WIFI support

[LostKobrakai]

Environment

• Elixir version (elixir -v): 1.10.4
• Nerves environment: (mix nerves.env --info)

|nerves_bootstrap| Environment Package List

  Pkg:         nerves_system_br
  Vsn:         1.13.2
  Type:        system_platform
  BuildRunner: {nil, []}

  Pkg:         nerves_system_rpi
  Vsn:         1.13.0
  Type:        system
  BuildRunner: {Nerves.Artifact.BuildRunners.Docker, []}

  Pkg:         nerves_toolchain_armv6_rpi_linux_gnueabi
  Vsn:         1.3.2
  Type:        toolchain
  BuildRunner: {Nerves.Artifact.BuildRunners.Local, []}

  Pkg:         nerves_toolchain_ctng
  Vsn:         1.7.2
  Type:        toolchain_platform
  BuildRunner: {nil, []}

|nerves_bootstrap| Loadpaths Start


Nerves environment
  MIX_TARGET:   rpi
  MIX_ENV:      dev

|nerves_bootstrap| Environment Variable List
  target:     rpi
  toolchain:  /Users/benni/.nerves/artifacts/nerves_toolchain_armv6_rpi_linux_gnueabi-darwin_x86_64-1.3.2
  system:     /Users/benni/.nerves/artifacts/nerves_system_rpi-portable-1.13.0
  app:        /Users/benni/Projects/ikea_frame

|nerves_bootstrap| Loadpaths End

• Additional information about your host, target hardware or environment that
  may help
  Rpi A+

Current behavior

There is a bunch of realtek firmware in /lib/firmware/rtlwifi:

iex(22)> File.ls "/lib/firmware/rtlwifi"
{:ok,
 ["rtl8188efw.bin", "rtl8188eufw.bin", "rtl8192cfw.bin", "rtl8192cfwU.bin",
  "rtl8192cfwU_B.bin", "rtl8192cufw.bin", "rtl8192cufw_A.bin",
  "rtl8192cufw_B.bin", "rtl8192cufw_TMSC.bin", "rtl8192defw.bin",
  "rtl8192eefw.bin", "rtl8192eu_ap_wowlan.bin", "rtl8192eu_nic.bin",
  "rtl8192eu_wowlan.bin", "rtl8192sefw.bin", "rtl8712u.bin",
  "rtl8723aufw_A.bin", "rtl8723aufw_B.bin", "rtl8723aufw_B_NoBT.bin",
  "rtl8723befw.bin", "rtl8723bs_ap_wowlan.bin", "rtl8723bs_bt.bin",
  "rtl8723bs_nic.bin", "rtl8723bs_wowlan.bin", "rtl8723bu_ap_wowlan.bin",
  "rtl8723bu_nic.bin", "rtl8723bu_wowlan.bin", "rtl8723fw.bin",
  "rtl8723fw_B.bin"]}

But my 8192cu based usb stick wasn't working and dmesg showed nothing being started/erroring or otherwise. lsusb listed the stick, but lsmod showed nothing in regards to wifi as well.

Expected behavior

Given the stick used to work with nerves a few years ago I opted to build a custom system with this:

diff --git a/linux-4.19.defconfig b/linux-4.19.defconfig
index 0e654db..49285ce 100644
--- a/linux-4.19.defconfig
+++ b/linux-4.19.defconfig
@@ -143,7 +143,7 @@ CONFIG_BRCMFMAC=m
 CONFIG_RT2X00=m
 CONFIG_RT2800USB=m
 CONFIG_RT2800USB_RT53XX=y
-# CONFIG_WLAN_VENDOR_REALTEK is not set
+CONFIG_RTL8192CU=m
 # CONFIG_WLAN_VENDOR_RSI is not set
 # CONFIG_WLAN_VENDOR_ST is not set
 # CONFIG_WLAN_VENDOR_TI is not set

With that change dmesg started to show messages related to rtlwifi and the stick worked.

I still don't feel like I have a good grasp on how all of that interacts exactly, but it seems this nerves system bundles a bunch of firmware currently not being used.

[lovebes]

I have the exact same issue with the exact same wifi driver.
How did you get access to the iex terminal if your WIFI doesn't work? Via wired connection?