diff --git a/mongoose.c b/mongoose.c
index 6c060435..5805752d 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -5004,6 +5004,284 @@ bool mg_l2_pppoe_rx(struct mg_tcpip_if *ifp, enum mg_l2proto *proto,
 
 #endif
 
+#ifdef MG_ENABLE_LINES
+#line 1 "src/lfs.c"
+#endif
+// Copyright (c) 2023 Cesanta Software Limited
+// SPDX-License-Identifier: GPL-2.0-only or commercial
+
+
+
+
+#if MG_ENABLE_LFS
+
+#include <fcntl.h>
+#include <littlefs/lfs.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#ifndef LFS_USE_RAM
+#define LFS_USE_RAM 0  // If 1, use RAM FS. If 0, use flash
+#endif
+
+#ifndef MG_LFS_BUF_SIZE
+#define MG_LFS_BUF_SIZE 64  // Buffer size used for reads, writes, and cache
+#endif
+
+#ifndef MG_LFS_FD_BASE
+#define MG_LFS_FD_BASE 12000  // Starting file descriptor number
+#endif
+
+#if LFS_USE_RAM && !defined(MG_LFS_BLOCK_SIZE)
+#define MG_LFS_BLOCK_SIZE 8192
+#endif
+
+#ifndef DT_DIR
+#define DT_DIR 4
+#endif
+#ifndef DT_REG
+#define DT_REG 8
+#endif
+
+typedef struct mg_lfs_fd DIR;
+struct dirent {
+  char d_name[LFS_NAME_MAX + 1];
+  unsigned char d_type;
+};
+
+struct mg_lfs_fd {
+  struct mg_lfs_fd *next;
+  bool isopen;
+  lfs_file_t file;
+  lfs_dir_t dir;
+  int fd;
+};
+
+static lfs_t s_lfs;
+static struct mg_lfs_fd *s_fds;
+static uint8_t *s_fs;
+static int s_next_fd = MG_LFS_FD_BASE;
+static bool s_lfs_ready;
+#if LFS_USE_RAM
+static uint8_t *s_ram_fs;
+#endif
+
+static int lfs_driver_read(const struct lfs_config *cfg, lfs_block_t block,
+                           lfs_off_t off, void *buf, lfs_size_t len);
+static int lfs_driver_prog(const struct lfs_config *cfg, lfs_block_t block,
+                           lfs_off_t off, const void *buf, lfs_size_t len);
+static int lfs_driver_erase(const struct lfs_config *cfg, lfs_block_t block);
+static int lfs_driver_sync(const struct lfs_config *cfg);
+
+static struct lfs_config s_cfg = {
+    .read = lfs_driver_read,
+    .prog = lfs_driver_prog,
+    .erase = lfs_driver_erase,
+    .sync = lfs_driver_sync,
+    .block_cycles = 200,
+    .cache_size = MG_LFS_BUF_SIZE,
+    .read_size = MG_LFS_BUF_SIZE,
+    .prog_size = MG_LFS_BUF_SIZE,
+    .lookahead_size = MG_LFS_BUF_SIZE / 8,
+};
+
+static bool flash_write_buf(void *addr, const void *buf, size_t len) {
+#if LFS_USE_RAM
+  memmove(addr, buf, len);
+  return true;
+#else
+  return mg_flash != NULL && mg_flash->write_fn(addr, buf, len);
+#endif
+}
+
+static int lfs_driver_read(const struct lfs_config *cfg, lfs_block_t block,
+                           lfs_off_t off, void *buf, lfs_size_t len) {
+  memmove(buf, &s_fs[block * cfg->block_size + off], len);
+  return 0;
+}
+
+static int lfs_driver_prog(const struct lfs_config *cfg, lfs_block_t block,
+                           lfs_off_t off, const void *buf, lfs_size_t len) {
+  uint8_t *dst = &s_fs[block * cfg->block_size + off];
+  if (!flash_write_buf(dst, buf, len)) return LFS_ERR_IO;
+  return 0;
+}
+
+static int lfs_driver_erase(const struct lfs_config *cfg, lfs_block_t block) {
+  (void) cfg, (void) block;
+  return 0;
+}
+
+static int lfs_driver_sync(const struct lfs_config *cfg) {
+  (void) cfg;
+  return 0;
+}
+
+bool mg_lfs_init(size_t size) {
+  int result = 0;
+  if (s_lfs_ready) return true;
+  if (size == 0) return false;
+#if LFS_USE_RAM
+  s_cfg.block_size = MG_LFS_BLOCK_SIZE;
+  if (s_ram_fs == NULL) s_ram_fs = (uint8_t *) mg_calloc(1, size);
+  s_fs = s_ram_fs;
+#else
+  if (mg_flash == NULL || mg_flash->secsz == 0 || mg_flash->size < size) return false;
+  if (mg_flash->write_fn == NULL) return false;
+  s_cfg.block_size = mg_flash->secsz;
+  s_fs = (uint8_t *) mg_flash->start + mg_flash->size - size;
+#endif
+  if (s_fs == NULL || s_cfg.block_size == 0 || size % s_cfg.block_size != 0) {
+    return false;
+  }
+  s_cfg.block_count = (lfs_size_t) (size / s_cfg.block_size);
+  if (s_cfg.block_count == 0) return false;
+  if (lfs_mount(&s_lfs, &s_cfg) != 0) {
+    lfs_format(&s_lfs, &s_cfg);
+    if (lfs_mount(&s_lfs, &s_cfg) != 0) result = -1;
+  }
+  s_lfs_ready = result == 0;
+  return s_lfs_ready;
+}
+
+static struct mg_lfs_fd *find_fd(int fd) {
+  struct mg_lfs_fd *f;
+  for (f = s_fds; f != NULL; f = f->next) {
+    if (f->isopen && f->fd == fd) return f;
+  }
+  return NULL;
+}
+
+static struct mg_lfs_fd *open_fd(void) {
+  struct mg_lfs_fd *f = NULL;
+  if (s_lfs_ready) {
+    f = (struct mg_lfs_fd *) mg_calloc(1, sizeof(*f));
+    if (f != NULL) {
+      f->isopen = true;
+      f->fd = s_next_fd++;
+      f->next = s_fds;
+      s_fds = f;
+      if (s_next_fd < MG_LFS_FD_BASE) s_next_fd = MG_LFS_FD_BASE;
+    }
+  }
+  return f;
+}
+
+static int close_fd(struct mg_lfs_fd *fd) {
+  struct mg_lfs_fd **f = &s_fds;
+  while (*f != NULL && *f != fd) f = &(*f)->next;
+  if (*f == NULL) return -1;
+  *f = fd->next;
+  fd->isopen = false;
+  mg_free(fd);
+  return 0;
+}
+
+int _open(const char *path, int flags, mode_t mode) {
+  int err, lfs_flags = 0, fd = -1;
+  struct mg_lfs_fd *f = open_fd();
+  (void) mode;
+  if (f == NULL) return -1;
+  fd = f->fd;
+  if ((flags & 3) == O_RDONLY) lfs_flags |= LFS_O_RDONLY;
+  if ((flags & 3) == O_WRONLY) lfs_flags |= LFS_O_WRONLY;
+  if ((flags & 3) == O_RDWR) lfs_flags |= LFS_O_RDWR;
+  if (flags & O_CREAT) lfs_flags |= LFS_O_CREAT;
+  if (flags & O_TRUNC) lfs_flags |= LFS_O_TRUNC;
+  if (flags & O_APPEND) lfs_flags |= LFS_O_APPEND;
+  err = lfs_file_open(&s_lfs, &f->file, path, lfs_flags);
+  if (err < 0) close_fd(f), fd = -1;
+  return fd;
+}
+
+int _close(int fd) {
+  struct mg_lfs_fd *f = find_fd(fd);
+  if (fd < 3) return 0;
+  if (f == NULL) return -1;
+  lfs_file_close(&s_lfs, &f->file);
+  close_fd(f);
+  return 0;
+}
+
+int _write(int fd, char *ptr, int len) {
+  struct mg_lfs_fd *f = find_fd(fd);
+  return fd < 3 ? len
+                : f == NULL ? -1 : lfs_file_write(&s_lfs, &f->file, ptr, len);
+}
+
+int _read(int fd, char *ptr, int len) {
+  struct mg_lfs_fd *f = find_fd(fd);
+  return fd < 3 ? 0 : f == NULL ? -1 : lfs_file_read(&s_lfs, &f->file, ptr, len);
+}
+
+int _lseek(int fd, int offset, int whence) {
+  struct mg_lfs_fd *f = find_fd(fd);
+  return fd < 3 ? 0
+                : f == NULL ? -1 : lfs_file_seek(&s_lfs, &f->file, offset,
+                                                  whence);
+}
+
+int _rename(const char *oldname, const char *newname) {
+  return s_lfs_ready ? lfs_rename(&s_lfs, oldname, newname) : -1;
+}
+
+int _unlink_r(void *r, const char *a) {
+  (void) r;
+  return s_lfs_ready ? lfs_remove(&s_lfs, a) : -1;
+}
+
+DIR *opendir(const char *name) {
+  struct mg_lfs_fd *f = open_fd();
+  if (f == NULL) return NULL;
+  if (lfs_dir_open(&s_lfs, &f->dir, name) != 0) {
+    close_fd(f);
+    return NULL;
+  }
+  return (DIR *) f;
+}
+
+int closedir(DIR *dir) {
+  struct mg_lfs_fd *f = (struct mg_lfs_fd *) dir;
+  if (f == NULL || find_fd(f->fd) != f) return -1;
+  lfs_dir_close(&s_lfs, &f->dir);
+  return close_fd(f);
+}
+
+struct dirent *readdir(DIR *dir) {
+  static struct dirent dirent;
+  struct mg_lfs_fd *f = (struct mg_lfs_fd *) dir;
+  struct lfs_info info;
+  if (f == NULL || !f->isopen) return NULL;
+  if (lfs_dir_read(&s_lfs, &f->dir, &info) < 1) return NULL;
+  memset(&dirent, 0, sizeof(dirent));
+  strncpy(dirent.d_name, info.name, sizeof(dirent.d_name) - 1);
+  if (info.type == LFS_TYPE_DIR) dirent.d_type |= DT_DIR;
+  if (info.type == LFS_TYPE_REG) dirent.d_type |= DT_REG;
+  return &dirent;
+}
+
+int _stat(const char *path, struct stat *st) {
+  struct lfs_info info;
+  if (!s_lfs_ready || lfs_stat(&s_lfs, path, &info) != 0) return -1;
+  st->st_mode = info.type == LFS_TYPE_DIR ? S_IFDIR : S_IFREG;
+  st->st_size = info.size;
+  return 0;
+}
+
+int _fstat(int fd, struct stat *st) {
+  if (fd >= 3 && find_fd(fd) == NULL) return -1;
+  st->st_mode = S_IFCHR;
+  return 0;
+}
+
+int mkdir(const char *path, mode_t mode) {
+  (void) mode;
+  return s_lfs_ready ? lfs_mkdir(&s_lfs, path) : -1;
+}
+
+#endif
+
 #ifdef MG_ENABLE_LINES
 #line 1 "src/log.c"
 #endif
@@ -9037,6 +9315,7 @@ bool mg_ota_end(void) {
   }
   return false;
 }
+struct mg_flash *mg_flash = &s_mg_flash_ch32v307;
 #endif
 
 #ifdef MG_ENABLE_LINES
@@ -9709,7 +9988,7 @@ bool mg_ota_end(void) {
   }
   return false;
 }
-
+struct mg_flash *mg_flash = &s_mg_flash_imxrt;
 #endif
 
 #ifdef MG_ENABLE_LINES
@@ -9923,6 +10202,7 @@ bool mg_ota_end(void) {
   }
   return false;
 }
+struct mg_flash *mg_flash = &s_mg_flash_mcxn;
 #endif
 
 #ifdef MG_ENABLE_LINES
@@ -10095,6 +10375,7 @@ bool mg_ota_end(void) {
   }
   return false;
 }
+struct mg_flash *mg_flash = &s_mg_flash_picosdk;
 #endif
 
 #ifdef MG_ENABLE_LINES
@@ -10462,7 +10743,7 @@ bool mg_ota_end(void) {
   }
   return false;
 }
-
+struct mg_flash *mg_flash = &s_mg_flash_frdm;
 #endif
 
 #ifdef MG_ENABLE_LINES
@@ -10697,6 +10978,7 @@ bool mg_ota_end(void) {
   }
   return false;
 }
+struct mg_flash *mg_flash = &s_mg_flash_stm32f;
 #endif
 
 #ifdef MG_ENABLE_LINES
@@ -10856,6 +11138,7 @@ bool mg_ota_end(void) {
   *(volatile unsigned long *) 0xe000ed0c = 0x5fa0004;
   return true;
 }
+struct mg_flash *mg_flash = &s_mg_flash_stm32h5;
 #endif
 
 #ifdef MG_ENABLE_LINES
@@ -11080,6 +11363,7 @@ bool mg_ota_end(void) {
   }
   return false;
 }
+struct mg_flash *mg_flash = &s_mg_flash_stm32h7;
 #endif
 
 #ifdef MG_ENABLE_LINES
diff --git a/mongoose.h b/mongoose.h
index 1684c72a..9a499ded 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -933,6 +933,10 @@ struct timeval {
 #define MG_ENABLE_FATFS 0
 #endif
 
+#ifndef MG_ENABLE_LFS
+#define MG_ENABLE_LFS 0
+#endif
+
 #ifndef MG_ENABLE_SSI
 #define MG_ENABLE_SSI 0
 #endif
@@ -3283,7 +3287,8 @@ void mg_ota_url_check(struct mg_mgr *mgr,
 
 
 
-#if MG_OTA != MG_OTA_NONE && MG_OTA != MG_OTA_CUSTOM
+
+#if (MG_OTA != MG_OTA_NONE && MG_OTA != MG_OTA_CUSTOM) || MG_ENABLE_LFS
 
 struct mg_flash {
   void *start;    // Address at which flash starts
@@ -3294,6 +3299,9 @@ struct mg_flash {
   bool (*swap_fn)(void);                           // Swap partitions
 };
 
+extern struct mg_flash *mg_flash;
+bool mg_lfs_init(size_t size);
+
 bool mg_ota_flash_begin(size_t new_firmware_size, struct mg_flash *flash);
 bool mg_ota_flash_write(const void *buf, size_t len, struct mg_flash *flash);
 bool mg_ota_flash_end(struct mg_flash *flash);
diff --git a/src/config.h b/src/config.h
index b66688a4..b38a4b70 100644
--- a/src/config.h
+++ b/src/config.h
@@ -48,6 +48,10 @@
 #define MG_ENABLE_FATFS 0
 #endif
 
+#ifndef MG_ENABLE_LFS
+#define MG_ENABLE_LFS 0
+#endif
+
 #ifndef MG_ENABLE_SSI
 #define MG_ENABLE_SSI 0
 #endif
diff --git a/src/flash.h b/src/flash.h
index 9fa04a4c..8b42bf73 100644
--- a/src/flash.h
+++ b/src/flash.h
@@ -1,7 +1,8 @@
 #include "arch.h"
+#include "config.h"
 #include "ota.h"
 
-#if MG_OTA != MG_OTA_NONE && MG_OTA != MG_OTA_CUSTOM
+#if (MG_OTA != MG_OTA_NONE && MG_OTA != MG_OTA_CUSTOM) || MG_ENABLE_LFS
 
 struct mg_flash {
   void *start;    // Address at which flash starts
@@ -12,6 +13,9 @@ struct mg_flash {
   bool (*swap_fn)(void);                           // Swap partitions
 };
 
+extern struct mg_flash *mg_flash;
+bool mg_lfs_init(size_t size);
+
 bool mg_ota_flash_begin(size_t new_firmware_size, struct mg_flash *flash);
 bool mg_ota_flash_write(const void *buf, size_t len, struct mg_flash *flash);
 bool mg_ota_flash_end(struct mg_flash *flash);
diff --git a/src/lfs.c b/src/lfs.c
new file mode 100644
index 00000000..e4b2c44f
--- /dev/null
+++ b/src/lfs.c
@@ -0,0 +1,274 @@
+// Copyright (c) 2023 Cesanta Software Limited
+// SPDX-License-Identifier: GPL-2.0-only or commercial
+
+#include "flash.h"
+#include "util.h"
+
+#if MG_ENABLE_LFS
+
+#include <fcntl.h>
+#include <littlefs/lfs.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#ifndef LFS_USE_RAM
+#define LFS_USE_RAM 0  // If 1, use RAM FS. If 0, use flash
+#endif
+
+#ifndef MG_LFS_BUF_SIZE
+#define MG_LFS_BUF_SIZE 64  // Buffer size used for reads, writes, and cache
+#endif
+
+#ifndef MG_LFS_FD_BASE
+#define MG_LFS_FD_BASE 12000  // Starting file descriptor number
+#endif
+
+#if LFS_USE_RAM && !defined(MG_LFS_BLOCK_SIZE)
+#define MG_LFS_BLOCK_SIZE 8192
+#endif
+
+#ifndef DT_DIR
+#define DT_DIR 4
+#endif
+#ifndef DT_REG
+#define DT_REG 8
+#endif
+
+typedef struct mg_lfs_fd DIR;
+struct dirent {
+  char d_name[LFS_NAME_MAX + 1];
+  unsigned char d_type;
+};
+
+struct mg_lfs_fd {
+  struct mg_lfs_fd *next;
+  bool isopen;
+  lfs_file_t file;
+  lfs_dir_t dir;
+  int fd;
+};
+
+static lfs_t s_lfs;
+static struct mg_lfs_fd *s_fds;
+static uint8_t *s_fs;
+static int s_next_fd = MG_LFS_FD_BASE;
+static bool s_lfs_ready;
+#if LFS_USE_RAM
+static uint8_t *s_ram_fs;
+#endif
+
+static int lfs_driver_read(const struct lfs_config *cfg, lfs_block_t block,
+                           lfs_off_t off, void *buf, lfs_size_t len);
+static int lfs_driver_prog(const struct lfs_config *cfg, lfs_block_t block,
+                           lfs_off_t off, const void *buf, lfs_size_t len);
+static int lfs_driver_erase(const struct lfs_config *cfg, lfs_block_t block);
+static int lfs_driver_sync(const struct lfs_config *cfg);
+
+static struct lfs_config s_cfg = {
+    .read = lfs_driver_read,
+    .prog = lfs_driver_prog,
+    .erase = lfs_driver_erase,
+    .sync = lfs_driver_sync,
+    .block_cycles = 200,
+    .cache_size = MG_LFS_BUF_SIZE,
+    .read_size = MG_LFS_BUF_SIZE,
+    .prog_size = MG_LFS_BUF_SIZE,
+    .lookahead_size = MG_LFS_BUF_SIZE / 8,
+};
+
+static bool flash_write_buf(void *addr, const void *buf, size_t len) {
+#if LFS_USE_RAM
+  memmove(addr, buf, len);
+  return true;
+#else
+  return mg_flash != NULL && mg_flash->write_fn(addr, buf, len);
+#endif
+}
+
+static int lfs_driver_read(const struct lfs_config *cfg, lfs_block_t block,
+                           lfs_off_t off, void *buf, lfs_size_t len) {
+  memmove(buf, &s_fs[block * cfg->block_size + off], len);
+  return 0;
+}
+
+static int lfs_driver_prog(const struct lfs_config *cfg, lfs_block_t block,
+                           lfs_off_t off, const void *buf, lfs_size_t len) {
+  uint8_t *dst = &s_fs[block * cfg->block_size + off];
+  if (!flash_write_buf(dst, buf, len)) return LFS_ERR_IO;
+  return 0;
+}
+
+static int lfs_driver_erase(const struct lfs_config *cfg, lfs_block_t block) {
+  (void) cfg, (void) block;
+  return 0;
+}
+
+static int lfs_driver_sync(const struct lfs_config *cfg) {
+  (void) cfg;
+  return 0;
+}
+
+bool mg_lfs_init(size_t size) {
+  int result = 0;
+  if (s_lfs_ready) return true;
+  if (size == 0) return false;
+#if LFS_USE_RAM
+  s_cfg.block_size = MG_LFS_BLOCK_SIZE;
+  if (s_ram_fs == NULL) s_ram_fs = (uint8_t *) mg_calloc(1, size);
+  s_fs = s_ram_fs;
+#else
+  if (mg_flash == NULL || mg_flash->secsz == 0 || mg_flash->size < size) return false;
+  if (mg_flash->write_fn == NULL) return false;
+  s_cfg.block_size = mg_flash->secsz;
+  s_fs = (uint8_t *) mg_flash->start + mg_flash->size - size;
+#endif
+  if (s_fs == NULL || s_cfg.block_size == 0 || size % s_cfg.block_size != 0) {
+    return false;
+  }
+  s_cfg.block_count = (lfs_size_t) (size / s_cfg.block_size);
+  if (s_cfg.block_count == 0) return false;
+  if (lfs_mount(&s_lfs, &s_cfg) != 0) {
+    lfs_format(&s_lfs, &s_cfg);
+    if (lfs_mount(&s_lfs, &s_cfg) != 0) result = -1;
+  }
+  s_lfs_ready = result == 0;
+  return s_lfs_ready;
+}
+
+static struct mg_lfs_fd *find_fd(int fd) {
+  struct mg_lfs_fd *f;
+  for (f = s_fds; f != NULL; f = f->next) {
+    if (f->isopen && f->fd == fd) return f;
+  }
+  return NULL;
+}
+
+static struct mg_lfs_fd *open_fd(void) {
+  struct mg_lfs_fd *f = NULL;
+  if (s_lfs_ready) {
+    f = (struct mg_lfs_fd *) mg_calloc(1, sizeof(*f));
+    if (f != NULL) {
+      f->isopen = true;
+      f->fd = s_next_fd++;
+      f->next = s_fds;
+      s_fds = f;
+      if (s_next_fd < MG_LFS_FD_BASE) s_next_fd = MG_LFS_FD_BASE;
+    }
+  }
+  return f;
+}
+
+static int close_fd(struct mg_lfs_fd *fd) {
+  struct mg_lfs_fd **f = &s_fds;
+  while (*f != NULL && *f != fd) f = &(*f)->next;
+  if (*f == NULL) return -1;
+  *f = fd->next;
+  fd->isopen = false;
+  mg_free(fd);
+  return 0;
+}
+
+int _open(const char *path, int flags, mode_t mode) {
+  int err, lfs_flags = 0, fd = -1;
+  struct mg_lfs_fd *f = open_fd();
+  (void) mode;
+  if (f == NULL) return -1;
+  fd = f->fd;
+  if ((flags & 3) == O_RDONLY) lfs_flags |= LFS_O_RDONLY;
+  if ((flags & 3) == O_WRONLY) lfs_flags |= LFS_O_WRONLY;
+  if ((flags & 3) == O_RDWR) lfs_flags |= LFS_O_RDWR;
+  if (flags & O_CREAT) lfs_flags |= LFS_O_CREAT;
+  if (flags & O_TRUNC) lfs_flags |= LFS_O_TRUNC;
+  if (flags & O_APPEND) lfs_flags |= LFS_O_APPEND;
+  err = lfs_file_open(&s_lfs, &f->file, path, lfs_flags);
+  if (err < 0) close_fd(f), fd = -1;
+  return fd;
+}
+
+int _close(int fd) {
+  struct mg_lfs_fd *f = find_fd(fd);
+  if (fd < 3) return 0;
+  if (f == NULL) return -1;
+  lfs_file_close(&s_lfs, &f->file);
+  close_fd(f);
+  return 0;
+}
+
+int _write(int fd, char *ptr, int len) {
+  struct mg_lfs_fd *f = find_fd(fd);
+  return fd < 3 ? len
+                : f == NULL ? -1 : lfs_file_write(&s_lfs, &f->file, ptr, len);
+}
+
+int _read(int fd, char *ptr, int len) {
+  struct mg_lfs_fd *f = find_fd(fd);
+  return fd < 3 ? 0 : f == NULL ? -1 : lfs_file_read(&s_lfs, &f->file, ptr, len);
+}
+
+int _lseek(int fd, int offset, int whence) {
+  struct mg_lfs_fd *f = find_fd(fd);
+  return fd < 3 ? 0
+                : f == NULL ? -1 : lfs_file_seek(&s_lfs, &f->file, offset,
+                                                  whence);
+}
+
+int _rename(const char *oldname, const char *newname) {
+  return s_lfs_ready ? lfs_rename(&s_lfs, oldname, newname) : -1;
+}
+
+int _unlink_r(void *r, const char *a) {
+  (void) r;
+  return s_lfs_ready ? lfs_remove(&s_lfs, a) : -1;
+}
+
+DIR *opendir(const char *name) {
+  struct mg_lfs_fd *f = open_fd();
+  if (f == NULL) return NULL;
+  if (lfs_dir_open(&s_lfs, &f->dir, name) != 0) {
+    close_fd(f);
+    return NULL;
+  }
+  return (DIR *) f;
+}
+
+int closedir(DIR *dir) {
+  struct mg_lfs_fd *f = (struct mg_lfs_fd *) dir;
+  if (f == NULL || find_fd(f->fd) != f) return -1;
+  lfs_dir_close(&s_lfs, &f->dir);
+  return close_fd(f);
+}
+
+struct dirent *readdir(DIR *dir) {
+  static struct dirent dirent;
+  struct mg_lfs_fd *f = (struct mg_lfs_fd *) dir;
+  struct lfs_info info;
+  if (f == NULL || !f->isopen) return NULL;
+  if (lfs_dir_read(&s_lfs, &f->dir, &info) < 1) return NULL;
+  memset(&dirent, 0, sizeof(dirent));
+  strncpy(dirent.d_name, info.name, sizeof(dirent.d_name) - 1);
+  if (info.type == LFS_TYPE_DIR) dirent.d_type |= DT_DIR;
+  if (info.type == LFS_TYPE_REG) dirent.d_type |= DT_REG;
+  return &dirent;
+}
+
+int _stat(const char *path, struct stat *st) {
+  struct lfs_info info;
+  if (!s_lfs_ready || lfs_stat(&s_lfs, path, &info) != 0) return -1;
+  st->st_mode = info.type == LFS_TYPE_DIR ? S_IFDIR : S_IFREG;
+  st->st_size = info.size;
+  return 0;
+}
+
+int _fstat(int fd, struct stat *st) {
+  if (fd >= 3 && find_fd(fd) == NULL) return -1;
+  st->st_mode = S_IFCHR;
+  return 0;
+}
+
+int mkdir(const char *path, mode_t mode) {
+  (void) mode;
+  return s_lfs_ready ? lfs_mkdir(&s_lfs, path) : -1;
+}
+
+#endif
diff --git a/src/ota_ch32v307.c b/src/ota_ch32v307.c
index d9347ac4..0093c680 100644
--- a/src/ota_ch32v307.c
+++ b/src/ota_ch32v307.c
@@ -109,4 +109,5 @@ bool mg_ota_end(void) {
   }
   return false;
 }
+struct mg_flash *mg_flash = &s_mg_flash_ch32v307;
 #endif
diff --git a/src/ota_imxrt.c b/src/ota_imxrt.c
index a1ec3d9a..49db3e37 100644
--- a/src/ota_imxrt.c
+++ b/src/ota_imxrt.c
@@ -589,5 +589,5 @@ bool mg_ota_end(void) {
   }
   return false;
 }
-
+struct mg_flash *mg_flash = &s_mg_flash_imxrt;
 #endif
diff --git a/src/ota_mcxn.c b/src/ota_mcxn.c
index acd041bb..110f2718 100644
--- a/src/ota_mcxn.c
+++ b/src/ota_mcxn.c
@@ -206,4 +206,5 @@ bool mg_ota_end(void) {
   }
   return false;
 }
+struct mg_flash *mg_flash = &s_mg_flash_mcxn;
 #endif
diff --git a/src/ota_picosdk.c b/src/ota_picosdk.c
index b6900ccf..2460b646 100644
--- a/src/ota_picosdk.c
+++ b/src/ota_picosdk.c
@@ -165,4 +165,5 @@ bool mg_ota_end(void) {
   }
   return false;
 }
+struct mg_flash *mg_flash = &s_mg_flash_picosdk;
 #endif
diff --git a/src/ota_rw612.c b/src/ota_rw612.c
index ee441d30..b0bae478 100644
--- a/src/ota_rw612.c
+++ b/src/ota_rw612.c
@@ -360,5 +360,5 @@ bool mg_ota_end(void) {
   }
   return false;
 }
-
+struct mg_flash *mg_flash = &s_mg_flash_frdm;
 #endif
diff --git a/src/ota_stm32f.c b/src/ota_stm32f.c
index 64025091..2e1aacd5 100644
--- a/src/ota_stm32f.c
+++ b/src/ota_stm32f.c
@@ -227,4 +227,5 @@ bool mg_ota_end(void) {
   }
   return false;
 }
+struct mg_flash *mg_flash = &s_mg_flash_stm32f;
 #endif
diff --git a/src/ota_stm32h5.c b/src/ota_stm32h5.c
index f03a2e4e..6977293a 100644
--- a/src/ota_stm32h5.c
+++ b/src/ota_stm32h5.c
@@ -152,4 +152,5 @@ bool mg_ota_end(void) {
   *(volatile unsigned long *) 0xe000ed0c = 0x5fa0004;
   return true;
 }
+struct mg_flash *mg_flash = &s_mg_flash_stm32h5;
 #endif
diff --git a/src/ota_stm32h7.c b/src/ota_stm32h7.c
index d70428c2..6ea5c28c 100644
--- a/src/ota_stm32h7.c
+++ b/src/ota_stm32h7.c
@@ -217,4 +217,5 @@ bool mg_ota_end(void) {
   }
   return false;
 }
+struct mg_flash *mg_flash = &s_mg_flash_stm32h7;
 #endif
diff --git a/tutorials/stm32/nucleo-h563zi/minimal-lfs/Makefile b/tutorials/stm32/nucleo-h563zi/minimal-lfs/Makefile
new file mode 100644
index 00000000..2aa83daa
--- /dev/null
+++ b/tutorials/stm32/nucleo-h563zi/minimal-lfs/Makefile
@@ -0,0 +1,66 @@
+# Copyright (c) 2026 Cesanta Software Limited
+# Environment setup: https://mongoose.ws/docs/getting-started/build-environment/
+
+CFLAGS  = -W -Wall -Wextra -Wundef -Wshadow -Wdouble-promotion
+CFLAGS += -Wformat-truncation -fno-common -Wconversion -Wno-sign-conversion
+CFLAGS += -g3 -Os -ffunction-sections -fdata-sections
+CFLAGS += -I. -Icmsis_core/CMSIS/Core/Include -Icmsis_h5/Include -Imongoose
+CFLAGS += -mcpu=cortex-m33 -mthumb -mfpu=fpv5-sp-d16 -mfloat-abi=hard $(CFLAGS_EXTRA)
+LDFLAGS ?= -Tlink.ld -nostdlib -nostartfiles --specs nosys.specs -lc -lgcc -Wl,--gc-sections -Wl,-Map=$@.map
+
+SOURCES = main.c hal.c
+SOURCES += littlefs/lfs.c littlefs/lfs_util.c
+SOURCES += cmsis_h5/Source/Templates/gcc/startup_stm32h563xx.s
+SOURCES += mongoose/mongoose.c
+
+# Disabled for littlefs/lfs.c
+CFLAGS += -Wno-conversion -Wno-shadow
+CFLAGS += -DMG_ENABLE_LFS=1
+
+all build example: firmware.bin
+
+mongoose/mongoose.c mongoose/mongoose.h:
+	cp ../../../../mongoose.[ch] mongoose/
+
+firmware.elf: cmsis_core cmsis_h5 littlefs hal.h link.ld Makefile $(SOURCES) mongoose/mongoose.h
+	arm-none-eabi-gcc $(SOURCES) $(CFLAGS) $(CFLAGS_EXTRA) $(LDFLAGS) -o $@
+
+firmware.bin: firmware.elf
+	arm-none-eabi-objcopy -O binary $< $@
+	@echo
+	@echo "To flash, run 'make flash', or use STM32CubeProgrammer"
+
+flash: firmware.bin
+	STM32_Programmer_CLI -c port=swd mode=UR -w firmware.elf -hardRst
+
+gdb: firmware.elf
+	arm-none-eabi-gdb -q $^ -ex='set confirm off' -ex 'target remote :61234'
+
+# Directory where STM32_Programmer_CLI binary lives
+CUBEPROG_DIR ?= $(dir $(shell which STM32_Programmer_CLI))
+gdb_server:
+	ST-LINK_gdbserver --port-number 61234 --log-level 1 --swd --verify --stm32cubeprogrammer-path $(CUBEPROG_DIR) --apid 1 --initialize-reset
+
+
+cmsis_core:
+	git clone -q -c advice.detachedHead=false --depth 1 -b 5.9.0 https://github.com/ARM-software/CMSIS_5 $@
+
+cmsis_h5:
+	git clone -q -c advice.detachedHead=false --depth 1 -b v1.6.0 https://github.com/STMicroelectronics/cmsis-device-h5 $@
+
+littlefs/lfs.c littlefs/lfs_util.c: littlefs
+littlefs:
+	git clone -q -c advice.detachedHead=false --depth 1 -b v2.11.3 https://github.com/littlefs-project/littlefs $@
+
+clean:
+	rm -rf firmware.* cmsis_* littlefs/ mongoose/mongoose.*
+
+# Automated remote test. Requires env variable VCON_API_KEY set. See https://vcon.io/automated-firmware-tests/
+DEVICE_URL ?= https://dash.vcon.io/api/v3/devices/11
+update: firmware.bin
+	curl --fail-with-body -su :$(VCON_API_KEY) $(DEVICE_URL)/ota --data-binary @$<
+
+test update: CFLAGS_EXTRA = -DUART_DEBUG=USART1
+test: update
+	curl --fail-with-body -su :$(VCON_API_KEY) $(DEVICE_URL)/tx?t=15 | tee /tmp/output.txt
+	grep 'READY, IP:' /tmp/output.txt       # Check for network init
diff --git a/tutorials/stm32/nucleo-h563zi/minimal-lfs/hal.c b/tutorials/stm32/nucleo-h563zi/minimal-lfs/hal.c
new file mode 100644
index 00000000..e519bff3
--- /dev/null
+++ b/tutorials/stm32/nucleo-h563zi/minimal-lfs/hal.c
@@ -0,0 +1,125 @@
+// Copyright (c) 2026 Cesanta Software Limited
+// All rights reserved
+
+#include "hal.h"
+
+bool hal_timer_expired(volatile uint64_t *t, uint64_t period, uint64_t now) {
+  uint64_t diff = now - *t;         // Wrap-safe elapsed time since last expiry
+  if (period == 0) return false;    // Avoid division by zero
+  if (diff < period) return false;  // Period has not elapsed yet
+  *t += (diff / period) * period;   // Preserve cadence, skip missed periods
+  return true;
+}
+
+static volatile uint64_t s_ticks;  // Milliseconds since boot
+void SysTick_Handler(void) {       // SyStick IRQ handler, triggered every 1ms
+  s_ticks++;
+}
+
+uint64_t hal_get_tick(void) {
+  return s_ticks;
+};
+
+uint32_t SystemCoreClock = 160000000;
+void SystemInit(void) {  // Called automatically by startup code
+  hal_system_init();     // Enable FPU
+  hal_clock_init();
+  SysTick_Config(SystemCoreClock / 1000);  // Sys tick every 1ms
+}
+
+void ExitRun0Mode(void) {
+}
+
+struct stat;
+__attribute__((weak)) int _fstat(int fd, struct stat *st) {
+  (void) fd, (void) st;
+  return -1;
+}
+
+extern unsigned char _end[];  // End of data section, start of heap. See link.ld
+static unsigned char *s_current_heap_end = _end;
+
+size_t hal_ram_used(void) {
+  return (size_t) (s_current_heap_end - _end);
+}
+
+size_t hal_ram_free(void) {
+  unsigned char endofstack;
+  return (size_t) (&endofstack - s_current_heap_end);
+}
+
+void *_sbrk(int incr) {
+  unsigned char *prev_heap;
+  unsigned char *heap_end = (unsigned char *) ((size_t) &heap_end - 256);
+  prev_heap = s_current_heap_end;
+  // Check how much space we  got from the heap end to the stack end
+  if (s_current_heap_end + incr > heap_end) return (void *) -1;
+  s_current_heap_end += incr;
+  return prev_heap;
+}
+
+__attribute__((weak)) int _open(const char *path) {
+  (void) path;
+  return -1;
+}
+
+__attribute__((weak)) int _close(int fd) {
+  (void) fd;
+  return -1;
+}
+
+__attribute__((weak)) int _isatty(int fd) {
+  (void) fd;
+  return 1;
+}
+
+__attribute__((weak)) int _lseek(int fd, int ptr, int dir) {
+  (void) fd, (void) ptr, (void) dir;
+  return 0;
+}
+
+__attribute__((weak)) void _exit(int status) {
+  (void) status;
+  for (;;) asm volatile("BKPT #0");
+}
+
+__attribute__((weak)) void _kill(int pid, int sig) {
+  (void) pid, (void) sig;
+}
+
+__attribute__((weak)) int _getpid(void) {
+  return -1;
+}
+
+__attribute__((weak)) int _write(int fd, char *ptr, int len) {
+  (void) fd, (void) ptr, (void) len;
+  return -1;
+}
+
+__attribute__((weak)) int _read(int fd, char *ptr, int len) {
+  (void) fd, (void) ptr, (void) len;
+  return -1;
+}
+
+__attribute__((weak)) int _link(const char *a, const char *b) {
+  (void) a, (void) b;
+  return -1;
+}
+
+__attribute__((weak)) int _unlink(const char *a) {
+  (void) a;
+  return -1;
+}
+
+__attribute__((weak)) int _stat(const char *path, struct stat *st) {
+  (void) path, (void) st;
+  return -1;
+}
+
+__attribute__((weak)) int mkdir(const char *path, int mode) {
+  (void) path, (void) mode;
+  return -1;
+}
+
+__attribute__((weak)) void _init(void) {
+}
diff --git a/tutorials/stm32/nucleo-h563zi/minimal-lfs/hal.h b/tutorials/stm32/nucleo-h563zi/minimal-lfs/hal.h
new file mode 100644
index 00000000..d66a7620
--- /dev/null
+++ b/tutorials/stm32/nucleo-h563zi/minimal-lfs/hal.h
@@ -0,0 +1,212 @@
+// Copyright (c) 2022-2026 Cesanta Software Limited
+// All rights reserved
+//
+// Datasheet: RM0481, devboard manual: UM3115
+// https://www.st.com/resource/en/reference_manual/rm0481-stm32h563h573-and-stm32h562-armbased-32bit-mcus-stmicroelectronics.pdf
+// Alternate functions: https://www.st.com/resource/en/datasheet/stm32h563vi.pdf
+
+#pragma once
+
+#include <stm32h563xx.h>
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+void hal_init(void);
+size_t hal_ram_free(void);
+size_t hal_ram_used(void);
+bool hal_timer_expired(volatile uint64_t *t, uint64_t prd, uint64_t now);
+uint64_t hal_get_tick(void);
+
+#define BIT(x) (1UL << (x))
+#define CLRSET(R, CLEARMASK, SETMASK) (R) = ((R) & ~(CLEARMASK)) | (SETMASK)
+#define PIN(bank, num) ((((bank) - 'A') << 8) | (num))
+#define PINNO(pin) (pin & 255)
+#define PINBANK(pin) (pin >> 8)
+
+#define HAL_ETH_PINS  \
+  PIN('A', 1), /* ETH_REF_CLK */ \
+  PIN('A', 2), /* ETH_MDIO */ \
+  PIN('A', 7), /* ETH_CRS_DV */ \
+  PIN('B', 15), /* ETH_TXD1 */ \
+  PIN('C', 1), /* ETH_MDC */ \
+  PIN('C', 4), /* ETH_RXD0 */ \
+  PIN('C', 5), /* ETH_RXD1 */ \
+  PIN('G', 11), /* ETH_TX_EN */ \
+  PIN('G', 13) /* ETH_TXD0 */
+
+// System clock (11.4, Figure 48; 11.4.5, Figure 51; 11.4.8
+// SYS_FREQUENCY <= 250 MHz; (CLOCK_FREQUENCY / HPRE) ; hclk = SYS_FREQUENCY
+// APB clocks <= 250 MHz. Configure flash latency (WS) in accordance to hclk
+// freq (7.3.4, Table 37)
+enum {
+  HAL_HPRE = 7,   // register value, divisor value = BIT(value - 7) = / 1
+  HAL_PPRE1 = 4,  // register values, divisor value = BIT(value - 3) = / 2
+  HAL_PPRE2 = 4,
+  HAL_PPRE3 = 4,
+};
+// Make sure your chip package uses the internal LDO, otherwise set PLL1_N = 200
+enum { PLL1_HSI = 64, PLL1_M = 32, PLL1_N = 250, PLL1_P = 2 };
+#define SYS_FREQUENCY \
+  ((PLL1_HSI * PLL1_N / PLL1_M / PLL1_P / (BIT(HAL_HPRE - 7))) * 1000000)
+#define AHB_FREQUENCY SYS_FREQUENCY
+#define APB2_FREQUENCY (AHB_FREQUENCY / (BIT(HAL_PPRE2 - 3)))
+#define APB1_FREQUENCY (AHB_FREQUENCY / (BIT(HAL_PPRE1 - 3)))
+
+static inline void spin(volatile uint32_t n) {
+  while (n--) (void) 0;
+}
+
+enum { HAL_GPIO_MODE_INPUT, HAL_GPIO_MODE_OUTPUT, HAL_GPIO_MODE_AF, HAL_GPIO_MODE_ANALOG };
+enum { HAL_GPIO_OTYPE_PUSH_PULL, HAL_GPIO_OTYPE_OPEN_DRAIN };
+enum { HAL_GPIO_SPEED_LOW, HAL_GPIO_SPEED_MEDIUM, HAL_GPIO_SPEED_HIGH, HAL_GPIO_SPEED_INSANE };
+enum { HAL_GPIO_PULL_NONE, HAL_GPIO_PULL_UP, HAL_GPIO_PULL_DOWN };
+
+#define HAL_GPIO(N) ((GPIO_TypeDef *) ((GPIOA_BASE_NS) + 0x400 * (N)))
+
+static GPIO_TypeDef *hal_gpio_bank(uint16_t pin) {
+  return HAL_GPIO(PINBANK(pin));
+}
+static inline void hal_gpio_toggle(uint16_t pin) {
+  GPIO_TypeDef *gpio = hal_gpio_bank(pin);
+  uint32_t mask = BIT(PINNO(pin));
+  gpio->BSRR = mask << (gpio->ODR & mask ? 16 : 0);
+}
+static inline int hal_gpio_read(uint16_t pin) {
+  return hal_gpio_bank(pin)->IDR & BIT(PINNO(pin)) ? 1 : 0;
+}
+static inline void hal_gpio_write(uint16_t pin, bool val) {
+  GPIO_TypeDef *gpio = hal_gpio_bank(pin);
+  gpio->BSRR = BIT(PINNO(pin)) << (val ? 0 : 16);
+}
+static inline void hal_gpio_init(uint16_t pin, uint8_t mode, uint8_t type,
+                             uint8_t speed, uint8_t pull, uint8_t af) {
+  GPIO_TypeDef *gpio = hal_gpio_bank(pin);
+  uint8_t n = (uint8_t) (PINNO(pin));
+  RCC->AHB2ENR |= BIT(PINBANK(pin));  // Enable GPIO clock
+  CLRSET(gpio->OTYPER, 1UL << n, ((uint32_t) type) << n);
+  CLRSET(gpio->OSPEEDR, 3UL << (n * 2), ((uint32_t) speed) << (n * 2));
+  CLRSET(gpio->PUPDR, 3UL << (n * 2), ((uint32_t) pull) << (n * 2));
+  CLRSET(gpio->AFR[n >> 3], 15UL << ((n & 7) * 4),
+         ((uint32_t) af) << ((n & 7) * 4));
+  CLRSET(gpio->MODER, 3UL << (n * 2), ((uint32_t) mode) << (n * 2));
+}
+static inline void hal_gpio_input(uint16_t pin) {
+  hal_gpio_init(pin, HAL_GPIO_MODE_INPUT, HAL_GPIO_OTYPE_PUSH_PULL, HAL_GPIO_SPEED_HIGH,
+            HAL_GPIO_PULL_NONE, 0);
+}
+static inline void hal_gpio_output(uint16_t pin) {
+  hal_gpio_init(pin, HAL_GPIO_MODE_OUTPUT, HAL_GPIO_OTYPE_PUSH_PULL, HAL_GPIO_SPEED_HIGH,
+            HAL_GPIO_PULL_NONE, 0);
+}
+
+static inline bool hal_uart_init(USART_TypeDef *uart, uint16_t tx_pin,
+                                 uint16_t rx_pin, unsigned long baud) {
+  uint32_t freq = 0;        // Bus frequency. UART1 is on APB2, rest on APB1
+
+  if (uart == USART1) {
+    freq = APB2_FREQUENCY, RCC->APB2ENR |= RCC_APB2ENR_USART1EN;
+  } else if (uart == USART2) {
+    freq = APB1_FREQUENCY, RCC->APB1LENR |= RCC_APB1LENR_USART2EN;
+  } else if (uart == USART3) {
+    freq = APB1_FREQUENCY, RCC->APB1LENR |= RCC_APB1LENR_USART3EN;
+  } else {
+    return false;
+  }
+  hal_gpio_init(tx_pin, HAL_GPIO_MODE_AF, HAL_GPIO_OTYPE_PUSH_PULL, HAL_GPIO_SPEED_HIGH, 0, 7U);
+  hal_gpio_init(rx_pin, HAL_GPIO_MODE_AF, HAL_GPIO_OTYPE_PUSH_PULL, HAL_GPIO_SPEED_HIGH, 0, 7U);
+  uart->CR1 = 0;                            // Disable UART
+  uart->BRR = freq / baud;                  // Set baud rate
+  uart->CR1 = USART_CR1_RE | USART_CR1_TE;  // Set mode to TX & RX
+  uart->CR1 |= USART_CR1_UE;                // Enable UART
+  return true;
+}
+static inline void hal_uart_write_byte(USART_TypeDef *uart, uint8_t byte) {
+  uart->TDR = byte;
+  while ((uart->ISR & BIT(7)) == 0) spin(1);
+}
+static inline void hal_uart_write_buf(USART_TypeDef *uart, char *buf, size_t len) {
+  while (len-- > 0) hal_uart_write_byte(uart, *(uint8_t *) buf++);
+}
+static inline int hal_uart_read_ready(USART_TypeDef *uart) {
+  return uart->ISR & BIT(5);  // If RXNE bit is set, data is ready
+}
+static inline uint8_t hal_uart_read_byte(USART_TypeDef *uart) {
+  return (uint8_t) (uart->RDR & 255);
+}
+
+static inline void hal_rng_init(void) {
+  RCC->CCIPR5 |= RCC_CCIPR5_RNGSEL_0;  // RNG clock source pll1_q_ck
+  RCC->AHB2ENR |= RCC_AHB2ENR_RNGEN;   // Enable RNG clock
+  RNG->CR |= RNG_CR_RNGEN;             // Enable RNG
+}
+static inline uint32_t hal_rng_read(void) {
+  while ((RNG->SR & RNG_SR_DRDY) == 0) spin(1);
+  return RNG->DR;
+}
+
+static inline bool hal_ldo_is_on(void) {
+  return (PWR->SCCR & PWR_SCCR_LDOEN) == PWR_SCCR_LDOEN;
+}
+
+// Hw pull-ups on PHY RXD0,1,DV to enable autonegotiation
+static inline void hal_ethernet_init(void) {
+  // Initialise Ethernet. Enable MAC GPIO pins, see UM3115 section 10.7
+  uint16_t pins[] = {HAL_ETH_PINS};
+  for (size_t i = 0; i < sizeof(pins) / sizeof(pins[0]); i++) {
+    hal_gpio_init(pins[i], HAL_GPIO_MODE_AF, HAL_GPIO_OTYPE_PUSH_PULL, HAL_GPIO_SPEED_INSANE,
+              HAL_GPIO_PULL_NONE, 11);  // 11 is the Ethernet function
+  }
+  NVIC_EnableIRQ(ETH_IRQn);           // Setup Ethernet IRQ handler
+  RCC->APB3ENR |= RCC_APB3ENR_SBSEN;  // Enable SBS clock
+  CLRSET(SBS->PMCR, SBS_PMCR_ETH_SEL_PHY, SBS_PMCR_ETH_SEL_PHY_2);  // RMII
+  RCC->AHB1ENR |= RCC_AHB1ENR_ETHEN | RCC_AHB1ENR_ETHRXEN | RCC_AHB1ENR_ETHTXEN;
+}
+
+#define UUID ((uint32_t *) UID_BASE)  // Unique 96-bit chip ID. TRM 59.1
+
+// Helper macro for MAC generation, byte reads not allowed
+#define GENERATE_LOCALLY_ADMINISTERED_MAC()                         \
+  {                                                                 \
+    2, UUID[0] & 255, (UUID[0] >> 10) & 255, (UUID[0] >> 19) & 255, \
+        UUID[1] & 255, UUID[2] & 255                                \
+  }
+
+static inline void hal_system_init(void) {
+  SCB->CPACR |= ((3UL << 20U) | (3UL << 22U));  // Enable FPU
+  __DSB();
+  __ISB();
+}
+
+static inline void hal_clock_init(void) {
+  // Set flash latency. RM0481, section 7.11.1, section 7.3.4 table 37
+  CLRSET(FLASH->ACR, (FLASH_ACR_WRHIGHFREQ_Msk | FLASH_ACR_LATENCY_Msk),
+         FLASH_ACR_LATENCY_5WS | FLASH_ACR_WRHIGHFREQ_1);
+
+  if (hal_ldo_is_on()) {
+    PWR->VOSCR = PWR_VOSCR_VOS_0 | PWR_VOSCR_VOS_1;  // Select VOS0
+  } else {
+    PWR->VOSCR = PWR_VOSCR_VOS_1;  // Select VOS1
+  }
+  uint32_t f = PWR->VOSCR;  // fake read to wait for bus clocking
+  while ((PWR->VOSSR & PWR_VOSSR_ACTVOSRDY) == 0) spin(1);
+  (void) f;
+  RCC->CR = RCC_CR_HSION;                          // Clear HSI clock divisor
+  while ((RCC->CR & RCC_CR_HSIRDY) == 0) spin(1);  // Wait until done
+  RCC->CFGR2 = (HAL_PPRE3 << 12) | (HAL_PPRE2 << 8) | (HAL_PPRE1 << 4) | (HAL_HPRE << 0);
+  RCC->PLL1DIVR =
+      ((PLL1_P - 1) << 9) | ((PLL1_N - 1) << 0);  // Set PLL1_P PLL1_N
+  // Enable P and Q divider outputs; set PLL1_M, select HSI as source,
+  // !PLL1VCOSEL, PLL1RGE=0
+  RCC->PLL1CFGR =
+      RCC_PLL1CFGR_PLL1QEN | RCC_PLL1CFGR_PLL1PEN | (PLL1_M << 8) | (1 << 0);
+  RCC->CR |= RCC_CR_PLL1ON;                         // Enable PLL1
+  while ((RCC->CR & RCC_CR_PLL1RDY) == 0) spin(1);  // Wait until done
+  RCC->CFGR1 |= (3 << 0);                           // Set clock source to PLL1
+  while ((RCC->CFGR1 & (7 << 3)) != (3 << 3)) spin(1);  // Wait until done
+
+  SystemCoreClock = SYS_FREQUENCY;
+}
diff --git a/tutorials/stm32/nucleo-h563zi/minimal-lfs/link.ld b/tutorials/stm32/nucleo-h563zi/minimal-lfs/link.ld
new file mode 100644
index 00000000..fac73050
--- /dev/null
+++ b/tutorials/stm32/nucleo-h563zi/minimal-lfs/link.ld
@@ -0,0 +1,31 @@
+ENTRY(Reset_Handler);
+MEMORY {
+  flash(rx) : ORIGIN = 0x08000000, LENGTH = 2048k
+  sram(rwx) : ORIGIN = 0x20000000, LENGTH = 640k
+}
+_estack = ORIGIN(sram) + LENGTH(sram);    /* End of RAM. stack points here */
+_sstack = _estack - 4098;
+
+SECTIONS {
+  .vectors  : { KEEP(*(.isr_vector)) }  > flash
+  .text     : { *(.text* .text.*) }     > flash
+  .rodata   : { *(.rodata*) }           > flash
+
+  .data : {
+    _sdata = .;
+    *(.first_data)
+    *(.ram)
+    *(.data SORT(.data.*))
+    _edata = .;
+  } > sram AT > flash
+  _sidata = LOADADDR(.data);
+
+  .bss : {
+    _sbss = .;
+    *(.bss SORT(.bss.*) COMMON)
+    _ebss = .;
+  } > sram
+
+  . = ALIGN(8);
+  _end = .;
+}
diff --git a/tutorials/stm32/nucleo-h563zi/minimal-lfs/main.c b/tutorials/stm32/nucleo-h563zi/minimal-lfs/main.c
new file mode 100644
index 00000000..8a810807
--- /dev/null
+++ b/tutorials/stm32/nucleo-h563zi/minimal-lfs/main.c
@@ -0,0 +1,89 @@
+// Copyright (c) 2026 Cesanta Software Limited
+// All rights reserved
+
+#include "hal.h"
+#include "mongoose.h"
+
+#ifndef UART_DEBUG
+#define UART_DEBUG USART3
+#define UART_DEBUG_TX_PIN PIN('D', 8)
+#define UART_DEBUG_RX_PIN PIN('D', 9)
+#else
+#define UART_DEBUG_TX_PIN PIN('A', 9)
+#define UART_DEBUG_RX_PIN PIN('A', 10)
+#endif
+
+#define LED_1 PIN('B', 0)  // On-board LED pin (green)
+#define LED_2 PIN('F', 4)  // On-board LED pin (yellow)
+#define LED_3 PIN('G', 4)  // On-board LED pin (red)
+
+#define LFS_SIZE (64 * 1024)
+
+static void blink_task(void) {
+  static uint64_t blink_timer = 0;
+  if (hal_timer_expired(&blink_timer, 500, hal_get_tick())) {
+    hal_gpio_toggle(LED_1);
+  }
+}
+
+uint64_t mg_millis(void) {
+  return hal_get_tick();
+}
+
+bool mg_random(void *buf, size_t len) {
+  for (size_t n = 0; n < len; n += sizeof(uint32_t)) {
+    uint32_t r = hal_rng_read();
+    memcpy((char *) buf + n, &r, n + sizeof(r) > len ? len - n : sizeof(r));
+  }
+  return true;
+}
+
+static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
+  if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {
+      mg_http_reply(c, 200, "", "{%m:%llu}\n", MG_ESC("tick"), hal_get_tick());
+    } else {
+      mg_http_reply(c, 200, "", "Hi from Mongoose, tick %llu\n", hal_get_tick());
+    }
+  }
+}
+
+static void log_fn(char ch, void *param) {
+  hal_uart_write_buf(param, &ch, 1);
+}
+
+int main(void) {
+  hal_uart_init(UART_DEBUG, UART_DEBUG_TX_PIN, UART_DEBUG_RX_PIN, 115200);
+  mg_log_set_fn(log_fn, UART_DEBUG);
+  hal_rng_init();
+  hal_gpio_output(LED_1);
+  hal_gpio_output(LED_2);
+  hal_gpio_output(LED_3);
+
+  hal_ethernet_init();
+
+  // Start a minimal web server
+  struct mg_mgr mgr;
+  mg_mgr_init(&mgr);
+  mg_http_listen(&mgr, "http://0.0.0.0", http_ev_handler, NULL);
+
+  // Initialise LFS, which enables stdio fopen/fwrite/...
+  if (mg_lfs_init(LFS_SIZE)) {
+    char buf[20] = "";
+    FILE *fp = fopen("a.txt", "r");
+    if (fp != NULL) fread(buf, 1, sizeof(buf) - 1, fp), fclose(fp);
+    MG_INFO(("BOOT COUNT: %s", buf));
+    fp = fopen("a.txt", "w+");
+    if (fp != NULL) fprintf(fp, "%d", atoi(buf) + 1), fclose(fp);
+  } else {
+    MG_ERROR(("LFS init failed"));
+  }
+
+  for (;;) {
+    mg_mgr_poll(&mgr, 0);
+    blink_task();
+  }
+
+  return 0;
+}
diff --git a/tutorials/stm32/nucleo-h563zi/minimal-lfs/mongoose/mongoose_config.h b/tutorials/stm32/nucleo-h563zi/minimal-lfs/mongoose/mongoose_config.h
new file mode 100644
index 00000000..64bb90c6
--- /dev/null
+++ b/tutorials/stm32/nucleo-h563zi/minimal-lfs/mongoose/mongoose_config.h
@@ -0,0 +1,45 @@
+#pragma once
+
+// See https://mongoose.ws/documentation/#build-options
+#define MG_ARCH MG_ARCH_ARMGCC
+#define MG_OTA MG_OTA_STM32H5
+#define MG_TLS MG_TLS_BUILTIN
+#define MG_IO_SIZE 2048
+
+#define MG_ENABLE_POSIX_FS 1
+#define MG_ENABLE_TCPIP 1
+#define MG_ENABLE_CUSTOM_MILLIS 1
+#define MG_ENABLE_CUSTOM_RANDOM 1
+#define MG_ENABLE_PACKED_FS 1
+#define MG_ENABLE_DRIVER_STM32H 1
+
+// #define MG_DRIVER_MDC_CR 4   // RMII MDC clock divider, from 0 to 4
+// #define MG_TCPIP_PHY_ADDR 0  // PHY address
+
+// For static IP configuration, define MG_TCPIP_{IP,MASK,GW}
+// By default, those are set to zero, meaning that DHCP is used
+//
+// #define MG_TCPIP_IP MG_IPV4(192, 168, 0, 10)
+// #define MG_TCPIP_GW MG_IPV4(192, 168, 0, 1)
+// #define MG_TCPIP_MASK MG_IPV4(255, 255, 255, 0)
+
+// Set custom MAC address. By default, it is randomly generated
+// Using a build-time constant:
+// #define MG_SET_MAC_ADDRESS(mac) do { mac[0] = 2; mac[1] = 3; mac[2] = 4; mac[3] = 5; mac[4] = 6; mac[5] = 7; } while (0)
+//
+// Using custom function:
+// extern void my_function(unsigned char *mac);
+// #define MG_SET_MAC_ADDRESS(mac) my_function(mac)
+
+// Construct MAC address from the MCU unique ID. It is defined in the
+// ST CMSIS header as UID_BASE
+#define MGUID ((uint32_t *) 0x08fff800)  // Unique 96-bit chip ID
+#define MG_SET_MAC_ADDRESS(mac)      \
+  do {                               \
+    mac[0] = 2;                      \
+    mac[1] = MGUID[0] & 255;         \
+    mac[2] = (MGUID[0] >> 10) & 255; \
+    mac[3] = (MGUID[0] >> 19) & 255; \
+    mac[4] = MGUID[1] & 255;         \
+    mac[5] = MGUID[2] & 255;         \
+  } while (0)