marfrit
9415b7e0f7
Out-of-tree Linux kernel module registering /dev/videoNN. Phase 8.1 scope: skeleton only — VIDIOC_QUERYCAP works, no codec ioctls / no vb2_queue / no controls yet. Real V4L2 plumbing throughout per "correctness before speed": platform_device + v4l2_device + video_device, properly nested with error paths and devm_kzalloc-managed lifetime. Per-cycle 9 discipline ports to kernel code: SPDX header, kernel coding style (8-tab, static-by-default), kerneldoc on structs, no shortcuts. Files (~250 LOC total): - kernel/Makefile — out-of-tree kbuild with checkpatch target - kernel/daedalus_v4l2_main.c — module init/exit + probe/remove Verification on hertz (Pi 5, 6.12.75+rpt-rpi-2712): - Builds clean with -Wall -Wextra. No warnings. - modprobe / rmmod round-trip clean. No dmesg taints beyond the expected "out-of-tree taint" line. - v4l2-ctl --list-devices shows: "daedalus-fourier V3D7+NEON (platform:daedalus_v4l2): /dev/video0" - VIDIOC_QUERYCAP returns driver/card/bus/caps as specified. - v4l2-compliance: 44/48 passing. The 4 failures are exactly the format/buffer ioctls Phase 8.2 will implement (ENUM_FMT, G_FMT, Scaling, REQBUFS) — not skeleton bugs, legitimately-absent features. Documentation: docs/phase_8_1_closure.md captures full verification output + Phase 8.2 plan. Phase 8.1 acceptance criteria met: - ✓ /dev/videoNN appears via v4l2-ctl --list-devices - ✓ VIDIOC_QUERYCAP responds with sensible values - ✓ rmmod is clean (no kref leaks) - ✓ v4l2-compliance passes except for explicit Phase 8.2 work Next: Phase 8.2 chardev bridge for kernel ↔ daemon IPC. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
kernel/ — daedalus-v4l2 Linux kernel module
Out-of-tree kernel module providing a V4L2 stateless decoder device that forwards work to a userspace daemon.
Status
Scaffold only. Phase 8.1 not yet started.
Build (when implemented)
make -C /lib/modules/$(uname -r)/build M=$(pwd)
sudo insmod daedalus_v4l2.ko
v4l2-ctl --list-devices # confirm /dev/videoNN appears
Layout (planned)
Makefile— kbuild stubdaedalus_v4l2_main.c— module init + V4L2 device registrationdaedalus_v4l2_chardev.c—/dev/daedalus-v4l2chardev for daemon communicationdaedalus_v4l2_v4l2.c— V4L2 ioctl dispatch (stateless controls)
License
GPLv2. Required for kernel module symbol compatibility.
Phase 8.1 starting point
Minimal example: register a /dev/videoNN that returns -ENOSYS on every ioctl. Validates that the kernel build works and v4l2-ctl can see the device.