tool migration: v2 exports + 10 external CLI binaries

rsapi v2: 14 new ABI function pointers appended after v1 — fs_resolve,
fs_dir_next (iterator), fs_create, fs_remove, fs_read, fs_write,
fs_size, fs_close, rtc_now, mem_stats, pci_probe, pci_device,
klog_dump, kernel_version.  New C-repr structs: DirEntry, RtcTime,
MemStats, PciDevice, KernelVersion.  ABI_VERSION bumped to 2.

Shell-side: build_exports() constructs the full table at runtime per
invocation (replaces static const).  14 kernel-side wrapper functions
bridge rsapi types to rsnix kernel APIs; fs_dir_next maintains a
per-handle cache of children() results for iteration.

Tool binaries (10 crates, all linked against rsapi only):
- date: rtc_now → formatted YYYY-MM-DD HH:MM:SS
- mem: heap/pages free/total via mem_stats
- pci: pci_probe + pci_device enumerate all devices
- cat: fs_read paths or get_line stdin; put_line output
- ls: fs_resolve + fs_dir_next iteration; trailing / for dirs
- mkdir: fs_create(path, true)
- touch: fs_create(path, false)
- rm: fs_remove(path)
- klog: klog_dump 2048 bytes → put_line
- info: rtc_now + kernel_version (minimal; mem/pci deferred)

Gate verified: date prints RTC; pci lists all 4 QEMU devices
(8086:29c0, 1234:1111, 8086:10d3, 8086:2918); hello/boom/count
still work; test-disk PASS; poweroff clean.

1 files changed, 100 insertions, 17 deletions

diff --git a/rsapi/src/lib.rs b/rsapi/src/lib.rs
index d7b69a2..dfe75d6 100644
--- a/rsapi/src/lib.rs
+++ b/rsapi/src/lib.rs
@@ -15,13 +15,12 @@ pub const EXPORTS_MAGIC: u32 = 0x5245_5853;
 
 /// ABI revision.  Bump on any signature change; the kernel refuses to run
 /// binaries whose required major exceeds its own.
-pub const ABI_VERSION: u32 = 1;
+pub const ABI_VERSION: u32 = 2;
 
 /// Entry-point signature.  `extern "C"` on the x86_64-unknown-uefi
 /// target is the Win64 convention: the three arguments arrive in
 /// RCX/RDX/R8 on both sides of the table.
-pub type EntryPoint =
-    extern "C" fn(exports: &'static Exports, argc: usize, argv: *const Arg) -> i32;
+pub type EntryPoint = extern "C" fn(exports: &'static Exports, argc: usize, argv: *const Arg) -> i32;
 
 /// One C-style argv element: pointer + length (rs-dos strings are not
 /// NUL-terminated in memory).
@@ -39,7 +38,7 @@ pub struct Line {
 }
 
 impl Line {
-    /// Borrow as a &str (lossy is impossible: lines are always UTF-8).
+    /// Borrow as a &str.
     pub fn as_str(&self) -> &'static str {
         unsafe { core::str::from_utf8_unchecked(core::slice::from_raw_parts(self.ptr, self.len)) }
     }
@@ -48,16 +47,75 @@ impl Line {
 /// Outcome of `get_line`.
 #[derive(Clone, Copy, PartialEq, Eq)]
 pub enum StreamResult {
-    /// A line is available (see `out`).
     Line,
-    /// Input exhausted.
     Eof,
-    /// Aborted (^C or upstream killed); stop immediately.
     Abort,
 }
 
 // ---------------------------------------------------------------------------
-// Exports table — v1
+// v2 types
+// ---------------------------------------------------------------------------
+
+/// Opaque file/directory handle returned by `fs_resolve` / `fs_create`.
+pub type FsHandle = i32;
+
+/// One directory entry returned by `fs_dir_next`.
+#[repr(C)]
+#[derive(Clone, Copy)]
+pub struct DirEntry {
+    pub name: Line,
+    pub is_dir: bool,
+    pub _pad: u8,
+    pub size: u64,
+}
+
+/// Real-time clock snapshot.
+#[repr(C)]
+#[derive(Clone, Copy)]
+pub struct RtcTime {
+    pub year: u16,
+    pub month: u8,
+    pub day: u8,
+    pub hour: u8,
+    pub minute: u8,
+    pub second: u8,
+    pub _pad: u8,
+}
+
+/// Memory statistics (heap + page allocator).
+#[repr(C)]
+#[derive(Clone, Copy)]
+pub struct MemStats {
+    pub heap_total: u64,
+    pub heap_free: u64,
+    pub pages_total: u64,
+    pub pages_free: u64,
+}
+
+/// One PCI device discovered at probe time.
+#[repr(C)]
+#[derive(Clone, Copy)]
+pub struct PciDevice {
+    pub bus: u8,
+    pub device: u8,
+    pub function: u8,
+    pub class: u8,
+    pub subclass: u8,
+    pub vendor: u16,
+    pub device_id: u16,
+}
+
+/// Kernel version information.
+#[derive(Clone, Copy)]
+pub struct KernelVersion {
+    pub name: Line,
+    pub major: u16,
+    pub minor: u16,
+    pub patch: u16,
+}
+
+// ---------------------------------------------------------------------------
+// Exports table — v2
 // ---------------------------------------------------------------------------
 
 /// The function table a binary receives.  Layout is fixed by `version`;
@@ -69,19 +127,44 @@ pub struct Exports {
     pub version: u32,
 
     // ---- console / streams (v1) ----
-    /// Print one line to the command's output stream.
-    /// Returns false when the consumer says stop (pager quit / head limit /
-    /// ^C) — the binary should wrap up promptly.
     pub put_line: fn(line: Line) -> bool,
-    /// Read one line from the command's input stream (only meaningful for
-    /// input consumers like cat/hexdump; otherwise returns Eof).
-    /// `out` receives the line when the result is `StreamResult::Line`.
     pub get_line: fn(out: &mut Line) -> StreamResult,
 
     // ---- lifecycle (v1) ----
-    /// Log one line to the kernel log ring (/dev/klog).
     pub log_line: fn(line: Line),
-    /// Exit code for the completion message to the spawner.
-    /// (Calling this is optional; returning from the entry point exits 0.)
     pub exit: fn(code: i32) -> !,
+
+    // ---- filesystem queries (v2) ----
+    /// Resolve a path to a handle; returns -1 on error.
+    pub fs_resolve: fn(path: Line) -> FsHandle,
+    /// Iterate directory entries: returns true and fills `out` while
+    /// entries remain; returns false when exhausted.  Resets position.
+    pub fs_dir_next: fn(handle: FsHandle, out: &mut DirEntry) -> bool,
+    /// Create a file (is_dir=false) or directory (is_dir=true) at path.
+    /// Returns 0 on success, -1 on error.
+    pub fs_create: fn(path: Line, is_dir: bool) -> i32,
+    /// Remove a file or empty directory.  Returns 0 on success.
+    pub fs_remove: fn(path: Line) -> i32,
+    /// Read `len` bytes from `handle` at `pos`.  Returns bytes actually
+    /// read, or -1 on error.
+    pub fs_read: fn(handle: FsHandle, buf: *mut u8, pos: u64, len: u64) -> i64,
+    /// Write `len` bytes to `handle` at `pos`.  Returns bytes written.
+    pub fs_write: fn(handle: FsHandle, buf: *const u8, pos: u64, len: u64) -> i64,
+    /// Get file/directory size in bytes.
+    pub fs_size: fn(handle: FsHandle) -> u64,
+    /// Close a handle (currently a no-op; reserved for future fd mgmt).
+    pub fs_close: fn(handle: FsHandle),
+
+    // ---- hardware queries (v2) ----
+    pub rtc_now: fn(out: &mut RtcTime),
+    pub mem_stats: fn(out: &mut MemStats),
+    /// Enumerate PCI: returns number of devices discovered.
+    pub pci_probe: fn() -> u32,
+    /// Get one PCI device by index (0-based).  Returns true on success.
+    pub pci_device: fn(index: u32, out: &mut PciDevice) -> bool,
+    /// Copy up to `cap` bytes of the kernel log ring into `buf`.
+    /// Returns bytes copied.
+    pub klog_dump: fn(buf: *mut u8, cap: u64) -> u64,
+    /// Fill `out` with kernel version info.
+    pub kernel_version: fn(out: &mut KernelVersion),
 }