diff --git a/Cargo.toml b/Cargo.toml
index 89d5bf1ff..0fab6d505 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,7 +11,6 @@ members = [
     "src/obconf",
     "src/tls",
 ]
-default-members = ["gui"]
 
 [profile.dev]
 panic = "abort"
diff --git a/kernel/src/malloc/stage2.rs b/kernel/src/malloc/stage2.rs
index 168cec577..27d3ee381 100644
--- a/kernel/src/malloc/stage2.rs
+++ b/kernel/src/malloc/stage2.rs
@@ -1,6 +1,6 @@
 use crate::config::PAGE_SIZE;
 use crate::context::{current_thread, CpuLocal};
-use crate::uma::{Uma, UmaZone};
+use crate::uma::{Uma, UmaFlags, UmaZone};
 use alloc::string::ToString;
 use alloc::sync::Arc;
 use alloc::vec::Vec;
@@ -23,7 +23,12 @@ impl Stage2 {
     const KMEM_ZMASK: usize = Self::KMEM_ZBASE - 1;
     const KMEM_ZSIZE: usize = PAGE_SIZE.get() >> Self::KMEM_ZSHIFT;
 
-    /// See `kmeminit` on the PS4 for a reference.
+    /// See `kmeminit` on the Orbis for a reference.
+    ///
+    /// # Reference offsets
+    /// | Version | Offset |
+    /// |---------|--------|
+    /// |PS4 11.00|0x1A4B80|
     pub fn new(uma: &mut Uma) -> Self {
         // The possible of maximum alignment that Layout allowed is a bit before the most
         // significant bit of isize (e.g. 0x4000000000000000 on 64 bit system). So we can use
@@ -46,7 +51,12 @@ impl Stage2 {
                 }
 
                 // Create zone.
-                let zone = Arc::new(uma.create_zone(size.to_string().into(), size, align - 1));
+                let zone = Arc::new(uma.create_zone(
+                    size.to_string().into(),
+                    size,
+                    align - 1,
+                    UmaFlags::new().with_malloc(true),
+                ));
 
                 while last <= size.get() {
                     zones.push(zone.clone());
diff --git a/kernel/src/uma/mod.rs b/kernel/src/uma/mod.rs
index c4a93b5f9..c00c7ce44 100644
--- a/kernel/src/uma/mod.rs
+++ b/kernel/src/uma/mod.rs
@@ -1,5 +1,6 @@
 pub use self::zone::*;
 use alloc::borrow::Cow;
+use bitfield_struct::bitfield;
 use core::num::NonZero;
 
 mod bucket;
@@ -9,20 +10,49 @@ mod zone;
 pub struct Uma {}
 
 impl Uma {
-    /// See `uma_startup` on the PS4 for a reference. Beware that our implementation cannot access
+    /// See `uma_startup` on the Orbis for a reference. Beware that our implementation cannot access
     /// the CPU context due to this function can be called before context activation.
     ///
     /// # Context safety
     /// This function does not require a CPU context.
+    ///
+    /// # Reference offsets
+    /// | Version | Offset |
+    /// |---------|--------|
+    /// |PS4 11.00|0x13CA70|
     pub fn new() -> Self {
         Self {}
     }
 
-    /// See `uma_zcreate` on the PS4 for a reference.
+    /// See `uma_zcreate` on the Orbis for a reference.
     ///
     /// # Context safety
     /// This function does not require a CPU context on **stage 1** heap.
-    pub fn create_zone(&mut self, _: Cow<'static, str>, _: NonZero<usize>, _: usize) -> UmaZone {
-        todo!()
+    ///
+    /// # Reference offsets
+    /// | Version | Offset |
+    /// |---------|--------|
+    /// |PS4 11.00|0x13DC80|
+    pub fn create_zone(
+        &mut self,
+        _: Cow<'static, str>,
+        _: NonZero<usize>,
+        _: usize,
+        _: UmaFlags,
+    ) -> UmaZone {
+        // The Orbis will allocate a new zone from masterzone_z. We choose to remove this since it
+        // does not idomatic to Rust, which mean our uma_zone itself can live on the stack.
+        UmaZone::new()
     }
 }
+
+/// Flags for [`Uma::create_zone()`].
+#[bitfield(u32)]
+pub struct UmaFlags {
+    #[bits(4)]
+    __: u8,
+    /// `UMA_ZONE_MALLOC`.
+    pub malloc: bool,
+    #[bits(27)]
+    __: u32,
+}
diff --git a/kernel/src/uma/zone.rs b/kernel/src/uma/zone.rs
index 73d8aeb39..107ab25aa 100644
--- a/kernel/src/uma/zone.rs
+++ b/kernel/src/uma/zone.rs
@@ -18,6 +18,19 @@ pub struct UmaZone {
 }
 
 impl UmaZone {
+    /// See `zone_ctor` on Orbis for a reference.
+    ///
+    /// # Context safety
+    /// This function does not require a CPU context on **stage 1** heap.
+    ///
+    /// # Reference offsets
+    /// | Version | Offset |
+    /// |---------|--------|
+    /// |PS4 11.00|0x13D490|
+    pub(super) fn new() -> Self {
+        todo!()
+    }
+
     pub fn size(&self) -> NonZero<usize> {
         self.size
     }