feat: ship native dev tools and target sysroot at 0:/usr

The devkit target in programs/GNUmakefile stages the native binutils
(as, ld, ar, nm, objcopy, objdump, readelf, ranlib, strip, size,
strings, addr2line, c++filt, elfedit as *.elf) into the image at
0:/usr/bin, plus a target-side sysroot: libc headers, montauk/ and
Api/ SDK headers and the freestanding C++ set at 0:/usr/include, and
libc.a + crt1/crti/crtn objects (with empty libm/libstdc++ stand-ins)
at 0:/usr/lib. ld's ldscripts ship under 0:/usr/x86_64-montauk.

The /usr prefix matches the binutils configure prefix, and the kernel
already resolves driveless absolute paths against the cwd drive, so
compiled-in /usr/lib search paths work natively on drive 0.

The shell resolves commands from 0:/usr/bin (after 0:/os) and tab
completion lists it. When toolchain/native/ has not been built, the
devkit step skips cleanly and the image builds as before.

Co-Authored-By: Claude Fable 5 <[email protected]>

kernel/src/Api/BuildNo.hpp

@@ -12,4 +12,4 @@
 
 #pragma once
 
-#define MONTAUK_BUILD_NUMBER 10
+#define MONTAUK_BUILD_NUMBER 11

programs/GNUmakefile

@@ -91,7 +91,7 @@ WPDST := $(patsubst $(WPDIR)/%,$(BINDIR)/os/wallpapers/%,$(WPSRC))
 
 .PHONY: all clean 2048 doom fetch wiki wikipedia weather imageviewer fontpreview spreadsheet wordprocessor pdfviewer disks devexplorer installer audio music video bluetooth network terminal klog procmgr powermgr calculator charmap login desktop shell rpgdemo paint tcc lua screenshot texteditor mandelbrot printers timezone printd printctl dialogs icons fonts configs bearssl libc tls libjpeg libjpegwrite install-apps libloader libs crashpad check-syscalls gen-syscalls
 
-all: bearssl libc libjpeg libjpegwrite tls libloader libs $(TARGETS) fetch wiki wikipedia weather imageviewer fontpreview spreadsheet wordprocessor pdfviewer disks devexplorer installer audio music video bluetooth network terminal klog procmgr powermgr calculator charmap 2048 doom rpgdemo paint tcc lua screenshot texteditor mandelbrot printers timezone printd printctl dialogs login desktop shell icons fonts install-apps crashpad $(MANDST) $(WWWDST) $(CA_CERTS) $(CONFIGDST) $(FWDST) $(LICDST) $(WPDST)
+all: bearssl libc libjpeg libjpegwrite tls libloader libs devkit $(TARGETS) fetch wiki wikipedia weather imageviewer fontpreview spreadsheet wordprocessor pdfviewer disks devexplorer installer audio music video bluetooth network terminal klog procmgr powermgr calculator charmap 2048 doom rpgdemo paint tcc lua screenshot texteditor mandelbrot printers timezone printd printctl dialogs login desktop shell icons fonts install-apps crashpad $(MANDST) $(WWWDST) $(CA_CERTS) $(CONFIGDST) $(FWDST) $(LICDST) $(WPDST)
 
 # Build BearSSL static library (cross-compiled for freestanding x86_64).
 BEARSSL_INCLUDES := -isystem $(shell cd .. && pwd)/kernel/freestnd-c-hdrs/x86_64/include -isystem $(abspath include/libc)
@@ -376,6 +376,35 @@ $(BINDIR)/os/%.elf: src/%/main.cpp link.ld GNUmakefile
 	$(CXX) $(CXXFLAGS) -c src/$*/main.cpp -o obj/$*/main.o
 	$(CXX) $(CXXFLAGS) $(LDFLAGS) obj/$*/main.o lib/libc/liblibc.a -o $@
 
+# ============================================================================
+# Native development kit: binutils built for MontaukOS plus a target
+# sysroot (headers, libc.a, crt objects) under 0:/usr. Skipped when the
+# native tools have not been built; see toolchain/README.md.
+# ============================================================================
+NATIVE_BIN := ../toolchain/native/usr/bin
+DEVKIT_TOOLS := as ld ar nm objcopy objdump readelf ranlib strip size strings addr2line c++filt elfedit
+
+.PHONY: devkit
+devkit: libc
+ifneq ($(wildcard $(NATIVE_BIN)/as),)
+	rm -rf $(BINDIR)/usr
+	mkdir -p $(BINDIR)/usr/bin $(BINDIR)/usr/lib $(BINDIR)/usr/include
+	for t in $(DEVKIT_TOOLS); do \
+	    cp $(NATIVE_BIN)/$$t $(BINDIR)/usr/bin/$$t.elf || exit 1; \
+	done
+	cp -r ../toolchain/native/usr/x86_64-montauk $(BINDIR)/usr/x86_64-montauk
+	cp -r include/libc/. $(BINDIR)/usr/include/
+	cp -r include/montauk $(BINDIR)/usr/include/montauk
+	cp -r include/Api $(BINDIR)/usr/include/Api
+	cp -r ../kernel/freestnd-cxx-hdrs/x86_64/include/. $(BINDIR)/usr/include/
+	cp lib/libc/liblibc.a $(BINDIR)/usr/lib/libc.a
+	cp lib/libc/crt1.o lib/libc/crti.o lib/libc/crtn.o $(BINDIR)/usr/lib/
+	ar rcs $(BINDIR)/usr/lib/libm.a
+	ar rcs $(BINDIR)/usr/lib/libstdc++.a
+else
+	@echo "devkit: toolchain/native/ not built; skipping native dev tools"
+endif
+
 clean:
 	rm -rf $(BINDIR) obj
 	$(MAKE) -C lib/bearssl clean

programs/src/shell/exec.cpp

@@ -84,13 +84,19 @@ int exec_external(const char* cmd, const char* args) {
     scat(path, name, sizeof(path));
     if (try_exec(path, finalArgs)) return 0;
 
-    // 5. Try 0:/games/<cmd>.elf
+    // 5. Try 0:/usr/bin/<cmd>.elf (native dev tools: as, ld, ar, ...)
+    scopy(path, "0:/usr/bin/", sizeof(path));
+    scat(path, name, sizeof(path));
+    scat(path, ".elf", sizeof(path));
+    if (try_exec(path, finalArgs)) return 0;
+
+    // 6. Try 0:/games/<cmd>.elf
     scopy(path, "0:/games/", sizeof(path));
     scat(path, name, sizeof(path));
     scat(path, ".elf", sizeof(path));
     if (try_exec(path, finalArgs)) return 0;
 
-    // 6. If on a non-zero drive, also try drive root
+    // 7. If on a non-zero drive, also try drive root
     if (current_drive != 0) {
         build_drive_path(current_drive, name, path, sizeof(path));
         if (try_exec(path, finalArgs)) return 0;

programs/src/shell/tabcompletion.cpp

@@ -148,6 +148,36 @@ int get_completions(		// returns no. of results
 		} 
 	}
 
+	// ---- Native dev tools (0:/usr/bin/*.elf) ----
+
+	const char* usr_names[RD_MAX]	= { };
+
+	int un = montauk::readdir("0:/usr/bin", usr_names, RD_MAX);
+
+	for (int i = 0; i < un; i++) {
+		/* Entries come back as "usr/bin/as.elf"; strip to the last
+		   slash, not the first. */
+		int inc = 0;
+		for (int j = 0; usr_names[i][j]; j++) {
+			if (usr_names[i][j] == '/')
+				inc = j + 1;
+		}
+
+		if (montauk::starts_with(usr_names[i] + inc, (const char*)string)) {
+			if (r >= arrayMax)
+				break;
+
+			if (!is_executable(usr_names[i]))
+				continue;
+
+			char* p = (char *)usr_names[i] + inc;
+			strip_elf_extension(p);
+
+			array[r] = (char *)p;
+			r++;
+		}
+	}
+
 	// ---- Shell builtins ----
 
 	size_t builtins_count = sizeof(shell_builtins) / sizeof(const char*);

toolchain/README.md

@@ -91,6 +91,11 @@ Notes:
   the tools themselves never spawn, and real process plumbing is the
   posix_spawn milestone that needs kernel support (exit codes in
   SYS_WAITPID, fd redirection wiring).
-- The staged tree in toolchain/native/ is not yet integrated into the
+- The `devkit` target in programs/GNUmakefile ships the staged tools
-  OS image; that needs a target-side sysroot layout decision (where
+  into the OS image at 0:/usr/bin (as.elf, ld.elf, ar.elf, ...) with a
-  headers, libc.a and crt objects live on 0:/).
+  target-side sysroot at 0:/usr/include + 0:/usr/lib (libc.a, crt
+  objects, empty libm/libstdc++). The kernel resolves driveless
+  absolute paths ("/usr/lib") against the cwd drive, so the binutils
+  --prefix=/usr layout works natively. The shell searches 0:/usr/bin
+  and tab-completes it. If toolchain/native/ has not been built the
+  devkit step is skipped and the image builds without it.