official 0:8e251d9511b8 186 error("error: %s (%d)\n", strerror(errno), -errno);
mbed_official 0:8e251d9511b8 187 }
mbed_official 0:8e251d9511b8 188
mbed_official 0:8e251d9511b8 189 // Display the numbers file
mbed_official 0:8e251d9511b8 190 printf("Opening \"/fs/numbers.txt\"... ");
mbed_official 0:8e251d9511b8 191 fflush(stdout);
mbed_official 0:8e251d9511b8 192 f = fopen("/fs/numbers.txt", "r");
mbed_official 0:8e251d9511b8 193 printf("%s\n", (!f ? "Fail :(" : "OK"));
mbed_official 0:8e251d9511b8 194 if (!f) {
mbed_official 0:8e251d9511b8 195 error("error: %s (%d)\n", strerror(errno), -errno);
mbed_official 0:8e251d9511b8 196 }
mbed_official 0:8e251d9511b8 197
mbed_official 0:8e251d9511b8 198 printf("numbers:\n");
mbed_official 0:8e251d9511b8 199 while (!feof(f)) {
mbed_official 0:8e251d9511b8 200 int c = fgetc(f);
mbed_official 0:8e251d9511b8 201 printf("%c", c);
mbed_official 0:8e251d9511b8 202 }
mbed_official 0:8e251d9511b8 203
mbed_official 0:8e251d9511b8 204 printf("\rClosing \"/fs/numbers.txt\"... ");
mbed_official 0:8e251d9511b8 205 fflush(stdout);
mbed_official 0:8e251d9511b8 206 err = fclose(f);
mbed_official 0:8e251d9511b8 207 printf("%s\n", (err < 0 ? "Fail :(" : "OK"));
mbed_official 0:8e251d9511b8 208 if (err < 0) {
mbed_official 0:8e251d9511b8 209 error("error: %s (%d)\n", strerror(errno), -errno);
mbed_official 0:8e251d9511b8 210 }
mbed_official 0:8e251d9511b8 211
mbed_official 0:8e251d9511b8 212 // Tidy up
mbed_official 0:8e251d9511b8 213 printf("Unmounting... ");
mbed_official 0:8e251d9511b8 214 fflush(stdout);
mbed_official 0:8e251d9511b8 215 err = fs.unmount();
mbed_official 0:8e251d9511b8 216 printf("%s\n", (err < 0 ? "Fail :(" : "OK"));
mbed_official 0:8e251d9511b8 217 if (err < 0) {
mbed_official 0:8e251d9511b8 218 error("error: %s (%d)\n", strerror(-err), err);
mbed_official 0:8e251d9511b8 219 }
mbed_official 0:8e251d9511b8 220
mbed_official 0:8e251d9511b8 221 printf("Mbed OS filesystem example done!\n");
mbed_official 0:8e251d9511b8 222 }
mbed_official 0:8e251d9511b8 223