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+llvm-efi
+========
+
+llvm-efi is a Bazel cc toolchain that uses the machine's host LLVM/clang with flags targeting freestanding EFI.
+EFI headers are not shipped as part of the toolchain, but are available as a cc_library from `@gnuefi//:gnuefi`.
+
+At some point, this toolchain should be replaced by a fully hermetic toolchain that doesn't depend on the host environment.
+
+Usage
+-----
+
+To use this toolchain explicitely while building a `cc_binary`, do:
+
+    bazel build --crosstool_top=//build/toolchain/llvm-efi:efi_cc_suite //foo/bar
+
+During an actual build however, the right toolchain should be selected using aspects or other Bazel configurability features, instead of a hardcoded `--crosstool_top`.
+
+fltused
+-------
+
+This is a special symbol emitted by MSVC-compatible compilers. In an EFI environment it can be ignored, but it needs to
+be defined. See fltused.c for more information on the symbol. Since we cannot build an object file with Bazel and
+building things for toolchains isn't a thing anyways, this file is prebuilt. If this ever needs to be rebuilt (which
+will probably never happen since there is only one static symbol in there) this can be done with the following clang
+invocation:
+
+    clang -target x86_64-unknown-windows -fno-ms-compatibility -fno-ms-extensions -ffreestanding -o fltused.o .o -c fltused.c
+