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

fusl/src/thread/powerpc/clone.s

+.text
+.global __clone
+.type __clone, %function
+__clone:
+# int clone(fn, stack, flags, arg, ptid, tls, ctid)
+#            a  b       c     d     e    f    g
+#            3  4       5     6     7    8    9
+# pseudo C code:
+# tid = syscall(SYS_clone,c,b,e,f,g);
+# if (!tid) syscall(SYS_exit, a(d));
+# return tid;
+
+# SYS_clone = 120
+# SYS_exit = 1
+
+# store non-volatile regs r30, r31 on stack in order to put our
+# start func and its arg there
+stwu 30, -16(1)
+stw 31, 4(1)
+
+# save r3 (func) into r30, and r6(arg) into r31
+mr 30, 3
+mr 31, 6
+
+#move c into first arg
+mr 3, 5
+#mr 4, 4
+mr 5, 7
+mr 6, 8
+mr 7, 9
+
+# move syscall number into r0    
+li 0, 120
+
+sc
+
+# check for syscall error
+bns+ 1f # jump to label 1 if no summary overflow.
+#else
+neg 3, 3 #negate the result (errno)
+1:
+# compare sc result with 0
+cmpwi cr7, 3, 0
+
+# if not 0, jump to end
+bne cr7, 2f
+
+#else: we're the child
+#call funcptr: move arg (d) into r3
+mr 3, 31
+#move r30 (funcptr) into CTR reg
+mtctr 30
+# call CTR reg
+bctrl
+# mov SYS_exit into r0 (the exit param is already in r3)
+li 0, 1
+sc
+
+2:
+
+# restore stack
+lwz 30, 0(1)
+lwz 31, 4(1)
+addi 1, 1, 16
+
+blr
+