fs: littlefs: sample: Add test with binary pattern file modification

This commit extends the littlefs test to use binary pattern file.

This file has the 0x55 and 0xAA patterns (to avoid fast wear leveling)
written alternately with special "marks" bytes on each eight position.
Those values are incremented each time the board boots. One can adjust
the size of this file with the TEST_FILE_SIZE define.

Signed-off-by: Lukasz Majewski <lukma@denx.de>

samples/subsys/fs/littlefs/README.rst

@@ -7,9 +7,11 @@ Overview
 ********
 
 This sample app demonstrates use of Zephyr's :ref:`file system API
-<file_system_api>` over `littlefs`_, using a file system with a file that
+<file_system_api>` over `littlefs`_, using file system with files that:
-counts the number of times the system has booted.  Other information
+* count the number of times the system has booted
-about the file system is also displayed.
+* holds binary pattern with properly incremented values in it
+
+Other information about the file system is also displayed.
 
 .. _littlefs:
    https://github.com/ARMmbed/littlefs

samples/subsys/fs/littlefs/src/main.c

@@ -20,6 +20,7 @@ LOG_MODULE_REGISTER(main);
 
 /* Matches LFS_NAME_MAX */
 #define MAX_PATH_LEN 255
+#define TEST_FILE_SIZE 547
 
 #define PARTITION_NODE DT_NODELABEL(lfs1)
 
@@ -35,6 +36,7 @@ static struct fs_mount_t lfs_storage_mnt = {
 };
 #endif /* PARTITION_NODE */
 
+static uint8_t file_test_pattern[TEST_FILE_SIZE];
 static int lsdir(const char *path)
 {
 	int res;
@@ -123,6 +125,128 @@ static int littlefs_increase_infile_value(char *fname)
 	return (rc < 0 ? rc : 0);
 }
 
+static void incr_pattern(uint8_t *p, uint16_t size, uint8_t inc)
+{
+	uint8_t fill = 0x55;
+
+	if (p[0] % 2 == 0) {
+		fill = 0xAA;
+	}
+
+	for (int i = 0; i < (size - 1); i++) {
+		if (i % 8 == 0) {
+			p[i] += inc;
+		} else {
+			p[i] = fill;
+		}
+	}
+
+	p[size - 1] += inc;
+}
+
+static void init_pattern(uint8_t *p, uint16_t size)
+{
+	uint8_t v = 0x1;
+
+	memset(p, 0x55, size);
+
+	for (int i = 0; i < size; i += 8) {
+		p[i] = v++;
+	}
+
+	p[size - 1] = 0xAA;
+}
+
+static void print_pattern(uint8_t *p, uint16_t size)
+{
+	int i, j = size / 16, k;
+
+	for (k = 0, i = 0; k < j; i += 16, k++) {
+		LOG_PRINTK("%02x %02x %02x %02x %02x %02x %02x %02x ",
+			   p[i], p[i+1], p[i+2], p[i+3],
+			   p[i+4], p[i+5], p[i+6], p[i+7]);
+		LOG_PRINTK("%02x %02x %02x %02x %02x %02x %02x %02x\n",
+			   p[i+8], p[i+9], p[i+10], p[i+11],
+			   p[i+12], p[i+13], p[i+14], p[i+15]);
+
+		/* Mark 512B (sector) chunks of the test file */
+		if ((k + 1) % 32 == 0) {
+			LOG_PRINTK("\n");
+		}
+	}
+
+	for (; i < size; i++) {
+		LOG_PRINTK("%02x ", p[i]);
+	}
+
+	LOG_PRINTK("\n");
+}
+
+static int littlefs_binary_file_adj(char *fname)
+{
+	struct fs_dirent dirent;
+	struct fs_file_t file;
+	int rc, ret;
+
+	/*
+	 * Uncomment below line to force re-creation of the test pattern
+	 * file on the littlefs FS.
+	 */
+	/* fs_unlink(fname); */
+	fs_file_t_init(&file);
+
+	rc = fs_open(&file, fname, FS_O_CREATE | FS_O_RDWR);
+	if (rc < 0) {
+		LOG_ERR("FAIL: open %s: %d", log_strdup(fname), rc);
+		return rc;
+	}
+
+	rc = fs_stat(fname, &dirent);
+	if (rc < 0) {
+		LOG_ERR("FAIL: stat %s: %d", log_strdup(fname), rc);
+		goto out;
+	}
+
+	/* Check if the file exists - if not just write the pattern */
+	if (rc == 0 && dirent.type == FS_DIR_ENTRY_FILE && dirent.size == 0) {
+		LOG_INF("Test file: %s not found, create one!",
+			log_strdup(fname));
+		init_pattern(file_test_pattern, sizeof(file_test_pattern));
+	} else {
+		rc = fs_read(&file, file_test_pattern,
+			     sizeof(file_test_pattern));
+		if (rc < 0) {
+			LOG_ERR("FAIL: read %s: [rd:%d]",
+				log_strdup(fname), rc);
+			goto out;
+		}
+		incr_pattern(file_test_pattern, sizeof(file_test_pattern), 0x1);
+	}
+
+	LOG_PRINTK("------ FILE: %s ------\n", fname);
+	print_pattern(file_test_pattern, sizeof(file_test_pattern));
+
+	rc = fs_seek(&file, 0, FS_SEEK_SET);
+	if (rc < 0) {
+		LOG_ERR("FAIL: seek %s: %d", log_strdup(fname), rc);
+		goto out;
+	}
+
+	rc = fs_write(&file, file_test_pattern, sizeof(file_test_pattern));
+	if (rc < 0) {
+		LOG_ERR("FAIL: write %s: %d", log_strdup(fname), rc);
+	}
+
+ out:
+	ret = fs_close(&file);
+	if (ret < 0) {
+		LOG_ERR("FAIL: close %s: %d", log_strdup(fname), ret);
+		return ret;
+	}
+
+	return (rc < 0 ? rc : 0);
+}
+
 static int littlefs_flash_erase(unsigned int id)
 {
 	const struct flash_area *pfa;
@@ -159,11 +283,13 @@ void main(void)
 #endif
 		;
 
-	char fname[MAX_PATH_LEN];
+	char fname1[MAX_PATH_LEN];
+	char fname2[MAX_PATH_LEN];
 	struct fs_statvfs sbuf;
 	int rc;
 
-	snprintf(fname, sizeof(fname), "%s/boot_count", mp->mnt_point);
+	snprintf(fname1, sizeof(fname1), "%s/boot_count", mp->mnt_point);
+	snprintf(fname2, sizeof(fname2), "%s/pattern.bin", mp->mnt_point);
 
 	rc = littlefs_flash_erase((uintptr_t)mp->storage_dev);
 	if (rc < 0) {
@@ -202,7 +328,12 @@ void main(void)
 		goto out;
 	}
 
-	rc = littlefs_increase_infile_value(fname);
+	rc = littlefs_increase_infile_value(fname1);
+	if (rc) {
+		goto out;
+	}
+
+	rc = littlefs_binary_file_adj(fname2);
 	if (rc) {
 		goto out;
 	}