Building a capability-based microkernel from scratch. Security researcher on the side.
Ferber is a capability-based microkernel written in Rust. Processes start with empty handle tables and receive resources explicitly. Uranium-238-v0.2.4 brings nonblocking channel syscalls, capability mutation, and full usable-RAM discovery to RISC-V 64 and x86-64.
QEMU smoke tests pass on both architectures. The original v0.2.4 implementation also passed kernel checks and userspace syscall probes on physical x86-64 hardware with 32 GiB installed; firmware reported 31.46 GiB managed across 23 extents. The Ferber re-release changes the project branding and artifact names.
| Area | Working now | Still to build |
|---|---|---|
| Memory | Usable firmware RAM discovery across extents, buddy allocator, VMO-backed pages, and Sv39 / PML4 address spaces | Reclaim UEFI boot-services memory; define allocator safety before enabling interrupt-context allocation |
| Tasks and authority | Hierarchical jobs, process and thread containers, empty process handle tables, handle close/duplication, capability inspection, attenuation, and revocation | Process/thread creation syscalls, scheduled yield, and complete exit cleanup |
| IPC | Nonblocking channel create/send/receive syscalls with bounded queues and transactional capability transfer; kernel FastCall primitive | Blocking receive, FastCall syscall integration, and transfer policy for graph-owning capabilities |
| Userspace boundary | U-mode / Ring 3 entry and return, checked user copies, and supervisor-isolation, RX-write, and NX-execution probes | VMO syscalls, ELF loading, init, and a usable userspace runtime |
| Shell and tools | — | Initramfs bootstrap, interactive shell, and fer, the userspace CLI for system services |
M1 still runs one resident task on one active CPU, and exit halts the kernel. fer begins as a userspace command skeleton that communicates with init and system services over channels. The roadmap builds it into Ferber’s management interface as those services come online.
VWH — cryptographic proof-of-presence for red team engagements. Ed25519 signatures, BLAKE3 note hashes, GPG-signed registry. "Valid" and "trustworthy" are not synonyms. VWH is built around that distinction.
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