There is a tool for editing and converting uboot images in different formats: cpio, gz, legacy, FIT etc. There is possible to add or update files in ramfs image.

Install .NET Core 3.1 runtime

Download dotnet binaries for your system (for example dotnet-runtime-3.1.32-linux-x64.tar.gz for x64 linux):

mkdir ~/.dotnet
tar -xf dotnet-runtime-3.1.32-linux-x64.tar.gz -C ~/.dotnet/
export PATH=~/.dotnet:$PATH
dotnet ./NyaImageTool.dll

1. Kernel: compressed raw, fit, android, raw, legacy
2. Ramfs: cpio, ext2, squashfs, cramfs, romfs, compressed cpio or ext2, legacy, fit, android image
3. Device tree: dtb, fit

Supported at now:

1. CPIO ASCII (RW)
2. EXT2 (RW)
3. SquashFs (RW)
4. CramFs (RW)
5. RomFs (RW)

Supported at now:

1. GZip (RW)
2. LZMA (RW)
3. LZ4 (RW)
4. BZIP2 (RW)
5. XZ (R)
6. LZO (R)
7. ZStd (RW)

LZMA compression is provided by LZMA SDK package. LZ4 compression is provided by FT.LZ4 package. BZIP2 compression is provided by SharpZipLib package. XZ compression is provided by SharpCompress package. LZO compression is provided by NyaLZO library (Decompression code is ported from lzo1x_decompress_safe.c) ZStd compression is provided by ZstdSharp package.

1. SFTP (server) SFTP server is available for fast inspecting a content of loaded filesystem.

SFTP server is provided by freesftpsharp and FxSsh. freesftpsharp is slightly rewrited and adopted for virtual fs.

2. TFTP (client/server) TFTP server is available to provide tftp-access to builded packages. TFTP client allow download and upload files. TFTP support is provided by tftp.net library.

There are need to add scp support to image and add version information (device id or other info). Run image processing:

./NyaImageTool.exe <scriptfilename>

If program is running without args, it will start in interactive shell mode:

Script is list of commands:

# Load original FIT image (kernel+devtree+ramfs[cpio.gz])...
load original.fit

# Add scp support
include include/scp.module

# Add image version file
file etc/version.txt version.txt rwxr--r-- 0 0

# Store modified FIT image...
store modified.fit

Empty lines are skipped. Lines, which starts with '#' are comments and skipped too.

Include another script:

include <scriptpath>

Information about loaded images:

info

Reset program state, drop all images:

reset

Echo any text:

echo <text>

Default load command (type and image format autodetect):

load <filename>

Load only one image from FIT image, where imagetype is "kernel", "ramfs" or "devtree":

load <filename.fit> <imagetype> fit

Load fs from legacy image:

load <filename.legacy> ramfs legacy

Load fs from compressed file (cpio, ext2, squashfs image):

load <filename.ct> ramfs <compression>

(compression) is "gzip", "lz4", "lzma", "bzip2", "zstd", "lzo"

Load fs from cpio file:

load <filename.cpio> ramfs cpio

Load fs from ext2 image:

load <filename.ext2> ramfs ext2

Load fs from squashfs image:

load <filename.sqfs> ramfs squashfs

Load fs from cramfs image:

load <filename.cramfs> ramfs cramfs

Load fs from romfs image:

load <filename.romfs> ramfs romfs

Load kernel from raw binary image:

load <filename.raw> kernel raw

Load kernel from archived image:

load <filename.ct> kernel <compression>

(compression) is "gzip", "lz4", "lzma", "bzip2", "zstd", "lzo"

Load kernel from legacy (uImage, zImage) image:

load <filename.img> kernel legacy

Load device tree from dtb:

load <filename.dtb> devtree dtb

Load device tree from compressed file (dtb image):

load <filename.ct> devtree <compression>

(compression) is "gzip", "lz4", "lzma", "bzip2", "zstd", "lzo"

To store images to legacy or FIT format, there is need to specify os/arch of these images, if they was loaded from images without such info (cpio, gz).

Store data as FIT image:

store <filename.fit>

Store fs as legacy image:

store <filename.legacy> ramfs legacy

Store fs as compressed cpio/ext2 archive:

store <filename.fs.ct> ramfs <compression>

(compression) is "gzip", "lz4", "lzma", "bzip2"

Store fs as romfs image:

store <filename.romfs> ramfs romfs

Store fs as cramfs image:

store <filename.cramfs> ramfs cramfs

Store fs as squashfs image:

store <filename.cpio> ramfs squashfs

Store fs as ext2 image:

store <filename.ext2> ramfs ext2

Store fs as cpio file:

store <filename.cpio> ramfs cpio

Store kernel as raw binary file:

store <kernel.raw> kernel raw

Store kernel as compressed image:

store <kernel.ct> kernel <compression>

(compression) is "gzip", "lz4", "lzma"

Store kernel as uncompressed legacy file:

store <kernel.uImage> kernel legacy

Store device tree as dtb:

store <filename.dtb> devtree dtb

Exporting files and folders to specified directory. If directory not exists, it will be created

export <path>

Update filesystem type:

set ramfs filesystem <fs>

(fs) is one of 'ext2', 'squashfs', 'cramfs', 'romfs' or 'cpio'.

Change squash compression type:

set ramfs squashfs.compression <compression>

(compression) is one of "gzip", "lzma", "lz4", "zstd"

Update target OS for image:

set <imagetype> os <ostype>

(imagetype) is "ramfs" or "kernel", or "all"

(ostype) is FIT os variants: "linux", etc...

Update target architecture for image:

set <imagetype> arch <arch>

(imagetype) is "ramfs", "kernel", "devtree" or "all"

(arch) is FIT arch variants: "arm", "arm64", "x86", "x86_64", etc.

Set image name (used in Legacy format):

set <imagetype> name <imagename>

Set compression type (for FIT/legacy):

set <imagetype> compression <compression>

(compression) is "none", "gzip", "lzma", "lz4", "bzip2", "zstd"

Set entry address (for kernel):

set kernel entry <hexaddress>

Set data load address (for kernel):

set kernel load <hexaddress>

Standart arguments for fs commands: (path) -- path in image filesystem (localpath) -- path in local filesystem (Windows etc) (mode) -- unix-like mode like "rwxr--r--" (user) -- user id. 0 for root (group) -- group id.

Add directory:

dir <path> <mode> <uid> <gid>

Add file:

file <path> <localpath> <mode> <uid> <gid>

Update file content:

file <path> <localpath>

Add symlink to :

slink <path> <target> <mode> <uid> <gid>

Add char device:

char <path> <major> <minor> <mode> <uid> <gid>

Add block device:

block <path> <major> <minor> <mode> <uid> <gid>

Add socket:

sock <path> <mode> <uid> <gid>

Add fifo:

fifo <path> <mode> <uid> <gid>

Remove file or dir or etc with excluded pathes (allowed * for mask):

rm <path1> [<path2>] [<path3>] [-<exclude1>] [-<exclude2>]

Change file mode:

chmod <path> <mode>

Change file owner:

chown <user>
chown <user> <group>

service <name> <command>

At now available only one service: 'sftp'. Commands is 'start', 'stop' or 'status'.

Print active directory:

pwd

Change active directory:

cd <path>

List items in active dir:

ls

List items in other dir:

ls <path>

Variables can be defined with command:

var <name> <value>

or

var <name>

Variable names starts with $: $image, $path etc.

Variables can be used instead parameters:

var $image zynq.fit
load $image

Variables can be used in conditions. If variable defined, command line will be executed.

<var>? <command> <args...>

Example:

# Define image1 variable
var $image1

# Update some config based on condition:
$image1? file etc/config.cfg files/image1/config.cfg
$image2? file etc/config.cfg files/image2/config.cfg

As variant, variables can contain part of path:

var $image image1
echo Image is $image
file etc/config.cfg files/$image/config.cfg

Plugin is a dll that contain adiitional functionality. Available plugins:

1. NyaFsSftp.dll
2. NyaFsLinux.dll
3. NyaFsTFtp.dll
4. NyaFsFiles.dll Plugins must be placed at 'plugins' folder, then they will be loaded on app startup.

Default server port is 22. Start server:

service sftp start

Stop server:

service sftp stop

Information about server parameters:

service sftp info

Port selection (while server is stopped):

service sftp set port <port>

There are need to setup in WinSCP connection settings sending null packets every 20-30 sec to keep connection alive. Timeout is 45 seconds.

Default server port is 69. Start server:

service tftp start

Stop server:

service tftp stop

Port selection (while server is stopped):

service tftp set port <port>

Information about server parameters:

service tftp info

Directory selection (while server is stopped):

service tftp set dir <directory>

Downloading from remote tftp server:

tftpget <filename> <server> <remotefilename>

(filename) - filename of file to write received data (server) - ip or hostname of remote server (remotefilename) - filename of requested file on server

Uploading to remote tftp server:

tftpput <filename> <server> <remotefilename>

(filename) - filename with content of sended file (server) - ip or hostname of remote server (remotefilename) - filename of target file on server

Copy file on local filesystem:

copy <src> <dst>

(src) - filename of file to be copied (dst) - filename of new file

Download file from http/https:

download <filename> <url>

(filename) - filename of file to write received data (url) - url of remote file

Remove file from local filesystem:

remove <filename>

Load local directory to filesystem: loaddir <path> <localdir> <dirmode> <filemode> <user> <group> Example: loaddir /tmp/xxx include/xxx rwxr-xr-x rw-r--r-- 0 0

Load files from zip archive to filesystem: loadzip <path> <zippath> <dirmode> <filemode> <user> <group> Example: loadzip /www www.zip rwxr-xr-x rw-r--r-- 0 0

List of all users (from /etc/passwd):

lsusr

List of password hashes (from /etc/shadow):

lshashes

Example of users inspection:

Set new password for user (/etc/shadow will be updated, SHA-512 hash is used by default):

mkpasswd <user> <password>

Check user password - is password valid for this user:

passwd <user> <password>
passwd <user>

(password) - password to check. If field is not specified, user will be checked for empty password.

Find user password from list of passwords (bruteforce, very slow, but applicable for finding which password from list of used passwords was used in loaded rootfs)

findpasswd <user> <listfilename>

(listfilename) is filename of file, which contains a list of passwords to check.