Robert Allan JamesandClaude Sonnet 5
90ee8deb6d
arch_early_init() unconditionally cleared satp on every boot, justified only by behavior observed under QEMU/EDK2 firmware (satp.MODE=10/Sv57, kernel identity-mapped within it). That reasoning never applied to the native U-Boot+OpenSBI boot path, where satp is conventionally already 0 at S-mode handoff -- the unconditional clear was likely a harmless no-op there, but on an unverified assumption. Fix: read satp.MODE first and return early when it's already 0 (nothing to switch away from, no safety argument needed). The unconditional csrw/sfence pair still runs unchanged for the confirmed QEMU/EDK2 case. No Sv39/Sv48/Sv57 page-table walker built -- out of proportion to this finding's severity. 3-arch acceptance: amd64/aarch64 don't compile this file, so their runs are non-regression on untouched files only. riscv64's own boot log confirms satp.MODE = 0xa at entry, so the mode != 0 branch ran and "satp cleared -- Bare mode, explicit" printed exactly as before the fix. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_019YcT3H2PQeyujrzjqS3Var
src/starkernel/
LithosAnanke — the bare-metal UEFI kernel that boots StarForth directly on
hardware (amd64/aarch64/riscv64). Built only via Makefile.starkernel; the
only valid acceptance test is the three-arch QEMU boot (see
.claude/CLAUDE.md), never make test.
kernel_main.c— kernel entry point, driving the boot milestones (console init, PMM, VMM, interrupts, timers, kmalloc heap, VM bootstrap).repl.c— kernel REPL.doe_log.c— kernel-side DoE (Design of Experiments) metrics logging.
Subdirectories:
arch/{amd64,aarch64,riscv64}/— per-architecture support (APIC/GIC/ PLIC interrupt controller, timers, boot/ISR assembly).boot/— UEFI loader, ELF loading, kernel command-line parsing.capsule/— capsule birth/run/load/validate pipeline.hal/— hardware-abstraction-layer implementation (console, framebuffer, VT100, memory, host services).hash/— XXHash64 content-addressing implementation.math/— kernel-build Q48.16 fixed-point arithmetic.memory/— physical/virtual memory managers and the kernel heap.pci/— PCI bus enumeration.virtio/— VirtIO block device driver.vm/— kernel VM subsystem (bootstrap, core interpreter, parity logging, capsule arena).
See include/starkernel/README.md for the corresponding headers.