diff --git a/build.rs b/build.rs
index ea55185d77023..88f4c5149035f 100644
--- a/build.rs
+++ b/build.rs
@@ -7,7 +7,7 @@ use std::str;
 // make sure to add it to this list as well.
 const ALLOWED_CFGS: &'static [&'static str] = &[
     "emscripten_new_stat_abi",
-    "espidf_time64",
+    "espidf_time32",
     "freebsd10",
     "freebsd11",
     "freebsd12",
diff --git a/libc-test/semver/trusty.txt b/libc-test/semver/trusty.txt
new file mode 100644
index 0000000000000..0c79d05701095
--- /dev/null
+++ b/libc-test/semver/trusty.txt
@@ -0,0 +1,49 @@
+AT_PAGESZ
+CLOCK_REALTIME
+MAP_FAILED
+PROT_READ
+PROT_WRITE
+STDERR_FILENO
+STDOUT_FILENO
+calloc
+clockid_t
+clock_gettime
+close
+c_char
+c_int
+c_int16_t
+c_int32_t
+c_int64_t
+c_int8_t
+c_long
+c_longlong
+c_schar
+c_short
+c_uchar
+c_uint
+c_uint16_t
+c_uint32_t
+c_uint64_t
+c_uint8_t
+c_ulong
+c_ulonglong
+c_ushort
+c_void
+free
+getauxval
+iovec
+malloc
+memalign
+mmap
+munmap
+nanosleep
+off_t
+posix_memalign
+realloc
+size_t
+ssize_t
+strlen
+timespec
+time_t
+write
+writev
diff --git a/src/lib.rs b/src/lib.rs
index 764d8e4cd096a..893b46ff3ab28 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -145,6 +145,12 @@ cfg_if! {
 
         mod teeos;
         pub use teeos::*;
+    } else if #[cfg(target_os = "trusty")] {
+        mod fixed_width_ints;
+        pub use fixed_width_ints::*;
+
+        mod trusty;
+        pub use trusty::*;
     } else if #[cfg(all(target_env = "sgx", target_vendor = "fortanix"))] {
         mod fixed_width_ints;
         pub use fixed_width_ints::*;
diff --git a/src/trusty.rs b/src/trusty.rs
new file mode 100644
index 0000000000000..68b13f70b5b3f
--- /dev/null
+++ b/src/trusty.rs
@@ -0,0 +1,101 @@
+pub use core::ffi::c_void;
+
+pub type size_t = usize;
+pub type ssize_t = isize;
+
+pub type off_t = i64;
+
+cfg_if! {
+    if #[cfg(any(target_arch = "aarch64", target_arch = "arm"))] {
+        pub type c_char = u8;
+    } else if #[cfg(target_arch = "x86_64")] {
+        pub type c_char = i8;
+    }
+}
+
+pub type c_schar = i8;
+pub type c_uchar = u8;
+pub type c_short = i16;
+pub type c_ushort = u16;
+pub type c_int = i32;
+pub type c_uint = u32;
+
+cfg_if! {
+    if #[cfg(target_pointer_width = "32")] {
+        pub type c_long = i32;
+        pub type c_ulong = u32;
+    } else if #[cfg(target_pointer_width = "64")] {
+        pub type c_long = i64;
+        pub type c_ulong = u64;
+    }
+}
+
+pub type c_longlong = i64;
+pub type c_ulonglong = u64;
+
+pub type c_uint8_t = u8;
+pub type c_uint16_t = u16;
+pub type c_uint32_t = u32;
+pub type c_uint64_t = u64;
+
+pub type c_int8_t = i8;
+pub type c_int16_t = i16;
+pub type c_int32_t = i32;
+pub type c_int64_t = i64;
+
+pub type c_float = f32;
+pub type c_double = f64;
+
+pub type time_t = c_long;
+
+pub type clockid_t = c_int;
+
+s! {
+    pub struct iovec {
+        pub iov_base: *mut ::c_void,
+        pub iov_len: ::size_t,
+    }
+
+    pub struct timespec {
+        pub tv_sec: time_t,
+        pub tv_nsec: c_long,
+    }
+}
+
+pub const PROT_READ: i32 = 1;
+pub const PROT_WRITE: i32 = 2;
+
+// Trusty only supports `CLOCK_BOOTTIME`.
+pub const CLOCK_BOOTTIME: clockid_t = 7;
+
+pub const STDOUT_FILENO: ::c_int = 1;
+pub const STDERR_FILENO: ::c_int = 2;
+
+pub const AT_PAGESZ: ::c_ulong = 6;
+
+pub const MAP_FAILED: *mut ::c_void = !0 as *mut ::c_void;
+
+extern "C" {
+    pub fn calloc(nobj: size_t, size: size_t) -> *mut c_void;
+    pub fn malloc(size: size_t) -> *mut c_void;
+    pub fn realloc(p: *mut c_void, size: size_t) -> *mut c_void;
+    pub fn free(p: *mut c_void);
+    pub fn memalign(align: ::size_t, size: ::size_t) -> *mut ::c_void;
+    pub fn posix_memalign(memptr: *mut *mut ::c_void, align: ::size_t, size: ::size_t) -> ::c_int;
+    pub fn write(fd: ::c_int, buf: *const ::c_void, count: ::size_t) -> ::ssize_t;
+    pub fn writev(fd: ::c_int, iov: *const ::iovec, iovcnt: ::c_int) -> ::ssize_t;
+    pub fn close(fd: ::c_int) -> ::c_int;
+    pub fn strlen(cs: *const c_char) -> size_t;
+    pub fn getauxval(type_: c_ulong) -> c_ulong;
+    pub fn mmap(
+        addr: *mut ::c_void,
+        len: ::size_t,
+        prot: ::c_int,
+        flags: ::c_int,
+        fd: ::c_int,
+        offset: off_t,
+    ) -> *mut ::c_void;
+    pub fn munmap(addr: *mut ::c_void, len: ::size_t) -> ::c_int;
+    pub fn clock_gettime(clk_id: ::clockid_t, tp: *mut ::timespec) -> ::c_int;
+    pub fn nanosleep(rqtp: *const ::timespec, rmtp: *mut ::timespec) -> ::c_int;
+}
diff --git a/src/unix/haiku/mod.rs b/src/unix/haiku/mod.rs
index 3a226e6696405..31f9f69d5b168 100644
--- a/src/unix/haiku/mod.rs
+++ b/src/unix/haiku/mod.rs
@@ -2093,6 +2093,8 @@ extern "C" {
         length: ::size_t,
         locale: ::locale_t,
     ) -> ::c_int;
+
+    pub fn getentropy(buf: *mut ::c_void, buflen: ::size_t) -> ::c_int;
 }
 
 #[link(name = "bsd")]
diff --git a/src/unix/mod.rs b/src/unix/mod.rs
index 04baabae8bfbf..12e20a46ff1c4 100644
--- a/src/unix/mod.rs
+++ b/src/unix/mod.rs
@@ -382,8 +382,8 @@ cfg_if! {
                    link(name = "c", cfg(not(target_feature = "crt-static"))))]
         extern {}
     } else if #[cfg(target_os = "emscripten")] {
-        #[link(name = "c")]
-        extern {}
+        // Don't pass -lc to Emscripten, it breaks. See:
+        // https://github.com/emscripten-core/emscripten/issues/22758
     } else if #[cfg(all(target_os = "android", feature = "rustc-dep-of-std"))] {
         #[link(name = "c", kind = "static", modifiers = "-bundle",
             cfg(target_feature = "crt-static"))]
diff --git a/src/unix/newlib/mod.rs b/src/unix/newlib/mod.rs
index 78e18d8ceac72..9aee0e4ea0c3f 100644
--- a/src/unix/newlib/mod.rs
+++ b/src/unix/newlib/mod.rs
@@ -52,7 +52,7 @@ cfg_if! {
 pub type useconds_t = u32;
 
 cfg_if! {
-    if #[cfg(any(target_os = "horizon", all(target_os = "espidf", espidf_time64)))] {
+    if #[cfg(any(target_os = "horizon", all(target_os = "espidf", not(espidf_time32))))] {
         pub type time_t = ::c_longlong;
     } else {
         pub type time_t = i32;
diff --git a/src/unix/nuttx/mod.rs b/src/unix/nuttx/mod.rs
index e3a3c15b338cc..e9f6c651f1e86 100644
--- a/src/unix/nuttx/mod.rs
+++ b/src/unix/nuttx/mod.rs
@@ -551,5 +551,7 @@ extern "C" {
     pub fn futimens(fd: i32, times: *const timespec) -> i32;
     pub fn pthread_condattr_setclock(attr: *mut pthread_condattr_t, clock_id: clockid_t) -> i32;
     pub fn pthread_set_name_np(thread: pthread_t, name: *const c_char) -> i32;
+    pub fn pthread_setname_np(thread: pthread_t, name: *const c_char) -> i32;
+    pub fn pthread_getname_np(thread: pthread_t, name: *mut c_char, len: usize) -> i32;
     pub fn getrandom(buf: *mut c_void, buflen: usize, flags: u32) -> isize;
 }