diff --git a/src/system/libroot/os/arch/riscv64/Jamfile b/src/system/libroot/os/arch/riscv64/Jamfile
index 57a3befd34..9b7898685c 100644
--- a/src/system/libroot/os/arch/riscv64/Jamfile
+++ b/src/system/libroot/os/arch/riscv64/Jamfile
@@ -22,6 +22,8 @@ for architectureObject in [ MultiArchSubDirSetup riscv64 ] {
 			time.cpp
 			thread.cpp
 
+			cachectl.cpp
+
 			generic_atomic.cpp
 			generic_stack_trace.cpp
 			generic_system_time_nsecs.cpp
diff --git a/src/system/libroot/os/arch/riscv64/cachectl.cpp b/src/system/libroot/os/arch/riscv64/cachectl.cpp
new file mode 100644
index 0000000000..616290c169
--- /dev/null
+++ b/src/system/libroot/os/arch/riscv64/cachectl.cpp
@@ -0,0 +1,11 @@
+/*
+ * Copyright 2021, Haiku, Inc.
+ * Distributed under the terms of the MIT License.
+ */
+
+
+extern "C" void
+__riscv_flush_icache(void *start, void *end, unsigned long int flags)
+{
+	__asm__ volatile ("fence.i");
+}
diff --git a/src/system/libroot/posix/glibc/stdlib/Jamfile b/src/system/libroot/posix/glibc/stdlib/Jamfile
index 7cbfd480d5..39626b462b 100644
--- a/src/system/libroot/posix/glibc/stdlib/Jamfile
+++ b/src/system/libroot/posix/glibc/stdlib/Jamfile
@@ -32,6 +32,7 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 			l64a.c
 			lcong48.c
 			lcong48_r.c
+			longlong.c
 			lrand48.c
 			lrand48_r.c
 			mrand48.c
diff --git a/src/system/libroot/posix/glibc/stdlib/longlong.c b/src/system/libroot/posix/glibc/stdlib/longlong.c
new file mode 100644
index 0000000000..064c4ef1b6
--- /dev/null
+++ b/src/system/libroot/posix/glibc/stdlib/longlong.c
@@ -0,0 +1,17 @@
+/*
+ * Copyright 2021, Haiku, Inc.
+ * Distributed under the terms of the MIT License.
+ */
+
+
+const char __clz_tab[256] =
+{
+	0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
+	6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
+	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+	8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+	8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+	8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+	8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8
+};