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

fusl/arch/mips/pthread_arch.h

Index: fusl/arch/mips/pthread_arch.h
diff --git a/fusl/arch/mips/pthread_arch.h b/fusl/arch/mips/pthread_arch.h
new file mode 100644
index 0000000000000000000000000000000000000000..8a49965496928b8d1df438f2d184c93678253300
--- /dev/null
+++ b/fusl/arch/mips/pthread_arch.h
@@ -0,0 +1,19 @@
+static inline struct pthread *__pthread_self()
+{
+#ifdef __clang__
+	char *tp;
+	__asm__ __volatile__ (".word 0x7c03e83b ; move %0, $3" : "=r" (tp) : : "$3" );
+#else
+	register char *tp __asm__("$3");
+	/* rdhwr $3,$29 */
+	__asm__ __volatile__ (".word 0x7c03e83b" : "=r" (tp) );
+#endif
+	return (pthread_t)(tp - 0x7000 - sizeof(struct pthread));
+}
+
+#define TLS_ABOVE_TP
+#define TP_ADJ(p) ((char *)(p) + sizeof(struct pthread) + 0x7000)
+
+#define DTP_OFFSET 0x8000
+
+#define MC_PC pc