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Case Study: mesa-amix (Mesa 3.1)

isoriano1968/mesa-amix is a Mesa 3.1 software-rendering port bootstrap for Amix, published 2026-07-03 alongside the X11R6.3 port it depends on ✅. The design goal is deliberately modest: get OpenGL rendering on Amix via Mesa's Xlib software driver, which renders client-side and ships pixels over the X protocol — so it needs no server-side GLX extension and no ZZ9000 3D acceleration ✅. Facts are ✅ from the repo at 78fe054 (brief §21); this is the bootstrap stage — the static libraries and demos are the first milestone, not a finished GL stack.

At a glance

Property Value Tag
Repo github.com/isoriano1968/mesa-amix ✅
Mesa version 3.1 (MesaLib-3.1 + MesaDemos-3.1 from the official Mesa archive) ✅
Rendering Xlib software driver — client-side; no GLX server extension needed ✅
Display target Xzz9000 (16-bit TrueColor), headers/libs from /usr/x11r6 ✅
Compiler GCC 2.7.2.3; -O -ansi -finline-functions -DAMIX -Dm68k -DSVR4 ✅
First milestone static libGL.a / libGLU.a / libglut.a + xdemos; then selected GLUT demos (gears, bounce, glutmech) before any shared-library work ✅
Excluded (for now) MIT-SHM, threads, CPU assembly, DRI, server-side GLX, ZZ9000 HW accel, shared libs ✅
Distribution overlay-only: install.sh fetches + SHA-256-verifies pristine Mesa 3.1 ✅
License Mesa's own terms (upstream) · MIT (new material) · GLUT 3.7 (demos/GLUT-3.7-NOTICE, for the vendored glutmech.c) ✅

The interesting part: Mesa 3.1 already knew about Amix

Upstream Mesa 3.1 — a 1999 release — already contains a historical AMIX build target ✅. The port keeps that target name but replaces the upstream multi-platform Make-config wholesale with an Amix-only version (config/Make-config.amix), because of a genuinely Amix-shaped problem: the old Amix make parses every rule in an included file, and upstream's Make-config contains malformed backslash continuations in unrelated platform targets that make it fail outright ✅. Deleting the other platforms, not fixing them, is the practical cure.

The Amix target boils down to ✅:

amix:
    $(MAKE) $(MFLAGS) -f Makefile.X11 targets \
    "GL_LIB = libGL.a"  "GLU_LIB = libGLU.a"  "GLUT_LIB = libglut.a" \
    "CC = gcc" \
    "CFLAGS = -O -ansi -finline-functions -DAMIX -Dm68k -DSVR4 \
        -I/usr/x11r6/xc/exports/include -I/usr/x11r6/include" \
    "XLIBS = -L/usr/x11r6/xc/exports/lib -L/usr/x11r6/lib \
        -lXmu -z nodefs -lXext -lX11 -lsocket -lnsl -lm"

Preparing and building

Same overlay pattern as the sibling repos ✅ — the repo holds only the Amix delta; install.sh downloads MesaLib-3.1.tar.gz + MesaDemos-3.1.tar.gz from the official Mesa archive, verifies SHA-256 against SOURCES.sha256, extracts, swaps in Make-config.amix, and adds amix-build.sh:

git clone https://github.com/isoriano1968/mesa-amix.git
cd mesa-amix
sh install.sh /export/amix/mesa3
# copy or mount /export/amix/mesa3/Mesa-3.1 as /usr/mesa3/Mesa-3.1 on Amix

On Amix, static first ✅:

cd /usr/mesa3/Mesa-3.1
sh amix-build.sh libs      # src → libGL.a (Xlib driver), src-glu → libGLU.a, src-glut → libglut.a
sh amix-build.sh xdemos    # minimal visual test clients

# run a demo against the ZZ9000 server:
DISPLAY=:1
LD_LIBRARY_PATH=/usr/x11r6/xc/exports/lib:/usr/lib
export DISPLAY LD_LIBRARY_PATH

Native Amix shared Mesa libraries (the ld -G -h / .sa ABI) come only after the static renderer and demos are proven ✅ — the same prove-the-simple-path-first discipline as the rest of the stack.

Ownership split with the X11R6.3 repo

Stated explicitly in PORTING.md ✅: the X11R6.3 repo owns any future server-side GLX extension; the Mesa repo owns the renderer, the GL/GLU/GLUT libraries, the demos, and the client-side GLX/Xlib integration. Mesa's tree is deliberately independent of the xc tree (/usr/mesa3/Mesa-3.1 vs /usr/x11r6) ✅.

State as of 2026-09-14 (HEAD 1065dcc, 5 commits)

Three commits after the one this page was written from (78fe054) ✅: b394471 adds gears.c and starts its idle loop reliably on Amix; 430b174 adds GLUT demo targets (amix-build.sh mech) and vendors glutmech.c from GLUT 3.7 into overlay/Mesa-3.1/demos/ with its own GLUT-3.7-NOTICE — a third upstream project beside Mesa and the port's MIT material; 1065dcc adds bounce.c and its idle loop. PORTING.md's sequence gained a step 5, build selected GLUT demos, pushing shared libraries to step 6 ✅. The XLIBS line above now also carries -lXmu -z nodefs -lXext ✅. No binary release or tag exists; the build is native (GCC 2.7.2.3) against X11R6.3 headers and libraries under /usr/x11r6 ✅. The README's Layout section still names the author's Windows build-host paths — read it as a personal layout, not a convention ✅.

See also

Sources