diff --git a/ci/build.sh b/ci/build.sh
index a593055834156..d695f6b25984a 100644
--- a/ci/build.sh
+++ b/ci/build.sh
@@ -253,6 +253,7 @@ riscv32i-unknown-none-elf \
 riscv32imac-unknown-none-elf \
 riscv32imc-unknown-none-elf \
 riscv32gc-unknown-linux-gnu \
+riscv64gc-unknown-freebsd \
 riscv64gc-unknown-linux-musl \
 riscv64gc-unknown-none-elf \
 riscv64imac-unknown-none-elf \
diff --git a/src/unix/bsd/freebsdlike/freebsd/freebsd11/mod.rs b/src/unix/bsd/freebsdlike/freebsd/freebsd11/mod.rs
index 88beb63987bea..1af555fa3655c 100644
--- a/src/unix/bsd/freebsdlike/freebsd/freebsd11/mod.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/freebsd11/mod.rs
@@ -459,7 +459,8 @@ extern "C" {
 
 cfg_if! {
     if #[cfg(any(target_arch = "x86_64",
-                 target_arch = "aarch64"))] {
+                 target_arch = "aarch64",
+                 target_arch = "riscv64"))] {
         mod b64;
         pub use self::b64::*;
     }
diff --git a/src/unix/bsd/freebsdlike/freebsd/freebsd12/mod.rs b/src/unix/bsd/freebsdlike/freebsd/freebsd12/mod.rs
index 159e6f58d00bb..25c70c89e9c16 100644
--- a/src/unix/bsd/freebsdlike/freebsd/freebsd12/mod.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/freebsd12/mod.rs
@@ -478,7 +478,8 @@ extern "C" {
 
 cfg_if! {
     if #[cfg(any(target_arch = "x86_64",
-                 target_arch = "aarch64"))] {
+                 target_arch = "aarch64",
+                 target_arch = "riscv64"))] {
         mod b64;
         pub use self::b64::*;
     }
diff --git a/src/unix/bsd/freebsdlike/freebsd/freebsd13/mod.rs b/src/unix/bsd/freebsdlike/freebsd/freebsd13/mod.rs
index 22613a281ae8a..ee8be8401a272 100644
--- a/src/unix/bsd/freebsdlike/freebsd/freebsd13/mod.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/freebsd13/mod.rs
@@ -555,7 +555,8 @@ extern "C" {
 
 cfg_if! {
     if #[cfg(any(target_arch = "x86_64",
-                 target_arch = "aarch64"))] {
+                 target_arch = "aarch64",
+                 target_arch = "riscv64"))] {
         mod b64;
         pub use self::b64::*;
     }
diff --git a/src/unix/bsd/freebsdlike/freebsd/freebsd14/mod.rs b/src/unix/bsd/freebsdlike/freebsd/freebsd14/mod.rs
index de5c2be6e4ce5..56269f7e8e3a7 100644
--- a/src/unix/bsd/freebsdlike/freebsd/freebsd14/mod.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/freebsd14/mod.rs
@@ -555,7 +555,8 @@ extern "C" {
 
 cfg_if! {
     if #[cfg(any(target_arch = "x86_64",
-                 target_arch = "aarch64"))] {
+                 target_arch = "aarch64",
+                 target_arch = "riscv64"))] {
         mod b64;
         pub use self::b64::*;
     }
diff --git a/src/unix/bsd/freebsdlike/freebsd/mod.rs b/src/unix/bsd/freebsdlike/freebsd/mod.rs
index c4069ec105501..0941d9f18e640 100644
--- a/src/unix/bsd/freebsdlike/freebsd/mod.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/mod.rs
@@ -4392,6 +4392,9 @@ cfg_if! {
     } else if #[cfg(target_arch = "powerpc")] {
         mod powerpc;
         pub use self::powerpc::*;
+    } else if #[cfg(target_arch = "riscv64")] {
+        mod riscv64;
+        pub use self::riscv64::*;
     } else {
         // Unknown target_arch
     }
diff --git a/src/unix/bsd/freebsdlike/freebsd/riscv64.rs b/src/unix/bsd/freebsdlike/freebsd/riscv64.rs
new file mode 100644
index 0000000000000..c91a8dfb253f9
--- /dev/null
+++ b/src/unix/bsd/freebsdlike/freebsd/riscv64.rs
@@ -0,0 +1,154 @@
+pub type c_char = u8;
+pub type c_long = i64;
+pub type c_ulong = u64;
+pub type wchar_t = ::c_int;
+pub type time_t = i64;
+pub type suseconds_t = ::c_long;
+pub type register_t = i64;
+
+// should be pub(crate), but that requires Rust 1.18.0
+cfg_if! {
+    if #[cfg(libc_const_size_of)] {
+        #[doc(hidden)]
+        pub const _ALIGNBYTES: usize = ::mem::size_of::<::c_longlong>() - 1;
+    } else {
+        #[doc(hidden)]
+        pub const _ALIGNBYTES: usize = 8 - 1;
+    }
+}
+
+s_no_extra_traits! {
+    pub struct gpregs {
+        pub gp_ra: ::register_t,
+        pub gp_sp: ::register_t,
+        pub gp_gp: ::register_t,
+        pub gp_tp: ::register_t,
+        pub gp_t: [::register_t; 7],
+        pub gp_s: [::register_t; 12],
+        pub gp_a: [::register_t; 8],
+        pub gp_sepc: ::register_t,
+        pub gp_sstatus: ::register_t,
+    }
+
+    pub struct fpregs {
+        pub fp_x: [[::register_t; 2]; 32],
+        pub fp_fcsr: ::register_t,
+        pub fp_flags: ::c_int,
+        pub fp_pad: ::c_int,
+    }
+
+    pub struct mcontext_t {
+        pub mc_gpregs: gpregs,
+        pub mc_fpregs: fpregs,
+        pub mc_flags: ::c_int,
+        pub mc_pad: ::c_int,
+        pub mc_spare: [u64; 8],
+    }
+}
+
+cfg_if! {
+    if #[cfg(feature = "extra_traits")] {
+        impl PartialEq for gpregs {
+            fn eq(&self, other: &gpregs) -> bool {
+                self.gp_ra == other.gp_ra &&
+                self.gp_sp == other.gp_sp &&
+                self.gp_gp == other.gp_gp &&
+                self.gp_tp == other.gp_tp &&
+                self.gp_t.iter().zip(other.gp_t.iter()).all(|(a, b)| a == b) &&
+                self.gp_s.iter().zip(other.gp_s.iter()).all(|(a, b)| a == b) &&
+                self.gp_a.iter().zip(other.gp_a.iter()).all(|(a, b)| a == b) &&
+                self.gp_sepc == other.gp_sepc &&
+                self.gp_sstatus == other.gp_sstatus
+            }
+        }
+        impl Eq for gpregs {}
+        impl ::fmt::Debug for gpregs {
+            fn fmt(&self, f: &mut ::fmt::Formatter) -> ::fmt::Result {
+                f.debug_struct("gpregs")
+                    .field("gp_ra", &self.gp_ra)
+                    .field("gp_sp", &self.gp_sp)
+                    .field("gp_gp", &self.gp_gp)
+                    .field("gp_tp", &self.gp_tp)
+                    .field("gp_t", &self.gp_t)
+                    .field("gp_s", &self.gp_s)
+                    .field("gp_a", &self.gp_a)
+                    .field("gp_sepc", &self.gp_sepc)
+                    .field("gp_sstatus", &self.gp_sstatus)
+                    .finish()
+            }
+        }
+        impl ::hash::Hash for gpregs {
+            fn hash<H: ::hash::Hasher>(&self, state: &mut H) {
+                self.gp_ra.hash(state);
+                self.gp_sp.hash(state);
+                self.gp_gp.hash(state);
+                self.gp_tp.hash(state);
+                self.gp_t.hash(state);
+                self.gp_s.hash(state);
+                self.gp_a.hash(state);
+                self.gp_sepc.hash(state);
+                self.gp_sstatus.hash(state);
+            }
+        }
+        impl PartialEq for fpregs {
+            fn eq(&self, other: &fpregs) -> bool {
+                self.fp_x == other.fp_x &&
+                self.fp_fcsr == other.fp_fcsr &&
+                self.fp_flags == other.fp_flags &&
+                self.fp_pad == other.fp_pad
+            }
+        }
+        impl Eq for fpregs {}
+        impl ::fmt::Debug for fpregs {
+            fn fmt(&self, f: &mut ::fmt::Formatter) -> ::fmt::Result {
+                f.debug_struct("fpregs")
+                    .field("fp_x", &self.fp_x)
+                    .field("fp_fcsr", &self.fp_fcsr)
+                    .field("fp_flags", &self.fp_flags)
+                    .field("fp_pad", &self.fp_pad)
+                    .finish()
+            }
+        }
+        impl ::hash::Hash for fpregs {
+            fn hash<H: ::hash::Hasher>(&self, state: &mut H) {
+                self.fp_x.hash(state);
+                self.fp_fcsr.hash(state);
+                self.fp_flags.hash(state);
+                self.fp_pad.hash(state);
+            }
+        }
+        impl PartialEq for mcontext_t {
+            fn eq(&self, other: &mcontext_t) -> bool {
+                self.mc_gpregs == other.mc_gpregs &&
+                self.mc_fpregs == other.mc_fpregs &&
+                self.mc_flags == other.mc_flags &&
+                self.mc_pad == other.mc_pad &&
+                self.mc_spare.iter().zip(other.mc_spare.iter()).all(|(a, b)| a == b)
+            }
+        }
+        impl Eq for mcontext_t {}
+        impl ::fmt::Debug for mcontext_t {
+            fn fmt(&self, f: &mut ::fmt::Formatter) -> ::fmt::Result {
+                f.debug_struct("mcontext_t")
+                    .field("mc_gpregs", &self.mc_gpregs)
+                    .field("mc_fpregs", &self.mc_fpregs)
+                    .field("mc_flags", &self.mc_flags)
+                    .field("mc_pad", &self.mc_pad)
+                    .field("mc_spare", &self.mc_spare)
+                    .finish()
+            }
+        }
+        impl ::hash::Hash for mcontext_t {
+            fn hash<H: ::hash::Hasher>(&self, state: &mut H) {
+                self.mc_gpregs.hash(state);
+                self.mc_fpregs.hash(state);
+                self.mc_flags.hash(state);
+                self.mc_pad.hash(state);
+                self.mc_spare.hash(state);
+            }
+        }
+    }
+}
+
+pub const MAP_32BIT: ::c_int = 0x00080000;
+pub const MINSIGSTKSZ: ::size_t = 4096; // 1024 * 4