mp-image-tool-esp32: Working with esp32 firmware files and devices
Tool for manipulating partition tables and files in MicroPython esp32 firmware
image files and device flash storage.
mp-image-tool-esp32
manipulates micropython esp32 firmware files and flash
storage on serial-attached ESP32 devices. It has been tested to work with ESP32,
ESP32-S2 and ESP32-S3 firmware images and devices.
Contents: Features | Installation |
Examples | Filesystem Operations | OTA Updates | Usage
$ mp-image-tool-esp32 ESP32_GENERIC-20231005-v1.21.0.bin
Opening image file: ESP32_GENERIC-20231005-v1.21.0.bin...
Chip type: esp32
Flash size: 4MB
Micropython App size: 0x186bb0 bytes (1,562 KB)
Partition table (flash size: 4MB):
# Name Type SubType Offset Size (End) Flags
nvs data nvs 0x9000 0x6000 0xf000 0x0 (24.0 kB)
phy_init data phy 0xf000 0x1000 0x10000 0x0 (4.0 kB)
factory app factory 0x10000 0x1f0000 0x200000 0x0 (1.9 MB)
vfs data fat 0x200000 0x200000 0x400000 0x0 (2.0 MB)
Micropython app fills 78.8% of factory partition (421 kB free)
Features
mp-image-tool-esp32
can operate on:
- micropython esp32 firmware files (including those downloaded from
micropython.org) or
- flash storage in esp32 devices attached via serial port.
Operations on files and esp32 devices
- Print a summary of the partition table of a micropython esp32 firmware file or
device
mp-image-tool-esp32 ESP32_GENERIC-20231005-v1.21.0.bin
ormp-image-tool-esp32 /dev/ttyUSB0
(Linux) ormp-image-tool-esp32 COM1
(Windows)
- Change the size of the flash storage programmed into the firmware header:
--resize-flash 8M
or -f 8M
- Rewrite or modify the partition table:
--table ota
: install an OTA-enabled partition table--table default
: install a default micropython table (non-OTA, without 'phy_init')--table original
: install the original default micropython table (non-OTA, with 'phy_init')--table nvs=6B,phy_init=1B,factory=0x1f0B,vfs=0
: specify a table layout--resize factory=2M,vfs=0x400K
: resize any partition (adjust other
parts to fit)--delete phy_init --resize nvs=0
: delete 'phy_init' and expand 'nvs' to
use free space--add vfs2=fat:2M:1M
: add a new FS data partition at offset 0x200000 with
size 0x100000--app-size 0x200000
: change the size of the app
partitions (use this
with --table ota
)
- Extract the micropython application image (
.app-bin
) from the firmware
or device
--extract-app
: the extracted .app-bin
file can be used for OTA firmware
updates.
- Modify the contents of partitions in the firmware:
--read factory=micropython.app-bin,nvs=nvs.bin
: read contents of
partitions into files--write factory=micropython.app-bin
: write contents of files into
partitions--write bootloader=bootloader.bin
: load a new bootloader from file--erase nvs,otadata
: erase partitions
When operating on micropython firmware files, mp-image-tool-esp32
will create
a copy of the firmware file with the partition table and partition contents
modified according to the options provided. The original firmware file is not
modified in any way. If no modification options are given, it will print the
partition table of filename
.
Operations on serial-attached esp32 devices
Use mp-image-tool-esp32 u0
to operate on the esp32 device attached to
/dev/ttyUSB0
. When operating on esp32 devices over a serial interface, the
following additional commands are available:
-
Perform operations on the files installed on the vfs
or other filesystem
partition:
--fs ls
will list all the files on the device filesystem--fs get . backup
will copy all the files on the device filesystem to
backup
on the local computer--fs put backup/* /
will copy all the files from backup
onto the
device filesystem .
- See below for more filesystem operations
-
Erase 'vfs' filesystem partitions:
--erase vfs
: erases the vfs
partition
- micropython will automatically build a fresh filesystem on the next boot
-
Use the OTA
mechanism to perform a micropython firmware update over the
serial interface to the device:
--ota-update micropython.app-bin
-
Flash a firmware (including any changes) to an esp32 device, eg:
mp-image-tool-esp32 firmware.bin --flash u0
ormp-image-tool-esp32 firmware.bin -f 8M --table ota --flash /dev/ttyACM1
mp-image-tool-esp32
will automatically use the right esptool
options to
flash the firmware for your device (you don't need to remember if you should
write to offset 0x0
or 0x1000
)
When operating on serial-attached esp32 devices, mp-image-tool-esp32
will
automatically erase any data
partitions (eg. nvs
, otadata
or vfs/fat
)
which have been moved or resized. Generally, micropython will re-initialise
these data
partitions on next boot. This prevents micropython attempting to
mount what appears to be a corrupt filesystem or nvs partition.
- Note: Since version 0.0.7,
mp-image-tool-esp32
will not automatically erase
filesytem partitions that have been increased in size. Micropython will
complain that the filesystem is corrupt on reboot because the filesystem does
not match the partition size, but this can be repaired with --fs grow vfs
or
use --erase vfs
to forcibly erase the partition.
mp-image-tool-esp32
uses the
esptool.py
program to perform the
operations on attached esp32 devices:
- Select the specific method used to perform operations on the device:
Installation
Install from PYPI
- Using pip:
pip install mp-image-tool-esp32
, or - Using uv:
uv tool install mp-image-tool-esp32
.
Install from github source
I recommend using uv
to install and manage
dependencies and dev environments.
git clone https://github.com/glenn20/mp-image-tool-esp32
cd mp-image-tool-esp32
uv build
uv tool install dist/mp_image_tool_esp32-0.0.12-py3-none-any.whl
To run the tests: uv run pytest
or uv run tox
.
Examples
Change the flash size of a firmware file and expand the vfs partition
$ mp-image-tool-esp32 ESP32_GENERIC-20231005-v1.21.0.bin -f 8M --resize vfs=0
Opening image file: ESP32_GENERIC-20231005-v1.21.0.bin...
Chip type: esp32
Flash size: 4MB
Micropython App size: 0x186bb0 bytes (1,562 KB)
Partition table (flash size: 4MB):
# Name Type SubType Offset Size (End) Flags
nvs data nvs 0x9000 0x6000 0xf000 0x0 (24.0 kB)
phy_init data phy 0xf000 0x1000 0x10000 0x0 (4.0 kB)
factory app factory 0x10000 0x1f0000 0x200000 0x0 (1.9 MB)
vfs data fat 0x200000 0x200000 0x400000 0x0 (2.0 MB)
Micropython app fills 78.8% of factory partition (421 kB free)
Resizing vfs partition to 0x600000 bytes.
Writing output file: ESP32_GENERIC-20231005-v1.21.0-8MB-vfs=0.bin...
Partition table (flash size: 8MB):
# Name Type SubType Offset Size (End) Flags
nvs data nvs 0x9000 0x6000 0xf000 0x0 (24.0 kB)
phy_init data phy 0xf000 0x1000 0x10000 0x0 (4.0 kB)
factory app factory 0x10000 0x1f0000 0x200000 0x0 (1.9 MB)
vfs data fat 0x200000 0x600000 0x800000 0x0 (6.0 MB)
Micropython app fills 78.8% of factory partition (421 kB free)
Change the flash size of firmware on a device and write an OTA partition table
$ mp-image-tool-esp32 u0 -f 8M --table ota
Opening esp32 device at: /dev/ttyUSB0...
Warning: End of last partition (0x400000) < flash size (0x800000).
Chip type: esp32
Flash size: 8MB
Partition table (flash size: 8MB):
# Name Type SubType Offset Size (End) Flags
nvs data nvs 0x9000 0x6000 0xf000 0x0 (24.0 kB)
phy_init data phy 0xf000 0x1000 0x10000 0x0 (4.0 kB)
factory app factory 0x10000 0x1f0000 0x200000 0x0 (1.9 MB)
vfs data fat 0x200000 0x200000 0x400000 0x0 (2.0 MB)
Warning: End of last partition (0x400000) < flash size (0x800000).
Writing new table to flash storage at /dev/ttyUSB0...
Partition table (flash size: 8MB):
# Name Type SubType Offset Size (End) Flags
nvs data nvs 0x9000 0x5000 0xe000 0x0 (20.0 kB)
otadata data ota 0xe000 0x2000 0x10000 0x0 (8.0 kB)
ota_0 app ota_0 0x10000 0x200000 0x210000 0x0 (2.0 MB)
ota_1 app ota_1 0x210000 0x200000 0x410000 0x0 (2.0 MB)
vfs data fat 0x410000 0x3f0000 0x800000 0x0 (3.9 MB)
Setting flash_size in bootloader to 8.0MB...
Erasing data partition: nvs...
Erasing data partition: otadata...
Warning: app partition 'ota_1' does not contain app image.
Erasing data partition: vfs...
Perform an OTA firmware update
$ mp-image-tool-esp32 u0 --ota-update ESP32_GENERIC-20231005-v1.21.0.app-bin
Opening esp32 device: /dev/ttyUSB0...
Chip type: esp32
Flash size: 8MB
Partition table (flash size: 8MB):
# Name Type SubType Offset Size (End) Flags
nvs data nvs 0x9000 0x5000 0xe000 0x0 (20.0 kB)
otadata data ota 0xe000 0x2000 0x10000 0x0 (8.0 kB)
ota_0 app ota_0 0x10000 0x200000 0x210000 0x0 (2.0 MB)
ota_1 app ota_1 0x210000 0x200000 0x410000 0x0 (2.0 MB)
vfs data fat 0x410000 0x3f0000 0x800000 0x0 (3.9 MB)
Performing OTA firmware upgrade from 'ESP32_GENERIC-20231005-v1.21.0-8MB-OTA.app-bin'...
Writing firmware to OTA partition ota_1...
Updating otadata partition...
Filesystem Operations
mp_image_tool_esp32
can be used to access and manipulate files installed on
the littlefsv2
filesystems, the default filesystem used by micropython on the
device flash storage (FAT filesystems are not supported). mp_image_tool_esp32
uses the littlefs-python
package
to operate on these filesystems.
The available fs comands are:
--fs df
: List current usage of filesystems.--fs ls /lib /data
: Recursively list the files in the /lib
and /data
directories of the vfs
partition.--fs get /lib /data backup
: Recursively copy /lib
and /data
from the device to ./backup
on the local host.--fs put backup/* /
: Recursively copy all files and dirs in backup/
to the
device.--fs cat boot.py
: Print out the contents of /boot.py
on the device.--fs mkdir /data
: Create a new directory on the device.--fs rm /boot.py /main.py
: Recursively delete files and directories on the device.--fs rename app.py main.py
: Rename files on the device.--fs mkfs vfs
: Create a new littlefsv2 filesystem on the vfs
partition
(will erase the partition first).--fs grow [vfs [blocks]]
: Grow the filesystem to fill the partition or to the
requested number of 4K-blocks.
- Note: micropython will not mount a filesystem unless it uses all the space
in the partition. Use this after you have used
--resize
to increase the
size of a filesystem partition.
Filenames on the device can be prefixed with a partition name to operate on a
filesystem partition other than vfs
, eg. --fs ls vfs2:/recordings
.
The --fs
commands operate directly on the filesystem on the flash storage, and
not through the micropython repl. Some operations may be much faster using
this method, though the current implementation does not yet support block
caching which should provide further performance improvements.
Eg. mp-image-tool-esp32 a0 --fs mkfs vfs --fs put ./rootfs/* /
will create
a new littlefs filesystem on the 'vfs' partition and initialise it with the
files from ./rootfs/
on the local computer.
You can also use littlefs-python
to build filesystem partitions on your computer and flash them to the device,
eg:
littlefs-python create --compact --no-pad --block-size 4096 --fs-size=2mb ./root-fs vfs.bin
mp-image-tool-esp32 u0 --write vfs=vfs.bin
will create a new littlefs filesystem image, fill it with files from the
root-fs directory and flash it to the vfs
partition on the device attached to
serial port /dev/ttyUSB0
.
OTA firmware updates
mp-image-tool-esp32
can be used to perform an OTA firmware update
over the serial interface to an OTA-enabled
esp32 device:
mp-image-tool-esp32 a1 --ota-update micropython.app-bin
ESP32 Over-The-Air updates
are intended to support firmware updates over wifi or bluetooth, but sometimes
it is convenient to push a firmware update to an OTA-enabled, USB-attached
device. This is the purpose of the --ota-update
option.
OTA updates must be performed using micropython app image firmware files.
You can :
- download a
.app-bin
firmware file from
micropython.org or - use
--extract-app
to extract a .app-bin
file from a micropython .bin
firmware file. For more options, see micropython app image.
OTA-enabled devices include those which:
- have been converted in place with
mp-image-tool-esp32 u0 --table ota
or - have been flashed with
OTA
enabled firmware files (see Firmware for OTA
updates):
- downloaded from
micropython.org or
- produced by
mp-image-tool-esp32 filename --table ota
.
OTA Rollback
CAUTION: If you update the firmware with --ota-update
and OTA rollback
is enabled, the device will automatically reset into the new firmware on
completion. If you then connect to the device over the serial port, your IDE or
terminal software may reset the device again. If your startup files have not
marked the firmware as valid
, your device will have rolled back to the
previous firmware before you get to work with it.
You can stop the rollback by marking the new firmware as valid with:
esp32.Partition.mark_app_valid_cancel_rollback()
(docs) orota.rollback.cancel()
if you use the
micropython-esp32-ota
tool.- In practice, this means you should call
esp32.Partition.mark_app_valid_cancel_rollback()
after every restart.
- Eg. in
main.py
-- or you might choose to wait till after your app has
initialised wifi and any other devices you require so you know the new
firmware is good for your app. - If it fails, just call
machine.hard_reset()
and
the device will revert to the previous firmware on restart.
Alternatively, you can use --no-rollback
to disable rollback for this update.
OTA rollback is enabled by default in the bootloader of:
- all micropython firmware files since
v1.21.0
and -OTA
micropython firmware files for earlier versions downloaded from
micropython.org.
If you use --table ota
to convert a non-OTA, pre-v1.21.0
firmware, it will
NOT support OTA rollback. You can replace the bootloader with one from
an OTA-enabled firmware or device, but it is just easier to start with
rollback-enabled firmware.
See micropython-esp32-ota
for an example of a tool which can perform conventional OTA firmware updates
over the wifi interface.
NOTE: You can also update the app firmware of a non-OTA device with:
mp-image-tool-esp32 --write factory=ESP32_GENERIC-20231005-v1.21.0.app-bin
- This will upgrade the micropython firmware on the device without erasing
the
nvs
partition (which is usually placed before the factory
partition on
the device), as would be the case for writing a full micropython firmware to
the device with esptool.py
.
Usage
usage: mp-image-tool-esp32 [-h] [-o FILE] [-q] [-n] [-x] [-f SIZE] [-a SIZE]
[-m METHOD] [-d]
[--log NAME=LEVEL[,NAME=LEVEL,...]] [--check-app]
[--no-rollback] [--baud RATE] [--ota-update FILE]
[--from-csv FILE]
[--table ota/default/original/NAME1=SUBTYPE:SIZE[,NAME2,...]]
[--delete NAME1[,NAME2]]
[--add NAME1:SUBTYPE:OFFSET:SIZE[,NAME2,...]]
[--resize NAME1=SIZE1[,NAME2=SIZE2]]
[--erase NAME1[,NAME2]] [--erase-fs NAME1[,NAME2]]
[--read NAME1=FILE1[,NAME2=FILE2,bootloader=FILE,...]]
[--write NAME1=FILE1[,NAME2=FILE2,bootloader=FILE,...]]
[--flash DEVICE] [--trimblocks] [--trim]
[--fs CMD [CMD ...]]
filename
Tool for manipulating MicroPython esp32 firmware files and flash storage on
esp32 devices.
positional arguments:
filename the esp32 firmware filename or serial device
options:
-h, --help show this help message and exit
-o FILE, --output FILE
output firmware filename (auto-generated if not given)
-q, --quiet set debug level to ERROR (default: INFO)
-n, --no-reset leave device in bootloader mode afterward
-x, --extract-app extract .app-bin from firmware
-f SIZE, --flash-size SIZE
size of flash for new partition table
-a SIZE, --app-size SIZE
size of factory and ota app partitions
-m METHOD, --method METHOD
esptool method: subprocess, command or direct
(default)
-d, --debug set debug level to DEBUG (default: INFO)
--log NAME=LEVEL[,NAME=LEVEL,...]
set the log level for the named loggers.
--check-app check app partitions and OTA config are valid
--no-rollback disable app rollback after OTA update
--baud RATE baud rate for serial port (default: 921600)
--ota-update FILE perform an OTA firmware upgrade over the serial port
--from-csv FILE load new partition table from CSV file
--table ota/default/original/NAME1=SUBTYPE:SIZE[,NAME2,...]
create new partition table, eg: "--table ota" (install
an OTA-enabled partition table), "--table default"
(default (non-OTA) partition table), "--table
nvs=7B,factory=2M,vfs=0". SUBTYPE is optional in most
cases (inferred from name).
--delete NAME1[,NAME2]
delete the named partitions
--add NAME1:SUBTYPE:OFFSET:SIZE[,NAME2,...]
add new partitions to table
--resize NAME1=SIZE1[,NAME2=SIZE2]
resize partitions eg. --resize
factory=2M,nvs=5B,vfs=0. If SIZE is 0, expand
partition to available space
--erase NAME1[,NAME2]
erase the named partitions
--erase-fs NAME1[,NAME2]
erase first 4 blocks of a partition on flash storage.
Micropython will initialise filesystem on next boot.
--read NAME1=FILE1[,NAME2=FILE2,bootloader=FILE,...]
copy partition contents (or bootloader) to file. Use
--trimblocks or --trim to remove trailing blank
blocks.
--write NAME1=FILE1[,NAME2=FILE2,bootloader=FILE,...]
write file(s) contents into partitions (or bootloader)
in the firmware.
--flash DEVICE flash new firmware to the serial-attached device.
--trimblocks Remove trailing blank blocks from data returned by
--read and --extract-app. This is useful for reading
app images and filesystems from flash storage.
--trim Like --trimblocks, but trims to 16-byte boundary. This
is appropriate for reading app images from flash
storage.
--fs CMD [CMD ...] Operate on files in the `vfs` or other filesystem
partitions.
Where SIZE is a decimal or hex number with an optional suffix (M=megabytes,
K=kilobytes, B=blocks (0x1000=4096 bytes)). --fs commands include: ls, get,
put, mkdir, rm, rename, cat, info, mkfs, df and grow. Options --erase-fs and
--ota-update can only be used when operating on serial-attached devices (not
firmware files). If the --flash option is provided, the firmware (including
any changes made) will be flashed to the device, eg: `mp-image-tool-esp32
firmware.bin --flash u0` is a convenient way to flash firmware to a device.