RADPx-OS Kernel (Radical Posix OS)  Crimson 0.1.4
POSIX-inspired kernel API with embedded and desktop VM targets
Crimson 0.1.4 Status

Crimson 0.1.4 is an experimental beta package line for RADPx-OS. The branch goal is to stabilize the kernel-facing API, x86 VM smoke path, Slint shell integration, overlay binding, filesystem profile, and driver model enough for repeatable testing.

Stable-Beta Surface

  • Kernel lifecycle, printk, boot info, time, memory stats, and terminal commands.
  • Task, wait queue, mutex, event, timer, scheduler, and basic multicore reporting APIs.
  • Device registry, ioctl encoding, input queues, framebuffer registration, TTY, PTY, block device, USB host-info, and VFS provider APIs.
  • I2C, SPI, DMA, module, IRQ, and overlay binding APIs.
  • x86 GRUB VM smoke target with rash as the default shell, framebuffer terminal, PTY/TTY path, JSON radinit services, persistent logs, FAT32 test volume, clean no-journal ext4 read/write profile, and RadBuild 0.2.1 os.rad build orchestration.
  • RadicalPackages .radpm packagegroups for terminal, desktop, networking, and SDK image composition.

Experimental Surface

  • POSIX process and syscall coverage is usable for the current shell tests but not a complete Unix userspace contract.
  • /bin/sh is currently pointed at rash for the x86 image so shebang scripts exercise the same shell implementation as the interactive path.
  • Shared-memory mmap/shm_open support is present for the x86 compositor smoke path, but not yet a complete POSIX memory-mapping implementation.
  • RADCompositor supports dirty-rectangle software composition and shm-backed producer surfaces; full Slint userspace apps and hardware page flip are still follow-up work.
  • Network APIs now include device/link/send/receive/poll shape, experimental IPv4/UDP datagram sockets, local TCP stream socket lifecycle support, and legacy virtio-net RX/TX queue ownership markers for the x86 VM target.
  • RP2350 HSTX/DVI and SPI panel output are documented as framebuffer output goals, with backend completeness still target-dependent.
  • Pi Zero 2 W has an experimental standalone bcm283x_pi payload, handoff ABI, platform split under platforms/a53, PL011 serial path, timer reads, mailbox framebuffer path, SD block-device registration scaffold, USB/input scaffolds, A53 MMU/table setup, process/COW self-tests, and Slint/RADCompositor parity markers.
  • DMA is available through the generic core and first consumed by SPI-style transfer paths.

Not Yet Complete

  • Full POSIX userland compatibility, dynamic ELF loading, complete fork/exec semantics across every target, full ext4 journaling, USB stacks, PCIe, wire-level TCP, DHCP/DNS, and production networking are beyond the current Crimson beta surface.
  • The Pi Zero 2 W path still needs hardware-real Circle FAT loader jump validation, eMMC command implementation, DWC OTG USB host enumeration, hardware HID input, full AArch64 EL0 ELF execution/fork/exec parity, and Slint framebuffer rendering before it matches the x86 VM path.