diff --git a/userspace/lib/ygglibc/include/assert.h b/userspace/lib/ygglibc/include/assert.h
index 5c3df984..857b6329 100644
--- a/userspace/lib/ygglibc/include/assert.h
+++ b/userspace/lib/ygglibc/include/assert.h
@@ -1,3 +1,9 @@
+#if defined(_ASSERT_H)
+#undef _ASSERT_H
+#undef assert
+#undef __ASSERT_VOID_CAST
+#endif
+
 #ifndef _ASSERT_H
 #define _ASSERT_H 1
 
diff --git a/userspace/lib/ygglibc/include/bits/errno.h b/userspace/lib/ygglibc/include/bits/errno.h
index f71b69d9..04889270 100644
--- a/userspace/lib/ygglibc/include/bits/errno.h
+++ b/userspace/lib/ygglibc/include/bits/errno.h
@@ -6,6 +6,8 @@ extern "C" {
 #endif
 
 extern _Thread_local int errno;
+extern char *program_invocation_short_name;
+extern char *program_invocation_name;
 
 #if defined(__cplusplus)
 }
diff --git a/userspace/lib/ygglibc/src/headers/errno/mod.rs b/userspace/lib/ygglibc/src/headers/errno/mod.rs
index f021c725..4cad1ca9 100644
--- a/userspace/lib/ygglibc/src/headers/errno/mod.rs
+++ b/userspace/lib/ygglibc/src/headers/errno/mod.rs
@@ -80,6 +80,12 @@ pub enum Errno {
     // Custom errnos
     ENOTSUPP = 66,
     ETIMEOUT = 67,
+
+    EILSEQ = 68,
+    EOVERFLOW = 69,
+    ENOTSUP = 70,
+
+    ELAST = 71,
 }
 
 static UNKNOWN_ERROR: &CStr = static_cstr!("Unknown error");
@@ -153,6 +159,9 @@ static ERRNO_STRINGS: &[&CStr] = &[
     // Custom errnos
     static_cstr!("Operation not supported"),
     static_cstr!("Operation timed out"),
+    // GNU errnos
+    static_cstr!("Invalid sequence"),
+    static_cstr!("Integer overflow"),
 ];
 
 impl Errno {
diff --git a/userspace/lib/ygglibc/src/headers/fcntl/mod.rs b/userspace/lib/ygglibc/src/headers/fcntl/mod.rs
index 49b8bc3f..d127c5c1 100644
--- a/userspace/lib/ygglibc/src/headers/fcntl/mod.rs
+++ b/userspace/lib/ygglibc/src/headers/fcntl/mod.rs
@@ -93,8 +93,8 @@ enum OpenMode {
 
 fn open_opts(opts: c_int, ap: &mut VaList) -> EResult<OpenMode> {
     if opts & O_DIRECTORY != 0 {
-        if opts & !O_DIRECTORY != 0 {
-            todo!();
+        if opts & !(O_DIRECTORY | O_SEARCH) != 0 {
+            todo!("***open(O_DIRECTORY | {:#x})", opts & !O_DIRECTORY);
         }
 
         return EResult::Ok(OpenMode::Directory);
@@ -126,10 +126,16 @@ fn open_opts(opts: c_int, ap: &mut VaList) -> EResult<OpenMode> {
     if opts & O_TRUNC != 0 {
         res |= OpenOptions::TRUNCATE;
     }
+    if opts & O_NONBLOCK != 0 {
+        // TODO O_NONBLOCK
+    }
+    if opts & O_NOCTTY != 0 {
+        // TODO O_NOCTTY
+    }
     // TODO O_CLOEXEC
 
-    if opts & (O_DSYNC | O_RSYNC | O_SYNC | O_TTY_INIT | O_NONBLOCK | O_NOFOLLOW | O_NOCTTY) != 0 {
-        todo!();
+    if opts & (O_DSYNC | O_RSYNC | O_SYNC | O_TTY_INIT | O_NOFOLLOW) != 0 {
+        todo!("Unhandled options: {:#x}", opts);
     }
 
     let mode = if need_mode {
@@ -162,7 +168,7 @@ unsafe fn vopenat(atfd: c_int, pathname: *const c_char, opts: c_int, mut ap: VaL
 
     let fd = match open_opts(opts, &mut ap)? {
         OpenMode::File(opts, mode) => RawFile::open_at(atfd, pathname, opts, mode)?.into_raw_fd(),
-        OpenMode::Directory => todo!(),
+        OpenMode::Directory => RawFile::open_directory_at(atfd, pathname)?.into_raw_fd(),
     };
 
     CFdResult::success(fd)
diff --git a/userspace/lib/ygglibc/src/headers/mod.rs b/userspace/lib/ygglibc/src/headers/mod.rs
index 5ecb3fc8..256c1b5a 100644
--- a/userspace/lib/ygglibc/src/headers/mod.rs
+++ b/userspace/lib/ygglibc/src/headers/mod.rs
@@ -133,6 +133,7 @@ pub mod sys_statvfs;
 pub mod sys_time;
 pub mod sys_times;
 pub mod sys_types;
+pub mod sys_uio;
 pub mod sys_utsname;
 pub mod sys_wait;
 
diff --git a/userspace/lib/ygglibc/src/headers/signal/mod.rs b/userspace/lib/ygglibc/src/headers/signal/mod.rs
index 4af1017c..e34fe9a7 100644
--- a/userspace/lib/ygglibc/src/headers/signal/mod.rs
+++ b/userspace/lib/ygglibc/src/headers/signal/mod.rs
@@ -22,12 +22,14 @@ pub type sig_handler_t = unsafe extern "C" fn(c_int);
 pub type sigset_t = u64;
 
 #[repr(C)]
-pub struct stack_t {
+pub struct __stack {
     pub ss_sp: *mut c_void,
     pub ss_flags: c_int,
     pub ss_size: usize,
 }
 
+pub type stack_t = __stack;
+
 #[repr(C)]
 pub struct sigevent {
     pub sigev_notify: c_int,
@@ -305,8 +307,17 @@ unsafe extern "C" fn siginterrupt(_signum: c_int, _b: c_int) -> c_int {
 }
 
 #[no_mangle]
-unsafe extern "C" fn sigismember(_mask: *const sigset_t, _signum: c_int) -> c_int {
-    todo!()
+unsafe extern "C" fn sigismember(mask: *const sigset_t, signum: c_int) -> c_int {
+    if signum > 63 || signum <= 0 {
+        error::errno = Errno::EINVAL;
+        return -1;
+    }
+    let mask = *mask.ensure();
+    if mask & (1 << signum) != 0 {
+        1
+    } else {
+        0
+    }
 }
 
 #[no_mangle]
diff --git a/userspace/lib/ygglibc/src/headers/stdio/file.rs b/userspace/lib/ygglibc/src/headers/stdio/file.rs
index 320c5819..c7531b7f 100644
--- a/userspace/lib/ygglibc/src/headers/stdio/file.rs
+++ b/userspace/lib/ygglibc/src/headers/stdio/file.rs
@@ -243,3 +243,29 @@ unsafe extern "C" fn setvbuf(
     fp.setvbuf(mode, buffer, size)?;
     CIntZeroResult::SUCCESS
 }
+
+#[no_mangle]
+unsafe extern "C" fn fpurge(_fp: *mut FILE) {
+    todo!("fpurge()")
+}
+
+#[no_mangle]
+unsafe extern "C" fn __fpurge(_fp: *mut FILE) {
+    todo!("__fpurge()")
+}
+
+#[no_mangle]
+unsafe extern "C" fn freading(fp: *mut FILE) -> c_int {
+    __freading(fp)
+}
+
+#[no_mangle]
+unsafe extern "C" fn __freading(fp: *mut FILE) -> c_int {
+    let fp = fp.ensure_mut();
+    fp.reading() as c_int
+}
+
+#[no_mangle]
+unsafe extern "C" fn __fseterr(_fp: *mut FILE) {
+    todo!("__fseterr()")
+}
diff --git a/userspace/lib/ygglibc/src/headers/stdio/printf/mod.rs b/userspace/lib/ygglibc/src/headers/stdio/printf/mod.rs
index fb937221..0088887a 100644
--- a/userspace/lib/ygglibc/src/headers/stdio/printf/mod.rs
+++ b/userspace/lib/ygglibc/src/headers/stdio/printf/mod.rs
@@ -142,7 +142,7 @@ fn printf_inner<W: FmtWriter>(output: &mut W, format: &[u8], mut ap: VaList) ->
                 b'L' => todo!(),
                 b'j' => todo!(),
                 b'z' | b'Z' => opts.size = FmtSize::Size,
-                b't' => todo!(),
+                b't' => opts.size = FmtSize::Size,
                 _ => break,
             }
             cur = fmt.next();
@@ -173,7 +173,11 @@ fn printf_inner<W: FmtWriter>(output: &mut W, format: &[u8], mut ap: VaList) ->
                     spec = Some(FmtSpec::String);
                 }
                 b'p' => spec = Some(FmtSpec::Pointer),
-                b'n' => todo!(),
+                b'n' => unsafe {
+                    let arg = ap.arg::<*mut c_int>();
+                    *arg = count as c_int;
+                    continue;
+                },
                 b'm' => todo!(),
                 b'%' => {
                     count += output.write(b"%")?;
diff --git a/userspace/lib/ygglibc/src/headers/sys_socket/cbindgen.toml b/userspace/lib/ygglibc/src/headers/sys_socket/cbindgen.toml
index 72a85dd8..b878ac96 100644
--- a/userspace/lib/ygglibc/src/headers/sys_socket/cbindgen.toml
+++ b/userspace/lib/ygglibc/src/headers/sys_socket/cbindgen.toml
@@ -2,7 +2,8 @@ language = "C"
 style = "Tag"
 
 sys_includes = [
-    "sys/types.h"
+    "sys/types.h",
+    "sys/uio.h"
 ]
 no_includes = true
 
diff --git a/userspace/lib/ygglibc/src/headers/sys_socket/mod.rs b/userspace/lib/ygglibc/src/headers/sys_socket/mod.rs
index b373735a..3f3dce31 100644
--- a/userspace/lib/ygglibc/src/headers/sys_socket/mod.rs
+++ b/userspace/lib/ygglibc/src/headers/sys_socket/mod.rs
@@ -5,7 +5,10 @@ use core::{
 
 use crate::{error::EResult, headers::errno::Errno, util::PointerExt};
 
-use super::netinet_in::{sockaddr_in, sockaddr_in6};
+use super::{
+    netinet_in::{sockaddr_in, sockaddr_in6},
+    sys_uio::__ygg_iovec_t,
+};
 
 mod io;
 mod option;
@@ -31,19 +34,12 @@ pub struct sockaddr {
 
 // TODO struct sockaddr_storage
 
-// TODO struct iovec from sys/uio.h
-#[derive(Clone, Copy, Debug)]
-#[repr(C)]
-pub struct iovec {
-    __dummy: u32,
-}
-
 #[derive(Clone, Copy, Debug)]
 #[repr(C)]
 pub struct msghdr {
     pub msg_name: *mut c_void,
     pub msg_namelen: socklen_t,
-    pub msg_iov: *mut iovec,
+    pub msg_iov: *mut __ygg_iovec_t,
     pub msg_iovlen: c_int,
     pub msg_control: *mut c_void,
     pub msg_controllen: socklen_t,
diff --git a/userspace/lib/ygglibc/src/headers/sys_stat/mod.rs b/userspace/lib/ygglibc/src/headers/sys_stat/mod.rs
index 885b197d..7f1a6319 100644
--- a/userspace/lib/ygglibc/src/headers/sys_stat/mod.rs
+++ b/userspace/lib/ygglibc/src/headers/sys_stat/mod.rs
@@ -1,12 +1,15 @@
 use core::{
     ffi::{c_char, c_int},
-    ptr::NonNull,
+    ptr::{null, NonNull},
 };
 
-use yggdrasil_rt::io::{FileAttr, FileMode, FileType, RawFd};
+use yggdrasil_rt::io::{
+    FileAttr, FileMetadataUpdate, FileMetadataUpdateMode, FileMode, FileType, RawFd,
+};
 
 use crate::{
-    error::{CIntZeroResult, TryFromExt},
+    error::{CIntZeroResult, ResultExt, TryFromExt},
+    headers::errno::Errno,
     io,
     util::{self, PointerStrExt},
 };
@@ -104,23 +107,32 @@ impl From<FileAttr> for stat {
 }
 
 #[no_mangle]
-unsafe extern "C" fn chmod(_pathname: *const c_char, _mode: mode_t) -> c_int {
-    todo!()
+unsafe extern "C" fn chmod(pathname: *const c_char, mode: mode_t) -> CIntZeroResult {
+    fchmodat(AT_FDCWD, pathname, mode, 0)
 }
 
 #[no_mangle]
-unsafe extern "C" fn fchmod(_fd: c_int, _mode: mode_t) -> c_int {
-    todo!()
+unsafe extern "C" fn fchmod(fd: c_int, mode: mode_t) -> CIntZeroResult {
+    fchmodat(fd, null(), mode, 0)
 }
 
 #[no_mangle]
 unsafe extern "C" fn fchmodat(
-    _fd: c_int,
-    _pathname: *const c_char,
-    _mode: mode_t,
+    fd: c_int,
+    pathname: *const c_char,
+    mode: mode_t,
     _opt: c_int,
-) -> c_int {
-    todo!()
+) -> CIntZeroResult {
+    let atfd = util::at_fd(fd)?;
+    let path = if pathname.is_null() {
+        ""
+    } else {
+        pathname.ensure_str()
+    };
+    let mode = unsafe { FileMode::from_raw((mode as u32) & 0o777) };
+    let update = FileMetadataUpdate::Permissions(FileMetadataUpdateMode::Set(mode));
+    unsafe { yggdrasil_rt::sys::update_metadata(atfd, path, &update) }.e_map_err(Errno::from)?;
+    CIntZeroResult::SUCCESS
 }
 
 #[no_mangle]
@@ -222,7 +234,8 @@ unsafe extern "C" fn stat(pathname: *const c_char, statbuf: *mut stat) -> CIntZe
 
 #[no_mangle]
 unsafe extern "C" fn futimens(_fd: c_int, _times: *const __ygg_timespec_t) -> c_int {
-    todo!()
+    log::warn!("TODO: futimens");
+    0
 }
 
 #[no_mangle]
diff --git a/userspace/lib/ygglibc/src/headers/sys_uio/cbindgen.toml b/userspace/lib/ygglibc/src/headers/sys_uio/cbindgen.toml
new file mode 100644
index 00000000..88baae53
--- /dev/null
+++ b/userspace/lib/ygglibc/src/headers/sys_uio/cbindgen.toml
@@ -0,0 +1,17 @@
+language = "C"
+style = "Tag"
+
+sys_includes = [
+    "stddef.h",
+    "stdint.h",
+    "sys/types.h",
+]
+no_includes = true
+
+include_guard = "_SYS_UIO_H"
+
+usize_type = "size_t"
+isize_type = "ssize_t"
+
+[export]
+include = ["iovec", "__ygg_iovec_t"]
diff --git a/userspace/lib/ygglibc/src/headers/sys_uio/mod.rs b/userspace/lib/ygglibc/src/headers/sys_uio/mod.rs
new file mode 100644
index 00000000..86a753af
--- /dev/null
+++ b/userspace/lib/ygglibc/src/headers/sys_uio/mod.rs
@@ -0,0 +1,20 @@
+use core::ffi::{c_int, c_void};
+
+#[derive(Clone, Copy, Debug)]
+#[repr(C)]
+pub struct iovec {
+    pub iov_base: *mut c_void,
+    pub iov_len: usize,
+}
+
+pub type __ygg_iovec_t = iovec;
+
+#[no_mangle]
+unsafe extern "C" fn readv(_fd: c_int, _slice: *const iovec, _flags: c_int) -> isize {
+    todo!()
+}
+
+#[no_mangle]
+unsafe extern "C" fn writev(_fd: c_int, _slice: *const iovec, _flags: c_int) -> isize {
+    todo!()
+}
diff --git a/userspace/lib/ygglibc/src/headers/unistd/exec.rs b/userspace/lib/ygglibc/src/headers/unistd/exec.rs
index d6e6c236..383243ff 100644
--- a/userspace/lib/ygglibc/src/headers/unistd/exec.rs
+++ b/userspace/lib/ygglibc/src/headers/unistd/exec.rs
@@ -27,6 +27,11 @@ unsafe extern "C" fn execp(file: *const c_char, argv: *const *mut c_char) -> c_i
     todo!()
 }
 
+#[no_mangle]
+unsafe extern "C" fn execvp(file: *const c_char, argv: *const *mut c_char) -> c_int {
+    todo!()
+}
+
 #[no_mangle]
 unsafe extern "C" fn execve(
     file: *const c_char,
diff --git a/userspace/lib/ygglibc/src/headers/unistd/fs.rs b/userspace/lib/ygglibc/src/headers/unistd/fs.rs
index 4264d90c..b74aadca 100644
--- a/userspace/lib/ygglibc/src/headers/unistd/fs.rs
+++ b/userspace/lib/ygglibc/src/headers/unistd/fs.rs
@@ -3,15 +3,17 @@ use core::{
     ptr::{null_mut, NonNull},
 };
 
+use yggdrasil_rt::io::RemoveFlags;
+
 use crate::{
-    error::{self, CIntZeroResult, CPtrResult, EResult, TryFromExt},
+    error::{self, CIntZeroResult, CPtrResult, EResult, ResultExt, TryFromExt},
     headers::{
         errno::Errno,
-        fcntl::{faccessat, AT_FDCWD},
+        fcntl::{faccessat, AT_FDCWD, AT_REMOVEDIR},
         sys_types::{gid_t, off_t, uid_t},
     },
     io::{self, raw::RawFile, FromRawFd},
-    util::{PointerExt, PointerStrExt},
+    util::{self, PointerExt, PointerStrExt},
 };
 
 pub const _PC_PATH_MAX: c_int = 0;
@@ -40,7 +42,8 @@ unsafe extern "C" fn fchdir(fd: c_int) -> c_int {
 
 #[no_mangle]
 unsafe extern "C" fn fchown(fd: c_int, uid: uid_t, gid: gid_t) -> c_int {
-    todo!()
+    log::warn!("TODO: fchown({uid}, {gid})");
+    0
 }
 
 #[no_mangle]
@@ -135,12 +138,17 @@ unsafe extern "C" fn truncate(path: *const c_char, size: off_t) -> c_int {
     todo!()
 }
 #[no_mangle]
-unsafe extern "C" fn unlink(path: *const c_char) -> c_int {
-    let path = path.ensure_str();
-    log::warn!("TODO: unlink({path:?})");
-    0
+unsafe extern "C" fn unlink(path: *const c_char) -> CIntZeroResult {
+    unlinkat(AT_FDCWD, path, 0)
 }
 #[no_mangle]
-unsafe extern "C" fn unlinkat(atfd: c_int, path: *const c_char, flags: c_int) -> c_int {
-    todo!()
+unsafe extern "C" fn unlinkat(atfd: c_int, path: *const c_char, flags: c_int) -> CIntZeroResult {
+    let atfd = util::at_fd(atfd)?;
+    let path = path.ensure_str();
+    let mut f = RemoveFlags::empty();
+    if flags & AT_REMOVEDIR != 0 {
+        f |= RemoveFlags::DIRECTORY;
+    }
+    unsafe { yggdrasil_rt::sys::remove(atfd, path, f) }.e_map_err(Errno::from)?;
+    CIntZeroResult::SUCCESS
 }
diff --git a/userspace/lib/ygglibc/src/io/managed.rs b/userspace/lib/ygglibc/src/io/managed.rs
index 5d2e7624..baf29938 100644
--- a/userspace/lib/ygglibc/src/io/managed.rs
+++ b/userspace/lib/ygglibc/src/io/managed.rs
@@ -294,6 +294,13 @@ impl FILE {
         self.lock.release();
     }
 
+    pub fn reading(&self) -> bool {
+        !self.flags.contains(FileFlags::WRITE)
+            || self
+                .last_operation
+                .map_or(false, |op| op == Direction::Read)
+    }
+
     // pub fn reset(&mut self) {
     //     if let Some(read_buffer) = self.read_buffer.as_mut() {
     //         read_buffer.reset();
diff --git a/userspace/lib/ygglibc/src/io/raw.rs b/userspace/lib/ygglibc/src/io/raw.rs
index cf49772d..5ef579db 100644
--- a/userspace/lib/ygglibc/src/io/raw.rs
+++ b/userspace/lib/ygglibc/src/io/raw.rs
@@ -24,6 +24,11 @@ impl RawFile {
         EResult::Ok(Self(fd))
     }
 
+    pub fn open_directory_at<P: AsRef<Path>>(at: Option<RawFd>, pathname: P) -> EResult<Self> {
+        let fd = unsafe { syscall::open_directory(at, pathname.as_ref().as_str()) }?;
+        EResult::Ok(Self(fd))
+    }
+
     pub unsafe fn close(&mut self) -> EResult<()> {
         unsafe { syscall::close(self.0) }?;
         EResult::Ok(())
diff --git a/userspace/lib/ygglibc/src/process.rs b/userspace/lib/ygglibc/src/process.rs
index da105559..bae932db 100644
--- a/userspace/lib/ygglibc/src/process.rs
+++ b/userspace/lib/ygglibc/src/process.rs
@@ -1,6 +1,7 @@
 use core::{
     ffi::{c_char, c_int, c_void, CStr},
     mem::MaybeUninit,
+    ptr::null_mut,
     time::Duration,
 };
 
@@ -29,6 +30,13 @@ impl DsoDestructor {
     }
 }
 
+#[allow(non_upper_case_globals)]
+#[no_mangle]
+static mut program_invocation_short_name: *mut c_char = null_mut();
+#[allow(non_upper_case_globals)]
+#[no_mangle]
+static mut program_invocation_name: *mut c_char = null_mut();
+
 static AT_EXIT: Mutex<Vec<extern "C" fn()>> = Mutex::new(Vec::new());
 // TODO this will be in the linker instead
 static AT_DSO_EXIT: Mutex<Vec<DsoDestructor>> = Mutex::new(Vec::new());
diff --git a/xtask/src/build/ports.rs b/xtask/src/build/ports.rs
index ac7503bb..199f1f38 100644
--- a/xtask/src/build/ports.rs
+++ b/xtask/src/build/ports.rs
@@ -85,6 +85,19 @@ impl Node for Port {
 }
 
 impl NormalPort {
+    fn default_c_dependencies(name: &str) -> Vec<String> {
+        let mut d = vec![];
+        d.push("meta-llvm".into());
+        d.push("meta-libc".into());
+        if name != "compiler-rt" {
+            d.push("compiler-rt".into());
+        }
+        if name != "compiler-rt" && name != "openlibm" {
+            d.push("openlibm".into());
+        }
+        d
+    }
+
     pub fn load(env: &BuildEnv, name: &str) -> Result<Self, PortError> {
         let manifest_dir = env.workspace_root.join("ports").join(name);
         let source_dir = env
@@ -108,7 +121,7 @@ impl NormalPort {
             Some(deps) => {
                 let mut d = vec![];
                 if deps.c_compiler.unwrap_or(true) {
-                    d.push("meta-llvm".into());
+                    d.extend_from_slice(&Self::default_c_dependencies(name));
                 }
                 if let Some(build) = deps.build.as_ref() {
                     d.extend(build.iter().cloned());
@@ -118,7 +131,7 @@ impl NormalPort {
                 }
                 d
             }
-            None => vec!["meta-llvm".into()],
+            None => Self::default_c_dependencies(name),
         };
 
         Ok(Self {