diff --git a/ci/azure-install-rust.yml b/ci/azure-install-rust.yml
index e78fe32faf6d0..31b07149bd4d8 100644
--- a/ci/azure-install-rust.yml
+++ b/ci/azure-install-rust.yml
@@ -8,7 +8,7 @@ steps:
       if command -v rustup; then
         # Uncomment when rustup on Azure is updated
         #rustup set profile minimal
-        rustup update $toolchain
+        rustup update --force $toolchain
         rustup default $toolchain
       else
         curl https://sh.rustup.rs -sSf | sh -s -- -y --default-toolchain $toolchain --profile=minimal
diff --git a/ci/build.sh b/ci/build.sh
index cde46cb451b8d..082f0dc683393 100644
--- a/ci/build.sh
+++ b/ci/build.sh
@@ -15,7 +15,7 @@ RUST=${TOOLCHAIN}
 echo "Testing Rust ${RUST} on ${OS}"
 
 if [ "${TOOLCHAIN}" = "nightly" ] ; then
-    cargo +nightly install cargo-xbuild -Z install-upgrade
+    cargo +nightly install cargo-xbuild
     rustup component add rust-src
 fi
 
@@ -220,6 +220,7 @@ nvptx64-nvidia-cuda \
 powerpc-unknown-linux-gnuspe \
 powerpc-unknown-netbsd \
 powerpc64-unknown-freebsd \
+riscv64gc-unknown-linux-gnu \
 riscv32imac-unknown-none-elf \
 riscv32imc-unknown-none-elf \
 sparc64-unknown-netbsd \
diff --git a/ci/dox.sh b/ci/dox.sh
index 0c89a2e17b1e9..271b54b4fab79 100644
--- a/ci/dox.sh
+++ b/ci/dox.sh
@@ -19,7 +19,7 @@ if ! rustc --version | grep -E "nightly" ; then
 fi
 
 rustup component add rust-src
-cargo +nightly install cargo-xbuild -Z install-upgrade
+cargo +nightly install cargo-xbuild
 
 # List all targets that do currently build successfully:
 # shellcheck disable=SC1003
diff --git a/ci/semver.sh b/ci/semver.sh
index 3412501a7215b..7e6ea663c8aca 100644
--- a/ci/semver.sh
+++ b/ci/semver.sh
@@ -13,7 +13,7 @@ if ! rustc --version | grep -E "nightly" ; then
     exit 1
 fi
 
-cargo +nightly install semverver -Z install-upgrade
+cargo +nightly install semverver
 
 TARGETS=
 case "${OS}" in
diff --git a/src/unix/linux_like/linux/gnu/b64/mod.rs b/src/unix/linux_like/linux/gnu/b64/mod.rs
index c91da0d98d1ca..40ce8441a9663 100644
--- a/src/unix/linux_like/linux/gnu/b64/mod.rs
+++ b/src/unix/linux_like/linux/gnu/b64/mod.rs
@@ -78,6 +78,9 @@ cfg_if! {
     } else if #[cfg(any(target_arch = "x86_64"))] {
         mod x86_64;
         pub use self::x86_64::*;
+    } else if #[cfg(any(target_arch = "riscv64"))] {
+        mod riscv64;
+        pub use self::riscv64::*;
     } else {
         // Unknown target_arch
     }
diff --git a/src/unix/linux_like/linux/gnu/b64/riscv64/mod.rs b/src/unix/linux_like/linux/gnu/b64/riscv64/mod.rs
new file mode 100644
index 0000000000000..c45c5b230bed7
--- /dev/null
+++ b/src/unix/linux_like/linux/gnu/b64/riscv64/mod.rs
@@ -0,0 +1,861 @@
+//! RISC-V-specific definitions for 64-bit linux-like values
+
+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 = ::c_long;
+
+pub type dev_t = ::c_ulong;
+pub type uid_t = ::c_uint;
+pub type gid_t = ::c_uint;
+pub type ino_t = ::c_ulong;
+pub type ino64_t = ::c_ulong;
+pub type mode_t = ::c_uint;
+pub type nlink_t = ::c_uint;
+pub type off_t = ::c_long;
+pub type off64_t = ::c_long;
+pub type pid_t = ::c_int;
+pub type blksize_t = ::c_int;
+pub type blkcnt_t = ::c_long;
+pub type fsblkcnt_t = ::c_ulong;
+pub type fsblkcnt64_t = ::c_ulong;
+pub type fsfilcnt_t = ::c_ulong;
+pub type fsfilcnt64_t = ::c_ulong;
+pub type suseconds_t = i64;
+pub type __u64 = ::c_ulonglong;
+
+s! {
+    pub struct pthread_attr_t {
+        __size: [::c_ulong; 7],
+    }
+
+    pub struct timespec {
+        pub tv_sec: time_t,
+        pub tv_nsec: ::c_long,
+    }
+
+    pub struct stat {
+        pub st_dev: dev_t,
+        pub st_ino: ino_t,
+        pub st_mode: mode_t,
+        pub st_nlink: nlink_t,
+        pub st_uid: uid_t,
+        pub st_gid: gid_t,
+        pub st_rdev: dev_t,
+        pub __pad1: dev_t,
+        pub st_size: off_t,
+        pub st_blksize: blksize_t,
+        pub __pad2: ::c_int,
+        pub st_blocks: blkcnt_t,
+        pub st_atime: time_t,
+        pub st_atime_nsec: ::c_long,
+        pub st_mtime: time_t,
+        pub st_mtime_nsec: ::c_long,
+        pub st_ctime: time_t,
+        pub st_ctime_nsec: ::c_long,
+        pub __unused: [::c_int; 2usize],
+    }
+
+    pub struct stat64 {
+        pub st_dev: dev_t,
+        pub st_ino: ino64_t,
+        pub st_mode: mode_t,
+        pub st_nlink: nlink_t,
+        pub st_uid: uid_t,
+        pub st_gid: gid_t,
+        pub st_rdev: dev_t,
+        pub __pad1: dev_t,
+        pub st_size: off64_t,
+        pub st_blksize: blksize_t,
+        pub __pad2: ::c_int,
+        pub st_blocks: blkcnt_t,
+        pub st_atime: time_t,
+        pub st_atime_nsec: ::c_long,
+        pub st_mtime: time_t,
+        pub st_mtime_nsec: ::c_long,
+        pub st_ctime: time_t,
+        pub st_ctime_nsec: ::c_long,
+        pub __unused: [::c_int; 2],
+    }
+
+    pub struct statfs {
+        pub f_type: ::c_long,
+        pub f_bsize: ::c_long,
+        pub f_blocks: fsblkcnt_t,
+        pub f_bfree: fsblkcnt_t,
+        pub f_bavail: fsblkcnt_t,
+        pub f_files: fsfilcnt_t,
+        pub f_ffree: fsfilcnt_t,
+        pub f_fsid: ::fsid_t,
+        pub f_namelen: ::c_long,
+        pub f_frsize: ::c_long,
+        pub f_flags: ::c_long,
+        pub f_spare: [::c_long; 4],
+    }
+
+    pub struct statfs64 {
+        pub f_type: ::c_long,
+        pub f_bsize: ::c_long,
+        pub f_blocks: fsblkcnt64_t,
+        pub f_bfree: fsblkcnt64_t,
+        pub f_bavail: fsblkcnt64_t,
+        pub f_files: fsfilcnt64_t,
+        pub f_ffree: fsfilcnt64_t,
+        pub f_fsid: ::fsid_t,
+        pub f_namelen: ::c_long,
+        pub f_frsize: ::c_long,
+        pub f_flags: ::c_long,
+        pub f_spare: [::c_long; 4],
+    }
+
+    pub struct statvfs {
+        pub f_bsize: ::c_ulong,
+        pub f_frsize: ::c_ulong,
+        pub f_blocks: fsblkcnt_t,
+        pub f_bfree: fsblkcnt_t,
+        pub f_bavail: fsblkcnt_t,
+        pub f_files: fsfilcnt_t,
+        pub f_ffree: fsfilcnt_t,
+        pub f_favail: fsfilcnt_t,
+        pub f_fsid: ::c_ulong,
+        pub f_flag: ::c_ulong,
+        pub f_namemax: ::c_ulong,
+        pub __f_spare: [::c_int; 6],
+    }
+
+    pub struct statvfs64 {
+        pub f_bsize: ::c_ulong,
+        pub f_frsize: ::c_ulong,
+        pub f_blocks: fsblkcnt64_t,
+        pub f_bfree: fsblkcnt64_t,
+        pub f_bavail: fsblkcnt64_t,
+        pub f_files: fsfilcnt64_t,
+        pub f_ffree: fsfilcnt64_t,
+        pub f_favail: fsfilcnt64_t,
+        pub f_fsid: ::c_ulong,
+        pub f_flag: ::c_ulong,
+        pub f_namemax: ::c_ulong,
+        pub __f_spare: [::c_int; 6],
+    }
+
+    pub struct siginfo_t {
+        pub si_signo: ::c_int,
+        pub si_errno: ::c_int,
+        pub si_code: ::c_int,
+        #[doc(hidden)]
+        #[deprecated(
+            since="0.2.54",
+            note="Please leave a comment on \
+                  https://github.com/rust-lang/libc/pull/1316 if you're using \
+                  this field"
+        )]
+        pub _pad: [::c_int; 29],
+        _align: [u64; 0],
+    }
+
+    pub struct stack_t {
+        pub ss_sp: *mut ::c_void,
+        pub ss_flags: ::c_int,
+        pub ss_size: ::size_t,
+    }
+
+    pub struct sigaction {
+        pub sa_sigaction: ::sighandler_t,
+        pub sa_mask: ::sigset_t,
+        pub sa_flags: ::c_int,
+        pub sa_restorer: ::Option<unsafe extern "C" fn()>,
+    }
+
+    pub struct sigset_t {
+        pub __val: [::c_ulong; 16],
+    }
+
+    pub struct ipc_perm {
+        pub __key: ::key_t,
+        pub uid: uid_t,
+        pub gid: gid_t,
+        pub cuid: uid_t,
+        pub cgid: gid_t,
+        pub mode: ::c_ushort,
+        pub __pad1: ::c_ushort,
+        pub __seq: ::c_ushort,
+        pub __pad2: ::c_ushort,
+        pub __unused1: ::c_ulong,
+        pub __unused2: ::c_ulong,
+    }
+
+    pub struct shmid_ds {
+        pub shm_perm: ipc_perm,
+        pub shm_segsz: ::size_t,
+        pub shm_atime: time_t,
+        pub shm_dtime: time_t,
+        pub shm_ctime: time_t,
+        pub shm_cpid: pid_t,
+        pub shm_lpid: pid_t,
+        pub shm_nattch: ::shmatt_t,
+        pub __unused5: ::c_ulong,
+        pub __unused6: ::c_ulong,
+    }
+
+    pub struct flock {
+        pub l_type: ::c_short,
+        pub l_whence: ::c_short,
+        pub l_start: ::off_t,
+        pub l_len: ::off_t,
+        pub l_pid: ::pid_t,
+    }
+}
+
+pub const POSIX_FADV_DONTNEED: ::c_int = 4;
+pub const POSIX_FADV_NOREUSE: ::c_int = 5;
+pub const VEOF: usize = 4;
+pub const TIOCGSOFTCAR: ::c_ulong = 21529;
+pub const TIOCSSOFTCAR: ::c_ulong = 21530;
+pub const TIOCGRS485: ::c_int = 21550;
+pub const TIOCSRS485: ::c_int = 21551;
+pub const O_APPEND: ::c_int = 1024;
+pub const O_CREAT: ::c_int = 64;
+pub const O_EXCL: ::c_int = 128;
+pub const O_NOCTTY: ::c_int = 256;
+pub const O_NONBLOCK: ::c_int = 2048;
+pub const O_SYNC: ::c_int = 1052672;
+pub const O_RSYNC: ::c_int = 1052672;
+pub const O_DSYNC: ::c_int = 4096;
+pub const O_FSYNC: ::c_int = 1052672;
+pub const O_NOATIME: ::c_int = 262144;
+pub const O_PATH: ::c_int = 2097152;
+pub const O_TMPFILE: ::c_int = 4259840;
+pub const MAP_GROWSDOWN: ::c_int = 256;
+pub const EDEADLK: ::c_int = 35;
+pub const ENAMETOOLONG: ::c_int = 36;
+pub const ENOLCK: ::c_int = 37;
+pub const ENOSYS: ::c_int = 38;
+pub const ENOTEMPTY: ::c_int = 39;
+pub const ELOOP: ::c_int = 40;
+pub const ENOMSG: ::c_int = 42;
+pub const EIDRM: ::c_int = 43;
+pub const ECHRNG: ::c_int = 44;
+pub const EL2NSYNC: ::c_int = 45;
+pub const EL3HLT: ::c_int = 46;
+pub const EL3RST: ::c_int = 47;
+pub const ELNRNG: ::c_int = 48;
+pub const EUNATCH: ::c_int = 49;
+pub const ENOCSI: ::c_int = 50;
+pub const EL2HLT: ::c_int = 51;
+pub const EBADE: ::c_int = 52;
+pub const EBADR: ::c_int = 53;
+pub const EXFULL: ::c_int = 54;
+pub const ENOANO: ::c_int = 55;
+pub const EBADRQC: ::c_int = 56;
+pub const EBADSLT: ::c_int = 57;
+pub const EMULTIHOP: ::c_int = 72;
+pub const EOVERFLOW: ::c_int = 75;
+pub const ENOTUNIQ: ::c_int = 76;
+pub const EBADFD: ::c_int = 77;
+pub const EBADMSG: ::c_int = 74;
+pub const EREMCHG: ::c_int = 78;
+pub const ELIBACC: ::c_int = 79;
+pub const ELIBBAD: ::c_int = 80;
+pub const ELIBSCN: ::c_int = 81;
+pub const ELIBMAX: ::c_int = 82;
+pub const ELIBEXEC: ::c_int = 83;
+pub const EILSEQ: ::c_int = 84;
+pub const ERESTART: ::c_int = 85;
+pub const ESTRPIPE: ::c_int = 86;
+pub const EUSERS: ::c_int = 87;
+pub const ENOTSOCK: ::c_int = 88;
+pub const EDESTADDRREQ: ::c_int = 89;
+pub const EMSGSIZE: ::c_int = 90;
+pub const EPROTOTYPE: ::c_int = 91;
+pub const ENOPROTOOPT: ::c_int = 92;
+pub const EPROTONOSUPPORT: ::c_int = 93;
+pub const ESOCKTNOSUPPORT: ::c_int = 94;
+pub const EOPNOTSUPP: ::c_int = 95;
+pub const EPFNOSUPPORT: ::c_int = 96;
+pub const EAFNOSUPPORT: ::c_int = 97;
+pub const EADDRINUSE: ::c_int = 98;
+pub const EADDRNOTAVAIL: ::c_int = 99;
+pub const ENETDOWN: ::c_int = 100;
+pub const ENETUNREACH: ::c_int = 101;
+pub const ENETRESET: ::c_int = 102;
+pub const ECONNABORTED: ::c_int = 103;
+pub const ECONNRESET: ::c_int = 104;
+pub const ENOBUFS: ::c_int = 105;
+pub const EISCONN: ::c_int = 106;
+pub const ENOTCONN: ::c_int = 107;
+pub const ESHUTDOWN: ::c_int = 108;
+pub const ETOOMANYREFS: ::c_int = 109;
+pub const ETIMEDOUT: ::c_int = 110;
+pub const ECONNREFUSED: ::c_int = 111;
+pub const EHOSTDOWN: ::c_int = 112;
+pub const EHOSTUNREACH: ::c_int = 113;
+pub const EALREADY: ::c_int = 114;
+pub const EINPROGRESS: ::c_int = 115;
+pub const ESTALE: ::c_int = 116;
+pub const EDQUOT: ::c_int = 122;
+pub const ENOMEDIUM: ::c_int = 123;
+pub const EMEDIUMTYPE: ::c_int = 124;
+pub const ECANCELED: ::c_int = 125;
+pub const ENOKEY: ::c_int = 126;
+pub const EKEYEXPIRED: ::c_int = 127;
+pub const EKEYREVOKED: ::c_int = 128;
+pub const EKEYREJECTED: ::c_int = 129;
+pub const EOWNERDEAD: ::c_int = 130;
+pub const ENOTRECOVERABLE: ::c_int = 131;
+pub const EHWPOISON: ::c_int = 133;
+pub const ERFKILL: ::c_int = 132;
+pub const SOL_SOCKET: ::c_int = 1;
+pub const SO_REUSEADDR: ::c_int = 2;
+pub const SO_TYPE: ::c_int = 3;
+pub const SO_ERROR: ::c_int = 4;
+pub const SO_DONTROUTE: ::c_int = 5;
+pub const SO_BROADCAST: ::c_int = 6;
+pub const SO_SNDBUF: ::c_int = 7;
+pub const SO_RCVBUF: ::c_int = 8;
+pub const SO_SNDBUFFORCE: ::c_int = 32;
+pub const SO_RCVBUFFORCE: ::c_int = 33;
+pub const SO_KEEPALIVE: ::c_int = 9;
+pub const SO_OOBINLINE: ::c_int = 10;
+pub const SO_NO_CHECK: ::c_int = 11;
+pub const SO_PRIORITY: ::c_int = 12;
+pub const SO_LINGER: ::c_int = 13;
+pub const SO_BSDCOMPAT: ::c_int = 14;
+pub const SO_REUSEPORT: ::c_int = 15;
+pub const SO_PASSCRED: ::c_int = 16;
+pub const SO_PEERCRED: ::c_int = 17;
+pub const SO_RCVLOWAT: ::c_int = 18;
+pub const SO_SNDLOWAT: ::c_int = 19;
+pub const SO_RCVTIMEO: ::c_int = 20;
+pub const SO_SNDTIMEO: ::c_int = 21;
+pub const SO_SECURITY_AUTHENTICATION: ::c_int = 22;
+pub const SO_SECURITY_ENCRYPTION_TRANSPORT: ::c_int = 23;
+pub const SO_SECURITY_ENCRYPTION_NETWORK: ::c_int = 24;
+pub const SO_BINDTODEVICE: ::c_int = 25;
+pub const SO_ATTACH_FILTER: ::c_int = 26;
+pub const SO_DETACH_FILTER: ::c_int = 27;
+pub const SO_GET_FILTER: ::c_int = 26;
+pub const SO_PEERNAME: ::c_int = 28;
+pub const SO_TIMESTAMP: ::c_int = 29;
+pub const SO_ACCEPTCONN: ::c_int = 30;
+pub const SO_PEERSEC: ::c_int = 31;
+pub const SO_PASSSEC: ::c_int = 34;
+pub const SO_TIMESTAMPNS: ::c_int = 35;
+pub const SCM_TIMESTAMPNS: ::c_int = 35;
+pub const SO_MARK: ::c_int = 36;
+pub const SO_PROTOCOL: ::c_int = 38;
+pub const SO_DOMAIN: ::c_int = 39;
+pub const SO_RXQ_OVFL: ::c_int = 40;
+pub const SO_WIFI_STATUS: ::c_int = 41;
+pub const SCM_WIFI_STATUS: ::c_int = 41;
+pub const SO_PEEK_OFF: ::c_int = 42;
+pub const SO_NOFCS: ::c_int = 43;
+pub const SO_LOCK_FILTER: ::c_int = 44;
+pub const SO_SELECT_ERR_QUEUE: ::c_int = 45;
+pub const SO_BUSY_POLL: ::c_int = 46;
+pub const SO_MAX_PACING_RATE: ::c_int = 47;
+pub const SO_BPF_EXTENSIONS: ::c_int = 48;
+pub const SO_INCOMING_CPU: ::c_int = 49;
+pub const SO_ATTACH_BPF: ::c_int = 50;
+pub const SO_DETACH_BPF: ::c_int = 27;
+pub const SOCK_STREAM: ::c_int = 1;
+pub const SOCK_DGRAM: ::c_int = 2;
+pub const SA_ONSTACK: ::c_int = 134217728;
+pub const SA_SIGINFO: ::c_int = 4;
+pub const SA_NOCLDWAIT: ::c_int = 2;
+pub const SIGTTIN: ::c_int = 21;
+pub const SIGTTOU: ::c_int = 22;
+pub const SIGXCPU: ::c_int = 24;
+pub const SIGXFSZ: ::c_int = 25;
+pub const SIGVTALRM: ::c_int = 26;
+pub const SIGPROF: ::c_int = 27;
+pub const SIGWINCH: ::c_int = 28;
+pub const SIGCHLD: ::c_int = 17;
+pub const SIGBUS: ::c_int = 7;
+pub const SIGUSR1: ::c_int = 10;
+pub const SIGUSR2: ::c_int = 12;
+pub const SIGCONT: ::c_int = 18;
+pub const SIGSTOP: ::c_int = 19;
+pub const SIGTSTP: ::c_int = 20;
+pub const SIGURG: ::c_int = 23;
+pub const SIGIO: ::c_int = 29;
+pub const SIGSYS: ::c_int = 31;
+pub const SIGSTKFLT: ::c_int = 16;
+pub const SIGPOLL: ::c_int = 29;
+pub const SIGPWR: ::c_int = 30;
+pub const SIG_SETMASK: ::c_int = 2;
+pub const SIG_BLOCK: ::c_int = 0;
+pub const SIG_UNBLOCK: ::c_int = 1;
+pub const POLLWRNORM: ::c_short = 256;
+pub const POLLWRBAND: ::c_short = 512;
+pub const O_ASYNC: ::c_int = 8192;
+pub const O_NDELAY: ::c_int = 2048;
+pub const PTRACE_DETACH: ::c_uint = 17;
+pub const EFD_NONBLOCK: ::c_int = 2048;
+pub const F_GETLK: ::c_int = 5;
+pub const F_GETOWN: ::c_int = 9;
+pub const F_SETOWN: ::c_int = 8;
+pub const F_SETLK: ::c_int = 6;
+pub const F_SETLKW: ::c_int = 7;
+pub const F_RDLCK: ::c_int = 0;
+pub const F_WRLCK: ::c_int = 1;
+pub const F_UNLCK: ::c_int = 2;
+pub const SFD_NONBLOCK: ::c_int = 2048;
+pub const TCSANOW: ::c_int = 0;
+pub const TCSADRAIN: ::c_int = 1;
+pub const TCSAFLUSH: ::c_int = 2;
+pub const TIOCLINUX: ::c_ulong = 21532;
+pub const TIOCGSERIAL: ::c_ulong = 21534;
+pub const TIOCEXCL: ::c_ulong = 21516;
+pub const TIOCNXCL: ::c_ulong = 21517;
+pub const TIOCSCTTY: ::c_ulong = 21518;
+pub const TIOCSTI: ::c_ulong = 21522;
+pub const TIOCMGET: ::c_ulong = 21525;
+pub const TIOCMBIS: ::c_ulong = 21526;
+pub const TIOCMBIC: ::c_ulong = 21527;
+pub const TIOCMSET: ::c_ulong = 21528;
+pub const TIOCCONS: ::c_ulong = 21533;
+pub const TIOCM_ST: ::c_int = 8;
+pub const TIOCM_SR: ::c_int = 16;
+pub const TIOCM_CTS: ::c_int = 32;
+pub const TIOCM_CAR: ::c_int = 64;
+pub const TIOCM_RNG: ::c_int = 128;
+pub const TIOCM_DSR: ::c_int = 256;
+pub const SFD_CLOEXEC: ::c_int = 524288;
+pub const NCCS: usize = 32;
+pub const O_TRUNC: ::c_int = 512;
+pub const O_CLOEXEC: ::c_int = 524288;
+pub const EBFONT: ::c_int = 59;
+pub const ENOSTR: ::c_int = 60;
+pub const ENODATA: ::c_int = 61;
+pub const ETIME: ::c_int = 62;
+pub const ENOSR: ::c_int = 63;
+pub const ENONET: ::c_int = 64;
+pub const ENOPKG: ::c_int = 65;
+pub const EREMOTE: ::c_int = 66;
+pub const ENOLINK: ::c_int = 67;
+pub const EADV: ::c_int = 68;
+pub const ESRMNT: ::c_int = 69;
+pub const ECOMM: ::c_int = 70;
+pub const EPROTO: ::c_int = 71;
+pub const EDOTDOT: ::c_int = 73;
+pub const SA_NODEFER: ::c_int = 1073741824;
+pub const SA_RESETHAND: ::c_int = -2147483648;
+pub const SA_RESTART: ::c_int = 268435456;
+pub const SA_NOCLDSTOP: ::c_int = 1;
+pub const EPOLL_CLOEXEC: ::c_int = 524288;
+pub const EFD_CLOEXEC: ::c_int = 524288;
+pub const __SIZEOF_PTHREAD_CONDATTR_T: usize = 4;
+pub const __SIZEOF_PTHREAD_MUTEXATTR_T: usize = 4;
+pub const O_DIRECT: ::c_int = 16384;
+pub const O_DIRECTORY: ::c_int = 65536;
+pub const O_NOFOLLOW: ::c_int = 131072;
+pub const MAP_HUGETLB: ::c_int = 262144;
+pub const MAP_LOCKED: ::c_int = 8192;
+pub const MAP_NORESERVE: ::c_int = 16384;
+pub const MAP_ANON: ::c_int = 32;
+pub const MAP_ANONYMOUS: ::c_int = 32;
+pub const MAP_DENYWRITE: ::c_int = 2048;
+pub const MAP_EXECUTABLE: ::c_int = 4096;
+pub const MAP_POPULATE: ::c_int = 32768;
+pub const MAP_NONBLOCK: ::c_int = 65536;
+pub const MAP_STACK: ::c_int = 131072;
+pub const EDEADLOCK: ::c_int = 35;
+pub const EUCLEAN: ::c_int = 117;
+pub const ENOTNAM: ::c_int = 118;
+pub const ENAVAIL: ::c_int = 119;
+pub const EISNAM: ::c_int = 120;
+pub const EREMOTEIO: ::c_int = 121;
+pub const FIOCLEX: ::c_ulong = 21585;
+pub const FIONCLEX: ::c_ulong = 21584;
+pub const FIONBIO: ::c_ulong = 21537;
+pub const MCL_CURRENT: ::c_int = 1;
+pub const MCL_FUTURE: ::c_int = 2;
+pub const SIGSTKSZ: ::size_t = 8192;
+pub const MINSIGSTKSZ: ::size_t = 2048;
+pub const CBAUD: ::tcflag_t = 4111;
+pub const TAB1: ::tcflag_t = 2048;
+pub const TAB2: ::tcflag_t = 4096;
+pub const TAB3: ::tcflag_t = 6144;
+pub const CR1: ::tcflag_t = 512;
+pub const CR2: ::tcflag_t = 1024;
+pub const CR3: ::tcflag_t = 1536;
+pub const FF1: ::tcflag_t = 32768;
+pub const BS1: ::tcflag_t = 8192;
+pub const VT1: ::tcflag_t = 16384;
+pub const VWERASE: usize = 14;
+pub const VREPRINT: usize = 12;
+pub const VSUSP: usize = 10;
+pub const VSTART: usize = 8;
+pub const VSTOP: usize = 9;
+pub const VDISCARD: usize = 13;
+pub const VTIME: usize = 5;
+pub const IXON: ::tcflag_t = 1024;
+pub const IXOFF: ::tcflag_t = 4096;
+pub const ONLCR: ::tcflag_t = 4;
+pub const CSIZE: ::tcflag_t = 48;
+pub const CS6: ::tcflag_t = 16;
+pub const CS7: ::tcflag_t = 32;
+pub const CS8: ::tcflag_t = 48;
+pub const CSTOPB: ::tcflag_t = 64;
+pub const CREAD: ::tcflag_t = 128;
+pub const PARENB: ::tcflag_t = 256;
+pub const PARODD: ::tcflag_t = 512;
+pub const HUPCL: ::tcflag_t = 1024;
+pub const CLOCAL: ::tcflag_t = 2048;
+pub const ECHOKE: ::tcflag_t = 2048;
+pub const ECHOE: ::tcflag_t = 16;
+pub const ECHOK: ::tcflag_t = 32;
+pub const ECHONL: ::tcflag_t = 64;
+pub const ECHOPRT: ::tcflag_t = 1024;
+pub const ECHOCTL: ::tcflag_t = 512;
+pub const ISIG: ::tcflag_t = 1;
+pub const ICANON: ::tcflag_t = 2;
+pub const PENDIN: ::tcflag_t = 16384;
+pub const NOFLSH: ::tcflag_t = 128;
+pub const CIBAUD: ::tcflag_t = 269418496;
+pub const CBAUDEX: ::tcflag_t = 4096;
+pub const VSWTC: usize = 7;
+pub const OLCUC: ::tcflag_t = 2;
+pub const NLDLY: ::tcflag_t = 256;
+pub const CRDLY: ::tcflag_t = 1536;
+pub const TABDLY: ::tcflag_t = 6144;
+pub const BSDLY: ::tcflag_t = 8192;
+pub const FFDLY: ::tcflag_t = 32768;
+pub const VTDLY: ::tcflag_t = 16384;
+pub const XTABS: ::tcflag_t = 6144;
+pub const B0: ::speed_t = 0;
+pub const B50: ::speed_t = 1;
+pub const B75: ::speed_t = 2;
+pub const B110: ::speed_t = 3;
+pub const B134: ::speed_t = 4;
+pub const B150: ::speed_t = 5;
+pub const B200: ::speed_t = 6;
+pub const B300: ::speed_t = 7;
+pub const B600: ::speed_t = 8;
+pub const B1200: ::speed_t = 9;
+pub const B1800: ::speed_t = 10;
+pub const B2400: ::speed_t = 11;
+pub const B4800: ::speed_t = 12;
+pub const B9600: ::speed_t = 13;
+pub const B19200: ::speed_t = 14;
+pub const B38400: ::speed_t = 15;
+pub const EXTA: ::speed_t = 14;
+pub const EXTB: ::speed_t = 15;
+pub const B57600: ::speed_t = 4097;
+pub const B115200: ::speed_t = 4098;
+pub const B230400: ::speed_t = 4099;
+pub const B460800: ::speed_t = 4100;
+pub const B500000: ::speed_t = 4101;
+pub const B576000: ::speed_t = 4102;
+pub const B921600: ::speed_t = 4103;
+pub const B1000000: ::speed_t = 4104;
+pub const B1152000: ::speed_t = 4105;
+pub const B1500000: ::speed_t = 4106;
+pub const B2000000: ::speed_t = 4107;
+pub const B2500000: ::speed_t = 4108;
+pub const B3000000: ::speed_t = 4109;
+pub const B3500000: ::speed_t = 4110;
+pub const B4000000: ::speed_t = 4111;
+pub const VEOL: usize = 11;
+pub const VEOL2: usize = 16;
+pub const VMIN: usize = 6;
+pub const IEXTEN: ::tcflag_t = 32768;
+pub const TOSTOP: ::tcflag_t = 256;
+pub const FLUSHO: ::tcflag_t = 4096;
+pub const EXTPROC: ::tcflag_t = 65536;
+pub const TCGETS: ::c_ulong = 21505;
+pub const TCSETS: ::c_ulong = 21506;
+pub const TCSETSW: ::c_ulong = 21507;
+pub const TCSETSF: ::c_ulong = 21508;
+pub const TCGETA: ::c_ulong = 21509;
+pub const TCSETA: ::c_ulong = 21510;
+pub const TCSETAW: ::c_ulong = 21511;
+pub const TCSETAF: ::c_ulong = 21512;
+pub const TCSBRK: ::c_ulong = 21513;
+pub const TCXONC: ::c_ulong = 21514;
+pub const TCFLSH: ::c_ulong = 21515;
+pub const TIOCINQ: ::c_ulong = 21531;
+pub const TIOCGPGRP: ::c_ulong = 21519;
+pub const TIOCSPGRP: ::c_ulong = 21520;
+pub const TIOCOUTQ: ::c_ulong = 21521;
+pub const TIOCGWINSZ: ::c_ulong = 21523;
+pub const TIOCSWINSZ: ::c_ulong = 21524;
+pub const FIONREAD: ::c_ulong = 21531;
+pub const __SIZEOF_PTHREAD_MUTEX_T: usize = 40;
+pub const __SIZEOF_PTHREAD_RWLOCK_T: usize = 56;
+pub const SYS_read: ::c_long = 63;
+pub const SYS_write: ::c_long = 64;
+pub const SYS_close: ::c_long = 57;
+pub const SYS_fstat: ::c_long = 80;
+pub const SYS_lseek: ::c_long = 62;
+pub const SYS_mmap: ::c_long = 222;
+pub const SYS_mprotect: ::c_long = 226;
+pub const SYS_munmap: ::c_long = 215;
+pub const SYS_brk: ::c_long = 214;
+pub const SYS_rt_sigaction: ::c_long = 134;
+pub const SYS_rt_sigprocmask: ::c_long = 135;
+pub const SYS_rt_sigreturn: ::c_long = 139;
+pub const SYS_ioctl: ::c_long = 29;
+pub const SYS_pread64: ::c_long = 67;
+pub const SYS_pwrite64: ::c_long = 68;
+pub const SYS_readv: ::c_long = 65;
+pub const SYS_writev: ::c_long = 66;
+pub const SYS_sched_yield: ::c_long = 124;
+pub const SYS_mremap: ::c_long = 216;
+pub const SYS_msync: ::c_long = 227;
+pub const SYS_mincore: ::c_long = 232;
+pub const SYS_madvise: ::c_long = 233;
+pub const SYS_shmget: ::c_long = 194;
+pub const SYS_shmat: ::c_long = 196;
+pub const SYS_shmctl: ::c_long = 195;
+pub const SYS_dup: ::c_long = 23;
+pub const SYS_nanosleep: ::c_long = 101;
+pub const SYS_getitimer: ::c_long = 102;
+pub const SYS_setitimer: ::c_long = 103;
+pub const SYS_getpid: ::c_long = 172;
+pub const SYS_sendfile: ::c_long = 71;
+pub const SYS_socket: ::c_long = 198;
+pub const SYS_connect: ::c_long = 203;
+pub const SYS_accept: ::c_long = 202;
+pub const SYS_sendto: ::c_long = 206;
+pub const SYS_recvfrom: ::c_long = 207;
+pub const SYS_sendmsg: ::c_long = 211;
+pub const SYS_recvmsg: ::c_long = 212;
+pub const SYS_shutdown: ::c_long = 210;
+pub const SYS_bind: ::c_long = 200;
+pub const SYS_listen: ::c_long = 201;
+pub const SYS_getsockname: ::c_long = 204;
+pub const SYS_getpeername: ::c_long = 205;
+pub const SYS_socketpair: ::c_long = 199;
+pub const SYS_setsockopt: ::c_long = 208;
+pub const SYS_getsockopt: ::c_long = 209;
+pub const SYS_clone: ::c_long = 220;
+pub const SYS_execve: ::c_long = 221;
+pub const SYS_exit: ::c_long = 93;
+pub const SYS_wait4: ::c_long = 260;
+pub const SYS_kill: ::c_long = 129;
+pub const SYS_uname: ::c_long = 160;
+pub const SYS_semget: ::c_long = 190;
+pub const SYS_semop: ::c_long = 193;
+pub const SYS_semctl: ::c_long = 191;
+pub const SYS_shmdt: ::c_long = 197;
+pub const SYS_msgget: ::c_long = 186;
+pub const SYS_msgsnd: ::c_long = 189;
+pub const SYS_msgrcv: ::c_long = 188;
+pub const SYS_msgctl: ::c_long = 187;
+pub const SYS_fcntl: ::c_long = 25;
+pub const SYS_flock: ::c_long = 32;
+pub const SYS_fsync: ::c_long = 82;
+pub const SYS_fdatasync: ::c_long = 83;
+pub const SYS_truncate: ::c_long = 45;
+pub const SYS_ftruncate: ::c_long = 46;
+pub const SYS_getcwd: ::c_long = 17;
+pub const SYS_chdir: ::c_long = 49;
+pub const SYS_fchdir: ::c_long = 50;
+pub const SYS_fchmod: ::c_long = 52;
+pub const SYS_fchown: ::c_long = 55;
+pub const SYS_umask: ::c_long = 166;
+pub const SYS_gettimeofday: ::c_long = 169;
+pub const SYS_getrlimit: ::c_long = 163;
+pub const SYS_getrusage: ::c_long = 165;
+pub const SYS_sysinfo: ::c_long = 179;
+pub const SYS_times: ::c_long = 153;
+pub const SYS_ptrace: ::c_long = 117;
+pub const SYS_getuid: ::c_long = 174;
+pub const SYS_syslog: ::c_long = 116;
+pub const SYS_getgid: ::c_long = 176;
+pub const SYS_setuid: ::c_long = 146;
+pub const SYS_setgid: ::c_long = 144;
+pub const SYS_geteuid: ::c_long = 175;
+pub const SYS_getegid: ::c_long = 177;
+pub const SYS_setpgid: ::c_long = 154;
+pub const SYS_getppid: ::c_long = 173;
+pub const SYS_setsid: ::c_long = 157;
+pub const SYS_setreuid: ::c_long = 145;
+pub const SYS_setregid: ::c_long = 143;
+pub const SYS_getgroups: ::c_long = 158;
+pub const SYS_setgroups: ::c_long = 159;
+pub const SYS_setresuid: ::c_long = 147;
+pub const SYS_getresuid: ::c_long = 148;
+pub const SYS_setresgid: ::c_long = 149;
+pub const SYS_getresgid: ::c_long = 150;
+pub const SYS_getpgid: ::c_long = 155;
+pub const SYS_setfsuid: ::c_long = 151;
+pub const SYS_setfsgid: ::c_long = 152;
+pub const SYS_getsid: ::c_long = 156;
+pub const SYS_capget: ::c_long = 90;
+pub const SYS_capset: ::c_long = 91;
+pub const SYS_rt_sigpending: ::c_long = 136;
+pub const SYS_rt_sigtimedwait: ::c_long = 137;
+pub const SYS_rt_sigqueueinfo: ::c_long = 138;
+pub const SYS_rt_sigsuspend: ::c_long = 133;
+pub const SYS_sigaltstack: ::c_long = 132;
+pub const SYS_personality: ::c_long = 92;
+pub const SYS_statfs: ::c_long = 43;
+pub const SYS_fstatfs: ::c_long = 44;
+pub const SYS_getpriority: ::c_long = 141;
+pub const SYS_setpriority: ::c_long = 140;
+pub const SYS_sched_setparam: ::c_long = 118;
+pub const SYS_sched_getparam: ::c_long = 121;
+pub const SYS_sched_setscheduler: ::c_long = 119;
+pub const SYS_sched_getscheduler: ::c_long = 120;
+pub const SYS_sched_get_priority_max: ::c_long = 125;
+pub const SYS_sched_get_priority_min: ::c_long = 126;
+pub const SYS_sched_rr_get_interval: ::c_long = 127;
+pub const SYS_mlock: ::c_long = 228;
+pub const SYS_munlock: ::c_long = 229;
+pub const SYS_mlockall: ::c_long = 230;
+pub const SYS_munlockall: ::c_long = 231;
+pub const SYS_vhangup: ::c_long = 58;
+pub const SYS_pivot_root: ::c_long = 41;
+pub const SYS_prctl: ::c_long = 167;
+pub const SYS_adjtimex: ::c_long = 171;
+pub const SYS_setrlimit: ::c_long = 164;
+pub const SYS_chroot: ::c_long = 51;
+pub const SYS_sync: ::c_long = 81;
+pub const SYS_acct: ::c_long = 89;
+pub const SYS_settimeofday: ::c_long = 170;
+pub const SYS_mount: ::c_long = 40;
+pub const SYS_umount2: ::c_long = 39;
+pub const SYS_swapon: ::c_long = 224;
+pub const SYS_swapoff: ::c_long = 225;
+pub const SYS_reboot: ::c_long = 142;
+pub const SYS_sethostname: ::c_long = 161;
+pub const SYS_setdomainname: ::c_long = 162;
+pub const SYS_init_module: ::c_long = 105;
+pub const SYS_delete_module: ::c_long = 106;
+pub const SYS_quotactl: ::c_long = 60;
+pub const SYS_nfsservctl: ::c_long = 42;
+pub const SYS_gettid: ::c_long = 178;
+pub const SYS_readahead: ::c_long = 213;
+pub const SYS_setxattr: ::c_long = 5;
+pub const SYS_lsetxattr: ::c_long = 6;
+pub const SYS_fsetxattr: ::c_long = 7;
+pub const SYS_getxattr: ::c_long = 8;
+pub const SYS_lgetxattr: ::c_long = 9;
+pub const SYS_fgetxattr: ::c_long = 10;
+pub const SYS_listxattr: ::c_long = 11;
+pub const SYS_llistxattr: ::c_long = 12;
+pub const SYS_flistxattr: ::c_long = 13;
+pub const SYS_removexattr: ::c_long = 14;
+pub const SYS_lremovexattr: ::c_long = 15;
+pub const SYS_fremovexattr: ::c_long = 16;
+pub const SYS_tkill: ::c_long = 130;
+pub const SYS_futex: ::c_long = 98;
+pub const SYS_sched_setaffinity: ::c_long = 122;
+pub const SYS_sched_getaffinity: ::c_long = 123;
+pub const SYS_io_setup: ::c_long = 0;
+pub const SYS_io_destroy: ::c_long = 1;
+pub const SYS_io_getevents: ::c_long = 4;
+pub const SYS_io_submit: ::c_long = 2;
+pub const SYS_io_cancel: ::c_long = 3;
+pub const SYS_lookup_dcookie: ::c_long = 18;
+pub const SYS_remap_file_pages: ::c_long = 234;
+pub const SYS_getdents64: ::c_long = 61;
+pub const SYS_set_tid_address: ::c_long = 96;
+pub const SYS_restart_syscall: ::c_long = 128;
+pub const SYS_semtimedop: ::c_long = 192;
+pub const SYS_fadvise64: ::c_long = 223;
+pub const SYS_timer_create: ::c_long = 107;
+pub const SYS_timer_settime: ::c_long = 110;
+pub const SYS_timer_gettime: ::c_long = 108;
+pub const SYS_timer_getoverrun: ::c_long = 109;
+pub const SYS_timer_delete: ::c_long = 111;
+pub const SYS_clock_settime: ::c_long = 112;
+pub const SYS_clock_gettime: ::c_long = 113;
+pub const SYS_clock_getres: ::c_long = 114;
+pub const SYS_clock_nanosleep: ::c_long = 115;
+pub const SYS_exit_group: ::c_long = 94;
+pub const SYS_epoll_ctl: ::c_long = 21;
+pub const SYS_tgkill: ::c_long = 131;
+pub const SYS_mbind: ::c_long = 235;
+pub const SYS_set_mempolicy: ::c_long = 237;
+pub const SYS_get_mempolicy: ::c_long = 236;
+pub const SYS_mq_open: ::c_long = 180;
+pub const SYS_mq_unlink: ::c_long = 181;
+pub const SYS_mq_timedsend: ::c_long = 182;
+pub const SYS_mq_timedreceive: ::c_long = 183;
+pub const SYS_mq_notify: ::c_long = 184;
+pub const SYS_mq_getsetattr: ::c_long = 185;
+pub const SYS_kexec_load: ::c_long = 104;
+pub const SYS_waitid: ::c_long = 95;
+pub const SYS_add_key: ::c_long = 217;
+pub const SYS_request_key: ::c_long = 218;
+pub const SYS_keyctl: ::c_long = 219;
+pub const SYS_ioprio_set: ::c_long = 30;
+pub const SYS_ioprio_get: ::c_long = 31;
+pub const SYS_inotify_add_watch: ::c_long = 27;
+pub const SYS_inotify_rm_watch: ::c_long = 28;
+pub const SYS_migrate_pages: ::c_long = 238;
+pub const SYS_openat: ::c_long = 56;
+pub const SYS_mkdirat: ::c_long = 34;
+pub const SYS_mknodat: ::c_long = 33;
+pub const SYS_fchownat: ::c_long = 54;
+pub const SYS_newfstatat: ::c_long = 79;
+pub const SYS_unlinkat: ::c_long = 35;
+pub const SYS_linkat: ::c_long = 37;
+pub const SYS_symlinkat: ::c_long = 36;
+pub const SYS_readlinkat: ::c_long = 78;
+pub const SYS_fchmodat: ::c_long = 53;
+pub const SYS_faccessat: ::c_long = 48;
+pub const SYS_pselect6: ::c_long = 72;
+pub const SYS_ppoll: ::c_long = 73;
+pub const SYS_unshare: ::c_long = 97;
+pub const SYS_set_robust_list: ::c_long = 99;
+pub const SYS_get_robust_list: ::c_long = 100;
+pub const SYS_splice: ::c_long = 76;
+pub const SYS_tee: ::c_long = 77;
+pub const SYS_sync_file_range: ::c_long = 84;
+pub const SYS_vmsplice: ::c_long = 75;
+pub const SYS_move_pages: ::c_long = 239;
+pub const SYS_utimensat: ::c_long = 88;
+pub const SYS_epoll_pwait: ::c_long = 22;
+pub const SYS_timerfd_create: ::c_long = 85;
+pub const SYS_fallocate: ::c_long = 47;
+pub const SYS_timerfd_settime: ::c_long = 86;
+pub const SYS_timerfd_gettime: ::c_long = 87;
+pub const SYS_accept4: ::c_long = 242;
+pub const SYS_signalfd4: ::c_long = 74;
+pub const SYS_eventfd2: ::c_long = 19;
+pub const SYS_epoll_create1: ::c_long = 20;
+pub const SYS_dup3: ::c_long = 24;
+pub const SYS_pipe2: ::c_long = 59;
+pub const SYS_inotify_init1: ::c_long = 26;
+pub const SYS_preadv: ::c_long = 69;
+pub const SYS_pwritev: ::c_long = 70;
+pub const SYS_rt_tgsigqueueinfo: ::c_long = 240;
+pub const SYS_perf_event_open: ::c_long = 241;
+pub const SYS_recvmmsg: ::c_long = 243;
+pub const SYS_fanotify_init: ::c_long = 262;
+pub const SYS_fanotify_mark: ::c_long = 263;
+pub const SYS_prlimit64: ::c_long = 261;
+pub const SYS_name_to_handle_at: ::c_long = 264;
+pub const SYS_open_by_handle_at: ::c_long = 265;
+pub const SYS_clock_adjtime: ::c_long = 266;
+pub const SYS_syncfs: ::c_long = 267;
+pub const SYS_sendmmsg: ::c_long = 269;
+pub const SYS_setns: ::c_long = 268;
+pub const SYS_getcpu: ::c_long = 168;
+pub const SYS_process_vm_readv: ::c_long = 270;
+pub const SYS_process_vm_writev: ::c_long = 271;
+pub const SYS_kcmp: ::c_long = 272;
+pub const SYS_finit_module: ::c_long = 273;
+pub const SYS_sched_setattr: ::c_long = 274;
+pub const SYS_sched_getattr: ::c_long = 275;
+pub const SYS_renameat2: ::c_long = 276;
+pub const SYS_seccomp: ::c_long = 277;
+pub const SYS_getrandom: ::c_long = 278;
+pub const SYS_memfd_create: ::c_long = 279;
+pub const SYS_bpf: ::c_long = 280;
+pub const SYS_execveat: ::c_long = 281;
+pub const SYS_userfaultfd: ::c_long = 282;
+pub const SYS_membarrier: ::c_long = 283;
+pub const SYS_mlock2: ::c_long = 284;
+pub const SYS_copy_file_range: ::c_long = 285;
+pub const SYS_preadv2: ::c_long = 286;
+pub const SYS_pwritev2: ::c_long = 287;
+pub const SYS_pkey_mprotect: ::c_long = 288;
+pub const SYS_pkey_alloc: ::c_long = 289;
+pub const SYS_pkey_free: ::c_long = 290;
+pub const SYS_statx: ::c_long = 291;
diff --git a/src/unix/linux_like/linux/gnu/mod.rs b/src/unix/linux_like/linux/gnu/mod.rs
index 6473a041ee6ad..c0cfd1f866d66 100644
--- a/src/unix/linux_like/linux/gnu/mod.rs
+++ b/src/unix/linux_like/linux/gnu/mod.rs
@@ -1031,7 +1031,8 @@ cfg_if! {
                         target_arch = "powerpc64",
                         target_arch = "mips64",
                         target_arch = "s390x",
-                        target_arch = "sparc64"))] {
+                        target_arch = "sparc64",
+                        target_arch = "riscv64"))] {
         mod b64;
         pub use self::b64::*;
     } else {