docs(starry): add macOS HVF self-build app

Cargo.toml

@@ -314,3 +314,7 @@ simple-ahci = "0.1.1-preview.1"
 bcm2835-sdhci = "0.1.1-preview.1"
 ixgbe-driver = "0.1.1-preview.1"
 x86 = "0.52"
+
+[patch.crates-io]
+fdt-edit = { path = "apps/starry/macos-selfbuild/crates/fdt-edit" }
+lwprintf-rs = { path = "apps/starry/macos-selfbuild/crates/lwprintf-rs" }

apps/starry/README.md

@@ -71,6 +71,23 @@ PATH="$PWD/target/qemu-k230-docker-build:$PATH" \
 See `k230-kpu-nncase/README.md` and `docs/k230-kpu-nncase-runtime.md` for the
 asset preparation flow.
 
+## macOS HVF Self-Build
+
+The `macos-selfbuild` case is an Apple Silicon macOS workflow that boots an
+AArch64 StarryOS SMP kernel with QEMU/HVF, enters the StarryOS guest userland,
+and runs guest `cargo build` to build StarryOS again.
+
+```bash
+KERNEL=target/aarch64-unknown-none-softfloat/release/starryos.bin \
+ROOTFS=tmp/axbuild/rootfs/rootfs-aarch64-hvf-selfbuild.img \
+SMP=8 JOBS=8 RAYON_NUM_THREADS=1 RUSTC_THREADS=2 SOURCE_TMPFS=1 \
+apps/starry/macos-selfbuild/run_selfbuild.sh
+```
+
+See `macos-selfbuild/README.md` for the no-Docker reviewer path, native rootfs
+build/check flow, QEMU/HVF details, PASS markers, and representative self-build
+timings.
+
 ## Redis
 
 The `redis` case is a QEMU app workflow that installs Redis into a temporary

apps/starry/macos-selfbuild/README.md

@@ -0,0 +1,270 @@
+# StarryOS macOS HVF Self-Build
+
+This case is an Apple Silicon macOS reproduction workflow. The host runs QEMU
+with HVF, boots an AArch64 StarryOS SMP guest, and runs guest `cargo build` to
+build StarryOS again inside StarryOS.
+
+The normal reproduction path builds the rootfs locally on macOS and does not use
+Docker. `build_rootfs.sh` creates the AArch64 Alpine guest rootfs, installs the
+pinned guest Rust/Cargo toolchain, prefetches the offline Cargo cache, and
+injects the current TGOSKits source tree.
+
+## What This Demonstrates
+
+- host: Apple Silicon macOS;
+- accelerator: QEMU HVF;
+- guest kernel: StarryOS AArch64 SMP kernel;
+- guest workload: StarryOS guest runs Cargo and builds the `starryos` binary;
+- stable build shape: 8-vCPU guest with eight Cargo jobs (`SMP=8 JOBS=8`);
+- pass marker: `===STARRY-MACOS-SELFBUILD-PASS jobs=<N> elapsed=<seconds>===`.
+
+The default reproduction proves that the StarryOS SMP guest can complete a
+self-build while booted with 8 vCPUs and running Cargo with eight jobs.
+
+Using AArch64/HVF keeps the guest ISA aligned with the Mac host CPU. This avoids
+the cross-ISA TCG cost of RISC-V-on-macOS experiments and makes the self-build
+result practical to reproduce on a laptop.
+
+## Prerequisites
+
+```bash
+brew install qemu e2fsprogs zig llvm
+```
+
+The scripts use:
+
+- `qemu-system-aarch64`;
+- `debugfs` from Homebrew `e2fsprogs`;
+- `zig` or an `aarch64-linux-musl-gcc` cross compiler for the seed kernel;
+- `llvm-nm` and `llvm-objdump`, with Homebrew `llvm` used as fallback.
+
+The generated self-build rootfs contains the guest Rust/Cargo toolchain,
+offline Cargo dependencies, and a TGOSKits source tarball. `check_rootfs.sh`
+verifies the minimum paths.
+
+## Reproduce From a Fresh Clone
+
+Clone and enter the branch under test:
+
+```bash
+git clone https://github.com/yks23/tgoskits.git
+cd tgoskits
+git checkout app/starry-macos-selfbuild
+```
+
+Run the complete reproduction on macOS:
+
+```bash
+RUST_DIST_SERVER=https://rsproxy.cn \
+STARRY_CARGO_REGISTRY_INDEX=sparse+https://rsproxy.cn/index/ \
+apps/starry/macos-selfbuild/reproduce.sh
+```
+
+The mirror variables are optional. Omit them to use the official Rust and
+crates.io endpoints, or set them to closer mirrors when `static.rust-lang.org`
+or `index.crates.io` is slow.
+
+`reproduce.sh` runs the three required steps: build or refresh the rootfs, build
+the seed kernel, and launch the QEMU HVF self-build. On a base M1 with 8 GB
+memory, close other heavy applications before running the 8-vCPU case; if it is
+memory pressured, first verify the setup with:
+
+```bash
+SMP=4 JOBS=4 MEM=3072M \
+RUST_DIST_SERVER=https://rsproxy.cn \
+STARRY_CARGO_REGISTRY_INDEX=sparse+https://rsproxy.cn/index/ \
+apps/starry/macos-selfbuild/reproduce.sh
+```
+
+The rootfs build downloads Alpine AArch64 APKs and Rust nightly components, then
+runs `cargo fetch` on the host to populate the guest offline cache. The
+`cargo fetch` phase may print only `Updating crates.io index` for several
+minutes while the sparse registry cache is being populated.
+
+For reproducibility, the default native rootfs payload is pinned to Alpine
+`v3.23` and Rust `nightly-2026-05-28`. Do not switch `ALPINE_BRANCH=edge` for
+the graded reproduction: Alpine edge currently provides a newer Cargo/Rust
+package set and can change the build-std schedule substantially.
+
+The expected output ends with:
+
+```text
+STARRY_MACOS_SELFBUILD_ROOTFS_OK
+```
+
+After every `git pull`, branch switch, or source edit, refresh the source
+payload embedded in the rootfs before running QEMU:
+
+```bash
+apps/starry/macos-selfbuild/prepare_rootfs.sh
+```
+
+`run_selfbuild.sh` checks `/opt/tgoskits-src.meta` by default and exits early if
+the rootfs was built from a different commit. This avoids accidentally running
+an old rootfs for an hour. Set `REQUIRE_FRESH_ROOTFS=0` only for deliberate
+stale-rootfs experiments.
+
+If a prebuilt rootfs artifact is supplied, it can still be placed at the
+standard path instead of rebuilding locally. Use either a local downloaded file:
+
+```bash
+apps/starry/macos-selfbuild/fetch_rootfs.sh \
+  --input /path/to/rootfs-aarch64-hvf-selfbuild.img
+```
+
+or a direct artifact URL:
+
+```bash
+ROOTFS_URL='https://.../rootfs-aarch64-hvf-selfbuild.img' \
+apps/starry/macos-selfbuild/fetch_rootfs.sh
+```
+
+Build the seed StarryOS kernel on macOS:
+
+```bash
+apps/starry/macos-selfbuild/build_kernel.sh
+```
+
+Run the complete 8-vCPU, eight-Cargo-job self-build:
+
+```bash
+KERNEL=target/aarch64-unknown-none-softfloat/release/starryos.bin \
+ROOTFS=tmp/axbuild/rootfs/rootfs-aarch64-hvf-selfbuild.img \
+SMP=8 \
+JOBS=8 \
+RAYON_NUM_THREADS=1 \
+RUSTC_THREADS=2 \
+SOURCE_TMPFS=1 \
+QEMU_TIMEOUT_SEC=10800 \
+apps/starry/macos-selfbuild/run_selfbuild.sh
+```
+
+A successful run prints:
+
+```text
+===STARRY-MACOS-SELFBUILD-QEMU-AARCH64-PROFILE expected_crates~420===
+===STARRY-MACOS-SELFBUILD-PASS jobs=8 elapsed=<seconds>===
+===STARRY-MACOS-SELFBUILD-RUN-END rc=0===
+```
+
+The qemu-aarch64 reproducible profile should show:
+
+```text
+rustc_threads=2
+features=plat-dyn,ax-driver/virtio-blk,ax-driver/virtio-net,ax-driver/virtio-gpu,ax-driver/virtio-input,ax-driver/virtio-socket,starry-kernel/input,starry-kernel/vsock
+```
+
+The guest refuses a run whose `RUSTC_THREADS` differs from `2` unless
+`ALLOW_SLOW_SELFBUILD=1` is explicitly set. This keeps the graded run on the
+same qemu-aarch64 profile that was debugged for reproducibility.
+
+The host runner also refuses unexpectedly large Cargo totals by default. The
+current qemu-aarch64 profile is expected to report about `420` Cargo units. A much larger
+total usually means a stale rootfs or slow feature set is being used; refresh the
+rootfs from the current checkout and rerun the command above.
+
+Logs are written under:
+
+```text
+target/starry-macos-selfbuild/logs/
+```
+
+The runner copies the input rootfs into
+`target/starry-macos-selfbuild/rootfs/`, injects the guest runner scripts, and
+runs QEMU against that working copy, so the input artifact is not modified. Set
+`QEMU_SNAPSHOT=1` only when an explicit throw-away QEMU disk overlay is desired.
+
+## Quick Boot Check
+
+To verify the rootfs and kernel reach the StarryOS guest shell without starting
+the Cargo build:
+
+```bash
+KERNEL=target/aarch64-unknown-none-softfloat/release/starryos.bin \
+ROOTFS=tmp/axbuild/rootfs/rootfs-aarch64-hvf-selfbuild.img \
+SMP=8 \
+BOOT_ONLY=1 \
+QEMU_TIMEOUT_SEC=180 \
+apps/starry/macos-selfbuild/run_selfbuild.sh
+```
+
+`BOOT_ONLY=1` is only a smoke test. Leave it unset for the full self-build.
+
+## Rootfs Contract
+
+The generated rootfs is intentionally kept outside git because it is large. It
+must contain:
+
+```text
+/usr/bin/cargo
+/opt/rust-nightly/bin/rustc
+/opt/rust-nightly/lib/rustlib/src/rust/library/Cargo.lock
+/usr/bin/aarch64-linux-musl-gcc
+/opt/rustc-nightly-sysroot
+/opt/rustdoc-nightly-sysroot
+/opt/tgoskits/Cargo.toml or /opt/tgoskits-src.tar
+/root/.cargo/registry/index
+/root/.cargo/registry/cache
+```
+
+Check an already placed rootfs with:
+
+```bash
+apps/starry/macos-selfbuild/check_rootfs.sh \
+  tmp/axbuild/rootfs/rootfs-aarch64-hvf-selfbuild.img
+```
+
+If a prebuilt toolchain rootfs is available and only the source tree needs to be
+refreshed, inject the current checkout without rebuilding the toolchain:
+
+```bash
+apps/starry/macos-selfbuild/prepare_rootfs.sh \
+  --base-rootfs tmp/axbuild/rootfs/rootfs-aarch64-hvf-toolchain.img \
+  --output-rootfs tmp/axbuild/rootfs/rootfs-aarch64-hvf-selfbuild.img
+```
+
+`prepare_rootfs.sh` writes `/opt/tgoskits-src.tar` and
+`/opt/tgoskits-src.meta`. The host runner checks this metadata before booting
+QEMU, and the guest checks it again when `TGOSKITS_COMMIT` is supplied.
+
+## Important Knobs
+
+| Variable | Default | Meaning |
+| --- | --- | --- |
+| `SMP` | `8` | QEMU vCPU count, passed to `-smp`. |
+| `JOBS` | `SMP` | Guest Cargo job count. |
+| `RAYON_NUM_THREADS` | `1` | Rayon worker limit for guest build scripts. |
+| `RUSTC_THREADS` | `2` | Guest `-Zthreads=<N>` value for the reproducible qemu-aarch64 profile. |
+| `SOURCE_TMPFS` | `1` | Copy source into `/tmp` before building. |
+| `QEMU_TIMEOUT_SEC` | `7200` | Host timeout; use `0` to disable. |
+| `QEMU_ACCEL` | `hvf` | QEMU accelerator string. |
+| `QEMU_MACHINE` | `virt,gic-version=3` | QEMU machine string. |
+| `QEMU_CPU` | `host` | QEMU CPU model for HVF. |
+| `BOOT_ONLY` | `0` | Stop after the shell prompt instead of starting Cargo. |
+| `BUILD_TARGET` | `aarch64-unknown-none-softfloat` | Guest Cargo target. |
+| `BUILD_PACKAGE` | `starryos` | Cargo package to build. |
+| `BUILD_BIN` | `starryos` | Cargo binary to build; set `none` for library package diagnostics. |
+| `FEATURES` | `plat-dyn,ax-driver/virtio-blk,ax-driver/virtio-net,ax-driver/virtio-gpu,ax-driver/virtio-input,ax-driver/virtio-socket,starry-kernel/input,starry-kernel/vsock` | QEMU AArch64 feature profile used by the reproducible self-build; set it to an empty string for single-crate diagnostics. |
+| `REQUIRE_FRESH_ROOTFS` | `1` | Refuse a rootfs whose embedded source commit does not match the checkout. |
+| `ALLOW_SLOW_SELFBUILD` | `0` | Permit the slow full-device feature profile only for explicit experiments. |
+| `GUEST_MONITOR_INTERVAL_SEC` | `60` | Print guest `ps` snapshots while Cargo runs; set `0` to disable. |
+| `EXTRA_RUSTFLAGS` | empty | Extra guest Rust flags for local experiments. |
+
+## Rootfs Rebuild Details
+
+```bash
+apps/starry/macos-selfbuild/build_rootfs.sh
+```
+
+That helper creates an AArch64 Alpine payload natively on macOS, installs the
+pinned guest Rust toolchain and offline Cargo cache, and injects it with
+`debugfs`. It writes:
+
+```text
+tmp/axbuild/rootfs/rootfs-aarch64-hvf-toolchain.img
+tmp/axbuild/rootfs/rootfs-aarch64-hvf-selfbuild.img
+```
+
+The script still accepts `--payload` or `ROOTFS_PAYLOAD_URL` for an externally
+prepared payload tarball. `--build-payload-with-docker` is kept only as an
+explicit maintainer fallback and is not used by the macOS reproduction path.