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

fusl/arch/sh/syscall_arch.h

+#define __SYSCALL_LL_E(x) \
+((union { long long ll; long l[2]; }){ .ll = x }).l[0], \
+((union { long long ll; long l[2]; }){ .ll = x }).l[1]
+#define __SYSCALL_LL_O(x) __SYSCALL_LL_E((x))
+
+/* The extra OR instructions are to work around a hardware bug:
+ * http://documentation.renesas.com/doc/products/mpumcu/tu/tnsh7456ae.pdf
+ */
+#define __asm_syscall(trapno, ...) do {   \
+        __asm__ __volatile__ (                \
+                "trapa #31\n"            \
+                "or r0, r0\n"                     \
+                "or r0, r0\n"                     \
+                "or r0, r0\n"                     \
+                "or r0, r0\n"                     \
+                "or r0, r0\n"                     \
+        : "=r"(r0) : __VA_ARGS__ : "memory"); \
+        return r0;                            \
+        } while (0)
+
+static inline long __syscall0(long n)
+{
+        register long r3 __asm__("r3") = n;
+        register long r0 __asm__("r0");
+        __asm_syscall(16, "r"(r3));
+}
+
+static inline long __syscall1(long n, long a)
+{
+        register long r3 __asm__("r3") = n;
+        register long r4 __asm__("r4") = a;
+        register long r0 __asm__("r0");
+        __asm_syscall(17, "r"(r3), "r"(r4));
+}
+
+static inline long __syscall2(long n, long a, long b)
+{
+        register long r3 __asm__("r3") = n;
+        register long r4 __asm__("r4") = a;
+        register long r5 __asm__("r5") = b;
+        register long r0 __asm__("r0");
+        __asm_syscall(18, "r"(r3), "r"(r4), "r"(r5));
+}
+
+static inline long __syscall3(long n, long a, long b, long c)
+{
+        register long r3 __asm__("r3") = n;
+        register long r4 __asm__("r4") = a;
+        register long r5 __asm__("r5") = b;
+        register long r6 __asm__("r6") = c;
+        register long r0 __asm__("r0");
+        __asm_syscall(19, "r"(r3), "r"(r4), "r"(r5), "r"(r6));
+}
+
+static inline long __syscall4(long n, long a, long b, long c, long d)
+{
+        register long r3 __asm__("r3") = n;
+        register long r4 __asm__("r4") = a;
+        register long r5 __asm__("r5") = b;
+        register long r6 __asm__("r6") = c;
+        register long r7 __asm__("r7") = d;
+        register long r0 __asm__("r0");
+        __asm_syscall(20, "r"(r3), "r"(r4), "r"(r5), "r"(r6), "r"(r7));
+}
+
+static inline long __syscall5(long n, long a, long b, long c, long d, long e)
+{
+        register long r3 __asm__("r3") = n;
+        register long r4 __asm__("r4") = a;
+        register long r5 __asm__("r5") = b;
+        register long r6 __asm__("r6") = c;
+        register long r7 __asm__("r7") = d;
+        register long r0 __asm__("r0") = e;
+        __asm_syscall(21, "r"(r3), "r"(r4), "r"(r5), "r"(r6), "r"(r7), "0"(r0));
+}
+
+static inline long __syscall6(long n, long a, long b, long c, long d, long e, long f)
+{
+        register long r3 __asm__("r3") = n;
+        register long r4 __asm__("r4") = a;
+        register long r5 __asm__("r5") = b;
+        register long r6 __asm__("r6") = c;
+        register long r7 __asm__("r7") = d;
+        register long r0 __asm__("r0") = e;
+        register long r1 __asm__("r1") = f;
+        __asm_syscall(22, "r"(r3), "r"(r4), "r"(r5), "r"(r6), "r"(r7), "0"(r0), "r"(r1));
+}