Release version 0.4 New features and major improvements since v0.3: - A20 Native ABI: realized and documented the native application binary interface. - x86_64 support: added support for the x86_64 architecture. - SMP multi-core: implemented SMP infrastructure with HAL abstraction. - Driver model: refactored and improved the driver framework. - FPU acceleration: enhanced FPU usage to speed up floating-point operations. - RISC-V TLB: optimized RISC-V TLB handling. - Init: implemented a better init process. - epoll: extended event polling support. - fastfetch: added fastfetch support. Notable fixes and compatibility: - Scheduler: fixed fork priority inheritance and aging for cyclictest/iozone. - Signals: per-thread signal masks, sigtimedwait timeout, tgkill validation, musl signal frame layout. - Futex: robust owner death handling. - Process/clone: clone3 validation, pidfd signal delivery, set_tid_address correctness. - Filesystem: ext4/ramfs/devfs updates, close_range, futimens, fchownat checks. - Networking: local socket backpressure, virtio_net TX deadlock prevention. - Memory: MAP_SHARED page-cache pin lifetime, fork/ext4 sleep-under-lock deadlocks. - Contest/LTP: expanded bounded LTP coverage, enabled more contest entries, fixed LTP syscall numbers and musl/glibc compatibility.