Auto merge of #18364 - lnicola:sync-from-rust, r=lnicola

minor: sync from downstream

35 files changed, 838 insertions, 194 deletions

diff --git a/library/std/src/fs.rs b/library/std/src/fs.rs
index 675140ff18f..8a0d2a7f5cf 100644
--- a/library/std/src/fs.rs
+++ b/library/std/src/fs.rs
@@ -2618,7 +2618,7 @@ pub fn remove_dir_all<P: AsRef<Path>>(path: P) -> io::Result<()> {
 /// # Platform-specific behavior
 ///
 /// This function currently corresponds to the `opendir` function on Unix
-/// and the `FindFirstFile` function on Windows. Advancing the iterator
+/// and the `FindFirstFileEx` function on Windows. Advancing the iterator
 /// currently corresponds to `readdir` on Unix and `FindNextFile` on Windows.
 /// Note that, this [may change in the future][changes].
 ///
diff --git a/library/std/src/keyword_docs.rs b/library/std/src/keyword_docs.rs
index 453b2708daa..30d43c8bbfd 100644
--- a/library/std/src/keyword_docs.rs
+++ b/library/std/src/keyword_docs.rs
@@ -2146,10 +2146,13 @@ mod unsafe_keyword {}
 
 #[doc(keyword = "use")]
 //
-/// Import or rename items from other crates or modules.
+/// Import or rename items from other crates or modules, or specify precise capturing
+/// with `use<..>`.
 ///
-/// Usually a `use` keyword is used to shorten the path required to refer to a module item.
-/// The keyword may appear in modules, blocks and even functions, usually at the top.
+/// ## Importing items
+///
+/// The `use` keyword is employed to shorten the path required to refer to a module item.
+/// The keyword may appear in modules, blocks, and even functions, typically at the top.
 ///
 /// The most basic usage of the keyword is `use path::to::item;`,
 /// though a number of convenient shortcuts are supported:
@@ -2190,19 +2193,48 @@ mod unsafe_keyword {}
 /// // Compiles.
 /// let _ = VariantA;
 ///
-/// // Does not compile !
+/// // Does not compile!
 /// let n = new();
 /// ```
 ///
-/// For more information on `use` and paths in general, see the [Reference].
+/// For more information on `use` and paths in general, see the [Reference][ref-use-decls].
 ///
 /// The differences about paths and the `use` keyword between the 2015 and 2018 editions
-/// can also be found in the [Reference].
+/// can also be found in the [Reference][ref-use-decls].
+///
+/// ## Precise capturing
+///
+/// The `use<..>` syntax is used within certain `impl Trait` bounds to control which generic
+/// parameters are captured. This is important for return-position `impl Trait` (RPIT) types,
+/// as it affects borrow checking by controlling which generic parameters can be used in the
+/// hidden type.
+///
+/// For example, the following function demonstrates an error without precise capturing in
+/// Rust 2021 and earlier editions:
+///
+/// ```rust,compile_fail,edition2021
+/// fn f(x: &()) -> impl Sized { x }
+/// ```
+///
+/// By using `use<'_>` for precise capturing, it can be resolved:
+///
+/// ```rust
+/// fn f(x: &()) -> impl Sized + use<'_> { x }
+/// ```
+///
+/// This syntax specifies that the elided lifetime be captured and therefore available for
+/// use in the hidden type.
+///
+/// In Rust 2024, opaque types automatically capture all lifetime parameters in scope.
+/// `use<..>` syntax serves as an important way of opting-out of that default.
+///
+/// For more details about precise capturing, see the [Reference][ref-impl-trait].
 ///
 /// [`crate`]: keyword.crate.html
 /// [`self`]: keyword.self.html
 /// [`super`]: keyword.super.html
-/// [Reference]: ../reference/items/use-declarations.html
+/// [ref-use-decls]: ../reference/items/use-declarations.html
+/// [ref-impl-trait]: ../reference/types/impl-trait.html
 mod use_keyword {}
 
 #[doc(keyword = "where")]
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 3ab65238368..8c1a3c76829 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -279,6 +279,8 @@
 //
 // Language features:
 // tidy-alphabetical-start
+#![cfg_attr(bootstrap, feature(strict_provenance))]
+#![cfg_attr(not(bootstrap), feature(strict_provenance_lints))]
 #![feature(alloc_error_handler)]
 #![feature(allocator_internals)]
 #![feature(allow_internal_unsafe)]
@@ -336,7 +338,6 @@
 #![feature(error_iter)]
 #![feature(exact_size_is_empty)]
 #![feature(exclusive_wrapper)]
-#![feature(exposed_provenance)]
 #![feature(extend_one)]
 #![feature(float_gamma)]
 #![feature(float_minimum_maximum)]
@@ -362,7 +363,6 @@
 #![feature(slice_range)]
 #![feature(std_internals)]
 #![feature(str_internals)]
-#![feature(strict_provenance)]
 #![feature(strict_provenance_atomic_ptr)]
 #![feature(ub_checks)]
 // tidy-alphabetical-end
diff --git a/library/std/src/os/unix/process.rs b/library/std/src/os/unix/process.rs
index 9aadd949116..ef5adaf2290 100644
--- a/library/std/src/os/unix/process.rs
+++ b/library/std/src/os/unix/process.rs
@@ -154,6 +154,7 @@ pub trait CommandExt: Sealed {
     /// required to gracefully handle errors it is recommended to use the
     /// cross-platform `spawn` instead.
     #[stable(feature = "process_exec2", since = "1.9.0")]
+    #[must_use]
     fn exec(&mut self) -> io::Error;
 
     /// Set executable argument
diff --git a/library/std/src/os/xous/ffi.rs b/library/std/src/os/xous/ffi.rs
index 1a4a940bf35..1db314e9dda 100644
--- a/library/std/src/os/xous/ffi.rs
+++ b/library/std/src/os/xous/ffi.rs
@@ -615,7 +615,7 @@ pub(crate) fn thread_id() -> Result<ThreadId, Error> {
 /// An error is generated if the `knob` is not a valid limit, or if the call
 /// would not succeed.
 pub(crate) fn adjust_limit(knob: Limits, current: usize, new: usize) -> Result<usize, Error> {
-    let mut a0 = Syscall::JoinThread as usize;
+    let mut a0 = Syscall::AdjustProcessLimit as usize;
     let mut a1 = knob as usize;
     let a2 = current;
     let a3 = new;
diff --git a/library/std/src/random.rs b/library/std/src/random.rs
index 604fa4df110..cdb88c795bf 100644
--- a/library/std/src/random.rs
+++ b/library/std/src/random.rs
@@ -40,6 +40,7 @@ use crate::sys::random as sys;
 /// Horizon                | `getrandom` shim
 /// Hurd, L4Re, QNX        | `/dev/urandom`
 /// Redox                  | `/scheme/rand`
+/// RTEMS                  | [`arc4random_buf`](https://docs.rtems.org/branches/master/bsp-howto/getentropy.html)
 /// SGX                    | [`rdrand`](https://en.wikipedia.org/wiki/RDRAND)
 /// SOLID                  | `SOLID_RNG_SampleRandomBytes`
 /// TEEOS                  | `TEE_GenerateRandom`
diff --git a/library/std/src/sys/alloc/xous.rs b/library/std/src/sys/alloc/xous.rs
index 9ea43445d02..321d30e0b11 100644
--- a/library/std/src/sys/alloc/xous.rs
+++ b/library/std/src/sys/alloc/xous.rs
@@ -1,3 +1,6 @@
+// FIXME(static_mut_refs): Do not allow `static_mut_refs` lint
+#![allow(static_mut_refs)]
+
 use crate::alloc::{GlobalAlloc, Layout, System};
 
 #[cfg(not(test))]
diff --git a/library/std/src/sys/pal/hermit/futex.rs b/library/std/src/sys/pal/hermit/futex.rs
index 21c5facd52f..670383b45ac 100644
--- a/library/std/src/sys/pal/hermit/futex.rs
+++ b/library/std/src/sys/pal/hermit/futex.rs
@@ -3,9 +3,14 @@ use crate::ptr::null;
 use crate::sync::atomic::AtomicU32;
 use crate::time::Duration;
 
+/// An atomic for use as a futex that is at least 32-bits but may be larger
+pub type Futex = AtomicU32;
+/// Must be the underlying type of Futex
+pub type Primitive = u32;
+
 /// An atomic for use as a futex that is at least 8-bits but may be larger.
-pub type SmallAtomic = AtomicU32;
-/// Must be the underlying type of SmallAtomic
+pub type SmallFutex = AtomicU32;
+/// Must be the underlying type of SmallFutex
 pub type SmallPrimitive = u32;
 
 pub fn futex_wait(futex: &AtomicU32, expected: u32, timeout: Option<Duration>) -> bool {
diff --git a/library/std/src/sys/pal/uefi/helpers.rs b/library/std/src/sys/pal/uefi/helpers.rs
index 4ced7065c82..abc8e69a285 100644
--- a/library/std/src/sys/pal/uefi/helpers.rs
+++ b/library/std/src/sys/pal/uefi/helpers.rs
@@ -10,7 +10,7 @@
 //! - More information about protocols can be found [here](https://edk2-docs.gitbook.io/edk-ii-uefi-driver-writer-s-guide/3_foundation/36_protocols_and_handles)
 
 use r_efi::efi::{self, Guid};
-use r_efi::protocols::{device_path, device_path_to_text};
+use r_efi::protocols::{device_path, device_path_to_text, shell};
 
 use crate::ffi::{OsStr, OsString};
 use crate::io::{self, const_io_error};
@@ -424,3 +424,24 @@ pub(crate) fn os_string_to_raw(s: &OsStr) -> Option<Box<[r_efi::efi::Char16]>> {
     let temp = s.encode_wide().chain(Some(0)).collect::<Box<[r_efi::efi::Char16]>>();
     if temp[..temp.len() - 1].contains(&0) { None } else { Some(temp) }
 }
+
+pub(crate) fn open_shell() -> Option<NonNull<shell::Protocol>> {
+    static LAST_VALID_HANDLE: AtomicPtr<crate::ffi::c_void> =
+        AtomicPtr::new(crate::ptr::null_mut());
+
+    if let Some(handle) = NonNull::new(LAST_VALID_HANDLE.load(Ordering::Acquire)) {
+        if let Ok(protocol) = open_protocol::<shell::Protocol>(handle, shell::PROTOCOL_GUID) {
+            return Some(protocol);
+        }
+    }
+
+    let handles = locate_handles(shell::PROTOCOL_GUID).ok()?;
+    for handle in handles {
+        if let Ok(protocol) = open_protocol::<shell::Protocol>(handle, shell::PROTOCOL_GUID) {
+            LAST_VALID_HANDLE.store(handle.as_ptr(), Ordering::Release);
+            return Some(protocol);
+        }
+    }
+
+    None
+}
diff --git a/library/std/src/sys/pal/uefi/os.rs b/library/std/src/sys/pal/uefi/os.rs
index 4eb7698b43a..27395f7c3c0 100644
--- a/library/std/src/sys/pal/uefi/os.rs
+++ b/library/std/src/sys/pal/uefi/os.rs
@@ -125,7 +125,7 @@ pub fn error_string(errno: RawOsError) -> String {
 }
 
 pub fn getcwd() -> io::Result<PathBuf> {
-    match uefi_shell::open_shell() {
+    match helpers::open_shell() {
         Some(shell) => {
             // SAFETY: path_ptr is managed by UEFI shell and should not be deallocated
             let path_ptr = unsafe { ((*shell.as_ptr()).get_cur_dir)(crate::ptr::null_mut()) };
@@ -144,7 +144,7 @@ pub fn getcwd() -> io::Result<PathBuf> {
 }
 
 pub fn chdir(p: &path::Path) -> io::Result<()> {
-    let shell = uefi_shell::open_shell().ok_or(unsupported_err())?;
+    let shell = helpers::open_shell().ok_or(unsupported_err())?;
 
     let mut p = helpers::os_string_to_raw(p.as_os_str())
         .ok_or(io::const_io_error!(io::ErrorKind::InvalidData, "Invalid path"))?;
@@ -192,44 +192,58 @@ pub fn current_exe() -> io::Result<PathBuf> {
     helpers::device_path_to_text(protocol).map(PathBuf::from)
 }
 
-pub struct Env(!);
+pub struct EnvStrDebug<'a> {
+    iter: &'a [(OsString, OsString)],
+}
+
+impl fmt::Debug for EnvStrDebug<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut list = f.debug_list();
+        for (a, b) in self.iter {
+            list.entry(&(a.to_str().unwrap(), b.to_str().unwrap()));
+        }
+        list.finish()
+    }
+}
+
+pub struct Env(crate::vec::IntoIter<(OsString, OsString)>);
 
 impl Env {
     // FIXME(https://github.com/rust-lang/rust/issues/114583): Remove this when <OsStr as Debug>::fmt matches <str as Debug>::fmt.
     pub fn str_debug(&self) -> impl fmt::Debug + '_ {
-        let Self(inner) = self;
-        match *inner {}
+        EnvStrDebug { iter: self.0.as_slice() }
     }
 }
 
 impl Iterator for Env {
     type Item = (OsString, OsString);
+
     fn next(&mut self) -> Option<(OsString, OsString)> {
-        self.0
+        self.0.next()
     }
 }
 
 impl fmt::Debug for Env {
-    fn fmt(&self, _: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let Self(inner) = self;
-        match *inner {}
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.0.fmt(f)
     }
 }
 
 pub fn env() -> Env {
-    panic!("not supported on this platform")
+    let env = uefi_env::get_all().expect("not supported on this platform");
+    Env(env.into_iter())
 }
 
-pub fn getenv(_: &OsStr) -> Option<OsString> {
-    None
+pub fn getenv(key: &OsStr) -> Option<OsString> {
+    uefi_env::get(key)
 }
 
-pub unsafe fn setenv(_: &OsStr, _: &OsStr) -> io::Result<()> {
-    Err(io::const_io_error!(io::ErrorKind::Unsupported, "cannot set env vars on this platform"))
+pub unsafe fn setenv(key: &OsStr, val: &OsStr) -> io::Result<()> {
+    uefi_env::set(key, val)
 }
 
-pub unsafe fn unsetenv(_: &OsStr) -> io::Result<()> {
-    Err(io::const_io_error!(io::ErrorKind::Unsupported, "cannot unset env vars on this platform"))
+pub unsafe fn unsetenv(key: &OsStr) -> io::Result<()> {
+    uefi_env::unset(key)
 }
 
 pub fn temp_dir() -> PathBuf {
@@ -261,36 +275,84 @@ pub fn getpid() -> u32 {
     panic!("no pids on this platform")
 }
 
-mod uefi_shell {
-    use r_efi::protocols::shell;
-
-    use super::super::helpers;
+mod uefi_env {
+    use crate::ffi::{OsStr, OsString};
+    use crate::io;
+    use crate::os::uefi::ffi::OsStringExt;
     use crate::ptr::NonNull;
-    use crate::sync::atomic::{AtomicPtr, Ordering};
-
-    pub fn open_shell() -> Option<NonNull<shell::Protocol>> {
-        static LAST_VALID_HANDLE: AtomicPtr<crate::ffi::c_void> =
-            AtomicPtr::new(crate::ptr::null_mut());
-
-        if let Some(handle) = NonNull::new(LAST_VALID_HANDLE.load(Ordering::Acquire)) {
-            if let Ok(protocol) = helpers::open_protocol::<shell::Protocol>(
-                handle,
-                r_efi::protocols::shell::PROTOCOL_GUID,
-            ) {
-                return Some(protocol);
-            }
+    use crate::sys::{helpers, unsupported_err};
+
+    pub(crate) fn get(key: &OsStr) -> Option<OsString> {
+        let shell = helpers::open_shell()?;
+        let mut key_ptr = helpers::os_string_to_raw(key)?;
+        unsafe { get_raw(shell, key_ptr.as_mut_ptr()) }
+    }
+
+    pub(crate) fn set(key: &OsStr, val: &OsStr) -> io::Result<()> {
+        let mut key_ptr = helpers::os_string_to_raw(key)
+            .ok_or(io::const_io_error!(io::ErrorKind::InvalidInput, "Invalid Key"))?;
+        let mut val_ptr = helpers::os_string_to_raw(val)
+            .ok_or(io::const_io_error!(io::ErrorKind::InvalidInput, "Invalid Value"))?;
+        unsafe { set_raw(key_ptr.as_mut_ptr(), val_ptr.as_mut_ptr()) }
+    }
+
+    pub(crate) fn unset(key: &OsStr) -> io::Result<()> {
+        let mut key_ptr = helpers::os_string_to_raw(key)
+            .ok_or(io::const_io_error!(io::ErrorKind::InvalidInput, "Invalid Key"))?;
+        unsafe { set_raw(key_ptr.as_mut_ptr(), crate::ptr::null_mut()) }
+    }
+
+    pub(crate) fn get_all() -> io::Result<Vec<(OsString, OsString)>> {
+        let shell = helpers::open_shell().ok_or(unsupported_err())?;
+
+        let mut vars = Vec::new();
+        let val = unsafe { ((*shell.as_ptr()).get_env)(crate::ptr::null_mut()) };
+
+        if val.is_null() {
+            return Ok(vars);
         }
 
-        let handles = helpers::locate_handles(shell::PROTOCOL_GUID).ok()?;
-        for handle in handles {
-            if let Ok(protocol) =
-                helpers::open_protocol::<shell::Protocol>(handle, shell::PROTOCOL_GUID)
-            {
-                LAST_VALID_HANDLE.store(handle.as_ptr(), Ordering::Release);
-                return Some(protocol);
+        let mut start = 0;
+
+        // UEFI Shell returns all keys seperated by NULL.
+        // End of string is denoted by two NULLs
+        for i in 0.. {
+            if unsafe { *val.add(i) } == 0 {
+                // Two NULL signal end of string
+                if i == start {
+                    break;
+                }
+
+                let key = OsString::from_wide(unsafe {
+                    crate::slice::from_raw_parts(val.add(start), i - start)
+                });
+                // SAFETY: val.add(start) is always NULL terminated
+                let val = unsafe { get_raw(shell, val.add(start)) }
+                    .ok_or(io::const_io_error!(io::ErrorKind::InvalidInput, "Invalid Value"))?;
+
+                vars.push((key, val));
+                start = i + 1;
             }
         }
 
-        None
+        Ok(vars)
+    }
+
+    unsafe fn get_raw(
+        shell: NonNull<r_efi::efi::protocols::shell::Protocol>,
+        key_ptr: *mut r_efi::efi::Char16,
+    ) -> Option<OsString> {
+        let val = unsafe { ((*shell.as_ptr()).get_env)(key_ptr) };
+        helpers::os_string_from_raw(val)
+    }
+
+    unsafe fn set_raw(
+        key_ptr: *mut r_efi::efi::Char16,
+        val_ptr: *mut r_efi::efi::Char16,
+    ) -> io::Result<()> {
+        let shell = helpers::open_shell().ok_or(unsupported_err())?;
+        let r =
+            unsafe { ((*shell.as_ptr()).set_env)(key_ptr, val_ptr, r_efi::efi::Boolean::FALSE) };
+        if r.is_error() { Err(io::Error::from_raw_os_error(r.as_usize())) } else { Ok(()) }
     }
 }
diff --git a/library/std/src/sys/pal/unix/fs.rs b/library/std/src/sys/pal/unix/fs.rs
index 567577b2b4d..f1f843a5f7a 100644
--- a/library/std/src/sys/pal/unix/fs.rs
+++ b/library/std/src/sys/pal/unix/fs.rs
@@ -189,7 +189,7 @@ cfg_has_statx! {{
             // See: https://github.com/rust-lang/rust/issues/65662
             //
             // FIXME what about transient conditions like `ENOMEM`?
-            let err2 = cvt(statx(0, ptr::null(), 0, libc::STATX_ALL, ptr::null_mut()))
+            let err2 = cvt(statx(0, ptr::null(), 0, libc::STATX_BASIC_STATS | libc::STATX_BTIME, ptr::null_mut()))
                 .err()
                 .and_then(|e| e.raw_os_error());
             if err2 == Some(libc::EFAULT) {
@@ -910,7 +910,7 @@ impl DirEntry {
                 fd,
                 name,
                 libc::AT_SYMLINK_NOFOLLOW | libc::AT_STATX_SYNC_AS_STAT,
-                libc::STATX_ALL,
+                libc::STATX_BASIC_STATS | libc::STATX_BTIME,
             ) } {
                 return ret;
             }
@@ -1194,7 +1194,7 @@ impl File {
                 fd,
                 c"".as_ptr() as *const c_char,
                 libc::AT_EMPTY_PATH | libc::AT_STATX_SYNC_AS_STAT,
-                libc::STATX_ALL,
+                libc::STATX_BASIC_STATS | libc::STATX_BTIME,
             ) } {
                 return ret;
             }
@@ -1767,7 +1767,7 @@ pub fn stat(p: &Path) -> io::Result<FileAttr> {
                 libc::AT_FDCWD,
                 p.as_ptr(),
                 libc::AT_STATX_SYNC_AS_STAT,
-                libc::STATX_ALL,
+                libc::STATX_BASIC_STATS | libc::STATX_BTIME,
             ) } {
                 return ret;
             }
@@ -1786,7 +1786,7 @@ pub fn lstat(p: &Path) -> io::Result<FileAttr> {
                 libc::AT_FDCWD,
                 p.as_ptr(),
                 libc::AT_SYMLINK_NOFOLLOW | libc::AT_STATX_SYNC_AS_STAT,
-                libc::STATX_ALL,
+                libc::STATX_BASIC_STATS | libc::STATX_BTIME,
             ) } {
                 return ret;
             }
diff --git a/library/std/src/sys/pal/unix/futex.rs b/library/std/src/sys/pal/unix/futex.rs
index cc725045c48..0fc765dc87a 100644
--- a/library/std/src/sys/pal/unix/futex.rs
+++ b/library/std/src/sys/pal/unix/futex.rs
@@ -11,9 +11,14 @@
 use crate::sync::atomic::AtomicU32;
 use crate::time::Duration;
 
+/// An atomic for use as a futex that is at least 32-bits but may be larger
+pub type Futex = AtomicU32;
+/// Must be the underlying type of Futex
+pub type Primitive = u32;
+
 /// An atomic for use as a futex that is at least 8-bits but may be larger.
-pub type SmallAtomic = AtomicU32;
-/// Must be the underlying type of SmallAtomic
+pub type SmallFutex = AtomicU32;
+/// Must be the underlying type of SmallFutex
 pub type SmallPrimitive = u32;
 
 /// Waits for a `futex_wake` operation to wake us.
diff --git a/library/std/src/sys/pal/unix/stack_overflow.rs b/library/std/src/sys/pal/unix/stack_overflow.rs
index ac0858e1de8..69b31da427f 100644
--- a/library/std/src/sys/pal/unix/stack_overflow.rs
+++ b/library/std/src/sys/pal/unix/stack_overflow.rs
@@ -265,9 +265,7 @@ mod imp {
     /// Modern kernels on modern hardware can have dynamic signal stack sizes.
     #[cfg(any(target_os = "linux", target_os = "android"))]
     fn sigstack_size() -> usize {
-        // FIXME: reuse const from libc when available?
-        const AT_MINSIGSTKSZ: crate::ffi::c_ulong = 51;
-        let dynamic_sigstksz = unsafe { libc::getauxval(AT_MINSIGSTKSZ) };
+        let dynamic_sigstksz = unsafe { libc::getauxval(libc::AT_MINSIGSTKSZ) };
         // If getauxval couldn't find the entry, it returns 0,
         // so take the higher of the "constant" and auxval.
         // This transparently supports older kernels which don't provide AT_MINSIGSTKSZ
diff --git a/library/std/src/sys/pal/wasm/atomics/futex.rs b/library/std/src/sys/pal/wasm/atomics/futex.rs
index 42913a99ee9..bdad0da73f0 100644
--- a/library/std/src/sys/pal/wasm/atomics/futex.rs
+++ b/library/std/src/sys/pal/wasm/atomics/futex.rs
@@ -6,9 +6,14 @@ use core::arch::wasm64 as wasm;
 use crate::sync::atomic::AtomicU32;
 use crate::time::Duration;
 
+/// An atomic for use as a futex that is at least 32-bits but may be larger
+pub type Futex = AtomicU32;
+/// Must be the underlying type of Futex
+pub type Primitive = u32;
+
 /// An atomic for use as a futex that is at least 8-bits but may be larger.
-pub type SmallAtomic = AtomicU32;
-/// Must be the underlying type of SmallAtomic
+pub type SmallFutex = AtomicU32;
+/// Must be the underlying type of SmallFutex
 pub type SmallPrimitive = u32;
 
 /// Wait for a futex_wake operation to wake us.
diff --git a/library/std/src/sys/pal/windows/c/bindings.txt b/library/std/src/sys/pal/windows/c/bindings.txt
index 9c2e4500da0..192c95fd203 100644
--- a/library/std/src/sys/pal/windows/c/bindings.txt
+++ b/library/std/src/sys/pal/windows/c/bindings.txt
@@ -2337,7 +2337,9 @@ Windows.Win32.Storage.FileSystem.FileStandardInfo
 Windows.Win32.Storage.FileSystem.FileStorageInfo
 Windows.Win32.Storage.FileSystem.FileStreamInfo
 Windows.Win32.Storage.FileSystem.FindClose
-Windows.Win32.Storage.FileSystem.FindFirstFileW
+Windows.Win32.Storage.FileSystem.FindExInfoBasic
+Windows.Win32.Storage.FileSystem.FindExSearchNameMatch
+Windows.Win32.Storage.FileSystem.FindFirstFileExW
 Windows.Win32.Storage.FileSystem.FindNextFileW
 Windows.Win32.Storage.FileSystem.FlushFileBuffers
 Windows.Win32.Storage.FileSystem.GetFileAttributesW
diff --git a/library/std/src/sys/pal/windows/c/windows_sys.rs b/library/std/src/sys/pal/windows/c/windows_sys.rs
index ab5f8919d7a..52444c2c009 100644
--- a/library/std/src/sys/pal/windows/c/windows_sys.rs
+++ b/library/std/src/sys/pal/windows/c/windows_sys.rs
@@ -26,7 +26,7 @@ windows_targets::link!("kernel32.dll" "system" fn DeviceIoControl(hdevice : HAND
 windows_targets::link!("kernel32.dll" "system" fn DuplicateHandle(hsourceprocesshandle : HANDLE, hsourcehandle : HANDLE, htargetprocesshandle : HANDLE, lptargethandle : *mut HANDLE, dwdesiredaccess : u32, binherithandle : BOOL, dwoptions : DUPLICATE_HANDLE_OPTIONS) -> BOOL);
 windows_targets::link!("kernel32.dll" "system" fn ExitProcess(uexitcode : u32) -> !);
 windows_targets::link!("kernel32.dll" "system" fn FindClose(hfindfile : HANDLE) -> BOOL);
-windows_targets::link!("kernel32.dll" "system" fn FindFirstFileW(lpfilename : PCWSTR, lpfindfiledata : *mut WIN32_FIND_DATAW) -> HANDLE);
+windows_targets::link!("kernel32.dll" "system" fn FindFirstFileExW(lpfilename : PCWSTR, finfolevelid : FINDEX_INFO_LEVELS, lpfindfiledata : *mut core::ffi::c_void, fsearchop : FINDEX_SEARCH_OPS, lpsearchfilter : *const core::ffi::c_void, dwadditionalflags : FIND_FIRST_EX_FLAGS) -> HANDLE);
 windows_targets::link!("kernel32.dll" "system" fn FindNextFileW(hfindfile : HANDLE, lpfindfiledata : *mut WIN32_FIND_DATAW) -> BOOL);
 windows_targets::link!("kernel32.dll" "system" fn FlushFileBuffers(hfile : HANDLE) -> BOOL);
 windows_targets::link!("kernel32.dll" "system" fn FormatMessageW(dwflags : FORMAT_MESSAGE_OPTIONS, lpsource : *const core::ffi::c_void, dwmessageid : u32, dwlanguageid : u32, lpbuffer : PWSTR, nsize : u32, arguments : *const *const i8) -> u32);
@@ -2501,6 +2501,9 @@ pub const FILE_WRITE_ATTRIBUTES: FILE_ACCESS_RIGHTS = 256u32;
 pub const FILE_WRITE_DATA: FILE_ACCESS_RIGHTS = 2u32;
 pub const FILE_WRITE_EA: FILE_ACCESS_RIGHTS = 16u32;
 pub const FILE_WRITE_THROUGH: NTCREATEFILE_CREATE_OPTIONS = 2u32;
+pub type FINDEX_INFO_LEVELS = i32;
+pub type FINDEX_SEARCH_OPS = i32;
+pub type FIND_FIRST_EX_FLAGS = u32;
 pub const FIONBIO: i32 = -2147195266i32;
 #[repr(C)]
 #[cfg(any(target_arch = "aarch64", target_arch = "arm64ec", target_arch = "x86_64"))]
@@ -2565,6 +2568,8 @@ pub const FileRenameInfoEx: FILE_INFO_BY_HANDLE_CLASS = 22i32;
 pub const FileStandardInfo: FILE_INFO_BY_HANDLE_CLASS = 1i32;
 pub const FileStorageInfo: FILE_INFO_BY_HANDLE_CLASS = 16i32;
 pub const FileStreamInfo: FILE_INFO_BY_HANDLE_CLASS = 7i32;
+pub const FindExInfoBasic: FINDEX_INFO_LEVELS = 1i32;
+pub const FindExSearchNameMatch: FINDEX_SEARCH_OPS = 0i32;
 pub type GENERIC_ACCESS_RIGHTS = u32;
 pub const GENERIC_ALL: GENERIC_ACCESS_RIGHTS = 268435456u32;
 pub const GENERIC_EXECUTE: GENERIC_ACCESS_RIGHTS = 536870912u32;
@@ -3307,7 +3312,6 @@ pub struct XSAVE_FORMAT {
     pub XmmRegisters: [M128A; 8],
     pub Reserved4: [u8; 224],
 }
-
 #[cfg(target_arch = "arm")]
 #[repr(C)]
 pub struct WSADATA {
diff --git a/library/std/src/sys/pal/windows/fs.rs b/library/std/src/sys/pal/windows/fs.rs
index aab471e28ea..b237fa481e2 100644
--- a/library/std/src/sys/pal/windows/fs.rs
+++ b/library/std/src/sys/pal/windows/fs.rs
@@ -114,7 +114,7 @@ impl Iterator for ReadDir {
     fn next(&mut self) -> Option<io::Result<DirEntry>> {
         if self.handle.0 == c::INVALID_HANDLE_VALUE {
             // This iterator was initialized with an `INVALID_HANDLE_VALUE` as its handle.
-            // Simply return `None` because this is only the case when `FindFirstFileW` in
+            // Simply return `None` because this is only the case when `FindFirstFileExW` in
             // the construction of this iterator returns `ERROR_FILE_NOT_FOUND` which means
             // no matchhing files can be found.
             return None;
@@ -1047,8 +1047,22 @@ pub fn readdir(p: &Path) -> io::Result<ReadDir> {
     let path = maybe_verbatim(&star)?;
 
     unsafe {
-        let mut wfd = mem::zeroed();
-        let find_handle = c::FindFirstFileW(path.as_ptr(), &mut wfd);
+        let mut wfd: c::WIN32_FIND_DATAW = mem::zeroed();
+        // this is like FindFirstFileW (see https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-findfirstfileexw),
+        // but with FindExInfoBasic it should skip filling WIN32_FIND_DATAW.cAlternateFileName
+        // (see https://learn.microsoft.com/en-us/windows/win32/api/minwinbase/ns-minwinbase-win32_find_dataw)
+        // (which will be always null string value and currently unused) and should be faster.
+        //
+        // We can pass FIND_FIRST_EX_LARGE_FETCH to dwAdditionalFlags to speed up things more,
+        // but as we don't know user's use profile of this function, lets be conservative.
+        let find_handle = c::FindFirstFileExW(
+            path.as_ptr(),
+            c::FindExInfoBasic,
+            &mut wfd as *mut _ as _,
+            c::FindExSearchNameMatch,
+            ptr::null(),
+            0,
+        );
 
         if find_handle != c::INVALID_HANDLE_VALUE {
             Ok(ReadDir {
@@ -1057,7 +1071,7 @@ pub fn readdir(p: &Path) -> io::Result<ReadDir> {
                 first: Some(wfd),
             })
         } else {
-            // The status `ERROR_FILE_NOT_FOUND` is returned by the `FindFirstFileW` function
+            // The status `ERROR_FILE_NOT_FOUND` is returned by the `FindFirstFileExW` function
             // if no matching files can be found, but not necessarily that the path to find the
             // files in does not exist.
             //
@@ -1079,7 +1093,7 @@ pub fn readdir(p: &Path) -> io::Result<ReadDir> {
 
             // Just return the error constructed from the raw OS error if the above is not the case.
             //
-            // Note: `ERROR_PATH_NOT_FOUND` would have been returned by the `FindFirstFileW` function
+            // Note: `ERROR_PATH_NOT_FOUND` would have been returned by the `FindFirstFileExW` function
             // when the path to search in does not exist in the first place.
             Err(Error::from_raw_os_error(last_error.code as i32))
         }
@@ -1220,7 +1234,7 @@ fn metadata(path: &Path, reparse: ReparsePoint) -> io::Result<FileAttr> {
     opts.custom_flags(c::FILE_FLAG_BACKUP_SEMANTICS | reparse.as_flag());
 
     // Attempt to open the file normally.
-    // If that fails with `ERROR_SHARING_VIOLATION` then retry using `FindFirstFileW`.
+    // If that fails with `ERROR_SHARING_VIOLATION` then retry using `FindFirstFileExW`.
     // If the fallback fails for any reason we return the original error.
     match File::open(path, &opts) {
         Ok(file) => file.file_attr(),
@@ -1237,13 +1251,20 @@ fn metadata(path: &Path, reparse: ReparsePoint) -> io::Result<FileAttr> {
             unsafe {
                 let path = maybe_verbatim(path)?;
 
-                // `FindFirstFileW` accepts wildcard file names.
+                // `FindFirstFileExW` accepts wildcard file names.
                 // Fortunately wildcards are not valid file names and
                 // `ERROR_SHARING_VIOLATION` means the file exists (but is locked)
                 // therefore it's safe to assume the file name given does not
                 // include wildcards.
-                let mut wfd = mem::zeroed();
-                let handle = c::FindFirstFileW(path.as_ptr(), &mut wfd);
+                let mut wfd: c::WIN32_FIND_DATAW = mem::zeroed();
+                let handle = c::FindFirstFileExW(
+                    path.as_ptr(),
+                    c::FindExInfoBasic,
+                    &mut wfd as *mut _ as _,
+                    c::FindExSearchNameMatch,
+                    ptr::null(),
+                    0,
+                );
 
                 if handle == c::INVALID_HANDLE_VALUE {
                     // This can fail if the user does not have read access to the
@@ -1253,7 +1274,7 @@ fn metadata(path: &Path, reparse: ReparsePoint) -> io::Result<FileAttr> {
                     // We no longer need the find handle.
                     c::FindClose(handle);
 
-                    // `FindFirstFileW` reads the cached file information from the
+                    // `FindFirstFileExW` reads the cached file information from the
                     // directory. The downside is that this metadata may be outdated.
                     let attrs = FileAttr::from(wfd);
                     if reparse == ReparsePoint::Follow && attrs.file_type().is_symlink() {
diff --git a/library/std/src/sys/pal/windows/futex.rs b/library/std/src/sys/pal/windows/futex.rs
index 4d6c4df9a5a..38afb8c043b 100644
--- a/library/std/src/sys/pal/windows/futex.rs
+++ b/library/std/src/sys/pal/windows/futex.rs
@@ -9,22 +9,27 @@ use core::{mem, ptr};
 use super::api::{self, WinError};
 use crate::sys::{c, dur2timeout};
 
+/// An atomic for use as a futex that is at least 32-bits but may be larger
+pub type Futex = AtomicU32;
+/// Must be the underlying type of Futex
+pub type Primitive = u32;
+
 /// An atomic for use as a futex that is at least 8-bits but may be larger.
-pub type SmallAtomic = AtomicU8;
-/// Must be the underlying type of SmallAtomic
+pub type SmallFutex = AtomicU8;
+/// Must be the underlying type of SmallFutex
 pub type SmallPrimitive = u8;
 
-pub unsafe trait Futex {}
+pub unsafe trait Futexable {}
 pub unsafe trait Waitable {
-    type Atomic;
+    type Futex;
 }
 macro_rules! unsafe_waitable_int {
     ($(($int:ty, $atomic:ty)),*$(,)?) => {
         $(
             unsafe impl Waitable for $int {
-                type Atomic = $atomic;
+                type Futex = $atomic;
             }
-            unsafe impl Futex for $atomic {}
+            unsafe impl Futexable for $atomic {}
         )*
     };
 }
@@ -42,15 +47,15 @@ unsafe_waitable_int! {
     (usize, AtomicUsize),
 }
 unsafe impl<T> Waitable for *const T {
-    type Atomic = AtomicPtr<T>;
+    type Futex = AtomicPtr<T>;
 }
 unsafe impl<T> Waitable for *mut T {
-    type Atomic = AtomicPtr<T>;
+    type Futex = AtomicPtr<T>;
 }
-unsafe impl<T> Futex for AtomicPtr<T> {}
+unsafe impl<T> Futexable for AtomicPtr<T> {}
 
 pub fn wait_on_address<W: Waitable>(
-    address: &W::Atomic,
+    address: &W::Futex,
     compare: W,
     timeout: Option<Duration>,
 ) -> bool {
@@ -63,30 +68,30 @@ pub fn wait_on_address<W: Waitable>(
     }
 }
 
-pub fn wake_by_address_single<T: Futex>(address: &T) {
+pub fn wake_by_address_single<T: Futexable>(address: &T) {
     unsafe {
         let addr = ptr::from_ref(address).cast::<c_void>();
         c::WakeByAddressSingle(addr);
     }
 }
 
-pub fn wake_by_address_all<T: Futex>(address: &T) {
+pub fn wake_by_address_all<T: Futexable>(address: &T) {
     unsafe {
         let addr = ptr::from_ref(address).cast::<c_void>();
         c::WakeByAddressAll(addr);
     }
 }
 
-pub fn futex_wait<W: Waitable>(futex: &W::Atomic, expected: W, timeout: Option<Duration>) -> bool {
+pub fn futex_wait<W: Waitable>(futex: &W::Futex, expected: W, timeout: Option<Duration>) -> bool {
     // return false only on timeout
     wait_on_address(futex, expected, timeout) || api::get_last_error() != WinError::TIMEOUT
 }
 
-pub fn futex_wake<T: Futex>(futex: &T) -> bool {
+pub fn futex_wake<T: Futexable>(futex: &T) -> bool {
     wake_by_address_single(futex);
     false
 }
 
-pub fn futex_wake_all<T: Futex>(futex: &T) {
+pub fn futex_wake_all<T: Futexable>(futex: &T) {
     wake_by_address_all(futex)
 }
diff --git a/library/std/src/sys/pal/xous/args.rs b/library/std/src/sys/pal/xous/args.rs
new file mode 100644
index 00000000000..00c44ca220a
--- /dev/null
+++ b/library/std/src/sys/pal/xous/args.rs
@@ -0,0 +1,53 @@
+use crate::ffi::OsString;
+use crate::sys::pal::xous::os::get_application_parameters;
+use crate::sys::pal::xous::os::params::ArgumentList;
+use crate::{fmt, vec};
+
+pub struct Args {
+    parsed_args_list: vec::IntoIter<OsString>,
+}
+
+pub fn args() -> Args {
+    let Some(params) = get_application_parameters() else {
+        return Args { parsed_args_list: vec![].into_iter() };
+    };
+
+    for param in params {
+        if let Ok(args) = ArgumentList::try_from(&param) {
+            let mut parsed_args = vec![];
+            for arg in args {
+                parsed_args.push(arg.into());
+            }
+            return Args { parsed_args_list: parsed_args.into_iter() };
+        }
+    }
+    Args { parsed_args_list: vec![].into_iter() }
+}
+
+impl fmt::Debug for Args {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.parsed_args_list.as_slice().fmt(f)
+    }
+}
+
+impl Iterator for Args {
+    type Item = OsString;
+    fn next(&mut self) -> Option<OsString> {
+        self.parsed_args_list.next()
+    }
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.parsed_args_list.size_hint()
+    }
+}
+
+impl DoubleEndedIterator for Args {
+    fn next_back(&mut self) -> Option<OsString> {
+        self.parsed_args_list.next_back()
+    }
+}
+
+impl ExactSizeIterator for Args {
+    fn len(&self) -> usize {
+        self.parsed_args_list.len()
+    }
+}
diff --git a/library/std/src/sys/pal/xous/mod.rs b/library/std/src/sys/pal/xous/mod.rs
index b211e94db65..a64cd068560 100644
--- a/library/std/src/sys/pal/xous/mod.rs
+++ b/library/std/src/sys/pal/xous/mod.rs
@@ -1,6 +1,5 @@
 #![forbid(unsafe_op_in_unsafe_fn)]
 
-#[path = "../unsupported/args.rs"]
 pub mod args;
 #[path = "../unsupported/env.rs"]
 pub mod env;
diff --git a/library/std/src/sys/pal/xous/net/dns.rs b/library/std/src/sys/pal/xous/net/dns.rs
index d0083c61837..1a2b56b4da5 100644
--- a/library/std/src/sys/pal/xous/net/dns.rs
+++ b/library/std/src/sys/pal/xous/net/dns.rs
@@ -6,6 +6,7 @@ use crate::os::xous::ffi::lend_mut;
 use crate::os::xous::services::{DnsLendMut, dns_server};
 
 pub struct DnsError {
+    #[allow(dead_code)]
     pub code: u8,
 }
 
diff --git a/library/std/src/sys/pal/xous/net/mod.rs b/library/std/src/sys/pal/xous/net/mod.rs
index dd8b765aa74..3e18ed24208 100644
--- a/library/std/src/sys/pal/xous/net/mod.rs
+++ b/library/std/src/sys/pal/xous/net/mod.rs
@@ -60,6 +60,7 @@ pub mod netc {
 
     #[derive(Copy, Clone)]
     pub struct sockaddr_in {
+        #[allow(dead_code)]
         pub sin_family: sa_family_t,
         pub sin_port: u16,
         pub sin_addr: in_addr,
@@ -72,6 +73,7 @@ pub mod netc {
 
     #[derive(Copy, Clone)]
     pub struct sockaddr_in6 {
+        #[allow(dead_code)]
         pub sin6_family: sa_family_t,
         pub sin6_port: u16,
         pub sin6_addr: in6_addr,
diff --git a/library/std/src/sys/pal/xous/os.rs b/library/std/src/sys/pal/xous/os.rs
index 8f8f35428c4..b0ab01a6383 100644
--- a/library/std/src/sys/pal/xous/os.rs
+++ b/library/std/src/sys/pal/xous/os.rs
@@ -1,29 +1,35 @@
 use super::unsupported;
+use crate::collections::HashMap;
 use crate::error::Error as StdError;
 use crate::ffi::{OsStr, OsString};
 use crate::marker::PhantomData;
 use crate::os::xous::ffi::Error as XousError;
 use crate::path::{self, PathBuf};
-use crate::{fmt, io};
+use crate::sync::atomic::{AtomicPtr, AtomicUsize, Ordering};
+use crate::sync::{Mutex, Once};
+use crate::{fmt, io, vec};
+
+pub(crate) mod params;
+
+static PARAMS_ADDRESS: AtomicPtr<u8> = AtomicPtr::new(core::ptr::null_mut());
 
 #[cfg(not(test))]
 #[cfg(feature = "panic_unwind")]
 mod eh_unwinding {
-    pub(crate) struct EhFrameFinder(usize /* eh_frame */);
-    pub(crate) static mut EH_FRAME_SETTINGS: EhFrameFinder = EhFrameFinder(0);
-    impl EhFrameFinder {
-        pub(crate) unsafe fn init(&mut self, eh_frame: usize) {
-            unsafe {
-                EH_FRAME_SETTINGS.0 = eh_frame;
-            }
-        }
-    }
+    pub(crate) struct EhFrameFinder;
+    pub(crate) static mut EH_FRAME_ADDRESS: usize = 0;
+    pub(crate) static EH_FRAME_SETTINGS: EhFrameFinder = EhFrameFinder;
+
     unsafe impl unwind::EhFrameFinder for EhFrameFinder {
         fn find(&self, _pc: usize) -> Option<unwind::FrameInfo> {
-            Some(unwind::FrameInfo {
-                text_base: None,
-                kind: unwind::FrameInfoKind::EhFrame(self.0),
-            })
+            if unsafe { EH_FRAME_ADDRESS == 0 } {
+                None
+            } else {
+                Some(unwind::FrameInfo {
+                    text_base: None,
+                    kind: unwind::FrameInfoKind::EhFrame(unsafe { EH_FRAME_ADDRESS }),
+                })
+            }
         }
     }
 }
@@ -41,12 +47,21 @@ mod c_compat {
     }
 
     #[no_mangle]
-    pub extern "C" fn _start(eh_frame: usize) {
+    pub extern "C" fn _start(eh_frame: usize, params_address: usize) {
         #[cfg(feature = "panic_unwind")]
-        unsafe {
-            super::eh_unwinding::EH_FRAME_SETTINGS.init(eh_frame);
+        {
+            unsafe { super::eh_unwinding::EH_FRAME_ADDRESS = eh_frame };
             unwind::set_custom_eh_frame_finder(&super::eh_unwinding::EH_FRAME_SETTINGS).ok();
         }
+
+        if params_address != 0 {
+            let params_address = crate::ptr::with_exposed_provenance_mut::<u8>(params_address);
+            if unsafe {
+                super::params::ApplicationParameters::new_from_ptr(params_address).is_some()
+            } {
+                super::PARAMS_ADDRESS.store(params_address, core::sync::atomic::Ordering::Relaxed);
+            }
+        }
         exit(unsafe { main() });
     }
 
@@ -116,44 +131,103 @@ pub fn current_exe() -> io::Result<PathBuf> {
     unsupported()
 }
 
-pub struct Env(!);
+pub(crate) fn get_application_parameters() -> Option<params::ApplicationParameters> {
+    let params_address = PARAMS_ADDRESS.load(Ordering::Relaxed);
+    unsafe { params::ApplicationParameters::new_from_ptr(params_address) }
+}
+
+// ---------- Environment handling ---------- //
+static ENV: AtomicUsize = AtomicUsize::new(0);
+static ENV_INIT: Once = Once::new();
+type EnvStore = Mutex<HashMap<OsString, OsString>>;
+
+fn get_env_store() -> &'static EnvStore {
+    ENV_INIT.call_once(|| {
+        let env_store = EnvStore::default();
+        if let Some(params) = get_application_parameters() {
+            for param in params {
+                if let Ok(envs) = params::EnvironmentBlock::try_from(&param) {
+                    let mut env_store = env_store.lock().unwrap();
+                    for env in envs {
+                        env_store.insert(env.key.into(), env.value.into());
+                    }
+                    break;
+                }
+            }
+        }
+        ENV.store(Box::into_raw(Box::new(env_store)) as _, Ordering::Relaxed)
+    });
+    unsafe { &*core::ptr::with_exposed_provenance::<EnvStore>(ENV.load(Ordering::Relaxed)) }
+}
+
+pub struct Env {
+    iter: vec::IntoIter<(OsString, OsString)>,
+}
+
+// FIXME(https://github.com/rust-lang/rust/issues/114583): Remove this when <OsStr as Debug>::fmt matches <str as Debug>::fmt.
+pub struct EnvStrDebug<'a> {
+    slice: &'a [(OsString, OsString)],
+}
+
+impl fmt::Debug for EnvStrDebug<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let Self { slice } = self;
+        f.debug_list()
+            .entries(slice.iter().map(|(a, b)| (a.to_str().unwrap(), b.to_str().unwrap())))
+            .finish()
+    }
+}
 
 impl Env {
     // FIXME(https://github.com/rust-lang/rust/issues/114583): Remove this when <OsStr as Debug>::fmt matches <str as Debug>::fmt.
     pub fn str_debug(&self) -> impl fmt::Debug + '_ {
-        let Self(inner) = self;
-        match *inner {}
+        let Self { iter } = self;
+        EnvStrDebug { slice: iter.as_slice() }
     }
 }
 
 impl fmt::Debug for Env {
-    fn fmt(&self, _: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let Self(inner) = self;
-        match *inner {}
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let Self { iter } = self;
+        f.debug_list().entries(iter.as_slice()).finish()
     }
 }
 
+impl !Send for Env {}
+impl !Sync for Env {}
+
 impl Iterator for Env {
     type Item = (OsString, OsString);
     fn next(&mut self) -> Option<(OsString, OsString)> {
-        self.0
+        self.iter.next()
+    }
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.iter.size_hint()
     }
 }
 
 pub fn env() -> Env {
-    panic!("not supported on this platform")
+    let clone_to_vec = |map: &HashMap<OsString, OsString>| -> Vec<_> {
+        map.iter().map(|(k, v)| (k.clone(), v.clone())).collect()
+    };
+
+    let iter = clone_to_vec(&*get_env_store().lock().unwrap()).into_iter();
+    Env { iter }
 }
 
-pub fn getenv(_: &OsStr) -> Option<OsString> {
-    None
+pub fn getenv(k: &OsStr) -> Option<OsString> {
+    get_env_store().lock().unwrap().get(k).cloned()
 }
 
-pub unsafe fn setenv(_: &OsStr, _: &OsStr) -> io::Result<()> {
-    Err(io::const_io_error!(io::ErrorKind::Unsupported, "cannot set env vars on this platform"))
+pub unsafe fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> {
+    let (k, v) = (k.to_owned(), v.to_owned());
+    get_env_store().lock().unwrap().insert(k, v);
+    Ok(())
 }
 
-pub unsafe fn unsetenv(_: &OsStr) -> io::Result<()> {
-    Err(io::const_io_error!(io::ErrorKind::Unsupported, "cannot unset env vars on this platform"))
+pub unsafe fn unsetenv(k: &OsStr) -> io::Result<()> {
+    get_env_store().lock().unwrap().remove(k);
+    Ok(())
 }
 
 pub fn temp_dir() -> PathBuf {
diff --git a/library/std/src/sys/pal/xous/os/params.rs b/library/std/src/sys/pal/xous/os/params.rs
new file mode 100644
index 00000000000..0d02cf35477
--- /dev/null
+++ b/library/std/src/sys/pal/xous/os/params.rs
@@ -0,0 +1,271 @@
+/// Xous passes a pointer to the parameter block as the second argument.
+/// This is used for passing flags such as environment variables. The
+/// format of the argument block is:
+///
+/// #[repr(C)]
+/// struct BlockHeader {
+///     /// Magic number that identifies this block. Must be printable ASCII.
+///     magic: [u8; 4],
+///
+///     /// The size of the data block. Does not include this header. May be 0.
+///     size: u32,
+///
+///     /// The contents of this block. Varies depending on the block type.
+///     data: [u8; 0],
+/// }
+///
+/// There is a BlockHeader at the start that has magic `AppP`, and the data
+/// that follows is the number of blocks present:
+///
+/// #[repr(C)]
+/// struct ApplicationParameters {
+///     magic: b"AppP",
+///     size: 4u32,
+///
+///     /// The size of the entire application slice, in bytes, including all headers
+///     length: u32,
+///
+///     /// Number of application parameters present. Must be at least 1 (this block)
+///     entries: (parameter_count as u32).to_bytes_le(),
+/// }
+///
+/// #[repr(C)]
+/// struct EnvironmentBlock {
+///     magic: b"EnvB",
+///
+///     /// Total number of bytes, excluding this header
+///     size: 2+data.len(),
+///
+///     /// The number of environment variables
+///     count: u16,
+///
+///     /// Environment variable iteration
+///     data: [u8; 0],
+/// }
+///
+/// Environment variables are present in an `EnvB` block. The `data` section is
+/// a sequence of bytes of the form:
+///
+///      (u16 /* key_len */; [0u8; key_len as usize] /* key */,
+///       u16 /* val_len */ [0u8; val_len as usize])
+///
+/// #[repr(C)]
+/// struct ArgumentList {
+///     magic: b"ArgL",
+///
+///     /// Total number of bytes, excluding this header
+///     size: 2+data.len(),
+///
+///     /// The number of arguments variables
+///     count: u16,
+///
+///     /// Argument variable iteration
+///     data: [u8; 0],
+/// }
+///
+/// Args are just an array of strings that represent command line arguments.
+/// They are a sequence of the form:
+///
+///      (u16 /* val_len */ [0u8; val_len as usize])
+use core::slice;
+
+use crate::ffi::OsString;
+
+/// Magic number indicating we have an environment block
+const ENV_MAGIC: [u8; 4] = *b"EnvB";
+
+/// Command line arguments list
+const ARGS_MAGIC: [u8; 4] = *b"ArgL";
+
+/// Magic number indicating the loader has passed application parameters
+const PARAMS_MAGIC: [u8; 4] = *b"AppP";
+
+#[cfg(test)]
+mod tests;
+
+pub(crate) struct ApplicationParameters {
+    data: &'static [u8],
+    offset: usize,
+    _entries: usize,
+}
+
+impl ApplicationParameters {
+    pub(crate) unsafe fn new_from_ptr(data: *const u8) -> Option<ApplicationParameters> {
+        if data.is_null() {
+            return None;
+        }
+
+        let magic = unsafe { core::slice::from_raw_parts(data, 4) };
+        let block_length = unsafe {
+            u32::from_le_bytes(slice::from_raw_parts(data.add(4), 4).try_into().ok()?) as usize
+        };
+        let data_length = unsafe {
+            u32::from_le_bytes(slice::from_raw_parts(data.add(8), 4).try_into().ok()?) as usize
+        };
+        let entries = unsafe {
+            u32::from_le_bytes(slice::from_raw_parts(data.add(12), 4).try_into().ok()?) as usize
+        };
+
+        // Check for the main header
+        if data_length < 16 || magic != PARAMS_MAGIC || block_length != 8 {
+            return None;
+        }
+
+        let data = unsafe { slice::from_raw_parts(data, data_length) };
+
+        Some(ApplicationParameters { data, offset: 0, _entries: entries })
+    }
+}
+
+impl Iterator for ApplicationParameters {
+    type Item = ApplicationParameter;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        // Fetch magic, ensuring we don't run off the end
+        if self.offset + 4 > self.data.len() {
+            return None;
+        }
+        let magic = &self.data[self.offset..self.offset + 4];
+        self.offset += 4;
+
+        // Fetch header size
+        if self.offset + 4 > self.data.len() {
+            return None;
+        }
+        let size = u32::from_le_bytes(self.data[self.offset..self.offset + 4].try_into().unwrap())
+            as usize;
+        self.offset += 4;
+
+        // Fetch data contents
+        if self.offset + size > self.data.len() {
+            return None;
+        }
+        let data = &self.data[self.offset..self.offset + size];
+        self.offset += size;
+
+        Some(ApplicationParameter { data, magic: magic.try_into().unwrap() })
+    }
+}
+
+pub(crate) struct ApplicationParameter {
+    data: &'static [u8],
+    magic: [u8; 4],
+}
+
+pub(crate) struct ApplicationParameterError;
+
+pub(crate) struct EnvironmentBlock {
+    _count: usize,
+    data: &'static [u8],
+    offset: usize,
+}
+
+impl TryFrom<&ApplicationParameter> for EnvironmentBlock {
+    type Error = ApplicationParameterError;
+
+    fn try_from(value: &ApplicationParameter) -> Result<Self, Self::Error> {
+        if value.data.len() < 2 || value.magic != ENV_MAGIC {
+            return Err(ApplicationParameterError);
+        }
+
+        let count = u16::from_le_bytes(value.data[0..2].try_into().unwrap()) as usize;
+
+        Ok(EnvironmentBlock { data: &value.data[2..], offset: 0, _count: count })
+    }
+}
+
+pub(crate) struct EnvironmentEntry {
+    pub key: &'static str,
+    pub value: &'static str,
+}
+
+impl Iterator for EnvironmentBlock {
+    type Item = EnvironmentEntry;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.offset + 2 > self.data.len() {
+            return None;
+        }
+        let key_len =
+            u16::from_le_bytes(self.data[self.offset..self.offset + 2].try_into().ok()?) as usize;
+        self.offset += 2;
+
+        if self.offset + key_len > self.data.len() {
+            return None;
+        }
+        let key = core::str::from_utf8(&self.data[self.offset..self.offset + key_len]).ok()?;
+        self.offset += key_len;
+
+        if self.offset + 2 > self.data.len() {
+            return None;
+        }
+        let value_len =
+            u16::from_le_bytes(self.data[self.offset..self.offset + 2].try_into().ok()?) as usize;
+        self.offset += 2;
+
+        if self.offset + value_len > self.data.len() {
+            return None;
+        }
+        let value = core::str::from_utf8(&self.data[self.offset..self.offset + value_len]).ok()?;
+        self.offset += value_len;
+
+        Some(EnvironmentEntry { key, value })
+    }
+}
+
+pub(crate) struct ArgumentList {
+    data: &'static [u8],
+    _count: usize,
+    offset: usize,
+}
+
+impl TryFrom<&ApplicationParameter> for ArgumentList {
+    type Error = ApplicationParameterError;
+
+    fn try_from(value: &ApplicationParameter) -> Result<Self, Self::Error> {
+        if value.data.len() < 2 || value.magic != ARGS_MAGIC {
+            return Err(ApplicationParameterError);
+        }
+        let count =
+            u16::from_le_bytes(value.data[0..2].try_into().or(Err(ApplicationParameterError))?)
+                as usize;
+        Ok(ArgumentList { data: &value.data[2..], _count: count, offset: 0 })
+    }
+}
+
+pub(crate) struct ArgumentEntry {
+    value: &'static str,
+}
+
+impl Into<&str> for ArgumentEntry {
+    fn into(self) -> &'static str {
+        self.value
+    }
+}
+
+impl Into<OsString> for ArgumentEntry {
+    fn into(self) -> OsString {
+        self.value.into()
+    }
+}
+
+impl Iterator for ArgumentList {
+    type Item = ArgumentEntry;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.offset + 2 > self.data.len() {
+            return None;
+        }
+        let value_len =
+            u16::from_le_bytes(self.data[self.offset..self.offset + 2].try_into().ok()?) as usize;
+        self.offset += 2;
+
+        if self.offset + value_len > self.data.len() {
+            return None;
+        }
+        let value = core::str::from_utf8(&self.data[self.offset..self.offset + value_len]).ok()?;
+        self.offset += value_len;
+
+        Some(ArgumentEntry { value })
+    }
+}
diff --git a/library/std/src/sys/pal/xous/os/params/tests.rs b/library/std/src/sys/pal/xous/os/params/tests.rs
new file mode 100644
index 00000000000..0ef04ee3091
--- /dev/null
+++ b/library/std/src/sys/pal/xous/os/params/tests.rs
@@ -0,0 +1,75 @@
+use super::*;
+use crate::collections::HashMap;
+use crate::io::Write;
+
+fn create_args_test() -> std::io::Result<Vec<u8>> {
+    let mut sample_data = vec![];
+    let mut h = HashMap::new();
+
+    h.insert("foo", "bar");
+    h.insert("baz", "qux");
+    h.insert("some", "val");
+
+    // Magic number
+    sample_data.write_all(&PARAMS_MAGIC)?;
+    // Size of the AppP block
+    sample_data.write_all(&4u32.to_le_bytes())?;
+    // Number of blocks
+    sample_data.write_all(&2u32.to_le_bytes())?;
+
+    // Magic number
+    sample_data.write_all(&ENV_MAGIC)?;
+    let mut data = vec![];
+    for (key, value) in h.iter() {
+        data.extend_from_slice(&(key.len() as u16).to_le_bytes());
+        data.extend_from_slice(key.as_bytes());
+        data.extend_from_slice(&(value.len() as u16).to_le_bytes());
+        data.extend_from_slice(value.as_bytes());
+    }
+    // Size of the EnvB block
+    sample_data.write_all(&(data.len() as u32 + 2).to_le_bytes())?;
+
+    // Number of environment variables
+    sample_data.write_all(&(h.len() as u16).to_le_bytes())?;
+
+    // Environment variables
+    sample_data.write_all(&data)?;
+
+    // Write command line arguments
+    let args = vec!["some", "command", "line variable", "entries"];
+    sample_data.write_all(&ARGS_MAGIC)?;
+    let mut args_size = 0;
+    for entry in args.iter() {
+        args_size += entry.len() + 2;
+    }
+    sample_data.write_all(&(args_size as u32 + 2).to_le_bytes())?;
+    sample_data.write_all(&(args.len() as u16).to_le_bytes())?;
+    for entry in args {
+        sample_data.write_all(&(entry.len() as u16).to_le_bytes())?;
+        sample_data.write_all(entry.as_bytes())?;
+    }
+
+    Ok(sample_data)
+}
+
+#[test]
+fn basic_arg_parsing() {
+    let arg_data = create_args_test().expect("couldn't create test data");
+    for byte in &arg_data {
+        print!("{:02x} ", byte);
+    }
+    println!();
+
+    let args = ApplicationParameters::new(&arg_data).expect("Unable to parse arguments");
+    for arg in args {
+        if let Ok(env) = EnvironmentBlock::try_from(&arg) {
+            for env in env {
+                println!("{}={}", env.key, env.value);
+            }
+        } else if let Ok(args) = ArgumentList::try_from(&arg) {
+            for arg in args {
+                println!("Arg: {}", arg.value);
+            }
+        }
+    }
+}
diff --git a/library/std/src/sys/random/arc4random.rs b/library/std/src/sys/random/arc4random.rs
index 32467e9ebaa..ffabaafbee8 100644
--- a/library/std/src/sys/random/arc4random.rs
+++ b/library/std/src/sys/random/arc4random.rs
@@ -12,6 +12,7 @@
 #[cfg(not(any(
     target_os = "haiku",
     target_os = "illumos",
+    target_os = "rtems",
     target_os = "solaris",
     target_os = "vita",
 )))]
@@ -21,6 +22,7 @@ use libc::arc4random_buf;
 #[cfg(any(
     target_os = "haiku", // See https://git.haiku-os.org/haiku/tree/headers/compatibility/bsd/stdlib.h
     target_os = "illumos", // See https://www.illumos.org/man/3C/arc4random
+    target_os = "rtems", // See https://docs.rtems.org/branches/master/bsp-howto/getentropy.html
     target_os = "solaris", // See https://docs.oracle.com/cd/E88353_01/html/E37843/arc4random-3c.html
     target_os = "vita", // See https://github.com/vitasdk/newlib/blob/b89e5bc183b516945f9ee07eef483ecb916e45ff/newlib/libc/include/stdlib.h#L74
 ))]
diff --git a/library/std/src/sys/random/mod.rs b/library/std/src/sys/random/mod.rs
index d625814d15b..edc2cacdfd8 100644
--- a/library/std/src/sys/random/mod.rs
+++ b/library/std/src/sys/random/mod.rs
@@ -17,6 +17,7 @@ cfg_if::cfg_if! {
         target_os = "illumos",
         target_os = "netbsd",
         target_os = "openbsd",
+        target_os = "rtems",
         target_os = "solaris",
         target_os = "vita",
     ))] {
diff --git a/library/std/src/sys/sync/condvar/futex.rs b/library/std/src/sys/sync/condvar/futex.rs
index 39cd97c01ea..0d0c5f0dbe7 100644
--- a/library/std/src/sys/sync/condvar/futex.rs
+++ b/library/std/src/sys/sync/condvar/futex.rs
@@ -1,6 +1,5 @@
-use crate::sync::atomic::AtomicU32;
 use crate::sync::atomic::Ordering::Relaxed;
-use crate::sys::futex::{futex_wait, futex_wake, futex_wake_all};
+use crate::sys::futex::{Futex, futex_wait, futex_wake, futex_wake_all};
 use crate::sys::sync::Mutex;
 use crate::time::Duration;
 
@@ -8,13 +7,13 @@ pub struct Condvar {
     // The value of this atomic is simply incremented on every notification.
     // This is used by `.wait()` to not miss any notifications after
     // unlocking the mutex and before waiting for notifications.
-    futex: AtomicU32,
+    futex: Futex,
 }
 
 impl Condvar {
     #[inline]
     pub const fn new() -> Self {
-        Self { futex: AtomicU32::new(0) }
+        Self { futex: Futex::new(0) }
     }
 
     // All the memory orderings here are `Relaxed`,
diff --git a/library/std/src/sys/sync/mutex/futex.rs b/library/std/src/sys/sync/mutex/futex.rs
index 81afa94b147..ce9b2daa5f8 100644
--- a/library/std/src/sys/sync/mutex/futex.rs
+++ b/library/std/src/sys/sync/mutex/futex.rs
@@ -1,11 +1,11 @@
 use crate::sync::atomic::Ordering::{Acquire, Relaxed, Release};
 use crate::sys::futex::{self, futex_wait, futex_wake};
 
-type Atomic = futex::SmallAtomic;
+type Futex = futex::SmallFutex;
 type State = futex::SmallPrimitive;
 
 pub struct Mutex {
-    futex: Atomic,
+    futex: Futex,
 }
 
 const UNLOCKED: State = 0;
@@ -15,7 +15,7 @@ const CONTENDED: State = 2; // locked, and other threads waiting (contended)
 impl Mutex {
     #[inline]
     pub const fn new() -> Self {
-        Self { futex: Atomic::new(UNLOCKED) }
+        Self { futex: Futex::new(UNLOCKED) }
     }
 
     #[inline]
diff --git a/library/std/src/sys/sync/once/futex.rs b/library/std/src/sys/sync/once/futex.rs
index 25588a4217b..10bfa81a6d7 100644
--- a/library/std/src/sys/sync/once/futex.rs
+++ b/library/std/src/sys/sync/once/futex.rs
@@ -1,39 +1,38 @@
 use crate::cell::Cell;
 use crate::sync as public;
-use crate::sync::atomic::AtomicU32;
 use crate::sync::atomic::Ordering::{Acquire, Relaxed, Release};
 use crate::sync::once::ExclusiveState;
-use crate::sys::futex::{futex_wait, futex_wake_all};
+use crate::sys::futex::{Futex, Primitive, futex_wait, futex_wake_all};
 
 // On some platforms, the OS is very nice and handles the waiter queue for us.
 // This means we only need one atomic value with 4 states:
 
 /// No initialization has run yet, and no thread is currently using the Once.
-const INCOMPLETE: u32 = 0;
+const INCOMPLETE: Primitive = 0;
 /// Some thread has previously attempted to initialize the Once, but it panicked,
 /// so the Once is now poisoned. There are no other threads currently accessing
 /// this Once.
-const POISONED: u32 = 1;
+const POISONED: Primitive = 1;
 /// Some thread is currently attempting to run initialization. It may succeed,
 /// so all future threads need to wait for it to finish.
-const RUNNING: u32 = 2;
+const RUNNING: Primitive = 2;
 /// Initialization has completed and all future calls should finish immediately.
-const COMPLETE: u32 = 3;
+const COMPLETE: Primitive = 3;
 
 // An additional bit indicates whether there are waiting threads:
 
 /// May only be set if the state is not COMPLETE.
-const QUEUED: u32 = 4;
+const QUEUED: Primitive = 4;
 
 // Threads wait by setting the QUEUED bit and calling `futex_wait` on the state
 // variable. When the running thread finishes, it will wake all waiting threads using
 // `futex_wake_all`.
 
-const STATE_MASK: u32 = 0b11;
+const STATE_MASK: Primitive = 0b11;
 
 pub struct OnceState {
     poisoned: bool,
-    set_state_to: Cell<u32>,
+    set_state_to: Cell<Primitive>,
 }
 
 impl OnceState {
@@ -49,8 +48,8 @@ impl OnceState {
 }
 
 struct CompletionGuard<'a> {
-    state_and_queued: &'a AtomicU32,
-    set_state_on_drop_to: u32,
+    state_and_queued: &'a Futex,
+    set_state_on_drop_to: Primitive,
 }
 
 impl<'a> Drop for CompletionGuard<'a> {
@@ -65,13 +64,13 @@ impl<'a> Drop for CompletionGuard<'a> {
 }
 
 pub struct Once {
-    state_and_queued: AtomicU32,
+    state_and_queued: Futex,
 }
 
 impl Once {
     #[inline]
     pub const fn new() -> Once {
-        Once { state_and_queued: AtomicU32::new(INCOMPLETE) }
+        Once { state_and_queued: Futex::new(INCOMPLETE) }
     }
 
     #[inline]
diff --git a/library/std/src/sys/sync/once/queue.rs b/library/std/src/sys/sync/once/queue.rs
index 17abaf0bf26..3e83a4a088f 100644
--- a/library/std/src/sys/sync/once/queue.rs
+++ b/library/std/src/sys/sync/once/queue.rs
@@ -23,7 +23,7 @@
 // You'll find a few more details in the implementation, but that's the gist of
 // it!
 //
-// Atomic orderings:
+// Futex orderings:
 // When running `Once` we deal with multiple atomics:
 // `Once.state_and_queue` and an unknown number of `Waiter.signaled`.
 // * `state_and_queue` is used (1) as a state flag, (2) for synchronizing the
diff --git a/library/std/src/sys/sync/rwlock/futex.rs b/library/std/src/sys/sync/rwlock/futex.rs
index 75ecc2ab5c5..df22c36dd5a 100644
--- a/library/std/src/sys/sync/rwlock/futex.rs
+++ b/library/std/src/sys/sync/rwlock/futex.rs
@@ -1,6 +1,5 @@
-use crate::sync::atomic::AtomicU32;
 use crate::sync::atomic::Ordering::{Acquire, Relaxed, Release};
-use crate::sys::futex::{futex_wait, futex_wake, futex_wake_all};
+use crate::sys::futex::{Futex, Primitive, futex_wait, futex_wake, futex_wake_all};
 
 pub struct RwLock {
     // The state consists of a 30-bit reader counter, a 'readers waiting' flag, and a 'writers waiting' flag.
@@ -10,41 +9,41 @@ pub struct RwLock {
     //   0x3FFF_FFFF: Write locked
     // Bit 30: Readers are waiting on this futex.
     // Bit 31: Writers are waiting on the writer_notify futex.
-    state: AtomicU32,
+    state: Futex,
     // The 'condition variable' to notify writers through.
     // Incremented on every signal.
-    writer_notify: AtomicU32,
+    writer_notify: Futex,
 }
 
-const READ_LOCKED: u32 = 1;
-const MASK: u32 = (1 << 30) - 1;
-const WRITE_LOCKED: u32 = MASK;
-const MAX_READERS: u32 = MASK - 1;
-const READERS_WAITING: u32 = 1 << 30;
-const WRITERS_WAITING: u32 = 1 << 31;
+const READ_LOCKED: Primitive = 1;
+const MASK: Primitive = (1 << 30) - 1;
+const WRITE_LOCKED: Primitive = MASK;
+const MAX_READERS: Primitive = MASK - 1;
+const READERS_WAITING: Primitive = 1 << 30;
+const WRITERS_WAITING: Primitive = 1 << 31;
 
 #[inline]
-fn is_unlocked(state: u32) -> bool {
+fn is_unlocked(state: Primitive) -> bool {
     state & MASK == 0
 }
 
 #[inline]
-fn is_write_locked(state: u32) -> bool {
+fn is_write_locked(state: Primitive) -> bool {
     state & MASK == WRITE_LOCKED
 }
 
 #[inline]
-fn has_readers_waiting(state: u32) -> bool {
+fn has_readers_waiting(state: Primitive) -> bool {
     state & READERS_WAITING != 0
 }
 
 #[inline]
-fn has_writers_waiting(state: u32) -> bool {
+fn has_writers_waiting(state: Primitive) -> bool {
     state & WRITERS_WAITING != 0
 }
 
 #[inline]
-fn is_read_lockable(state: u32) -> bool {
+fn is_read_lockable(state: Primitive) -> bool {
     // This also returns false if the counter could overflow if we tried to read lock it.
     //
     // We don't allow read-locking if there's readers waiting, even if the lock is unlocked
@@ -55,14 +54,14 @@ fn is_read_lockable(state: u32) -> bool {
 }
 
 #[inline]
-fn has_reached_max_readers(state: u32) -> bool {
+fn has_reached_max_readers(state: Primitive) -> bool {
     state & MASK == MAX_READERS
 }
 
 impl RwLock {
     #[inline]
     pub const fn new() -> Self {
-        Self { state: AtomicU32::new(0), writer_notify: AtomicU32::new(0) }
+        Self { state: Futex::new(0), writer_notify: Futex::new(0) }
     }
 
     #[inline]
@@ -225,7 +224,7 @@ impl RwLock {
     /// If both are waiting, this will wake up only one writer, but will fall
     /// back to waking up readers if there was no writer to wake up.
     #[cold]
-    fn wake_writer_or_readers(&self, mut state: u32) {
+    fn wake_writer_or_readers(&self, mut state: Primitive) {
         assert!(is_unlocked(state));
 
         // The readers waiting bit might be turned on at any point now,
@@ -290,7 +289,7 @@ impl RwLock {
 
     /// Spin for a while, but stop directly at the given condition.
     #[inline]
-    fn spin_until(&self, f: impl Fn(u32) -> bool) -> u32 {
+    fn spin_until(&self, f: impl Fn(Primitive) -> bool) -> Primitive {
         let mut spin = 100; // Chosen by fair dice roll.
         loop {
             let state = self.state.load(Relaxed);
@@ -303,13 +302,13 @@ impl RwLock {
     }
 
     #[inline]
-    fn spin_write(&self) -> u32 {
+    fn spin_write(&self) -> Primitive {
         // Stop spinning when it's unlocked or when there's waiting writers, to keep things somewhat fair.
         self.spin_until(|state| is_unlocked(state) || has_writers_waiting(state))
     }
 
     #[inline]
-    fn spin_read(&self) -> u32 {
+    fn spin_read(&self) -> Primitive {
         // Stop spinning when it's unlocked or read locked, or when there's waiting threads.
         self.spin_until(|state| {
             !is_write_locked(state) || has_readers_waiting(state) || has_writers_waiting(state)
diff --git a/library/std/src/sys/sync/thread_parking/futex.rs b/library/std/src/sys/sync/thread_parking/futex.rs
index ce852eaadc4..c8f7f26386a 100644
--- a/library/std/src/sys/sync/thread_parking/futex.rs
+++ b/library/std/src/sys/sync/thread_parking/futex.rs
@@ -4,7 +4,7 @@ use crate::sync::atomic::Ordering::{Acquire, Release};
 use crate::sys::futex::{self, futex_wait, futex_wake};
 use crate::time::Duration;
 
-type Atomic = futex::SmallAtomic;
+type Futex = futex::SmallFutex;
 type State = futex::SmallPrimitive;
 
 const PARKED: State = State::MAX;
@@ -12,7 +12,7 @@ const EMPTY: State = 0;
 const NOTIFIED: State = 1;
 
 pub struct Parker {
-    state: Atomic,
+    state: Futex,
 }
 
 // Notes about memory ordering:
@@ -39,7 +39,7 @@ impl Parker {
     /// Constructs the futex parker. The UNIX parker implementation
     /// requires this to happen in-place.
     pub unsafe fn new_in_place(parker: *mut Parker) {
-        unsafe { parker.write(Self { state: Atomic::new(EMPTY) }) };
+        unsafe { parker.write(Self { state: Futex::new(EMPTY) }) };
     }
 
     // Assumes this is only called by the thread that owns the Parker,
diff --git a/library/std/src/sys/thread_local/native/mod.rs b/library/std/src/sys/thread_local/native/mod.rs
index f498dee0899..a5dffe3c458 100644
--- a/library/std/src/sys/thread_local/native/mod.rs
+++ b/library/std/src/sys/thread_local/native/mod.rs
@@ -49,20 +49,21 @@ pub use lazy::Storage as LazyStorage;
 #[unstable(feature = "thread_local_internals", issue = "none")]
 #[rustc_macro_transparency = "semitransparent"]
 pub macro thread_local_inner {
-    // used to generate the `LocalKey` value for const-initialized thread locals
+    // NOTE: we cannot import `LocalKey`, `LazyStorage` or `EagerStorage` with a `use` because that
+    // can shadow user provided type or type alias with a matching name. Please update the shadowing
+    // test in `tests/thread.rs` if these types are renamed.
+
+    // Used to generate the `LocalKey` value for const-initialized thread locals.
     (@key $t:ty, const $init:expr) => {{
         const __INIT: $t = $init;
 
         unsafe {
-            use $crate::mem::needs_drop;
-            use $crate::thread::LocalKey;
-            use $crate::thread::local_impl::EagerStorage;
-
-            LocalKey::new(const {
-                if needs_drop::<$t>() {
+            $crate::thread::LocalKey::new(const {
+                if $crate::mem::needs_drop::<$t>() {
                     |_| {
                         #[thread_local]
-                        static VAL: EagerStorage<$t> = EagerStorage::new(__INIT);
+                        static VAL: $crate::thread::local_impl::EagerStorage<$t>
+                            = $crate::thread::local_impl::EagerStorage::new(__INIT);
                         VAL.get()
                     }
                 } else {
@@ -84,21 +85,19 @@ pub macro thread_local_inner {
         }
 
         unsafe {
-            use $crate::mem::needs_drop;
-            use $crate::thread::LocalKey;
-            use $crate::thread::local_impl::LazyStorage;
-
-            LocalKey::new(const {
-                if needs_drop::<$t>() {
+            $crate::thread::LocalKey::new(const {
+                if $crate::mem::needs_drop::<$t>() {
                     |init| {
                         #[thread_local]
-                        static VAL: LazyStorage<$t, ()> = LazyStorage::new();
+                        static VAL: $crate::thread::local_impl::LazyStorage<$t, ()>
+                            = $crate::thread::local_impl::LazyStorage::new();
                         VAL.get_or_init(init, __init)
                     }
                 } else {
                     |init| {
                         #[thread_local]
-                        static VAL: LazyStorage<$t, !> = LazyStorage::new();
+                        static VAL: $crate::thread::local_impl::LazyStorage<$t, !>
+                            = $crate::thread::local_impl::LazyStorage::new();
                         VAL.get_or_init(init, __init)
                     }
                 }
diff --git a/library/std/src/sys/thread_local/os.rs b/library/std/src/sys/thread_local/os.rs
index 26ce3322a16..f5a2aaa6c6a 100644
--- a/library/std/src/sys/thread_local/os.rs
+++ b/library/std/src/sys/thread_local/os.rs
@@ -15,19 +15,24 @@ pub macro thread_local_inner {
         $crate::thread::local_impl::thread_local_inner!(@key $t, { const INIT_EXPR: $t = $init; INIT_EXPR })
     },
 
-    // used to generate the `LocalKey` value for `thread_local!`
+    // NOTE: we cannot import `Storage` or `LocalKey` with a `use` because that can shadow user
+    // provided type or type alias with a matching name. Please update the shadowing test in
+    // `tests/thread.rs` if these types are renamed.
+
+    // used to generate the `LocalKey` value for `thread_local!`.
     (@key $t:ty, $init:expr) => {{
         #[inline]
         fn __init() -> $t { $init }
 
+        // NOTE: this cannot import `LocalKey` or `Storage` with a `use` because that can shadow
+        // user provided type or type alias with a matching name. Please update the shadowing test
+        // in `tests/thread.rs` if these types are renamed.
         unsafe {
-            use $crate::thread::LocalKey;
-            use $crate::thread::local_impl::Storage;
-
             // Inlining does not work on windows-gnu due to linking errors around
             // dllimports. See https://github.com/rust-lang/rust/issues/109797.
-            LocalKey::new(#[cfg_attr(windows, inline(never))] |init| {
-                static VAL: Storage<$t> = Storage::new();
+            $crate::thread::LocalKey::new(#[cfg_attr(windows, inline(never))] |init| {
+                static VAL: $crate::thread::local_impl::Storage<$t>
+                    = $crate::thread::local_impl::Storage::new();
                 VAL.get(init, __init)
             })
         }