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+# Self-serving an ARM build
+
+Mozilla announced the intent to deprecate ARMv7 HF builds of
+geckodriver in September 2018.  This does not mean you can no longer
+use geckodriver on ARM systems, and this document explains how you
+can self-service a build for ARMv7 HF.
+
+Assuming you have already checked out [central], the steps to
+cross-compile ARMv7 from a Linux host system is as follows:
+
+  1. If you don’t have Rust installed:
+
+      ```shell
+      % curl https://sh.rustup.rs -sSf | sh
+      ```
+
+  2. Install cross-compiler toolchain:
+
+      ```shell
+      % apt install gcc-arm-linux-gnueabihf libc6-armhf-cross libc6-dev-armhf-cross
+      ```
+
+  3. Create a new shell, or to reuse the existing shell:
+
+      ```shell
+      % source $HOME/.cargo/env
+      ```
+
+  4. Install rustc target toolchain:
+
+      ```shell
+      % rustup target install armv7-unknown-linux-gnueabihf
+      ```
+
+  5. Put this in [testing/geckodriver/.cargo/config]:
+
+      ```rust
+      [target.armv7-unknown-linux-gnueabihf]
+      linker = "arm-linux-gnueabihf-gcc"
+      ```
+
+  6. Build geckodriver from testing/geckodriver:
+
+      ```shell
+      % cd testing/geckodriver
+      % cargo build --release --target armv7-unknown-linux-gnueabihf
+      ```
+
+[central]: https://hg.mozilla.org/mozilla-central/
+[testing/geckodriver/.cargo/config]: https://searchfox.org/mozilla-central/source/testing/geckodriver/.cargo/config