gex/web

web

The page that runs gex in a browser, and the builds of what it loads:

• the browser shim, the shared kernel module and the seed, from shims/browser and shims/kernel (build-assets.sh);
• Mesa for wasm32, from the third_party/mesa submodule. It draws through Gallium's gex_wgpu driver on the browser's WebGPU. A guest's GL calls reach it through guest/gl and web/mesa/gexgl-mesa.cpp (build-mesa-wasm.sh);
• Xwayland as wasm32, which runs in a Worker of the page and talks to shims/hostwl (build-xwayland-wasm.sh);
• the guest root filesystems come from the debdemo repository, which writes them into web/public/rootfs (and the desktop demo's launcher packages into web/public/pkgs).

The two builds

build	dist	threads	hosting
multi-process (default)	web/dist	each guest thread is a Worker on shared memory	needs COOP/COEP (SharedArrayBuffer)
single-thread	web/dist-sp	every guest thread is a fiber in one Worker	any static host

Both builds load the same shim, kernel and seed. Each builds its own Mesa and Xwayland, with or without -pthread. The dists ship stripped wasm. Unstripped copies stay in target/web-debug/<mp|sp>/, and --debug ships them instead.

git submodule update --init third_party/mesa
web/build-all.sh             # multi-process
web/build-all.sh --sp        # single-thread
web/build-all.sh --both
node web/serve-dist.mjs 8088 --sp-port 8089

The first Mesa build also builds Tint (tint/build-tint.sh), so it takes much longer than later ones. Stripping needs wasm-tools (cargo install wasm-tools).

Ejected programs

build-eject-page.sh builds the page library that an ejected project ships. eject-site.mjs PROJECT OUT packs a built 32-bit Wine project into a static site: the library, its runtime and Mesa, zstd-compressed assets, and the headers the host must send. The site's index.html belongs to the project, so the library can be imported into a page of your own. Its API, start(), is in src/README.md.

The desktop demo

build-demo.sh builds the desktop page into web/dist-demo. Its guest side (the base rootfs and the launcher's packages) comes from the debdemo repository, built against this checkout first:

make -C path/to/debdemo native GEXCC_PREFIX=...   # the gexcc .deb pool, once
make -C path/to/debdemo desktop GEX_DIR=$PWD      # web/public/rootfs/base.tar.zst, web/public/pkgs
web/build-demo.sh

Without them build-demo.sh stops and says so. The other pages (build-all.sh) need nothing from debdemo; their Debian demos say when their rootfs is missing.