diff --git a/local/patches/gcc-redox-port/apply-redox-port.py b/local/patches/gcc-redox-port/apply-redox-port.py
new file mode 100755
index 0000000000..7572643d04
--- /dev/null
+++ b/local/patches/gcc-redox-port/apply-redox-port.py
@@ -0,0 +1,266 @@
+#!/usr/bin/env python3
+"""Apply the Redox target port to a pristine GCC source tree.
+
+Usage: apply-redox-port.py <gcc-source-root> [--check]
+
+Extracted from redox-os/gcc branch redox-13.2.0 (see README.md). The port is
+13 files: 5 Redox-owned (copied verbatim from files/) and 8 existing GCC files
+that need a `*-*-redox*` arm registered.
+
+Every edit is anchored on stable upstream text and is IDEMPOTENT: a file that
+already mentions redox in the relevant place is left alone. Anchors were chosen
+to be the kind of plumbing that changes slowly between GCC releases; if one
+stops matching after a version bump, the script reports it rather than silently
+producing a half-ported tree.
+
+NOTE: gcc/configure and libstdc++-v3/configure also reference redox in the
+13.2.0 fork, but they are GENERATED. Do not patch them here -- regenerate from
+crossconfig.m4 with autoconf after running this script.
+"""
+
+import shutil
+import sys
+from pathlib import Path
+
+HERE = Path(__file__).resolve().parent
+FILES = HERE / "files"
+
+# --- blocks to insert, keyed by file -----------------------------------------
+
+CONFIG_GCC_OS = """*-*-redox*)
+  gas=yes
+  gnu_ld=yes
+  default_use_cxa_atexit=yes
+  gcc_cv_initfini_array=yes
+  tmake_file="${tmake_file} t-slibgcc"
+  extra_options="${extra_options} redox.opt"
+  case ${enable_threads} in
+    yes)
+      thread_file='posix'
+      ;;
+  esac
+  case ${target} in
+    i[34567]86-*-redox* | x86_64-*-redox*)
+      xm_file=i386/xm-redox.h
+      ;;
+    aarch64-*-redox*)
+      xm_file=aarch64/xm-redox.h
+      ;;
+    riscv64*-*-redox*)
+      xm_file=riscv/xm-redox.h
+      ;;
+  esac
+  ;;
+"""
+
+CONFIG_GCC_TARGETS = """aarch64-*-redox*)
+\ttm_file="${tm_file} elfos.h aarch64/aarch64-elf.h aarch64/aarch64-elf-raw.h redox.h newlib-stdint.h"
+\t;;
+i[34567]86-*-redox*)
+\ttm_file="${tm_file} i386/unix.h i386/att.h elfos.h i386/i386elf.h redox.h newlib-stdint.h"
+\t;;
+riscv64*-*-redox*)
+\ttm_file="${tm_file} elfos.h riscv/elf.h redox.h newlib-stdint.h"
+\t;;
+x86_64-*-redox*)
+\ttm_file="${tm_file} i386/unix.h i386/att.h elfos.h i386/i386elf.h i386/x86-64.h redox.h newlib-stdint.h"
+\t;;
+"""
+
+CONFIG_HOST = """  i[34567]86-*-redox* | x86_64-*-redox*)
+    host_xm_file=i386/xm-redox.h
+    ;;
+  aarch64-*-redox*)
+    host_xm_file=aarch64/xm-redox.h
+    ;;
+  riscv64*-*-redox*)
+    host_xm_file=riscv/xm-redox.h
+    ;;
+"""
+
+CONFIG_BUILD = """  i[34567]86-*-redox* | x86_64-*-redox* )
+    build_xm_file=i386/xm-redox.h
+    ;;
+  aarch64-*-redox*)
+    build_xm_file=aarch64/xm-redox.h
+    ;;
+  riscv64*-*-redox*)
+    build_xm_file=riscv/xm-redox.h
+    ;;
+"""
+
+LIBGCC_OS = """*-*-redox*)
+  extra_parts="$extra_parts crtbegin.o crtbeginS.o crtend.o crtendS.o"
+  tmake_file="$tmake_file t-crtstuff-pic t-libgcc-pic"
+  tmake_file="$tmake_file t-slibgcc t-slibgcc-gld t-slibgcc-elf-ver"
+  ;;
+"""
+
+LIBGCC_TARGETS = """i[34567]86-*-redox*)
+\ttmake_file="$tmake_file i386/t-crtstuff"
+\t;;
+x86_64-*-redox*)
+\ttmake_file="$tmake_file i386/t-crtstuff"
+\t;;
+aarch64-*-redox*)
+\textra_parts="$extra_parts crtfastmath.o"
+\ttmake_file="${tmake_file} ${cpu_type}/t-aarch64"
+\ttmake_file="${tmake_file} ${cpu_type}/t-lse t-slibgcc-libgcc"
+\ttmake_file="${tmake_file} ${cpu_type}/t-softfp t-softfp t-crtfm"
+\tmd_unwind_header=aarch64/aarch64-unwind.h
+\t;;
+"""
+
+CROSSCONFIG_AARCH64 = """  aarch64-*-redox* | riscv64*-*-redox*)
+    SECTION_FLAGS='-ffunction-sections -fdata-sections'
+    AC_SUBST(SECTION_FLAGS)
+    AC_DEFINE(HAVE_ALIGNED_ALLOC)
+    ;;
+
+"""
+
+CROSSCONFIG_GENERIC = """  *-redox*)
+    GLIBCXX_CHECK_COMPILER_FEATURES
+    GLIBCXX_CHECK_LINKER_FEATURES
+    GLIBCXX_CHECK_MATH_SUPPORT
+    GLIBCXX_CHECK_STDLIB_SUPPORT
+    AC_CHECK_FUNCS(aligned_alloc posix_memalign memalign _aligned_malloc)
+    ;;
+"""
+
+MKFIXINC = """    aarch64-*-redox* | \\
+    i?86-*-redox* | \\
+    riscv64*-*-redox* | \\
+    x86_64-*-redox* | \\
+"""
+
+OS_DEFINES = """
+// Causes issues on Redox
+#define _GLIBCXX_USE_WEAK_REF 0
+"""
+
+# (relative path, anchor text, block, insert_before)
+EDITS = [
+    ("gcc/config.gcc",  "*-*-netbsd*)",                CONFIG_GCC_OS,      True),
+    ("gcc/config.gcc",  "i[34567]86-pc-msdosdjgpp*)",  CONFIG_GCC_TARGETS, True),
+    ("gcc/config.host", "esac",                        CONFIG_HOST,        True),
+    ("gcc/config.build", "esac",                       CONFIG_BUILD,       True),
+    ("libgcc/config.host", "*-*-rtems*)",              LIBGCC_OS,          True),
+    ("libgcc/config.host", "i[34567]86-*-elf*)",       LIBGCC_TARGETS,     True),
+    ("libstdc++-v3/crossconfig.m4", "  *-hpux*)",      CROSSCONFIG_AARCH64, True),
+    # GCC 16 moved *-solaris* into the *-linux* arm and consolidated the
+    # mingw32 targets, so these two anchors differ from 13.2.0.
+    ("libstdc++-v3/crossconfig.m4", "  *-mingw32*)",   CROSSCONFIG_GENERIC, True),
+    ("fixincludes/mkfixinc.sh", "    *-mingw32* | \\", MKFIXINC,      True),
+]
+
+
+def already_ported(path: Path, marker: str = "redox") -> bool:
+    try:
+        return marker in path.read_text(encoding="utf-8", errors="replace").lower()
+    except OSError:
+        return False
+
+
+def apply_edit(root: Path, rel: str, anchor: str, block: str, check: bool) -> str:
+    p = root / rel
+    if not p.is_file():
+        return f"MISSING  {rel}"
+    text = p.read_text(encoding="utf-8", errors="replace")
+    # Idempotency must be per-EDIT, not per-file: crossconfig.m4 and
+    # config.gcc each take TWO separate blocks, so a whole-file "does it
+    # mention redox" test would silently skip the second one.
+    # Match the probe as a COMPLETE line. A substring test is wrong here:
+    # the generic block starts "*-redox*)", which occurs inside the already
+    # inserted "aarch64-*-redox* | riscv64*-*-redox*)" and made the second
+    # crossconfig.m4 block silently skip.
+    # Probe on the block's LONGEST line, matched whole. The first line is not
+    # distinctive enough: CONFIG_GCC_TARGETS starts "aarch64-*-redox*)", which
+    # also appears (indented) inside CONFIG_GCC_OS, so a first-line probe made
+    # the tm_file arms silently skip.
+    probe = max((l.strip() for l in block.strip().splitlines()), key=len)
+    if probe and any(l.strip() == probe for l in text.splitlines()):
+        return f"skip     {rel} (block already present)"
+    idx = text.find(anchor)
+    if idx == -1:
+        return f"ANCHOR-FAIL {rel} :: {anchor!r} not found -- re-derive for this GCC version"
+    if check:
+        return f"would-apply {rel} at offset {idx}"
+    p.write_text(text[:idx] + block + text[idx:], encoding="utf-8")
+    return f"applied  {rel}"
+
+
+def main() -> int:
+    if len(sys.argv) < 2:
+        print(__doc__)
+        return 2
+    root = Path(sys.argv[1]).resolve()
+    check = "--check" in sys.argv
+    if not (root / "gcc" / "config.gcc").is_file():
+        print(f"ERROR: {root} does not look like a GCC source tree", file=sys.stderr)
+        return 2
+
+    rc = 0
+
+    # 1. Redox-owned files (pure copies -- always safe).
+    for src in sorted(FILES.rglob("*")):
+        if not src.is_file():
+            continue
+        rel = src.relative_to(FILES)
+        dst = root / rel
+        if check:
+            print(f"would-copy {rel}")
+            continue
+        dst.parent.mkdir(parents=True, exist_ok=True)
+        shutil.copy2(src, dst)
+        print(f"copied   {rel}")
+
+    # 2. config.sub: add redox to the recognised OS list.
+    cs = root / "config.sub"
+    if cs.is_file():
+        t = cs.read_text(encoding="utf-8", errors="replace")
+        if "redox" in t:
+            print("skip     config.sub (already references redox)")
+        elif "| fuchsia* " in t:
+            if not check:
+                cs.write_text(t.replace("| fuchsia* ", "| fuchsia* | redox* ", 1),
+                              encoding="utf-8")
+            print(("would-apply " if check else "applied  ") + "config.sub")
+        else:
+            print("ANCHOR-FAIL config.sub :: '| fuchsia* ' not found")
+            rc = 1
+
+    # 3. os_defines.h: append before the trailing #endif.
+    od = root / "libstdc++-v3/config/os/generic/os_defines.h"
+    if od.is_file():
+        t = od.read_text(encoding="utf-8", errors="replace")
+        if "Redox" in t:
+            print("skip     os_defines.h (already references Redox)")
+        else:
+            i = t.rfind("#endif")
+            if i == -1:
+                print("ANCHOR-FAIL os_defines.h :: no trailing #endif")
+                rc = 1
+            else:
+                if not check:
+                    od.write_text(t[:i] + OS_DEFINES + "\n" + t[i:], encoding="utf-8")
+                print(("would-apply " if check else "applied  ") + "os_defines.h")
+
+    # 4. Anchored insertions.
+    for rel, anchor, block, _ in EDITS:
+        msg = apply_edit(root, rel, anchor, block, check)
+        print(msg)
+        if "ANCHOR-FAIL" in msg or "MISSING" in msg:
+            rc = 1
+
+    print()
+    print("NEXT: regenerate configure from crossconfig.m4 with autoconf "
+          "(gcc/configure and libstdc++-v3/configure are GENERATED).")
+    if rc:
+        print("One or more anchors failed -- the tree is NOT fully ported.",
+              file=sys.stderr)
+    return rc
+
+
+if __name__ == "__main__":
+    sys.exit(main())