LeonOS 4 Docs

This directory tracks the architecture and operational notes that are useful when changing the kernel, loader, installer, or user ABI.

ABI: syscall subset and device model.
Kernel / user-space boundaries: what the kernel and the storage layer own after the middle layer was removed, and how old LEONACL.SYS, handoff and RPR formats are treated.
Linux ABI audit and per-syscall status: remaining compatibility work.
musl migration: runtime, SDK and binary compatibility.
Unix permissions: implemented contracts and verification.
Timer validation: timer and Vim evidence and remaining gaps.
Syscalls: syscall entry convention, syscall table, mmap/munmap, process calls, and ioctl groups.
Filesystem: Unix-style root paths, ext2 default root plus exFAT/FAT32/ISO 9660 support, bundled .hlp help documents, and current limits.
Drivers: bootstrap drivers, loadable .drv modules, ABI, and management policy.
Build system: GNU Make layout, target graph (kernel / userland / runtime / sdk / installer / rpr-pages / pages), incremental and concurrent build rules, and Pages assembly contract.
APK preparation: rootfs-to-APK packaging and the signing pipeline that feeds make rpr-pages.
Remote Package Repository: RPR machine interface, make pages assembly, GitHub Pages publishing, and how verify-pages.sh guards the tree.
EEVDF scheduler: fair-scheduling rules, per-CPU fairness, SMP state, and known limitations.
Execution lock: the global kernel service transaction, the 2026-09-18 read-side anonymous-fault fast path, and the boundaries that still serialise cross-core syscalls.
Desktop performance: compositor refresh path and the framebuffer-present behaviour that gates Doom and Terminal frame rates.
Kernel Debug: five-click activation, one-shot boot state, kerneldebug.sys, and the ostui diagnostic interface.
Boot and Integrity: loader boot flow, SHA-256 component checks, installer compatibility, and trust boundary.
Build and Installer: generated build graph, packaging outputs, installer payload layout, and WSL validation commands.
Application Registry: manifest format, discovery roots, compatibility behavior, and SDK API.
Advanced Installation: TTY-only manual installation, GPT initialization, partitioning, filesystem setup, and UEFI payload install.
Browser: browser.elf, current HTML renderer limits, and the staged path toward a full litehtml port.
Third-Party Code: submodule paths, upstream licenses, and integration status for bundled external code.

Tools

tools/analyze_boot_log.py parses loader, kernel, ELF, dynamic linker, CPU exception, storage, and ACPI messages. It accepts a file or standard input and preserves one-based evidence line numbers:


python tools/analyze_boot_log.py boot.log
python tools/analyze_boot_log.py boot.log --json tools/dist/boot-report.json
cat boot.log | python tools/analyze_boot_log.py - --strict
python tools/analyze_boot_log.py --self-test

--strict returns a non-zero status when an error or fatal finding is present, which makes the analyzer suitable for CI/QEMU smoke-test wrappers.

tools/check_licenses.py checks initialized submodules, staged image and installer payloads, SDK directories or ZIP archives, and the installer acknowledgements policy. It uses an explicit license manifest so disabled components are not reported as missing:


python tools/check_licenses.py
python tools/check_licenses.py --strict
python tools/check_licenses.py --sdk LeonOS4-Developer-SDK.zip \
  --json tools/dist/license-report.json
python tools/check_licenses.py --self-test

Raw FAT/VMDK/ISO files are reported as skipped; pass the mounted or staged directory (or a ZIP) to verify their contents. The default excluded-credit policy rejects llama2.c, TinyLlama, and karpathy in the installer's acknowledgements page. Add project-specific forbidden names with repeated --excluded-credit options.