Hi Team, I’ve successfully built Firefox v135 from source on our internal development RISC-V64 platform running on Ubuntu 22.04 with GNOME 42.9 (Xorg & Wayland), Our RISC-V Development platform does include a GPU HW which support HW Acceleration for GNOME & other 3rd Apps (Supporting X & Wayland), and Work seamlessly without any issues. The FireFox v135 Application (via ./mach run) starts up normally. But the major issue I'm observing is that Firefox browser is very slow and laggy, especially during search operations and video playback on YouTube I see a poor performance. Upon further check I found that the most of the work is getting done over the CPU and the utilization is quite high, which is causing the FireFox to perform poorly. I also did try to switching to "Use hardware acceleration when available" in the Mozilla FireFox Settings, but still there is no difference with or without this check and Mozilla FireFox browsing Experience is very poor. Kindly do let me know how we can enhance and improve the overall performance of FireFox Browsing Experience on my RISC-V platform. Any Support and Help is highly appreciative! Attached a Build Steps and Configuration used for building Mozilla FireFox v135 on my RISC-V64 platform, let us know if there is anything missed. Thank you! ------------------------------ **BUILD STEPS** ------------------------------ 1. Clone the Firefox source (v135.0.1): git clone --branch FIREFOX_135_0_1_RELEASE --single-branch --depth 1 https://github.com/mozilla-firefox/firefox.git cd firefox 2. Install required dependencies: sudo apt-get update sudo apt-get install -y curl python3-dev libnspr4 libgtk-3-dev llvm-14 llvm-dev clang libclang-dev libx11-xcb-dev libevent-dev libdbus-glib-1-dev m4 libnspr4-dev meson 3. Install Rust: curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh source $HOME/.cargo/env 4. Install Python and Rust-related tools: pip install --upgrade pip pip install uniffi-bindgen referencing==0.29.1 cargo install cbindgen 5. Apply the RISC-V compatibility patch: patch -Np1 -i firefox-riscv64-hack.patch 6. Create the mozconfig file with custom build options: ac_add_options --with-app-name=firefox ac_add_options --disable-release ac_add_options --enable-hardening ac_add_options --enable-rust-simd ac_add_options --enable-linker=bfd ac_add_options --disable-bootstrap ac_add_options --enable-official-branding ac_add_options --with-branding=browser/branding/official ac_add_options --enable-update-channel=release ac_add_options --with-unsigned-addon-scopes=app,system ac_add_options --allow-addon-sideload ac_add_options --enable-default-toolkit=cairo-gtk3-wayland ac_add_options --with-system-zlib ac_add_options --disable-strip ac_add_options --disable-install-strip ac_add_options --enable-system-ffi ac_add_options --with-system-libevent ac_add_options --with-system-nspr #ac_add_options --with-system-nss ac_add_options --disable-updater ac_add_options --disable-tests ac_add_options --enable-alsa ac_add_options --without-wasm-sandboxed-libraries 7. Vendor Rust dependencies: ./mach vendor rust --ignore-modified 8. Upgrade Cairo from 1.16.0 to 1.18.4: # Extract and build Cairo 1.18.4 tar -xvf cairo-1.18.4.tar.xz cd cairo-1.18.4 mkdir build && cd build meson .. --prefix=/usr/local ninja sudo meson install 9. Build Firefox: cd firefox ./mach build Regards, Saiteja.