diff --git a/examples/acipher-rs/ta/src/main.rs b/examples/acipher-rs/ta/src/main.rs
index b8ea6853..8418e07f 100644
--- a/examples/acipher-rs/ta/src/main.rs
+++ b/examples/acipher-rs/ta/src/main.rs
@@ -17,7 +17,6 @@
 
 #![no_std]
 #![no_main]
-#![feature(c_size_t)]
 
 extern crate alloc;
 
diff --git a/examples/acipher-rs/ta/ta_static.rs b/examples/acipher-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/acipher-rs/ta/ta_static.rs
+++ b/examples/acipher-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/aes-rs/ta/src/main.rs b/examples/aes-rs/ta/src/main.rs
index fcceb7b9..71612854 100644
--- a/examples/aes-rs/ta/src/main.rs
+++ b/examples/aes-rs/ta/src/main.rs
@@ -17,7 +17,6 @@
 
 #![no_std]
 #![no_main]
-#![feature(c_size_t)]
 
 extern crate alloc;
 
diff --git a/examples/aes-rs/ta/ta_static.rs b/examples/aes-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/aes-rs/ta/ta_static.rs
+++ b/examples/aes-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/authentication-rs/ta/src/main.rs b/examples/authentication-rs/ta/src/main.rs
index 02bdcaa9..247aa6b2 100644
--- a/examples/authentication-rs/ta/src/main.rs
+++ b/examples/authentication-rs/ta/src/main.rs
@@ -17,7 +17,6 @@
 
 #![no_std]
 #![no_main]
-#![feature(c_size_t)]
 
 extern crate alloc;
 
diff --git a/examples/authentication-rs/ta/ta_static.rs b/examples/authentication-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/authentication-rs/ta/ta_static.rs
+++ b/examples/authentication-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/big_int-rs/ta/src/main.rs b/examples/big_int-rs/ta/src/main.rs
index 6049176b..01ae6f09 100644
--- a/examples/big_int-rs/ta/src/main.rs
+++ b/examples/big_int-rs/ta/src/main.rs
@@ -17,7 +17,6 @@
 
 #![no_std]
 #![no_main]
-#![feature(c_size_t)]
 
 use optee_utee::BigInt;
 use optee_utee::{
diff --git a/examples/big_int-rs/ta/ta_static.rs b/examples/big_int-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/big_int-rs/ta/ta_static.rs
+++ b/examples/big_int-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/diffie_hellman-rs/ta/src/main.rs b/examples/diffie_hellman-rs/ta/src/main.rs
index d812eb54..7a08abcf 100644
--- a/examples/diffie_hellman-rs/ta/src/main.rs
+++ b/examples/diffie_hellman-rs/ta/src/main.rs
@@ -17,7 +17,6 @@
 
 #![no_std]
 #![no_main]
-#![feature(c_size_t)]
 
 extern crate alloc;
 
diff --git a/examples/diffie_hellman-rs/ta/ta_static.rs b/examples/diffie_hellman-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/diffie_hellman-rs/ta/ta_static.rs
+++ b/examples/diffie_hellman-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/digest-rs/ta/src/main.rs b/examples/digest-rs/ta/src/main.rs
index 5080bf88..1cc159e1 100644
--- a/examples/digest-rs/ta/src/main.rs
+++ b/examples/digest-rs/ta/src/main.rs
@@ -17,7 +17,6 @@
 
 #![no_std]
 #![no_main]
-#![feature(c_size_t)]
 
 extern crate alloc;
 
diff --git a/examples/digest-rs/ta/ta_static.rs b/examples/digest-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/digest-rs/ta/ta_static.rs
+++ b/examples/digest-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/error_handling-rs/ta/src/main.rs b/examples/error_handling-rs/ta/src/main.rs
index 7f13f911..755e5afd 100644
--- a/examples/error_handling-rs/ta/src/main.rs
+++ b/examples/error_handling-rs/ta/src/main.rs
@@ -17,7 +17,6 @@
 
 #![no_std]
 #![no_main]
-#![feature(c_size_t)]
 
 extern crate alloc;
 
diff --git a/examples/error_handling-rs/ta/ta_static.rs b/examples/error_handling-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/error_handling-rs/ta/ta_static.rs
+++ b/examples/error_handling-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/hello_world-rs/ta/src/main.rs b/examples/hello_world-rs/ta/src/main.rs
index f952896b..8ef0567b 100644
--- a/examples/hello_world-rs/ta/src/main.rs
+++ b/examples/hello_world-rs/ta/src/main.rs
@@ -17,7 +17,6 @@
 
 #![no_std]
 #![no_main]
-#![feature(c_size_t)]
 
 use optee_utee::{
     ta_close_session, ta_create, ta_destroy, ta_invoke_command, ta_open_session, trace_println,
diff --git a/examples/hello_world-rs/ta/ta_static.rs b/examples/hello_world-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/hello_world-rs/ta/ta_static.rs
+++ b/examples/hello_world-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/hotp-rs/ta/src/main.rs b/examples/hotp-rs/ta/src/main.rs
index 8bc1720d..2d20f721 100644
--- a/examples/hotp-rs/ta/src/main.rs
+++ b/examples/hotp-rs/ta/src/main.rs
@@ -17,7 +17,6 @@
 
 #![no_std]
 #![no_main]
-#![feature(c_size_t)]
 
 extern crate alloc;
 
diff --git a/examples/hotp-rs/ta/ta_static.rs b/examples/hotp-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/hotp-rs/ta/ta_static.rs
+++ b/examples/hotp-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/message_passing_interface-rs/ta/src/main.rs b/examples/message_passing_interface-rs/ta/src/main.rs
index e79f78b2..5b9f361b 100644
--- a/examples/message_passing_interface-rs/ta/src/main.rs
+++ b/examples/message_passing_interface-rs/ta/src/main.rs
@@ -16,7 +16,6 @@
 // under the License.
 
 #![no_main]
-#![feature(c_size_t)]
 
 use optee_utee::{
     ta_close_session, ta_create, ta_destroy, ta_invoke_command, ta_open_session, trace_println,
diff --git a/examples/message_passing_interface-rs/ta/ta_static.rs b/examples/message_passing_interface-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/message_passing_interface-rs/ta/ta_static.rs
+++ b/examples/message_passing_interface-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/random-rs/ta/src/main.rs b/examples/random-rs/ta/src/main.rs
index 92ec6731..b419b28a 100644
--- a/examples/random-rs/ta/src/main.rs
+++ b/examples/random-rs/ta/src/main.rs
@@ -17,7 +17,6 @@
 
 #![no_std]
 #![no_main]
-#![feature(c_size_t)]
 
 extern crate alloc;
 
diff --git a/examples/random-rs/ta/ta_static.rs b/examples/random-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/random-rs/ta/ta_static.rs
+++ b/examples/random-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/secure_storage-rs/ta/src/main.rs b/examples/secure_storage-rs/ta/src/main.rs
index 8ffce52e..f1bc47f0 100644
--- a/examples/secure_storage-rs/ta/src/main.rs
+++ b/examples/secure_storage-rs/ta/src/main.rs
@@ -17,7 +17,6 @@
 
 #![no_std]
 #![no_main]
-#![feature(c_size_t)]
 
 extern crate alloc;
 
diff --git a/examples/secure_storage-rs/ta/ta_static.rs b/examples/secure_storage-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/secure_storage-rs/ta/ta_static.rs
+++ b/examples/secure_storage-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/serde-rs/ta/src/main.rs b/examples/serde-rs/ta/src/main.rs
index c0918c2f..7f239c01 100644
--- a/examples/serde-rs/ta/src/main.rs
+++ b/examples/serde-rs/ta/src/main.rs
@@ -18,7 +18,6 @@
 #![no_main]
 // this is the workaround for the error:
 // error[E0658]: use of unstable library feature 'c_size_t'
-#![feature(c_size_t)]
 
 use optee_utee::{
     ta_close_session, ta_create, ta_destroy, ta_invoke_command, ta_open_session, trace_println,
diff --git a/examples/serde-rs/ta/ta_static.rs b/examples/serde-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/serde-rs/ta/ta_static.rs
+++ b/examples/serde-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/signature_verification-rs/ta/src/main.rs b/examples/signature_verification-rs/ta/src/main.rs
index 0f34cc32..cc03b895 100644
--- a/examples/signature_verification-rs/ta/src/main.rs
+++ b/examples/signature_verification-rs/ta/src/main.rs
@@ -17,7 +17,6 @@
 
 #![no_std]
 #![no_main]
-#![feature(c_size_t)]
 
 extern crate alloc;
 
diff --git a/examples/signature_verification-rs/ta/ta_static.rs b/examples/signature_verification-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/signature_verification-rs/ta/ta_static.rs
+++ b/examples/signature_verification-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/supp_plugin-rs/ta/src/main.rs b/examples/supp_plugin-rs/ta/src/main.rs
index 307064a8..c1b4a796 100644
--- a/examples/supp_plugin-rs/ta/src/main.rs
+++ b/examples/supp_plugin-rs/ta/src/main.rs
@@ -17,7 +17,6 @@
 
 #![no_std]
 #![no_main]
-#![feature(c_size_t)]
 
 extern crate alloc;
 
diff --git a/examples/supp_plugin-rs/ta/ta_static.rs b/examples/supp_plugin-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/supp_plugin-rs/ta/ta_static.rs
+++ b/examples/supp_plugin-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/tcp_client-rs/ta/src/main.rs b/examples/tcp_client-rs/ta/src/main.rs
index de5c12e5..e8712248 100644
--- a/examples/tcp_client-rs/ta/src/main.rs
+++ b/examples/tcp_client-rs/ta/src/main.rs
@@ -16,7 +16,6 @@
 // under the License.
 
 #![no_main]
-#![feature(c_size_t)]
 
 use optee_utee::net::TcpStream;
 use optee_utee::{
diff --git a/examples/tcp_client-rs/ta/ta_static.rs b/examples/tcp_client-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/tcp_client-rs/ta/ta_static.rs
+++ b/examples/tcp_client-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/time-rs/ta/src/main.rs b/examples/time-rs/ta/src/main.rs
index fbd73a1c..9ec91da6 100644
--- a/examples/time-rs/ta/src/main.rs
+++ b/examples/time-rs/ta/src/main.rs
@@ -17,7 +17,6 @@
 
 #![no_std]
 #![no_main]
-#![feature(c_size_t)]
 
 use optee_utee::Time;
 use optee_utee::{
diff --git a/examples/time-rs/ta/ta_static.rs b/examples/time-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/time-rs/ta/ta_static.rs
+++ b/examples/time-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/tls_client-rs/ta/src/main.rs b/examples/tls_client-rs/ta/src/main.rs
index b1de4106..fb64c4b9 100644
--- a/examples/tls_client-rs/ta/src/main.rs
+++ b/examples/tls_client-rs/ta/src/main.rs
@@ -16,7 +16,6 @@
 // under the License.
 
 #![no_main]
-#![feature(c_size_t)]
 
 use optee_utee::net::TcpStream;
 use optee_utee::{
diff --git a/examples/tls_client-rs/ta/ta_static.rs b/examples/tls_client-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/tls_client-rs/ta/ta_static.rs
+++ b/examples/tls_client-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/tls_server-rs/ta/src/main.rs b/examples/tls_server-rs/ta/src/main.rs
index 0beb9ecf..2b4ebb74 100644
--- a/examples/tls_server-rs/ta/src/main.rs
+++ b/examples/tls_server-rs/ta/src/main.rs
@@ -16,7 +16,6 @@
 // under the License.
 
 #![no_main]
-#![feature(c_size_t)]
 
 use optee_utee::{
     ta_close_session, ta_create, ta_destroy, ta_invoke_command, ta_open_session, trace_println,
diff --git a/examples/tls_server-rs/ta/ta_static.rs b/examples/tls_server-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/tls_server-rs/ta/ta_static.rs
+++ b/examples/tls_server-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [
diff --git a/examples/udp_socket-rs/ta/src/main.rs b/examples/udp_socket-rs/ta/src/main.rs
index 4f3025da..812f4181 100644
--- a/examples/udp_socket-rs/ta/src/main.rs
+++ b/examples/udp_socket-rs/ta/src/main.rs
@@ -16,7 +16,6 @@
 // under the License.
 
 #![no_main]
-#![feature(c_size_t)]
 
 use optee_utee::net::UdpSocket;
 use optee_utee::{
diff --git a/examples/udp_socket-rs/ta/ta_static.rs b/examples/udp_socket-rs/ta/ta_static.rs
index 53ca2109..20e1d977 100644
--- a/examples/udp_socket-rs/ta/ta_static.rs
+++ b/examples/udp_socket-rs/ta/ta_static.rs
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use core::ffi::*;
+use core::ffi::{c_int, c_void};
 use core::mem;
 use core::primitive::u64;
 
@@ -39,13 +39,13 @@ pub static ta_head: optee_utee_sys::ta_head = optee_utee_sys::ta_head {
 pub static ta_heap: [u8; TA_DATA_SIZE as usize] = [0; TA_DATA_SIZE as usize];
 
 #[no_mangle]
-pub static ta_heap_size: c_size_t = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
+pub static ta_heap_size: usize = mem::size_of::<u8>() * TA_DATA_SIZE as usize;
 static FLAG_BOOL: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_SINGLE_INSTANCE) != 0;
 static FLAG_MULTI: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_MULTI_SESSION) != 0;
 static FLAG_INSTANCE: bool = (TA_FLAGS & optee_utee_sys::TA_FLAG_INSTANCE_KEEP_ALIVE) != 0;
 
 #[no_mangle]
-pub static ta_num_props: c_size_t = 9;
+pub static ta_num_props: usize = 9;
 
 #[no_mangle]
 pub static ta_props: [optee_utee_sys::user_ta_property; 9] = [