diff --git a/Cargo.lock b/Cargo.lock
index 130e238..da46856 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -16,6 +16,7 @@ dependencies = [
 name = "abi"
 version = "0.1.0"
 dependencies = [
+ "embedded-graphics",
  "shared",
 ]
 
diff --git a/abi/Cargo.toml b/abi/Cargo.toml
index 80cc90d..e7aaf0e 100644
--- a/abi/Cargo.toml
+++ b/abi/Cargo.toml
@@ -4,4 +4,5 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+embedded-graphics = "0.8.1"
 shared = { path = "../shared" }
diff --git a/abi/src/lib.rs b/abi/src/lib.rs
index f97455e..2ed0f97 100644
--- a/abi/src/lib.rs
+++ b/abi/src/lib.rs
@@ -1,11 +1,16 @@
 #![no_std]
 
-use core::ffi::c_void;
+pub use embedded_graphics::{
+    Pixel,
+    geometry::Point,
+    pixelcolor::{Rgb565, RgbColor},
+};
 use shared::keyboard::{KeyCode, KeyEvent, KeyState, Modifiers};
 
 // Instead of extern, declare a static pointer in a dedicated section
 #[unsafe(no_mangle)]
 #[unsafe(link_section = ".user_reloc")]
+#[allow(non_upper_case_globals)]
 pub static mut call_abi_ptr: usize = 0;
 
 // Helper to call it
@@ -16,5 +21,8 @@ pub unsafe fn call_abi(call: *const Syscall) {
 
 #[repr(C)]
 pub enum Syscall {
-    DrawPixel { x: u32, y: u32, color: u16 },
+    DrawIter {
+        pixels: *const Pixel<Rgb565>,
+        len: usize,
+    },
 }
diff --git a/kernel/src/abi.rs b/kernel/src/abi.rs
index 1f8c3ba..dcc1bed 100644
--- a/kernel/src/abi.rs
+++ b/kernel/src/abi.rs
@@ -3,6 +3,7 @@ use defmt::info;
 use embassy_futures::block_on;
 use embedded_graphics::{
     Drawable,
+    draw_target::DrawTarget,
     pixelcolor::Rgb565,
     prelude::{Point, RgbColor, Size},
     primitives::{PrimitiveStyle, Rectangle, StyledDrawable},
@@ -15,19 +16,17 @@ pub extern "C" fn call_abi(call: *const Syscall) {
     info!("called abi");
     let call = unsafe { &*call };
     match call {
-        Syscall::DrawPixel { x, y, color } => {
-            draw_pixel(*x, *y, *color);
+        Syscall::DrawIter { pixels, len } => {
+            // SAFETY: we're trusting the user program here
+            let slice = unsafe { core::slice::from_raw_parts(*pixels, *len) };
+
+            let framebuffer = block_on(FRAMEBUFFER.lock());
+            framebuffer
+                .borrow_mut()
+                .as_mut()
+                .unwrap()
+                .draw_iter(slice.iter().copied())
+                .unwrap();
         }
     }
 }
-
-fn draw_pixel(x: u32, y: u32, color: u16) {
-    info!("draw pixel abi called");
-    let framebuffer = block_on(FRAMEBUFFER.lock());
-    Rectangle::new(Point::new(x as i32, y as i32), Size::new(1, 1))
-        .draw_styled(
-            &PrimitiveStyle::with_fill(Rgb565::RED),
-            *framebuffer.borrow_mut().as_mut().unwrap(),
-        )
-        .unwrap();
-}
diff --git a/user-apps/calculator/Cargo.toml b/user-apps/calculator/Cargo.toml
index 13d39be..8b3311f 100644
--- a/user-apps/calculator/Cargo.toml
+++ b/user-apps/calculator/Cargo.toml
@@ -4,4 +4,4 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
-abi = { path ="../../abi" }
+abi = { path = "../../abi" }
diff --git a/user-apps/calculator/src/main.rs b/user-apps/calculator/src/main.rs
index 3c26e28..3a174be 100644
--- a/user-apps/calculator/src/main.rs
+++ b/user-apps/calculator/src/main.rs
@@ -1,7 +1,7 @@
 #![no_std]
 #![no_main]
 
-use abi::{Syscall, call_abi};
+use abi::{Pixel, Point, Rgb565, RgbColor, Syscall, call_abi};
 use core::panic::PanicInfo;
 
 #[panic_handler]
@@ -11,14 +11,23 @@ fn panic(_info: &PanicInfo) -> ! {
 
 #[unsafe(no_mangle)]
 pub extern "C" fn _start() {
-    for i in 0..300 {
-        for o in 0..300 {
-            let call = Syscall::DrawPixel {
-                x: i,
-                y: o,
-                color: 0,
-            };
-            unsafe { call_abi(&call) };
-        }
+    // Local pixel buffer
+    let mut pixels = [Pixel(Point { x: 50, y: 50 }, Rgb565::RED); 300];
+    for (i, p) in pixels.iter_mut().enumerate() {
+        *p = Pixel(
+            Point {
+                x: i as i32,
+                y: i as i32,
+            },
+            Rgb565::RED,
+        )
     }
+
+    // Construct syscall with raw pointer + length
+    let call = Syscall::DrawIter {
+        pixels: pixels.as_ptr(), // raw pointer
+        len: pixels.len(),       // number of elements
+    };
+
+    unsafe { call_abi(&call) };
 }