docs: correct the layout block, and note what a copy leaves behind

README's layout predated the BIOS/UEFI split. moving-to-linux.md now
says what is gitignored and therefore absent from a clone: dist/ holds
61 MB of upstream tarballs, so copy it or let the build re-fetch them --
make ports verifies each against a known SHA-256 either way.

.claude/memory/MEMORY.md

@@ -1,6 +1,7 @@
 - [SchOS rename + git](schos-rename-and-git.md) — Schunix is SchOS and the kernel is SchIFT; the tree is under local git, and the two bugs the rename caused.
 - [Cross-platform build](schos-cross-platform-build.md) - Windows, Linux, macOS and BSD all build it; clang everywhere, and the four host assumptions that used to break.
 - [Memory sync](schos-memory-sync.md) - memory lives in the repo at .claude/memory/; tools/memory-sync.sh moves it between machines.
+- [The Linux machine](schos-linux-machine.md) - Fedora laptop at /home/nexoniarz/Documents/SchOS; the three things only it can test.
 - [Performance and init](schos-performance-and-init.md) - BSIZE must equal SCHFS_BLKSIZE (4-34x), and why Ctrl-C could kill pid 1.
 - [Trusting bootcheck](schos-bootcheck-trust.md) - it silently stopped running; count the [ok] lines, never just grep FAIL.
 - [schinit](schos-schinit.md) - process 1 is launchd-shaped; job manifests, and why setsid() cost the shell its terminal.

.claude/memory/schos-linux-machine.md

@@ -0,0 +1,43 @@
+---
+name: schos-linux-machine
+description: The Fedora laptop, its project path and memory key, and the three things only it can test
+metadata:
+  node_type: project
+---
+
+Nexoniarz works from **two machines** and moved the project to the second on
+2026-08-09.
+
+| | Windows desktop | Fedora laptop |
+|---|---|---|
+| path | `D:\DEV\SchOS` | `/home/nexoniarz/Documents/SchOS` |
+| memory key | `D--DEV-SchOS` | `-home-nexoniarz-Documents-SchOS` |
+
+Fedora 44, Ryzen 5 7000-series, RTX 4050, 16 GB DDR5. The GPU is irrelevant to
+the build — QEMU runs headless for tests.
+
+`tools/posix/setup-fedora.sh` installs the toolchain (`--check` to only report).
+`docs/moving-to-linux.md` is the procedure. Memory moves with
+[[schos-memory-sync]]: `import` after arriving, `export` and commit after a
+session that learned something.
+
+**Three things only the Linux machine can do**, and they are the reason the move
+matters:
+
+1. **`make ports`** builds musl, toybox and mksh from source. Windows cannot do
+   it at all — the build skips ports and uses whatever is staged in `sysroot/`,
+   which is why `sysroot/bin/sh` still carries the pre-rename symbol
+   `__schunix_tp`.
+2. **The SchFS round-trip test** needs symlinks and hard links, which Git Bash
+   cannot create, so it skips on Windows. **It has never actually run** — the
+   one part of SchFS with no coverage.
+3. **KVM.** A Ryzen box has SVM, so QEMU runs at native speed. Deliberately not
+   the Makefile default: the suite's timings were set under TCG.
+
+**PowerShell has no Fedora package**, and `tools/windows/bootcheck.ps1` is the
+test suite. pwsh runs it on Linux fine; it comes from Microsoft's repo or the
+GitHub tarball. Nothing else needs it.
+
+**Never push.** There is no git remote and there should not be one until
+Nexoniarz says otherwise — see [[nexoniarz-sharing-preference]]. "Push to git"
+in this project means commit locally.

README.md

@@ -105,7 +105,7 @@ make schfs-check                       # SchFS B-tree, object and image suites
 kernel/     arch/ core/ dev/ drivers/ fs/ net/ proc/ sys/
   fs/schfs/     the filesystem -- same source the host tools compile
 include/    kernel and userland headers
-boot/       bootblock and stage 2 (VBE splash, boot menu)
+boot/       bios/ (MBR, stage 2, VBE splash)  uefi/ (PE loader)
 lib/ cmd/   first-party userland runtime and programs
 ports/      third-party software built from source
 tools/      windows/ (.ps1)  posix/ (.sh)  python/ (.py)  and .c/.pl

docs/moving-to-linux.md

@@ -18,6 +18,19 @@ git log --oneline | head -3     # should show the same commits
 git status                      # should be clean
 ```
 
+### What is not in the repo
+
+`build/`, `sysroot/` and `dist/` are all gitignored, so `rsync -a` of the
+working tree carries them but a `git clone` would not. Two are worth thinking
+about:
+
+- **`dist/`** holds the upstream tarballs — musl, toybox, mksh, the DOOM WADs,
+  `usb.ids`. 61 MB of other people's release artefacts. Copy it to save the
+  download, or let the build fetch them again; `make ports` calls `curl` and
+  verifies each against a known SHA-256, so a re-download is safe either way.
+  Without a network connection, copy it.
+- **`sysroot/`** is assembled by the build.
+
 `build/` and `sysroot/` are ignored and do not need copying — `make` rebuilds
 them. **One exception**: `sysroot/bin/` holds musl, toybox and mksh, which
 cannot be built on Windows and so were staged there once. On Linux they *can*