Hi !
I m new in this topic, and i have a problem for install openwrt on my new pbe 5ac 500,
i connect to putty with my code and when i have to download file i have this message :
On the remote side of the window (the router), change the directory to /tmp and drop the file there.
It is important to use /tmp as the destination directory as it is a RAM drive and has enough space to hold a firmware image. Trying to copy to a directory that is on flash will overfill the flash.
Then go back to the Putty window and continue the installation process using commands on the router.
On the router, ls -l /tmp should show the file there. I think that the stock OS also has sha256sum if you want to confirm the file hash against the one listed on the OpenWrt download page.