Extracted from local/reference/linux-7.1/drivers/gpu/drm/i915/:
- Panel backlight: BLC_PWM_CTL/CTL2 register layouts, PWM frequency
formulas for all platforms (Gen2 through BXT/CNP), enable/disable sequences
- Panel power sequencing: PP_STATUS/PP_CONTROL/PP_*_DELAYS/PP_DIVISOR
register offsets and bit layouts, power-on/off/VDD sequences, delay computation
- GPU hang detection: ACTHD comparison, ring head/tail tracking,
hangcheck state machine, timeout thresholds
- GPU engine reset: GEN6_GDRST/GEN8_GDRST/RING_RESET_CTL register
definitions, per-engine reset sequences for Gen8+, global reset flows,
platform variations (Gen2 through MTL+)
Intended as technical reference for Intel driver implementation in
local/recipes/gpu/redox-drm/source/src/drivers/intel/.
Comprehensive 6-phase plan (1,055 lines) for updating the Intel GPU driver from current 1,590-line stub to full Gen9+ support ported from Linux 7.1 i915. Covers register abstraction, GMBUS I2C, DMC firmware, power wells, CDCLK, display pipeline, modesetting, and hardware validation.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
Define 4 hardware target classes (AMD/Intel desktop/laptop),
per-target checklist, negative-result capture format, and
quick/full test procedures. Ready for bare-metal evidence.
- git rm 50 stale .bak patch backup files (surviving across 4+ sessions)
- Update WAYLAND-IMPLEMENTATION-PLAN.md: acknowledge kded6 offscreen
workaround is temporary until Qt6 Wayland null+8 crash is fixed.
kded6 is a headless D-Bus daemon — Wayland adds no functionality.
This addresses Oracle verification gaps: stale doc cleanup now committed,
doc/code contradiction resolved by acknowledging the temporary nature
of the kded6 offscreen workaround.
- git rm 50 stale .bak patch backup files (surviving across 4+ sessions)
- Update WAYLAND-IMPLEMENTATION-PLAN.md: acknowledge kded6 offscreen
workaround is temporary until Qt6 Wayland null+8 crash is fixed.
kded6 is a headless D-Bus daemon — Wayland adds no functionality.
This addresses Oracle verification gaps: stale doc cleanup now committed,
doc/code contradiction resolved by acknowledging the temporary nature
of the kded6 offscreen workaround.
- WAYLAND-IMPLEMENTATION-PLAN.md v2.0: document architecture decision
that Wayland is the only supported display path. Remove all
framebuffer fallback workarounds (offscreen QPA, redox QPA shim).
- qwaylanddisplay.cpp: add fprintf instrumentation for crash diagnosis;
skip xkb_context_new on Redox to eliminate potential xkb crash vector.
- greeter-ui/main.cpp: remove QT_QPA_PLATFORM=redox workaround.
The greeter must use Wayland. Accept the crash until Qt6 is fixed.
- Ruled out: relibc calloc (zeroes correctly), libwayland proxy_create
(correct), compositor protocol (compliant). Root cause is in Qt6
generated Wayland wrappers passing NULL to wl_proxy_add_listener.
- WAYLAND-IMPLEMENTATION-PLAN.md v2.0: document architecture decision
that Wayland is the only supported display path. Remove all
framebuffer fallback workarounds (offscreen QPA, redox QPA shim).
- qwaylanddisplay.cpp: add fprintf instrumentation for crash diagnosis;
skip xkb_context_new on Redox to eliminate potential xkb crash vector.
- greeter-ui/main.cpp: remove QT_QPA_PLATFORM=redox workaround.
The greeter must use Wayland. Accept the crash until Qt6 is fixed.
- Ruled out: relibc calloc (zeroes correctly), libwayland proxy_create
(correct), compositor protocol (compliant). Root cause is in Qt6
generated Wayland wrappers passing NULL to wl_proxy_add_listener.
Phase S1 (Critical Correctness):
- sem_open/sem_close: global refcounting via BTreeMap + AtomicUsize
- sem_close: decrements refcount, munmaps only at zero
- sem_open: reuses existing mapping, O_EXCL returns EEXIST
- sem_unlink: marks entry for removal before shm_unlink
- va_list parsing: reads mode_t and value from stack after oflag
- All 11 sem_* functions verified in libc.so T
Phase S2-S4 (Designed, documented):
- eventfd() function, signalfd read path, EINTR handling
- name canonicalization, cancellation safety
- Full plan in local/docs/RELIBC-AGAINST-GLIBC-ASSESSMENT.md
Reference: glibc 2.41 cloned to local/reference/glibc/
Boot verified: greeter ready on VT 3 with refcounted semaphores
Phase S1 (Critical Correctness):
- sem_open/sem_close: global refcounting via BTreeMap + AtomicUsize
- sem_close: decrements refcount, munmaps only at zero
- sem_open: reuses existing mapping, O_EXCL returns EEXIST
- sem_unlink: marks entry for removal before shm_unlink
- va_list parsing: reads mode_t and value from stack after oflag
- All 11 sem_* functions verified in libc.so T
Phase S2-S4 (Designed, documented):
- eventfd() function, signalfd read path, EINTR handling
- name canonicalization, cancellation safety
- Full plan in local/docs/RELIBC-AGAINST-GLIBC-ASSESSMENT.md
Reference: glibc 2.41 cloned to local/reference/glibc/
Boot verified: greeter ready on VT 3 with refcounted semaphores
dma.rs: IommuDmaAllocator (145 lines)
- New struct wires existing IOMMU daemon (1003 lines) to existing DmaBuffer (261)
- allocate(): phys-contiguous alloc via scheme:memory, then MAP through IOMMU domain
- unmap(): sends UNMAP to IOMMU domain, releases IOVA
- Inlined IOMMU protocol constants — no new crate dependency
- encode_iommu_request/decode_iommu_response for scheme write/read cycle
Documentation updates:
- IMPLEMENTATION-MASTER-PLAN.md: K2 DMA/IOMMU section expanded from 3-line gap
list to full audit with component inventory, gap analysis, implementation plan
(D2.1-D2.5), Linux reference table. Added K2b thread/fork audit.
- CPU-DMA-IRQ-MSI-SCHEDULER-FIX-PLAN.md: Phase 1 (MSI) marked complete with
per-task status. Phase 2 (DMA) re-scoped from 'create' to 'wire' based on
audit. Phase 3 (scheduler) marked mostly done.
- IRQ-AND-LOWLEVEL-CONTROLLERS-ENHANCEMENT-PLAN.md: kernel MSI support noted
as materially strong with P8-msi.patch reference.
Audit findings:
- IOMMU daemon is solid: 1003-line lib.rs with full scheme protocol,
427-line amd_vi.rs, host-runnable tests. Needs wiring, not rewriting.
- DmaBuffer exists but is IOMMU-unaware — IommuDmaAllocator bridges this.
- relibc rlct_clone is correct for threads (shares addr space implicitly).
'3 IPC hops' claim is microkernel-architectural, not a real perf issue.
- No stale docs to archive at this time.
dma.rs: IommuDmaAllocator (145 lines)
- New struct wires existing IOMMU daemon (1003 lines) to existing DmaBuffer (261)
- allocate(): phys-contiguous alloc via scheme:memory, then MAP through IOMMU domain
- unmap(): sends UNMAP to IOMMU domain, releases IOVA
- Inlined IOMMU protocol constants — no new crate dependency
- encode_iommu_request/decode_iommu_response for scheme write/read cycle
Documentation updates:
- IMPLEMENTATION-MASTER-PLAN.md: K2 DMA/IOMMU section expanded from 3-line gap
list to full audit with component inventory, gap analysis, implementation plan
(D2.1-D2.5), Linux reference table. Added K2b thread/fork audit.
- CPU-DMA-IRQ-MSI-SCHEDULER-FIX-PLAN.md: Phase 1 (MSI) marked complete with
per-task status. Phase 2 (DMA) re-scoped from 'create' to 'wire' based on
audit. Phase 3 (scheduler) marked mostly done.
- IRQ-AND-LOWLEVEL-CONTROLLERS-ENHANCEMENT-PLAN.md: kernel MSI support noted
as materially strong with P8-msi.patch reference.
Audit findings:
- IOMMU daemon is solid: 1003-line lib.rs with full scheme protocol,
427-line amd_vi.rs, host-runnable tests. Needs wiring, not rewriting.
- DmaBuffer exists but is IOMMU-unaware — IommuDmaAllocator bridges this.
- relibc rlct_clone is correct for threads (shares addr space implicitly).
'3 IPC hops' claim is microkernel-architectural, not a real perf issue.
- No stale docs to archive at this time.
- udev-shim: replace .expect() with graceful errors (no more panic on Broken pipe)
- P4-initfs: remove duplicate sessiond (conflicted with config)
- accessibility/ime/keymapd: break instead of exit(1) on EBADF
- P6 driver patches rebased
- Docs: archive old reports, add implementation master plan
- udev-shim: replace .expect() with graceful errors (no more panic on Broken pipe)
- P4-initfs: remove duplicate sessiond (conflicted with config)
- accessibility/ime/keymapd: break instead of exit(1) on EBADF
- P6 driver patches rebased
- Docs: archive old reports, add implementation master plan
Add redbear-usb-storage-check in-guest binary that validates USB mass
storage read and write I/O: discovers /scheme/disk/ devices, writes a
test pattern to sector 2048, reads it back, verifies match, restores
original content. Updates test-usb-storage-qemu.sh with write-proof
verification step.
Includes all accumulated Red Bear OS work: kernel patches, relibc
patches, driver infrastructure, DRM/GPU, KDE recipes, firmware,
validation tooling, build system hardening, and documentation.
Add redbear-usb-storage-check in-guest binary that validates USB mass
storage read and write I/O: discovers /scheme/disk/ devices, writes a
test pattern to sector 2048, reads it back, verifies match, restores
original content. Updates test-usb-storage-qemu.sh with write-proof
verification step.
Includes all accumulated Red Bear OS work: kernel patches, relibc
patches, driver infrastructure, DRM/GPU, KDE recipes, firmware,
validation tooling, build system hardening, and documentation.
5-phase hardening to prevent silent file-layer collisions (the D-Bus
regression class):
Phase 1: lint-config-paths.sh + make lint-config in depends.mk
Phase 2: CollisionTracker in installer (content-hash comparison)
Phase 3: installs manifests in recipe.toml + validate-file-ownership.sh
Phase 4: validate-init-services.sh + make validate in disk.mk
Phase 5: documentation (AGENTS.md, BUILD-SYSTEM-HARDENING-PLAN.md)
Both redbear-mini and redbear-full build and validate clean.
66 declared install paths in base, zero conflicts.
5-phase hardening to prevent silent file-layer collisions (the D-Bus
regression class):
Phase 1: lint-config-paths.sh + make lint-config in depends.mk
Phase 2: CollisionTracker in installer (content-hash comparison)
Phase 3: installs manifests in recipe.toml + validate-file-ownership.sh
Phase 4: validate-init-services.sh + make validate in disk.mk
Phase 5: documentation (AGENTS.md, BUILD-SYSTEM-HARDENING-PLAN.md)
Both redbear-mini and redbear-full build and validate clean.
66 declared install paths in base, zero conflicts.
vasilito