diff --git a/abi/src/lib.rs b/abi/src/lib.rs
index e8daf7c..efbb865 100644
--- a/abi/src/lib.rs
+++ b/abi/src/lib.rs
@@ -25,11 +25,12 @@ pub fn get_key() -> KeyEvent {
 }
 
 pub mod display {
+    use abi_sys::CPixel;
     use embedded_graphics::{
         Pixel,
         geometry::{Dimensions, Point},
         pixelcolor::{Rgb565, RgbColor},
-        prelude::{DrawTarget, Size},
+        prelude::{DrawTarget, IntoStorage, Size},
         primitives::Rectangle,
     };
 
@@ -42,8 +43,27 @@ pub mod display {
         abi_sys::lock_display(lock);
     }
 
+    const BUF_SIZE: usize = 1024; // tune this for performance
+
     fn draw_iter(pixels: &[Pixel<Rgb565>]) {
-        abi_sys::draw_iter(pixels.as_ptr(), pixels.len())
+        let mut cpixels: [CPixel; BUF_SIZE] = [const {
+            CPixel {
+                x: 0,
+                y: 0,
+                color: 0,
+            }
+        }; BUF_SIZE];
+        for (px, cpx) in pixels.iter().zip(cpixels.iter_mut()) {
+            let Pixel(pos, color) = px;
+            let color: u16 = color.into_storage(); // convert Rgb565 -> u16
+            *cpx = CPixel {
+                x: pos.x,
+                y: pos.y,
+                color,
+            };
+        }
+
+        abi_sys::draw_iter(cpixels.as_ptr(), cpixels.len())
     }
 
     pub struct Display;
@@ -68,7 +88,6 @@ pub mod display {
         where
             I: IntoIterator<Item = Pixel<Self::Color>>,
         {
-            const BUF_SIZE: usize = 1024; // tune this for performance
             let mut buf: [Pixel565; BUF_SIZE] = [Pixel(Point::new(0, 0), Rgb565::BLACK); BUF_SIZE];
 
             let mut count = 0;
diff --git a/abi_sys/src/lib.rs b/abi_sys/src/lib.rs
index 89c0427..5f0aa78 100644
--- a/abi_sys/src/lib.rs
+++ b/abi_sys/src/lib.rs
@@ -1,10 +1,16 @@
 #![no_std]
 
-use embedded_graphics::{Pixel, pixelcolor::Rgb565};
+use embedded_graphics::{
+    Pixel,
+    pixelcolor::Rgb565,
+    prelude::{IntoStorage, Point},
+};
 use embedded_sdmmc::DirEntry;
-use strum::{EnumCount, EnumIter};
+use strum::EnumIter;
 
-#[derive(Clone, Copy, EnumIter, EnumCount)]
+pub const ABI_CALL_TABLE_COUNT: usize = 9;
+
+#[derive(Clone, Copy, EnumIter)]
 #[repr(u8)]
 pub enum CallAbiTable {
     PrintString = 0,
@@ -17,11 +23,12 @@ pub enum CallAbiTable {
     ReadFile = 7,
     FileLen = 8,
 }
+
 pub type EntryFn = fn();
 
 #[unsafe(no_mangle)]
 #[unsafe(link_section = ".syscall_table")]
-pub static mut CALL_ABI_TABLE: [usize; CallAbiTable::COUNT] = [0; CallAbiTable::COUNT];
+pub static mut CALL_ABI_TABLE: [usize; ABI_CALL_TABLE_COUNT] = [0; ABI_CALL_TABLE_COUNT];
 
 pub type PrintAbi = extern "C" fn(ptr: *const u8, len: usize);
 
@@ -50,10 +57,37 @@ pub extern "C" fn lock_display(lock: bool) {
     f(lock);
 }
 
-pub type DrawIterAbi = extern "C" fn(ptr: *const Pixel<Rgb565>, len: usize);
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct CPixel {
+    pub x: i32,
+    pub y: i32,
+    pub color: u16,
+}
+
+impl Into<CPixel> for Pixel<Rgb565> {
+    fn into(self) -> CPixel {
+        CPixel {
+            x: self.0.x,
+            y: self.0.y,
+            color: self.1.into_storage(),
+        }
+    }
+}
+
+impl Into<Pixel<Rgb565>> for CPixel {
+    fn into(self) -> Pixel<Rgb565> {
+        let r5 = ((self.color >> 11) & 0x1F) as u8;
+        let g6 = ((self.color >> 5) & 0x3F) as u8;
+        let b5 = (self.color & 0x1F) as u8;
+        Pixel(Point::new(self.x, self.y), Rgb565::new(r5, g6, b5))
+    }
+}
+
+pub type DrawIterAbi = extern "C" fn(ptr: *const CPixel, len: usize);
 
 #[unsafe(no_mangle)]
-pub extern "C" fn draw_iter(ptr: *const Pixel<Rgb565>, len: usize) {
+pub extern "C" fn draw_iter(ptr: *const CPixel, len: usize) {
     let f: DrawIterAbi =
         unsafe { core::mem::transmute(CALL_ABI_TABLE[CallAbiTable::DrawIter as usize]) };
     f(ptr, len);
diff --git a/cbindgen.toml b/cbindgen.toml
new file mode 100644
index 0000000..56fe889
--- /dev/null
+++ b/cbindgen.toml
@@ -0,0 +1,4 @@
+language = "C"
+
+[macro_expansion]
+bitflags = true
diff --git a/kernel/src/abi.rs b/kernel/src/abi.rs
index e61bc24..9f1a607 100644
--- a/kernel/src/abi.rs
+++ b/kernel/src/abi.rs
@@ -1,6 +1,6 @@
 use abi_sys::{
-    DrawIterAbi, FileLen, GenRand, ListDir, LockDisplay, PrintAbi, ReadFile, RngRequest, SleepAbi,
-    keyboard::*,
+    CPixel, DrawIterAbi, FileLen, GenRand, ListDir, LockDisplay, PrintAbi, ReadFile, RngRequest,
+    SleepAbi, keyboard::*,
 };
 use alloc::{string::ToString, vec::Vec};
 use core::sync::atomic::Ordering;
@@ -43,10 +43,12 @@ pub extern "C" fn lock_display(lock: bool) {
 
 const _: DrawIterAbi = draw_iter;
 // TODO: maybe return result
-pub extern "C" fn draw_iter(pixels: *const Pixel<Rgb565>, len: usize) {
+pub extern "C" fn draw_iter(cpixels: *const CPixel, len: usize) {
     // SAFETY: caller guarantees `ptr` is valid for `len` bytes
-    let pixels = unsafe { core::slice::from_raw_parts(pixels, len) };
-    unsafe { FRAMEBUFFER.draw_iter(pixels.iter().copied()).unwrap() }
+    let cpixels = unsafe { core::slice::from_raw_parts(cpixels, len) };
+
+    let iter = cpixels.iter().copied().map(|c: CPixel| c.into());
+    unsafe { FRAMEBUFFER.draw_iter(iter).unwrap() }
 }
 
 pub static mut KEY_CACHE: Queue<KeyEvent, 32> = Queue::new();