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RedBear-OS/local
vasilito f09a094993 docs: 3D driver plan covering Mesa 26.1.4 + virgl + Intel (PTL) + AMD
Comprehensive 3D userland plan based on direct code audit of the
Mesa 26.1.4 build, redox-drm Intel backend, virgl runtime path,
amdgpu C port, and libdrm enablement. Seven critical gaps identified
that block all hardware-accelerated 3D rendering on Red Bear OS
beyond llvmpipe fallback:

1. Mesa gallium-drivers=softpipe,llvmpipe,virgl — NO iris, NO crocus,
   NO radeonsi. The README/CHANGELOG claim that 'all 6 Red Bear
   Mesa patches are wired' is incorrect: only 5 are wired; patches
   03 and 06 are orphans because patch 03 targets
   src/egl/drivers/dri2/platform_redox.c which does not exist in
   Mesa 26.1.4 upstream (the file was removed). Patches 03/06
   cannot be cleanly reapplied — they need re-creation against
   the current Mesa API.

2. No 'redox' EGL platform in Mesa 26.1.4. EGL_PLATFORM=wayland
   resolves to swrast (llvmpipe) on Redox. virgl and iris are
   never auto-selected.

3. No Mesa winsys for Redox (src/gallium/winsys/redox/ does not
   exist). The virgl driver uses upstream's generic
   virgl_drm_winsys which depends on libdrm's redox.patch to
   redirect ioctls to scheme:drm.

4. Intel kernel backend supports only Gen9–Gen14 (Meteor Lake).
   No Lunar Lake (Xe2, Gen15) device IDs. No Panther Lake (Xe3,
   Gen16) device IDs. The display version table stops at 14.

5. No Vulkan built (vulkan-drivers= empty). No anv (Intel), no
   radv (AMD), no venus (virtio-gpu Vulkan).

6. The redox_private_cs_submit ABI exists in redox-drm (real
   implementation for Intel ring submission with seqno tracking,
   space-wait, MI_FLUSH_DW) but no Mesa gallium driver consumes it.

7. The amdgpu C port is display-only (DC modeset, no render/3D).
   It does NOT provide a Mesa radeonsi winsys. Stages 2-4 of the
   amdgpu recipe are intentionally empty (no Linux TTM/core
   source).

The plan file (786 lines) covers:
- Verified code state from direct read (Mesa recipe, Intel
  backend, virgl, amdgpu, libdrm)
- Reality-vs-claim corrections (6 overclaims in current docs)
- Hardware-acceleration status table (10 paths)
- 7-phase execution plan with explicit acceptance criteria
  for each phase:
    Phase 1: Validate current virgl runtime path (1-2 weeks)
    Phase 2: Add Lunar Lake and Panther Lake device IDs
    Phase 3: Restore the Redox EGL platform (re-create)
    Phase 4: Add Intel iris (Gen8-Gen14) — biggest piece, 8-12 weeks
    Phase 5: Add AMD radeonsi — 6-8 weeks
    Phase 6: Vulkan (enables anv/radv) — 2-4 weeks
    Phase 7: Panther Lake kernel driver — 12-16 weeks
- Validation matrix per vendor
- File-level change catalog
- Risk register
- Operating rule: 'code presence is not support; build success
  is not support; llvmpipe is not acceleration; an env-override
  that requires manual setup is not a runtime path'.
2026-07-25 00:25:12 +09:00
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