diff --git a/kernel/src/syscall/imp/mod.rs b/kernel/src/syscall/imp/mod.rs
index b4b9ef7d..1e4aaac3 100644
--- a/kernel/src/syscall/imp/mod.rs
+++ b/kernel/src/syscall/imp/mod.rs
@@ -3,8 +3,9 @@ use core::mem::MaybeUninit;
 pub(crate) use abi::{
     error::Error,
     io::{
-        AccessMode, DirectoryEntry, FileAttr, FileMode, MountOptions, OpenOptions, PipeOptions,
-        PollControl, RawFd, TerminalOptions, TerminalSize, TimerOptions, UnmountOptions,
+        AccessMode, DirectoryEntry, FileAttr, FileMode, FileSync, MountOptions, OpenOptions,
+        PipeOptions, PollControl, RawFd, TerminalOptions, TerminalSize, TimerOptions,
+        UnmountOptions,
     },
     mem::{MappingFlags, MappingSource},
     net::SocketType,
diff --git a/kernel/src/syscall/imp/sys_io.rs b/kernel/src/syscall/imp/sys_io.rs
index 40aba23f..0966178a 100644
--- a/kernel/src/syscall/imp/sys_io.rs
+++ b/kernel/src/syscall/imp/sys_io.rs
@@ -4,7 +4,7 @@ use abi::{
     error::Error,
     io::{
         AccessMode, ChannelPublisherId, DeviceRequest, DirectoryEntry, FileAttr, FileControl,
-        FileMetadataUpdate, FileMode, FilesystemControl, MessageDestination, OpenOptions,
+        FileMetadataUpdate, FileMode, FileSync, FilesystemControl, MessageDestination, OpenOptions,
         PipeOptions, PollControl, RawFd, ReceivedMessageMetadata, Rename, SeekFrom, SentMessage,
         TerminalOptions, TerminalSize, TimerOptions,
     },
@@ -95,6 +95,18 @@ pub(crate) fn read(fd: RawFd, buffer: &mut [u8]) -> Result<usize, Error> {
     run_with_io(&process, |io| io.files.file(fd)?.read(buffer))
 }
 
+pub(crate) fn truncate(fd: RawFd, size: u64) -> Result<(), Error> {
+    let _ = fd;
+    let _ = size;
+    todo!()
+}
+
+pub(crate) fn fsync(fd: RawFd, what: FileSync) -> Result<(), Error> {
+    let _ = fd;
+    let _ = what;
+    todo!()
+}
+
 pub(crate) fn read_at(fd: RawFd, pos: u64, buffer: &mut [u8]) -> Result<usize, Error> {
     let thread = Thread::current();
     let process = thread.process();
diff --git a/lib/abi/def/io.abi b/lib/abi/def/io.abi
index 6518775f..1198aec8 100644
--- a/lib/abi/def/io.abi
+++ b/lib/abi/def/io.abi
@@ -32,6 +32,11 @@ bitfield FileMode(u32) {
     USER_READ: 8,
 }
 
+bitfield FileSync(u32) {
+    DATA: 0,
+    METADATA: 1,
+}
+
 bitfield AccessMode(u32) {
     READ: 0,
     WRITE: 1,
diff --git a/lib/abi/def/yggdrasil.abi b/lib/abi/def/yggdrasil.abi
index c65c06d2..2ca678af 100644
--- a/lib/abi/def/yggdrasil.abi
+++ b/lib/abi/def/yggdrasil.abi
@@ -117,6 +117,8 @@ syscall close(fd: RawFd) -> Result<()>;
 syscall write(fd: RawFd, data: &[u8]) -> Result<usize>;
 syscall read(fd: RawFd, data: &mut [u8]) -> Result<usize>;
 syscall seek(fd: RawFd, pos: SeekFrom, output: &mut u64) -> Result<()>;
+syscall truncate(fd: RawFd, size: u64) -> Result<()>;
+syscall fsync(fd: RawFd, what: FileSync) -> Result<()>;
 syscall read_at(fd: RawFd, pos: u64, data: &mut [u8]) -> Result<usize>;
 syscall write_at(fd: RawFd, pos: u64, data: &[u8]) -> Result<usize>;
 
diff --git a/lib/abi/src/io/file.rs b/lib/abi/src/io/file.rs
index 9d5989c3..9d6a68bb 100644
--- a/lib/abi/src/io/file.rs
+++ b/lib/abi/src/io/file.rs
@@ -2,6 +2,8 @@ use core::fmt;
 
 use abi_lib::SyscallRegister;
 
+use crate::time::SystemTime;
+
 use super::FileMode;
 
 /// Describes an action done on a file descriptor
@@ -21,11 +23,24 @@ pub enum FileMetadataUpdateMode {
     AndNot,
 }
 
+/// Describes how file times are updated
+#[derive(Debug, Clone)]
+pub struct FileTimesUpdate {
+    /// Last accessed time
+    pub atime: Option<SystemTime>,
+    /// Last modified time
+    pub mtime: Option<SystemTime>,
+    /// Created time
+    pub ctime: Option<SystemTime>,
+}
+
 /// Describes a modification to a file's metadata
 #[derive(Debug, Clone)]
 pub enum FileMetadataUpdate {
     /// Changes file permissions
     Permissions(FileMode, FileMetadataUpdateMode),
+    /// Changes file mtime/atime/ctime
+    Times(FileTimesUpdate),
 }
 
 /// Describes a seek operation for a regular file
diff --git a/lib/abi/src/io/mod.rs b/lib/abi/src/io/mod.rs
index 1ed109e2..a23d656a 100644
--- a/lib/abi/src/io/mod.rs
+++ b/lib/abi/src/io/mod.rs
@@ -6,12 +6,14 @@ mod input;
 mod terminal;
 
 pub use crate::generated::{
-    AccessMode, DirectoryEntry, FileAttr, FileMode, FileType, GroupId, MountOptions, OpenOptions,
-    PipeOptions, PollControl, RawFd, TimerOptions, UnmountOptions, UserId,
+    AccessMode, DirectoryEntry, FileAttr, FileMode, FileSync, FileType, GroupId, MountOptions,
+    OpenOptions, PipeOptions, PollControl, RawFd, TimerOptions, UnmountOptions, UserId,
 };
 pub use channel::{ChannelPublisherId, MessageDestination, ReceivedMessageMetadata, SentMessage};
 pub use device::{DeviceRequest, Framebuffer};
-pub use file::{FileControl, FileMetadataUpdate, FileMetadataUpdateMode, SeekFrom};
+pub use file::{
+    FileControl, FileMetadataUpdate, FileMetadataUpdateMode, FileTimesUpdate, SeekFrom,
+};
 pub use filesystem::FilesystemControl;
 pub use input::{KeyboardKey, KeyboardKeyCode, KeyboardKeyEvent};
 pub use terminal::{
diff --git a/lib/runtime/src/io.rs b/lib/runtime/src/io.rs
index 6e2b9c55..bdeef76e 100644
--- a/lib/runtime/src/io.rs
+++ b/lib/runtime/src/io.rs
@@ -25,7 +25,8 @@ use core::str::FromStr;
 
 pub use abi::io::{
     AccessMode, DirectoryEntry, FileAttr, FileMetadataUpdate, FileMetadataUpdateMode, FileMode,
-    FileType, OpenOptions, PipeOptions, RawFd, Rename, SeekFrom, TimerOptions,
+    FileSync, FileTimesUpdate, FileType, OpenOptions, PipeOptions, RawFd, Rename, SeekFrom,
+    TimerOptions,
 };
 
 use abi::{error::Error, io::DeviceRequest, process::ProcessOption, util::FixedString};
diff --git a/lib/runtime/src/sys/mod.rs b/lib/runtime/src/sys/mod.rs
index dee77d47..7990b98f 100644
--- a/lib/runtime/src/sys/mod.rs
+++ b/lib/runtime/src/sys/mod.rs
@@ -16,9 +16,9 @@ mod generated {
     use abi::{
         error::Error,
         io::{
-            AccessMode, ChannelPublisherId, DirectoryEntry, FileAttr, FileMode, MountOptions,
-            OpenOptions, PipeOptions, PollControl, RawFd, TerminalOptions, TerminalSize,
-            TimerOptions, UnmountOptions,
+            AccessMode, ChannelPublisherId, DirectoryEntry, FileAttr, FileMode, FileSync,
+            MountOptions, OpenOptions, PipeOptions, PollControl, RawFd, TerminalOptions,
+            TerminalSize, TimerOptions, UnmountOptions,
         },
         mem::{MappingFlags, MappingSource},
         net::SocketType,