Rebasedlinuxhostgl

CHANGELOG.md

@@ -150,6 +150,26 @@ hashes are given where a change is easiest to understand by reading the commit.
   `nvram` ones, so both chips get a real MAC regardless of machine profile.
 ### Graphics and host OpenGL
 
+- **Host GL on Linux.** `--features hostgl` now has an EGL backend
+  (`iris-hostgl/src/backend/egl.rs`): headless contexts in the compatibility
+  profile with no surface at all (every drawable was already a framebuffer
+  object), on Mesa's surfaceless platform, so no X or Wayland session is
+  involved. libEGL is opened at run time; building links libGL (glvnd):
+  `libgl-dev` on Debian/Ubuntu, `libglvnd-devel` on Fedora, `libglvnd` on
+  Arch. Running needs libEGL and Mesa's EGL and DRI drivers: `libegl1
+  libegl-mesa0 libgl1-mesa-dri` on Debian/Ubuntu (`libegl-mesa0` alone does
+  not bring libEGL), `mesa-libEGL mesa-dri-drivers` on Fedora, `mesa` on
+  Arch. glvnd and Mesa hand
+  out a stub for any `gl*` name, so entry points are looked up only when the
+  context's version or extensions provide them (`src/avail.rs`, generated
+  from the pinned registry by `tools/gl_avail.py`). The service's own texture
+  names now count down from the top, out of the way of Mesa's, which come
+  from the bottom whatever the program asked for. Debian 12 arm64 (Mesa
+  22.3, virgl, GL 4.0 compatibility): hostgl tests 31/31, gltest 167/167 n32
+  and o32, glcheck with the reference checksum, irisgltest, Quake 3. Fedora
+  44, Arch and Ubuntu 24.04 (x86_64, Mesa's software renderer, no GPU):
+  builds, hostgl tests 31/31. See
+  `rules/hostgl/linux-egl-and-mesa.md`.
 - **Host GL no longer stops the machine while it draws.** A host call is
   answered on the emulated CPU's thread, so while host GL replayed a
   command buffer (2-5 ms for a big one) no instruction ran and no interrupt

Cargo.toml

@@ -1,7 +1,7 @@
 [workspace]
 members = ["iris-gui", "iris-hostcall"]
 # iris-hostgl is built only through `--features hostgl`, never by a plain or
-# `--workspace` build: it links the host's OpenGL (CGL today), which hosts
+# `--workspace` build: it links the host's OpenGL (OpenGL.framework, libGL), which hosts
 # such as RISC-V boards do not have.
 exclude = ["iris-hostgl"]
 
@@ -253,8 +253,9 @@ hostcall = ["dep:iris-hostcall"]
 # Host OpenGL for IRIX programs (iris-hostgl/): host call 3000, answered by
 # replaying the replacement libGL's command stream on the host GPU. The IRIX
 # side libraries are the iris-guest-tools project
-# (github.com/atomchild411/iris-guest-tools). macOS only for now (CGL); on
-# other hosts the service is not registered and the guest's libGL says so.
+# (github.com/atomchild411/iris-guest-tools). macOS (CGL) and Linux (EGL with
+# libGL); on other hosts the service is not registered and the guest's libGL
+# says so.
 # Off by default, and iris-hostgl is outside the workspace members, so
 # nothing builds it unless this feature is asked for.
 hostgl = ["hostcall", "dep:iris-hostgl"]

FEATURES.md

@@ -49,7 +49,7 @@ Select with `cargo build --release --features <comma-separated-list>`; add
 | `jitv2_smc_check` | Report writes to the executing code page; disable inline memory to observe all stores. | `jitv2` |
 | `pcap` | Raw Ethernet bridge backend; needs host capture library/driver and capture permissions. | `dep:pcap` |
 | `hostcall` | Private user-mode guest syscall services 3000–3009; IRIX handles other calls. | `dep:iris-hostcall` |
-| `hostgl` | Guest replacement-libGL command replay; macOS CGL backend only. | `hostcall`, `dep:iris-hostgl` |
+| `hostgl` | Guest replacement-libGL command replay; macOS (CGL) and Linux (EGL) backends. | `hostcall`, `dep:iris-hostgl` |
 
 Cargo also exposes these **implicit optional-dependency features**:
 `cranelift-codegen`, `cranelift-frontend`, `cranelift-jit`, `cranelift-module`, `cranelift-native`, `region`, `target-lexicon`, `wasmtime-jit-icache-coherence`. They enable library dependencies,
@@ -515,7 +515,7 @@ both the interpreter and jitv2.
 | `jitv2_smc_check` | Report writes into the page the CPU is executing (run with `j2 inline_mem off`) |
 | `jitv2_opcodefusion` | jitv2 LUI+ORI/ADDIU and branch+NOP fusion (off by default; see "JIT compilers") |
 | `j2wp` | Compatibility alias for `jitv2`; whole-page compilation is the only implementation |
-| `hostcall` / `hostgl` | Private host-service syscalls / host OpenGL for IRIX programs; `hostgl` has a macOS CGL backend |
+| `hostcall` / `hostgl` | Private host-service syscalls / host OpenGL for IRIX programs; `hostgl` has macOS (CGL) and Linux (EGL) backends |
 | `debug_cache` | Track one cache line across all operations |
 | `tlbvmap` | Vestigial; the vmap TLB fast path is always on |
 | `r5ksc`, `r5ksc_triton` | Refuse to build: no working R5000 secondary-cache model yet (`rules/testing/r5k-l1i-cache-bugs.md`) |

TODO.md

@@ -232,9 +232,9 @@ condition; update the linked guide and changelog when it lands.
 
 ## Host services, GUI, and delivery
 
-- [ ] **Implementation — HostGL platform and extension coverage.** macOS CGL
-  is the only backend; Linux/Windows builds register no GL service. Either add
-  those backends or keep availability explicit. Inventory unavailable GL
+- [ ] **Implementation — HostGL platform and extension coverage.** macOS (CGL)
+  and Linux (EGL) have backends; Windows builds register no GL service. Either
+  add that backend or keep availability explicit. Inventory unavailable GL
   entry points and finish SGIS detail/sharpen/filter query result lengths,
   which currently report unsupported. Complete when guest capability queries,
   marshalling/readback, contexts/drawables, and representative GL apps behave

iris-gui-README.md

@@ -40,7 +40,7 @@ emulation will be noticeably slow.
 |---|---|
 | `pcap` | PCAP bridged networking; the Networking tab lists host interfaces. Needs libpcap / a WinPcap-compatible SDK |
 | `hostcall` | Host services for IRIX programs over private syscalls 3000-3009. No per-machine setting — the Debug tab just reports it's built in |
-| `hostgl` | Host OpenGL for IRIX programs (implies `hostcall`); IRIX's replacement libGL replays its GL calls on the host GPU. macOS (CGL) only for now — builds elsewhere but registers no backend |
+| `hostgl` | Host OpenGL for IRIX programs (implies `hostcall`); IRIX's replacement libGL replays its GL calls on the host GPU. macOS (CGL) and Linux (EGL; needs libGL to build, libEGL and Mesa's EGL/DRI drivers at run time; see CHANGELOG) — builds elsewhere but registers no backend |
 | `premiere` | `iris/lightning` + `iris/idle-pause` for maximum in-process speed |
 | `bundled` | Distributed build: hides the iris.toml import/export items. Set by the Release workflow |
 | `appstore` | Mac App Store build: implies `bundled`, hides the CI tab, enables security-scoped bookmarks and folder grants |

iris-gui/src/config_ui.rs

@@ -1587,11 +1587,11 @@ fn show_debug(ui: &mut Ui, cfg: &mut MachineConfig) -> ConfigAction {
         ui.end_row();
         ui.label("Host services / Host GL");
         ui.label(match (build_features::HOSTCALL, build_features::HOSTGL) {
-            (_, true) => "built in — IRIX OpenGL programs render on the host GPU (CGL)",
-            (true, false) if cfg!(target_os = "macos") =>
+            (_, true) => "built in — IRIX OpenGL programs render on the host GPU",
+            (true, false) if cfg!(any(target_os = "macos", target_os = "linux")) =>
                 "hostcall only — rebuild with --features hostgl for host OpenGL",
             (true, false) =>
-                "hostcall only — host GL has no backend on this OS yet (macOS/CGL only)",
+                "hostcall only — host GL has no backend on this OS yet (macOS and Linux only)",
             (false, _) => "not built — rebuild with --features hostgl for host OpenGL",
         });
         ui.end_row();

iris-hostgl/Cargo.toml

@@ -9,7 +9,7 @@ license = "BSD-3-Clause"
 iris-hostcall = { path = "../iris-hostcall" }
 log = "0.4"
 
-# The only backend so far is Apple's OpenGL.framework (CGL); elsewhere the
-# crate builds and registers nothing.
-[target.'cfg(target_os = "macos")'.dependencies]
+# Backends: Apple's OpenGL.framework (CGL) on the Mac, EGL with libGL (glvnd)
+# on Linux; elsewhere the crate builds and registers nothing.
+[target.'cfg(any(target_os = "macos", target_os = "linux"))'.dependencies]
 libc = "0.2"

iris-hostgl/src/accum.rs

@@ -27,22 +27,23 @@
 //! state is saved around each pass and put back, so nothing it can see moves.
 
 use std::collections::HashMap;
-use std::ffi::{c_void, CString};
+use std::ffi::{c_char, c_void, CString};
 
 use crate::gl::*;
 
-#[link(name = "OpenGL", kind = "framework")]
+#[cfg_attr(target_os = "macos", link(name = "OpenGL", kind = "framework"))]
+#[cfg_attr(target_os = "linux", link(name = "GL"))]
 extern "C" {
     fn glCreateShader(kind: u32) -> u32;
-    fn glShaderSource(s: u32, count: i32, strings: *const *const i8, lengths: *const i32);
+    fn glShaderSource(s: u32, count: i32, strings: *const *const c_char, lengths: *const i32);
     fn glCompileShader(s: u32);
     fn glGetShaderiv(s: u32, pname: u32, out: *mut i32);
     fn glCreateProgram() -> u32;
     fn glAttachShader(p: u32, s: u32);
     fn glLinkProgram(p: u32);
     fn glGetProgramiv(p: u32, pname: u32, out: *mut i32);
     fn glUseProgram(p: u32);
-    fn glGetUniformLocation(p: u32, name: *const i8) -> i32;
+    fn glGetUniformLocation(p: u32, name: *const c_char) -> i32;
     fn glUniform1i(loc: i32, v: i32);
     fn glUniform4f(loc: i32, a: f32, b: f32, c: f32, d: f32);
     fn glGenTextures(n: i32, ids: *mut u32);