Add a "fork" of musl as //fusl.

fusl/INSTALL

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+
+Quick Installation Guide for musl libc
+======================================
+
+There are many different ways to install musl depending on your usage
+case. This document covers only the build and installation of musl by
+itself, which is useful for upgrading an existing musl-based system or
+compiler toolchain, or for using the provided musl-gcc wrapper with an
+existing non-musl-based compiler.
+
+Building complete native or cross-compiler toolchains is outside the
+scope of this INSTALL file. More information can be found on the musl
+website and community wiki.
+
+
+Build Prerequisites
+-------------------
+
+The only build-time prerequisites for musl are GNU Make and a
+freestanding C99 compiler toolchain targeting the desired instruction
+set architecture and ABI, with support for gcc-style inline assembly,
+weak aliases, and stand-alone assembly source files.
+
+The system used to build musl does not need to be Linux-based, nor do
+the Linux kernel headers need to be available.
+
+If support for dynamic linking is desired, some further requirements
+are placed on the compiler and linker. In particular, the linker must
+support the -Bsymbolic-functions option.
+
+At present, GCC 4.6 or later is the recommended compiler for building
+musl. Any earlier version of GCC with full C99 support should also
+work, but may be subject to minor floating point conformance issues on
+i386 targets. Sufficiently recent versions of PCC and LLVM/clang are
+also believed to work, but have not been tested as heavily; prior to
+Fall 2012, both had known bugs that affected musl. Firm/cparser is
+also believed to work but lacks support for producing shared
+libraries. GCC 4.9.0 and 4.9.1 are known to have a serious bug
+(#61144) which affects musl. Beginning with version 1.1.4 musl
+attempts to work around the bug, but these compiler versions are still
+considered unstable and unsupported.
+
+
+
+Supported Targets
+-----------------
+
+musl can be built for the following CPU instruction set architecture
+and ABI combinations:
+
+* i386
+    * Minimum CPU model is actually 80486 unless kernel emulation of
+      the `cmpxchg` instruction is added
+
+* x86_64
+
+* ARM
+    * EABI, standard or hard-float VFP variant
+    * Little-endian default; big-endian variants also supported
+    * Compiler toolchains only support armv4t and later
+
+* MIPS
+    * ABI is o32
+    * Big-endian default; little-endian variants also supported
+    * Default ABI variant uses FPU registers; alternate soft-float ABI
+      that does not use FPU registers or instructions is available
+    * MIPS2 or later, or kernel emulation of ll/sc (standard in Linux)
+      is required
+
+* PowerPC
+    * Only 32-bit is supported
+    * Compiler toolchain must provide 64-bit long double, not IBM
+      double-double or IEEE quad
+    * For dynamic linking, compiler toolchain must be configured for
+      "secure PLT" variant
+
+* Microblaze
+    * Big-endian default; little-endian variants also supported
+    * Soft-float
+    * Requires support for lwx/swx instructions
+
+The following additional targets are available for build, but may not
+work correctly and may not yet have ABI stability:
+
+* SuperH (SH)
+    * Little-endian by default; big-engian variant also supported
+    * Full FPU ABI or soft-float ABI is supported, but the
+      single-precision-only FPU ABI is not supported (musl always
+      requires IEEE single and double to be supported)
+
+* x32 (x86_64 ILP32 ABI)
+
+
+
+Build and Installation Procedure
+--------------------------------
+
+To build and install musl:
+
+1. Run the provided configure script from the top-level source
+   directory, passing on its command line any desired options.
+
+2. Run "make" to compile.
+
+3. Run "make install" with appropriate privileges to write to the
+   target locations.
+
+The configure script attempts to determine automatically the correct
+target architecture based on the compiler being used. For some
+compilers, this may not be possible. If detection fails or selects the
+wrong architecture, you can provide an explicit selection on the
+configure command line.
+
+By default, configure installs to a prefix of "/usr/local/musl". This
+differs from the behavior of most configure scripts, and is chosen
+specifically to avoid clashing with libraries already present on the
+system. DO NOT set the prefix to "/usr", "/usr/local", or "/" unless
+you're upgrading libc on an existing musl-based system. Doing so will
+break your existing system when you run "make install" and it may be
+difficult to recover.
+
+
+
+Notes on Dynamic Linking
+------------------------
+
+If dynamic linking is enabled, one file needs to be installed outside
+of the installation prefix: /lib/ld-musl-$ARCH.so.1. This is the
+dynamic linker. Its pathname is hard-coded into all dynamic-linked
+programs, so for the sake of being able to share binaries between
+systems, a consistent location should be used everywhere. Note that
+the same applies to glibc and its dynamic linker, which is named
+/lib/ld-linux.so.2 on i386 systems.
+
+If for some reason it is impossible to install the dynamic linker in
+its standard location (for example, if you are installing without root
+privileges), the --syslibdir option to configure can be used to
+provide a different location
+
+At runtime, the dynamic linker needs to know the paths to search for
+shared libraries. You should create a text file named
+/etc/ld-musl-$ARCH.path (where $ARCH matches the architecture name
+used in the dynamic linker) containing a list of directories where you
+want the dynamic linker to search for shared libraries, separated by
+colons or newlines. If the dynamic linker has been installed in a
+non-default location, the path file also needs to reside at that
+location (../etc relative to the chosen syslibdir).
+
+If you do not intend to use dynamic linking, you may disable it by
+passing --disable-shared to configure; this also cuts the build time
+in half.
+
+
+
+Checking for Successful Installation
+------------------------------------
+
+After installing, you should be able to use musl via the musl-gcc
+wrapper. For example:
+
+cat > hello.c <<EOF
+#include <stdio.h>
+int main()
+{
+	printf("hello, world!\n");
+	return 0;
+}
+EOF
+/usr/local/musl/bin/musl-gcc hello.c
+./a.out
+
+To configure autoconf-based program to compile and link against musl,
+set the CC variable to musl-gcc when running configure, as in:
+
+CC=musl-gcc ./configure ...
+
+You will probably also want to use --prefix when building libraries to
+ensure that they are installed under the musl prefix and not in the
+main host system library directories.