diff --git a/lib/runtime-core/src/types.rs b/lib/runtime-core/src/types.rs
index 9ee5270dd..d9e983f34 100644
--- a/lib/runtime-core/src/types.rs
+++ b/lib/runtime-core/src/types.rs
@@ -77,6 +77,19 @@ where
 {
     const TYPE: Type;
 }
+
+unsafe impl WasmExternType for i8 {
+    const TYPE: Type = Type::I32;
+}
+unsafe impl WasmExternType for u8 {
+    const TYPE: Type = Type::I32;
+}
+unsafe impl WasmExternType for i16 {
+    const TYPE: Type = Type::I32;
+}
+unsafe impl WasmExternType for u16 {
+    const TYPE: Type = Type::I32;
+}
 unsafe impl WasmExternType for i32 {
     const TYPE: Type = Type::I32;
 }
diff --git a/lib/wasi/src/lib.rs b/lib/wasi/src/lib.rs
index b62f84dfb..3dcb2f7cb 100644
--- a/lib/wasi/src/lib.rs
+++ b/lib/wasi/src/lib.rs
@@ -1,3 +1,4 @@
+mod ptr;
 mod state;
 mod syscalls;
 mod utils;
diff --git a/lib/wasi/src/ptr.rs b/lib/wasi/src/ptr.rs
new file mode 100644
index 000000000..efc851858
--- /dev/null
+++ b/lib/wasi/src/ptr.rs
@@ -0,0 +1,89 @@
+use std::{cell::Cell, fmt, marker::PhantomData, mem};
+use wasmer_runtime_core::{
+    memory::Memory,
+    types::{Type, ValueType, WasmExternType},
+};
+
+pub struct Array;
+pub struct Item;
+
+#[repr(transparent)]
+pub struct WasmPtr<T: Copy, Ty = Item> {
+    offset: u32,
+    _phantom: PhantomData<(T, Ty)>,
+}
+
+impl<T: Copy, Ty> WasmPtr<T, Ty> {
+    pub fn new(offset: u32) -> Self {
+        Self {
+            offset,
+            _phantom: PhantomData,
+        }
+    }
+
+    pub fn offset(self) -> u32 {
+        self.offset
+    }
+}
+
+impl<T: Copy + ValueType> WasmPtr<T, Item> {
+    pub fn deref<'a>(self, memory: &'a Memory) -> Option<&'a Cell<T>> {
+        if (self.offset as usize) + mem::size_of::<T>() >= memory.size().bytes().0 {
+            return None;
+        }
+        unsafe {
+            let cell_ptr = memory
+                .view::<T>()
+                .get_unchecked((self.offset() as usize) / mem::size_of::<T>())
+                as *const _;
+            Some(&*cell_ptr)
+        }
+    }
+}
+
+impl<T: Copy + ValueType> WasmPtr<T, Array> {
+    pub fn deref<'a>(self, memory: &'a Memory, length: u32) -> Option<&'a [Cell<T>]> {
+        if (self.offset as usize) + (mem::size_of::<T>() * (length as usize))
+            >= memory.size().bytes().0
+        {
+            return None;
+        }
+
+        unsafe {
+            let cell_ptrs = memory.view::<T>().get_unchecked(
+                ((self.offset() as usize) / mem::size_of::<T>())
+                    ..((self.offset() as usize) / mem::size_of::<T>()) + (length as usize),
+            ) as *const _;
+            Some(&*cell_ptrs)
+        }
+    }
+}
+
+unsafe impl<T: Copy, Ty> WasmExternType for WasmPtr<T, Ty> {
+    const TYPE: Type = Type::I32;
+}
+
+impl<T: Copy, Ty> Clone for WasmPtr<T, Ty> {
+    fn clone(&self) -> Self {
+        Self {
+            offset: self.offset,
+            _phantom: PhantomData,
+        }
+    }
+}
+
+impl<T: Copy, Ty> Copy for WasmPtr<T, Ty> {}
+
+impl<T: Copy, Ty> PartialEq for WasmPtr<T, Ty> {
+    fn eq(&self, other: &Self) -> bool {
+        self.offset == other.offset
+    }
+}
+
+impl<T: Copy, Ty> Eq for WasmPtr<T, Ty> {}
+
+impl<T: Copy, Ty> fmt::Debug for WasmPtr<T, Ty> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "WasmPtr({:#x})", self.offset)
+    }
+}
diff --git a/lib/wasi/src/syscalls/mod.rs b/lib/wasi/src/syscalls/mod.rs
index 0c5f2f9b0..606c877a2 100644
--- a/lib/wasi/src/syscalls/mod.rs
+++ b/lib/wasi/src/syscalls/mod.rs
@@ -1,4 +1,12 @@
-use crate::state::WasiState;
+#![allow(unused)]
+
+mod types;
+
+use self::types::*;
+use crate::{
+    ptr::{Array, WasmPtr},
+    state::WasiState,
+};
 use wasmer_runtime_core::{memory::Memory, vm::Ctx};
 
 #[allow(clippy::mut_from_ref)]
@@ -34,11 +42,13 @@ fn write_buffer_array(
 /// - `char *argv_buf`
 ///     A pointer to a buffer to write the argument string data.
 ///
-pub fn args_get(ctx: &mut Ctx, ptr_buffer_offset: u32, buffer_offset: u32) {
+pub fn args_get(ctx: &mut Ctx, ptr_buffer_offset: u32, buffer_offset: u32) -> __wasi_errno_t {
     let state = get_wasi_state(ctx);
     let memory = ctx.memory(0);
 
     write_buffer_array(memory, &*state.args, ptr_buffer_offset, buffer_offset);
+
+    __WASI_ESUCCESS
 }
 
 /// ### `args_sizes_get()`
@@ -48,7 +58,7 @@ pub fn args_get(ctx: &mut Ctx, ptr_buffer_offset: u32, buffer_offset: u32) {
 ///     The number of arguments.
 /// - `size_t *argv_buf_size`
 ///     The size of the argument string data.
-pub fn args_sizes_get(ctx: &mut Ctx, argc_out: u32, argv_buf_size_out: u32) {
+pub fn args_sizes_get(ctx: &mut Ctx, argc_out: u32, argv_buf_size_out: u32) -> __wasi_errno_t {
     let state = get_wasi_state(ctx);
     let memory = ctx.memory(0);
 
@@ -57,12 +67,23 @@ pub fn args_sizes_get(ctx: &mut Ctx, argc_out: u32, argv_buf_size_out: u32) {
 
     memory.view::<u32>()[(argc_out / 4) as usize].set(arg_count as u32);
     memory.view::<u32>()[(argv_buf_size_out / 4) as usize].set(total_arg_size as u32);
+
+    __WASI_ESUCCESS
 }
 
-pub fn clock_res_get(ctx: &mut Ctx) {
+pub fn clock_res_get(
+    ctx: &mut Ctx,
+    clock_id: __wasi_clockid_t,
+    resolution: WasmPtr<__wasi_timestamp_t>,
+) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn clock_time_get(ctx: &mut Ctx) {
+pub fn clock_time_get(
+    ctx: &mut Ctx,
+    clock_id: __wasi_clockid_t,
+    precision: __wasi_timestamp_t,
+    time: WasmPtr<__wasi_timestamp_t>,
+) -> __wasi_errno_t {
     unimplemented!()
 }
 
@@ -74,11 +95,13 @@ pub fn clock_time_get(ctx: &mut Ctx) {
 ///     A pointer to a buffer to write the environment variable pointers.
 /// - `char *environ_buf`
 ///     A pointer to a buffer to write the environment variable string data.
-pub fn environ_get(ctx: &mut Ctx, environ: u32, environ_buf: u32) {
+pub fn environ_get(ctx: &mut Ctx, environ: u32, environ_buf: u32) -> __wasi_errno_t {
     let state = get_wasi_state(ctx);
     let memory = ctx.memory(0);
 
     write_buffer_array(memory, &*state.args, environ, environ_buf);
+
+    __WASI_ESUCCESS
 }
 
 /// ### `environ_sizes_get()`
@@ -88,7 +111,11 @@ pub fn environ_get(ctx: &mut Ctx, environ: u32, environ_buf: u32) {
 ///     The number of environment variables.
 /// - `size_t *environ_buf_size`
 ///     The size of the environment variable string data.
-pub fn environ_sizes_get(ctx: &mut Ctx, environ_count_out: u32, environ_buf_size_out: u32) {
+pub fn environ_sizes_get(
+    ctx: &mut Ctx,
+    environ_count_out: u32,
+    environ_buf_size_out: u32,
+) -> __wasi_errno_t {
     let state = get_wasi_state(ctx);
     let memory = ctx.memory(0);
 
@@ -97,122 +124,185 @@ pub fn environ_sizes_get(ctx: &mut Ctx, environ_count_out: u32, environ_buf_size
 
     memory.view::<u32>()[(environ_count_out / 4) as usize].set(env_count as u32);
     memory.view::<u32>()[(environ_buf_size_out / 4) as usize].set(total_env_size as u32);
+
+    __WASI_ESUCCESS
 }
 
-pub fn fd_advise(ctx: &mut Ctx) {
+pub fn fd_advise(
+    ctx: &mut Ctx,
+    fd: __wasi_fd_t,
+    offset: __wasi_filesize_t,
+    len: __wasi_filesize_t,
+    advice: __wasi_advice_t,
+) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_allocate(ctx: &mut Ctx) {
+pub fn fd_allocate(
+    ctx: &mut Ctx,
+    fd: __wasi_fd_t,
+    offset: __wasi_filesize_t,
+    len: __wasi_filesize_t,
+) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_close(ctx: &mut Ctx) {
+pub fn fd_close(ctx: &mut Ctx, fd: __wasi_fd_t) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_datasync(ctx: &mut Ctx) {
+pub fn fd_datasync(ctx: &mut Ctx, fd: __wasi_fd_t) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_fdstat_get(ctx: &mut Ctx) {
+pub fn fd_fdstat_get(
+    ctx: &mut Ctx,
+    fd: __wasi_fd_t,
+    buf: WasmPtr<__wasi_fdstat_t>,
+) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_fdstat_set_flags(ctx: &mut Ctx) {
+pub fn fd_fdstat_set_flags(
+    ctx: &mut Ctx,
+    fd: __wasi_fd_t,
+    flags: __wasi_fdflags_t,
+) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_fdstat_set_rights(ctx: &mut Ctx) {
+pub fn fd_fdstat_set_rights(
+    ctx: &mut Ctx,
+    fd: __wasi_fd_t,
+    fs_rights_base: __wasi_rights_t,
+    fs_rights_inheriting: __wasi_rights_t,
+) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_filestat_get(ctx: &mut Ctx) {
+pub fn fd_filestat_get(
+    ctx: &mut Ctx,
+    fd: __wasi_fd_t,
+    buf: WasmPtr<__wasi_filestat_t>,
+) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_filestat_set_size(ctx: &mut Ctx) {
+pub fn fd_filestat_set_size(
+    ctx: &mut Ctx,
+    fd: __wasi_fd_t,
+    st_size: __wasi_filesize_t,
+) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_filestat_set_times(ctx: &mut Ctx) {
+pub fn fd_filestat_set_times(
+    ctx: &mut Ctx,
+    fd: __wasi_fd_t,
+    st_atim: __wasi_timestamp_t,
+    st_mtim: __wasi_timestamp_t,
+    fst_flags: __wasi_fstflags_t,
+) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_pread(ctx: &mut Ctx) {
+pub fn fd_pread(
+    ctx: &mut Ctx,
+    fd: __wasi_fd_t,
+    iovs: WasmPtr<__wasi_iovec_t, Array>,
+    iovs_len: u32,
+    offset: __wasi_filesize_t,
+    nread: WasmPtr<u32>,
+) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_prestat_get(ctx: &mut Ctx) {
+pub fn fd_prestat_get(
+    ctx: &mut Ctx,
+    fd: __wasi_fd_t,
+    buf: WasmPtr<__wasi_fdstat_t>,
+) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_prestat_dir_name(ctx: &mut Ctx) {
+pub fn fd_prestat_dir_name(
+    ctx: &mut Ctx,
+    fd: __wasi_fd_t,
+    path: WasmPtr<u8, Array>,
+    path_len: u32,
+) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_pwrite(ctx: &mut Ctx) {
+pub fn fd_pwrite(
+    ctx: &mut Ctx,
+    fd: __wasi_fd_t,
+    iovs: WasmPtr<__wasi_ciovec_t, Array>,
+    iovs_len: u32,
+    offset: __wasi_filesize_t,
+    nwritten: WasmPtr<u32>,
+) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_read(ctx: &mut Ctx) {
+pub fn fd_read(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_readdir(ctx: &mut Ctx) {
+pub fn fd_readdir(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_renumber(ctx: &mut Ctx) {
+pub fn fd_renumber(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_seek(ctx: &mut Ctx) {
+pub fn fd_seek(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_sync(ctx: &mut Ctx) {
+pub fn fd_sync(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_tell(ctx: &mut Ctx) {
+pub fn fd_tell(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn fd_write(ctx: &mut Ctx) {
+pub fn fd_write(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn path_create_directory(ctx: &mut Ctx) {
+pub fn path_create_directory(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn path_filestat_get(ctx: &mut Ctx) {
+pub fn path_filestat_get(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn path_filestat_set_times(ctx: &mut Ctx) {
+pub fn path_filestat_set_times(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn path_link(ctx: &mut Ctx) {
+pub fn path_link(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn path_open(ctx: &mut Ctx) {
+pub fn path_open(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn path_readlink(ctx: &mut Ctx) {
+pub fn path_readlink(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn path_remove_directory(ctx: &mut Ctx) {
+pub fn path_remove_directory(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn path_rename(ctx: &mut Ctx) {
+pub fn path_rename(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn path_symlink(ctx: &mut Ctx) {
+pub fn path_symlink(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn path_unlink_file(ctx: &mut Ctx) {
+pub fn path_unlink_file(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn poll_oneoff(ctx: &mut Ctx) {
+pub fn poll_oneoff(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
 pub fn proc_exit(ctx: &mut Ctx) {
     unimplemented!()
 }
-pub fn proc_raise(ctx: &mut Ctx) {
+pub fn proc_raise(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn random_get(ctx: &mut Ctx) {
+pub fn random_get(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn sched_yield(ctx: &mut Ctx) {
+pub fn sched_yield(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn sock_recv(ctx: &mut Ctx) {
+pub fn sock_recv(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn sock_send(ctx: &mut Ctx) {
+pub fn sock_send(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
-pub fn sock_shutdown(ctx: &mut Ctx) {
+pub fn sock_shutdown(ctx: &mut Ctx) -> __wasi_errno_t {
     unimplemented!()
 }
diff --git a/lib/wasi/src/syscalls/types.rs b/lib/wasi/src/syscalls/types.rs
index 6a927a301..bda4bd1b5 100644
--- a/lib/wasi/src/syscalls/types.rs
+++ b/lib/wasi/src/syscalls/types.rs
@@ -1,5 +1,8 @@
 #![allow(non_camel_case_types)]
 
+use crate::ptr::{Array, WasmPtr};
+use wasmer_runtime_core::types::{ValueError, ValueType};
+
 pub type __wasi_advice_t = u8;
 pub const __WASI_ADVICE_DONTNEED: u8 = 0;
 pub const __WASI_ADVICE_NOREUSE: u8 = 1;
@@ -11,7 +14,7 @@ pub const __WASI_ADVICE_WILLNEED: u8 = 5;
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 #[repr(C)]
 pub struct __wasi_ciovec_t {
-    pub buf: u32,
+    pub buf: WasmPtr<u8, Array>,
     pub buf_len: u32,
 }
 
@@ -205,7 +208,7 @@ pub type __wasi_inode_t = u64;
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 #[repr(C)]
 pub struct __wasi_iovec_t {
-    pub buf: u32,
+    pub buf: WasmPtr<u8, Array>,
     pub buf_len: u32,
 }