firmware-linux software package provides Binary firmware for various drivers in the Linux kernel (meta-package), you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install firmware-linux
firmware-linux is installed in your system.
Make ensure the firmware-linux package were installed using the commands given below,
$ sudo dpkg-query -l | grep firmware-linux *
You will get with firmware-linux package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Meta packages |
| Package | firmware-linux |
| Version | 20160824-1 |
| Description | Binary firmware for various drivers in the Linux kernel (meta-package) |
| Sub Section | Meta packages |