ti-processor-sdk-linux-am335x-evm-03.00.00.04-Linux-x86-Install.bin, Failed to connect SFTP subsystem. Remote host may not have sftp-server installed.

Horea Aflat 32

I installed the new Linux distribution ti-processor-sdk-linux-am335x-evm-03.00.00.04-Linux-x86-Install.bin: on my board am335x and on my host Ubuntu 16.04, 64 bits.

I created a HelloWorld project in CCS 6.1.3 following the instructions for cross compiling:

But when I run I get the error:

Error during file upload.

Failed to connect SFTP subsystem. Remote host may not have sftp server installed.

I can connect with ssh to the board.

Please check the attached pictures:

over 9 years ago

0 Pavel Botev over 9 years ago

TI__Guru**** 170625 points

Hi Horea,

Please have a look in the below e2e threads:

e2e.ti.com/.../665267
e2e.ti.com/.../216721

Regards,
Pavel

0 Horea Aflat 32 over 9 years ago in reply to Pavel Botev

Prodigy 195 points

Pavel,

The answer is that the openssh package is not included into the kernel image.
But...
At the previous version is was. I did not have this problems.
And second this was my question. I think the image has a bug.
Will you publish a new image?
Or please give me instructions for a workaround.

Thanks
Horea

0 Horea Aflat 32 over 9 years ago in reply to Horea Aflat 32

Prodigy 195 points

Pavel,

I tried to recompile the kernel using:
processors.wiki.ti.com/.../Linux_Kernel_Users_Guide
But:
~/ti-processor-sdk-linux-am335x-evm-03.00.00.04/board-support/linux-4.4.12+gitAUTOINC+3639bea54a-g3639bea54a/
modules.builtin
modules.order
there is no openssh.
What should I modify?
Do you believe the other version real time linux has the same problems, or I should try it?

Thanks
Horea

0 Pavel Botev over 9 years ago in reply to Horea Aflat 32

TI__Guru**** 170625 points

Horea Aflat 32 said:
The answer is that the openssh package is not included into the kernel image.
But...
At the previous version is was. I did not have this problems.

Do you mean that you do not have this issue with ti-processor-sdk-linux-am335x-evm-02.00.02.11/board-support/linux-4.1.18 ?

Regards,
Pavel

0 Pavel Botev over 9 years ago in reply to Horea Aflat 32

TI__Guru**** 170625 points

Horea Aflat 32 said:
~/ti-processor-sdk-linux-am335x-evm-03.00.00.04/board-support/linux-4.4.12+gitAUTOINC+3639bea54a-g3639bea54a/
modules.builtin
modules.order
there is no openssh.
What should I modify?

I do not think openssh package can be integrated into the linux kernel zImage. Openssh package is installed into the root filesystem. AM335x PSDK 3 comes with openssh-sftp-server 7.1p2, while the previous AM335x PSDK 2 comes with openssh-sftp-server 6.7p1

Regards,
Pavel

0 Horea Aflat 32 over 9 years ago in reply to Pavel Botev

Prodigy 195 points

Pavel,

The previous version worked without problems. I succeeded to connect from CCS and QTCreator.

Thanks
Horea

0 Horea Aflat 32 over 9 years ago in reply to Pavel Botev

Prodigy 195 points

Pavel,

I checked on board.
The sftp server is installed.
Package: openssh-sftp-server
Version: 7.1p2-r0.arago0.10

The sftp-server path is: /usr/libexec/sftp-server
When I try to connect from host the error message is:
sh: /usr/lib/openssh/sftp-server: No such file or directory
Connection closed

I think the paths do not match.
Can you please check on your side.

Thanks
Horea

0 Pavel Botev over 9 years ago in reply to Horea Aflat 32

TI__Guru**** 170625 points

Horea,

In PSDK2 we have the sftp server at the below location:

tisdk-rootfs-image-am335x-evm/usr/lib/openssh/sftp-server

While in PSDK3 we have the sftp server at the below location:

tisdk-rootfs-image-am335x-evm/usr/libexec/sftp-server

Can you check if the /usr/libexec/sftp-server process is running on the AM335x device? See the below wiki page for more info:

Horea Aflat 32 said:
The sftp-server path is: /usr/libexec/sftp-server
When I try to connect from host the error message is:
sh: /usr/lib/openssh/sftp-server: No such file or directory
Connection closed

Can you provide me a screen shot?

Regards,

Pavel

0 Horea Aflat 32 over 9 years ago in reply to Pavel Botev

Prodigy 195 points

Pavel,

Basically CCS does not work to query the processes on am335x.

It says Internal error. I attached a print screen.

But I can connect with ssh and I attached a txt file with the results ps -aux.

sftp-server is not in the list.

7870.am335x_ps.txt

Thanks

Horea

0 Horea Aflat 32 over 9 years ago in reply to Horea Aflat 32

Prodigy 195 points

Pavel,

If you can provide me instructions how to manually start sftp-server, it will be great.

Thanks
Horea

0 Pavel Botev over 9 years ago in reply to Horea Aflat 32

TI__Guru**** 170625 points

Horea,

In the below post, the sftp-server is started manually:

e2e.ti.com/.../1749820

Regards,
Pavel

0 Horea Aflat 32 over 9 years ago in reply to Horea Aflat 32

Prodigy 195 points

Pavel,

I found out that if in the file:
/etc/ssh/sshd_config

I add the entry:
Subsystem sftp /usr/libexec/sftp-server

The server should start.
Basically it not.

Do you have any idea?

Thanks
Horea

0 Horea Aflat 32 over 9 years ago in reply to Horea Aflat 32

Prodigy 195 points

Pavel,

I made rollback to linux 2 and it is working the debug:

Thanks

Horea

0 Horea Aflat 32 over 9 years ago in reply to Horea Aflat 32

Prodigy 195 points

Pavel,

I connected am335x at Internet and I have access to your repositories using opkg.
I tried to reinstall the package but it says:
opkg_download_cmd: Cannot find package openssh-sftp-server - 7.1p2-r0.arago0.10.
Can you please check on your side if the package is available for download.
And also when I update the opkg I received some errors like:
opkg_download_backend: Failed to download gtjenkins.itg.ti.com/.../Packages.gz, wget returned 1.

Another solution is to use linux 2 and download opencv package.

OpenCV libraries are the reason that I am interesed into linux 3.

What do you think? Opencv libraries will work on linux 2?

Thanks
Horea

0 Pavel Botev over 9 years ago in reply to Horea Aflat 32

TI__Guru**** 170625 points

Horea Aflat 32 said:
I found out that if in the file:
/etc/ssh/sshd_config

I add the entry:
Subsystem sftp /usr/libexec/sftp-server

I do not find /etc/ssh/sshd_config in ti-processor-sdk-linux-am335x-evm-03.00.00.04/filesystem/tisdk-rootfs-image-am335x-evm

We can start the sftp-server with the below command:

$/usr/libexec# ./sftp-server &

Then we check with "ps aux", and the sftp-server is listed.

Regards,
Pavel

0 Pavel Botev over 9 years ago in reply to Pavel Botev

TI__Guru**** 170625 points

We also check PSDK2 /usr/lib/openssh/sftp-server, the sftp-server is not started by default, I suspect the CCS is the one who start it. So check if starting PSDK3 sftp-server manually (outside of the CCS) will work for you. If not, I will check with the CCS team how to fix the path to the correct location of the sftp-server within the CCS environment.

Regards,
Pavel

0 Horea Aflat 32 over 9 years ago in reply to Pavel Botev

Prodigy 195 points

Pavel,

I started the sftp-server on PSDK3 and check the process status and is running.
I started CCS and I got the same error:
Error during file upload.
Failed to connect SFTP subsystem: Remote host may not have sftp-server installed : java.io.IOException: inputstream is closed

On CCS there is an option: "Skip download to target." which makes CCS to not use sftp-server.
But in this case there is still an error: CCS remains hang-up and does not start the debuger.

Anyway I am using PSDK2 which is working very well.

Thanks
Horea

0 Thomas Maltesen over 9 years ago in reply to Pavel Botev

Intellectual 450 points

I have the same problem, seems there is something wrong with SFTP in the latest version 3.00.00.04
Previously I have used SFTP server in version 1 and 2. So in all previous and also SDK, 2.00.02.11 is was working fine.
I do not find a solution in any of the threads, has anyone found a solution yet?

0 Pavel Botev over 9 years ago in reply to Thomas Maltesen

TI__Guru**** 170625 points

Thomas,

I am checking with the CCS team regarding how to switch from rootfs/usr/lib/openssh/sftp-server to rootfs/usr/libexec/sftp-server

I will update this thread when I have more info on this.

Regards,
Pavel

0 Thomas Maltesen over 9 years ago in reply to Pavel Botev

Intellectual 450 points

Just a note, for me this has nothing to do with CCS. I am not using CCS, just plain SFTP access to my target.

0 Pavel Botev over 9 years ago in reply to Thomas Maltesen

TI__Guru**** 170625 points

Thomas,

From what I was able to find, SFTP is used from the CCS:

processors.wiki.ti.com/.../Processor_Linux_SDK_CCS_Remote_System_Explorer_Setup
processors.wiki.ti.com/.../Processor_SDK_Linux_Training:_Hands_on_with_the_Linux_SDK
processors.wiki.ti.com/.../How_to_setup_Remote_System_Explorer_plug-in
e2e.ti.com/.../819089

Can you provide more info of your SFTP non-CCS issue? Do you use QT like in the e2e threads below?

e2e.ti.com/.../200794
e2e.ti.com/.../484715

Regards,
Pavel

0 Thomas Maltesen over 9 years ago in reply to Pavel Botev

Intellectual 450 points

I can only imagine that it is reasonable that CCS uses SFTP to tranfer debug images. I do nok know QT, but it is reasonable to think that it uses SFTP protocol to transfer files to target during debugging similar to CCS.

Since SFTP is a pretty standard protocol for file transfer, there are many different "clients" that can be used.

I use the FileZilla only for file transfer to the target. It is a standard FTP/SFTP client.

Since I wrote I have installed another SFTP client (winSCP), it does not work either so it is defently something with SFTP in the SDK.

I have a target build with SDK 2.0..11 also running, it is working with both.

0 Thomas Maltesen over 9 years ago in reply to Thomas Maltesen

Intellectual 450 points

I do not think it has to do with encryption (SSL), not 100% sure though; but at least SSH encrypted terminal connection is still functional.

0 Pavel Botev over 9 years ago in reply to Thomas Maltesen

TI__Guru**** 170625 points

Thomas,

If I understand correctly, you are able to transfer files between the host and the AM335x board through SFTP (SSH file transfer protocol) (Secure File Transfer Protocol) with ti-processor-sdk-linux-am335x-evm-02.00.02.11 tisdk-rootfs/usr/lib/openssh/sftp-server ?

But you are not able to transfer files between the host and the AM335x board through SFTP with ti-processor-sdk-linux-am335x-evm-03.00.00.04 tisdk-rootfs/usr/libexec/sftp-server ?

Can you provide us the exact steps to reproduce this issue with ti-processor-sdk-linux-am335x-evm-03.00.00.04?

Regards,
Pavel

0 Kevin Schuster over 9 years ago in reply to Pavel Botev

Expert 1210 points

I have the same problem here, using a AM57xx board.

I was working with the 2.00.02.11 SDK version via CCS6 Remote System Explorer to access the file system of the board. Everything worked out fine, no connection problems. i reached the point where I needed the update of the Kernel version, so I found out that there the new SDK version includes a higher version.

I updated my SC-card from ti-processor-sdk-linux-am57xx-evm-02.00.02.11 to ti-processor-sdk-linux-am57xx-evm-03.00.00.04 and now the Remote System Explorer of CCS6 shows me the same error message like from the others, when I try to connect to the board:

"Failed to connect SFTP subsystem: Remote host may not have sftp-server installed : java.io.IOException: inputstream is closed"

Strangly, the SSH Terminal is working after accepting the error message, but I cannot access the file system of the board.

I tried to start the SFTP-server manually in background, like you said, but it is not solving the problem. Any other suggestions?

0 Pavel Botev over 9 years ago in reply to Kevin Schuster

TI__Guru**** 170625 points

I received info from the PSDK team. There are working on the issue with the PSDK3 sftp-server, and we are targeting to get it fixed for the next version of the PSDK 3.1. The new PSDK 3.1 release should be available from ti.com by the middle of October.

0 Thomas Maltesen over 9 years ago in reply to Pavel Botev

Intellectual 450 points

Yes, you understood. Also 2.00 working and 3.00 not working.

Do you still need reproduction?

Nearly clean install of SDK (both versions) very few kernel changes for realtimeclock and I/O, default rootfs. SD Card created with SDK util. And after target is running I connect with FileZilla SFTP client. (succesfull in version 2 and previous builds, broken in version 3 SDK).

0 Pavel Botev over 9 years ago in reply to Thomas Maltesen

TI__Guru**** 170625 points

Thomas Maltesen said:
Do you still need reproduction?

No, I do not

0 Jacob Stiffler over 9 years ago in reply to Horea Aflat 32

TI__Prodigy 490 points

Horea,

The root cause of this problem has been located in the dropbear package. Dropbear controls the ssh connections and will invoke the sftp-server on the target platform.

Dropbear has the path to the sftp-server built into the executable, and the problem is that this path was not updated along with the openssh-sftp-server package.

To check this, run the following command:

root@am335x-evm:~# strings $(which dropbear) | grep sftp-server
/usr/lib/openssh/sftp-server

Dropbear does not expose much configuration through external files. Therefore the simplest workaround is to create symlink from the old path to the new.

root@am335x-evm:~# mkdir -pv /usr/lib/openssh
created directory: '/usr/lib/openssh'
root@am335x-evm:~# ln -sv /usr/libexec/sftp-server /usr/lib/openssh/
'/usr/lib/openssh/sftp-server' -> '/usr/libexec/sftp-server'

This will be resolved in the next Processor SDK release.

0 Thomas Maltesen over 9 years ago in reply to Jacob Stiffler

Intellectual 450 points

Great this is working!

Processors

Processors forum

ti-processor-sdk-linux-am335x-evm-03.00.00.04-Linux-x86-Install.bin, Failed to connect SFTP subsystem. Remote host may not have sftp-server installed.