works

.gitignore

@@ -1,3 +1,4 @@
 /target
 *.uf2
 abi_sys.h
+assets/gif/bad_apple.gif

Cargo.lock

@@ -18,10 +18,8 @@ version = "0.1.0"
 dependencies = [
  "abi_sys",
  "embedded-graphics",
- "embedded-sdmmc",
+ "once_cell",
  "rand_core 0.9.3",
- "spin",
- "talc",
 ]
 
 [[package]]
@@ -32,7 +30,6 @@ dependencies = [
  "cbindgen",
  "defmt 0.3.100",
  "embedded-graphics",
- "embedded-sdmmc",
  "strum",
 ]
 
@@ -1039,6 +1036,7 @@ dependencies = [
 [[package]]
 name = "embedded-snake"
 version = "0.0.3"
+source = "git+https://github.com/LegitCamper/embedded-snake-rs#3986819c55819283dc5c1e89717d2a2f52e9b161"
 dependencies = [
  "embedded-graphics",
  "rand_core 0.9.3",
@@ -1283,6 +1281,16 @@ dependencies = [
  "wasip2",
 ]
 
+[[package]]
+name = "gif"
+version = "0.1.0"
+dependencies = [
+ "abi",
+ "embedded-graphics",
+ "selection_ui",
+ "tinygif",
+]
+
 [[package]]
 name = "goblin"
 version = "0.10.2"
@@ -2182,6 +2190,16 @@ version = "0.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c1257cd4248b4132760d6524d6dda4e053bc648c9070b960929bf50cfb1e7add"
 
+[[package]]
+name = "selection_ui"
+version = "0.1.0"
+dependencies = [
+ "abi",
+ "embedded-graphics",
+ "embedded-layout",
+ "embedded-text",
+]
+
 [[package]]
 name = "semver"
 version = "0.9.0"
@@ -2551,6 +2569,15 @@ dependencies = [
  "embedded-graphics",
 ]
 
+[[package]]
+name = "tinygif"
+version = "0.0.4"
+source = "git+https://github.com/LegitCamper/tinygif#083c0efbdbeb21835de30425e234247340f6e370"
+dependencies = [
+ "embedded-graphics",
+ "heapless",
+]
+
 [[package]]
 name = "toml"
 version = "0.5.11"

Cargo.toml

@@ -4,9 +4,11 @@ members = [
   "kernel",
   "abi_sys",
   "abi",
+  "selection_ui",
   "user-apps/calculator",
   "user-apps/snake",
   "user-apps/gallery",
+  "user-apps/gif",
 ]
 
 [profile.release]
@@ -17,10 +19,12 @@ codegen-units = 1
 
 [profile.release-binary]
 inherits = "release"
+codegen-units = 1
 lto = true
 debug = false
-opt-level = "s"
+opt-level = "z"
+panic = "abort"
 
 [profile.dev]
 lto = true
-opt-level = "z"
+opt-level = "s"

abi/Cargo.toml

@@ -4,9 +4,7 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
-embedded-sdmmc = { version = "0.9.0", default-features = false }
-embedded-graphics = "0.8.1"
 abi_sys = { path = "../abi_sys" }
-talc = "4.4.3"
+embedded-graphics = "0.8.1"
-spin = "0.10.0"
+once_cell = { version = "1", default-features = false }
 rand_core = "0.9.3"

abi/src/lib.rs

@@ -1,27 +1,45 @@
 #![no_std]
-
+#![allow(static_mut_refs)]
-pub use abi_sys::keyboard;
-use abi_sys::{RngRequest, keyboard::KeyEvent};
-use rand_core::RngCore;
-use talc::*;
 
 extern crate alloc;
 
-static mut ARENA: [u8; 10000] = [0; 10000];
+pub use abi_sys::{self, keyboard};
+use abi_sys::{RngRequest, alloc, dealloc, keyboard::KeyEvent};
+pub use alloc::format;
+use core::alloc::{GlobalAlloc, Layout};
+use rand_core::RngCore;
 
 #[global_allocator]
-static ALLOCATOR: Talck<spin::Mutex<()>, ClaimOnOom> =
+static ALLOC: Alloc = Alloc;
-    Talc::new(unsafe { ClaimOnOom::new(Span::from_array(core::ptr::addr_of!(ARENA).cast_mut())) })
-        .lock();
 
-pub fn print(msg: &str) {
+struct Alloc;
-    abi_sys::print(msg.as_ptr(), msg.len());
+
+unsafe impl GlobalAlloc for Alloc {
+    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+        alloc(layout.into())
+    }
+
+    unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
+        dealloc(ptr, layout.into());
+    }
+}
+
+#[macro_export]
+macro_rules! print {
+    ($($arg:tt)*) => {{
+        let s = $crate::format!($($arg)*);
+        $crate::abi_sys::print(s.as_ptr(), s.len());
+    }};
 }
 
 pub fn sleep(ms: u64) {
     abi_sys::sleep(ms);
 }
 
+pub fn get_ms() -> u64 {
+    abi_sys::get_ms()
+}
+
 pub fn get_key() -> KeyEvent {
     abi_sys::keyboard::get_key().into()
 }
@@ -41,11 +59,10 @@ pub mod display {
 
     pub type Pixel565 = Pixel<Rgb565>;
 
-    pub fn lock_display(lock: bool) {
+    const BUF_SIZE: usize = 15 * 1024; // tune this for performance
-        abi_sys::lock_display(lock);
+    static mut BUF: [CPixel; BUF_SIZE] = [CPixel::new(); BUF_SIZE];
-    }
+    // const BUF_SIZE: usize = 250 * 1024; // tune this for performance
-
+    // static mut BUF: Lazy<Vec<CPixel>> = Lazy::new(|| vec![const { CPixel::new() }; BUF_SIZE]);
-    const BUF_SIZE: usize = 1024; // tune this for performance
 
     pub struct Display;
 
@@ -69,21 +86,19 @@ pub mod display {
         where
             I: IntoIterator<Item = Pixel<Self::Color>>,
         {
-            let mut buf: [CPixel; BUF_SIZE] = [CPixel::new(); BUF_SIZE];
-
             let mut count = 0;
             for p in pixels {
-                buf[count] = p.into();
+                unsafe { BUF[count] = p.into() };
                 count += 1;
 
-                if count == BUF_SIZE {
+                if count == BUF_SIZE - 1 {
-                    abi_sys::draw_iter(buf.as_ptr(), count);
+                    abi_sys::draw_iter(unsafe { BUF.as_ptr() }, count);
                     count = 0;
                 }
             }
 
             if count > 0 {
-                abi_sys::draw_iter(buf.as_ptr(), count);
+                abi_sys::draw_iter(unsafe { BUF.as_ptr() }, count);
             }
 
             Ok(())
@@ -125,7 +140,9 @@ impl RngCore for Rng {
 }
 
 pub mod fs {
-    use embedded_sdmmc::DirEntry;
+    use core::fmt::Display;
+
+    use alloc::{format, vec::Vec};
 
     pub fn read_file(file: &str, read_from: usize, buf: &mut [u8]) -> usize {
         abi_sys::read_file(
@@ -137,8 +154,85 @@ pub mod fs {
         )
     }
 
-    pub fn list_dir(path: &str, files: &mut [Option<DirEntry>]) -> usize {
+    pub struct FileName<'a> {
-        abi_sys::list_dir(path.as_ptr(), path.len(), files.as_mut_ptr(), files.len())
+        full: &'a str,
+        base: &'a str,
+        ext: Option<&'a str>,
+    }
+
+    impl<'a> FileName<'a> {
+        pub fn full_name(&self) -> &str {
+            self.full
+        }
+
+        pub fn base(&self) -> &str {
+            self.base
+        }
+
+        pub fn extension(&self) -> Option<&str> {
+            self.ext
+        }
+    }
+
+    impl<'a> Display for FileName<'a> {
+        fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+            write!(f, "{}", self.full_name())
+        }
+    }
+
+    impl<'a> From<&'a str> for FileName<'a> {
+        fn from(s: &'a str) -> FileName<'a> {
+            let full = s;
+
+            // Split on last dot for extension
+            let (base, ext) = match s.rfind('.') {
+                Some(idx) => (&s[..idx], Some(&s[idx + 1..])),
+                None => (s, None),
+            };
+
+            FileName { full, base, ext }
+        }
+    }
+
+    const MAX_ENTRY_NAME_LEN: usize = 25;
+    const MAX_ENTRIES: usize = 25;
+
+    #[derive(Clone, Copy)]
+    pub struct Entries([[u8; MAX_ENTRY_NAME_LEN]; MAX_ENTRIES]);
+
+    impl Entries {
+        pub fn new() -> Self {
+            Self([[0; MAX_ENTRY_NAME_LEN]; MAX_ENTRIES])
+        }
+
+        /// Get list of file names after listing
+        pub fn entries<'a>(&'a self) -> Vec<FileName<'a>> {
+            self.0
+                .iter()
+                .filter_map(|buf| {
+                    let nul_pos = buf.iter().position(|&b| b == 0).unwrap_or(buf.len());
+                    Some(core::str::from_utf8(&buf[..nul_pos]).ok()?.into())
+                })
+                .collect()
+        }
+
+        fn as_ptrs(&mut self) -> [*mut u8; MAX_ENTRIES] {
+            let mut ptrs: [*mut u8; MAX_ENTRIES] = [core::ptr::null_mut(); MAX_ENTRIES];
+            for (i, buf) in self.0.iter_mut().enumerate() {
+                ptrs[i] = buf.as_mut_ptr();
+            }
+            ptrs
+        }
+    }
+
+    pub fn list_dir(path: &str, entries: &mut Entries) -> usize {
+        abi_sys::list_dir(
+            path.as_ptr(),
+            path.len(),
+            entries.as_ptrs().as_mut_ptr(),
+            MAX_ENTRIES,
+            MAX_ENTRY_NAME_LEN,
+        )
     }
 
     pub fn file_len(str: &str) -> usize {

abi_sys/Cargo.toml

@@ -4,14 +4,14 @@ version = "0.1.0"
 edition = "2024"
 
 [features]
-default = []
+default = ["alloc"]
+alloc = []
 defmt = ["dep:defmt"]
 
 [dependencies]
 strum = { version = "0.27.2", default-features = false, features = ["derive"] }
 bitflags = "2.9.4"
 embedded-graphics = "0.8.1"
-embedded-sdmmc = { version = "0.9.0", default-features = false }
 defmt = { version = "0.3", optional = true }
 
 [build-dependencies]

abi_sys/src/lib.rs

@@ -1,42 +1,87 @@
 #![no_std]
+#[cfg(feature = "alloc")]
+use core::alloc::Layout;
 
+use core::ffi::c_char;
 use embedded_graphics::{
     Pixel,
     pixelcolor::{Rgb565, raw::RawU16},
     prelude::{IntoStorage, Point},
 };
-use embedded_sdmmc::DirEntry;
+use strum::{EnumCount, EnumIter};
-use strum::EnumIter;
-
-pub const ABI_CALL_TABLE_COUNT: usize = 10;
-
-#[derive(Clone, Copy, EnumIter)]
-#[repr(u8)]
-pub enum CallAbiTable {
-    PrintString = 0,
-    SleepMs = 1,
-    GetMs = 2,
-    LockDisplay = 3,
-    DrawIter = 4,
-    GetKey = 5,
-    GenRand = 6,
-    ListDir = 7,
-    ReadFile = 8,
-    FileLen = 9,
-}
 
 pub type EntryFn = fn();
 
+pub const ABI_CALL_TABLE_COUNT: usize = 11;
+const _: () = assert!(ABI_CALL_TABLE_COUNT == CallTable::COUNT);
+
+#[derive(Clone, Copy, EnumIter, EnumCount)]
+#[repr(u8)]
+pub enum CallTable {
+    Alloc = 0,
+    Dealloc = 1,
+    PrintString = 2,
+    SleepMs = 3,
+    GetMs = 4,
+    DrawIter = 5,
+    GetKey = 6,
+    GenRand = 7,
+    ListDir = 8,
+    ReadFile = 9,
+    FileLen = 10,
+}
+
 #[unsafe(no_mangle)]
 #[unsafe(link_section = ".syscall_table")]
 pub static mut CALL_ABI_TABLE: [usize; ABI_CALL_TABLE_COUNT] = [0; ABI_CALL_TABLE_COUNT];
 
+#[cfg(feature = "alloc")]
+#[repr(C)]
+pub struct CLayout {
+    size: usize,
+    alignment: usize,
+}
+
+#[cfg(feature = "alloc")]
+impl Into<Layout> for CLayout {
+    fn into(self) -> Layout {
+        unsafe { Layout::from_size_align_unchecked(self.size, self.alignment) }
+    }
+}
+
+#[cfg(feature = "alloc")]
+impl From<Layout> for CLayout {
+    fn from(value: Layout) -> Self {
+        Self {
+            size: value.size(),
+            alignment: value.align(),
+        }
+    }
+}
+
+pub type AllocAbi = extern "C" fn(layout: CLayout) -> *mut u8;
+
+#[unsafe(no_mangle)]
+pub extern "C" fn alloc(layout: CLayout) -> *mut u8 {
+    let f: AllocAbi = unsafe { core::mem::transmute(CALL_ABI_TABLE[CallTable::Alloc as usize]) };
+    f(layout)
+}
+
+pub type DeallocAbi = extern "C" fn(ptr: *mut u8, layout: CLayout);
+
+#[unsafe(no_mangle)]
+pub extern "C" fn dealloc(ptr: *mut u8, layout: CLayout) {
+    let f: DeallocAbi =
+        unsafe { core::mem::transmute(CALL_ABI_TABLE[CallTable::Dealloc as usize]) };
+    f(ptr, layout)
+}
+
 pub type PrintAbi = extern "C" fn(ptr: *const u8, len: usize);
 
 #[unsafe(no_mangle)]
 pub extern "C" fn print(ptr: *const u8, len: usize) {
     let f: PrintAbi =
-        unsafe { core::mem::transmute(CALL_ABI_TABLE[CallAbiTable::PrintString as usize]) };
+        unsafe { core::mem::transmute(CALL_ABI_TABLE[CallTable::PrintString as usize]) };
     f(ptr, len);
 }
 
@@ -45,7 +90,7 @@ pub type SleepMsAbi = extern "C" fn(ms: u64);
 #[unsafe(no_mangle)]
 pub extern "C" fn sleep(ms: u64) {
     let f: SleepMsAbi =
-        unsafe { core::mem::transmute(CALL_ABI_TABLE[CallAbiTable::SleepMs as usize]) };
+        unsafe { core::mem::transmute(CALL_ABI_TABLE[CallTable::SleepMs as usize]) };
     f(ms);
 }
 
@@ -53,19 +98,10 @@ pub type GetMsAbi = extern "C" fn() -> u64;
 
 #[unsafe(no_mangle)]
 pub extern "C" fn get_ms() -> u64 {
-    let f: GetMsAbi = unsafe { core::mem::transmute(CALL_ABI_TABLE[CallAbiTable::GetMs as usize]) };
+    let f: GetMsAbi = unsafe { core::mem::transmute(CALL_ABI_TABLE[CallTable::GetMs as usize]) };
     f()
 }
 
-pub type LockDisplay = extern "C" fn(lock: bool);
-
-#[unsafe(no_mangle)]
-pub extern "C" fn lock_display(lock: bool) {
-    let f: LockDisplay =
-        unsafe { core::mem::transmute(CALL_ABI_TABLE[CallAbiTable::LockDisplay as usize]) };
-    f(lock);
-}
-
 #[repr(C)]
 #[derive(Copy, Clone)]
 pub struct CPixel {
@@ -75,7 +111,7 @@ pub struct CPixel {
 }
 
 impl CPixel {
-    pub fn new() -> Self {
+    pub const fn new() -> Self {
         Self {
             x: 0,
             y: 0,
@@ -105,12 +141,12 @@ pub type DrawIterAbi = extern "C" fn(ptr: *const CPixel, len: usize);
 #[unsafe(no_mangle)]
 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]) };
+        unsafe { core::mem::transmute(CALL_ABI_TABLE[CallTable::DrawIter as usize]) };
     f(ptr, len);
 }
 
 pub mod keyboard {
-    use crate::{CALL_ABI_TABLE, CallAbiTable};
+    use crate::{CALL_ABI_TABLE, CallTable};
 
     bitflags::bitflags! {
         #[derive(Default, Debug, PartialEq, Eq, Clone, Copy)]
@@ -333,7 +369,7 @@ pub mod keyboard {
     #[unsafe(no_mangle)]
     pub extern "C" fn get_key() -> KeyEventC {
         let f: GetKeyAbi =
-            unsafe { core::mem::transmute(CALL_ABI_TABLE[CallAbiTable::GetKey as usize]) };
+            unsafe { core::mem::transmute(CALL_ABI_TABLE[CallTable::GetKey as usize]) };
         f()
     }
 }
@@ -350,7 +386,7 @@ pub type GenRand = extern "C" fn(req: &mut RngRequest);
 #[unsafe(no_mangle)]
 pub extern "C" fn gen_rand(req: &mut RngRequest) {
     unsafe {
-        let ptr = CALL_ABI_TABLE[CallAbiTable::GenRand as usize];
+        let ptr = CALL_ABI_TABLE[CallTable::GenRand as usize];
         let f: GenRand = core::mem::transmute(ptr);
         f(req)
     }
@@ -359,21 +395,23 @@ pub extern "C" fn gen_rand(req: &mut RngRequest) {
 pub type ListDir = extern "C" fn(
     str: *const u8,
     len: usize,
-    files: *mut Option<DirEntry>,
+    entries: *mut *mut c_char,
     file_len: usize,
+    max_entry_str_len: usize,
 ) -> usize;
 
 #[unsafe(no_mangle)]
 pub extern "C" fn list_dir(
     str: *const u8,
     len: usize,
-    files: *mut Option<DirEntry>,
+    entries: *mut *mut c_char,
-    file_len: usize,
+    entry_count: usize,
+    max_entry_str_len: usize,
 ) -> usize {
     unsafe {
-        let ptr = CALL_ABI_TABLE[CallAbiTable::ListDir as usize];
+        let ptr = CALL_ABI_TABLE[CallTable::ListDir as usize];
         let f: ListDir = core::mem::transmute(ptr);
-        f(str, len, files, file_len)
+        f(str, len, entries, entry_count, max_entry_str_len)
     }
 }
 
@@ -394,7 +432,7 @@ pub extern "C" fn read_file(
     buf_len: usize,
 ) -> usize {
     unsafe {
-        let ptr = CALL_ABI_TABLE[CallAbiTable::ReadFile as usize];
+        let ptr = CALL_ABI_TABLE[CallTable::ReadFile as usize];
         let f: ReadFile = core::mem::transmute(ptr);
         f(str, len, read_from, buf, buf_len)
     }
@@ -405,7 +443,7 @@ pub type FileLen = extern "C" fn(str: *const u8, len: usize) -> usize;
 #[unsafe(no_mangle)]
 pub extern "C" fn file_len(str: *const u8, len: usize) -> usize {
     unsafe {
-        let ptr = CALL_ABI_TABLE[CallAbiTable::FileLen as usize];
+        let ptr = CALL_ABI_TABLE[CallTable::FileLen as usize];
         let f: FileLen = core::mem::transmute(ptr);
         f(str, len)
     }

justfile

@@ -16,3 +16,4 @@ userapps: cbindgen
     just userapp calculator
     just userapp snake
     just userapp gallery
+    just userapp gif

kernel/Cargo.toml

@@ -90,7 +90,7 @@ spin = "0.10.0"
 num_enum = { version = "0.7.4", default-features = false }
 goblin = { version = "0.10.1", default-features = false, features = ["elf32"] }
 talc = "4.4.3"
-embedded-alloc = "0.6.0"
+embedded-alloc = { version = "0.6.0", features = ["allocator_api"] }
 bumpalo = "3.19.0"
 
 abi_sys = { path = "../abi_sys" }

kernel/pimoroni2w.x

@@ -2,7 +2,7 @@ MEMORY {
     FLASH : ORIGIN = 0x10000000, LENGTH = 16M - 4K
 
     RAM : ORIGIN = 0x20000000, LENGTH = 512K
-    SRAM4 : ORIGIN = 0x20080000, LENGTH = 4K
+    # SRAM4 : ORIGIN = 0x20080000, LENGTH = 4K
     SRAM5 : ORIGIN = 0x20081000, LENGTH = 4K
 }
 

kernel/src/abi.rs

@@ -1,20 +1,45 @@
 use abi_sys::{
-    CPixel, DrawIterAbi, FileLen, GenRand, GetMsAbi, ListDir, LockDisplay, PrintAbi, ReadFile,
+    AllocAbi, CLayout, CPixel, DeallocAbi, DrawIterAbi, FileLen, GenRand, GetMsAbi, ListDir,
-    RngRequest, SleepMsAbi, keyboard::*,
+    PrintAbi, ReadFile, RngRequest, SleepMsAbi, keyboard::*,
 };
 use alloc::{string::ToString, vec::Vec};
-use core::sync::atomic::Ordering;
+use core::{alloc::GlobalAlloc, ffi::c_char, ptr, sync::atomic::Ordering};
 use embassy_rp::clocks::{RoscRng, clk_sys_freq};
 use embassy_time::Instant;
 use embedded_graphics::draw_target::DrawTarget;
-use embedded_sdmmc::{DirEntry, LfnBuffer};
+use embedded_sdmmc::LfnBuffer;
 use heapless::spsc::Queue;
 
 use crate::{
-    display::{FB_PAUSED, FRAMEBUFFER},
+    display::FRAMEBUFFER,
+    framebuffer::FB_PAUSED,
     storage::{Dir, File, SDCARD},
 };
 
+const _: AllocAbi = alloc;
+pub extern "C" fn alloc(layout: CLayout) -> *mut u8 {
+    // SAFETY: caller guarantees layout is valid
+    unsafe {
+        if cfg!(feature = "pimoroni2w") {
+            crate::heap::HEAP.alloc(layout.into())
+        } else {
+            alloc::alloc::alloc(layout.into())
+        }
+    }
+}
+
+const _: DeallocAbi = dealloc;
+pub extern "C" fn dealloc(ptr: *mut u8, layout: CLayout) {
+    // SAFETY: caller guarantees ptr and layout are valid
+    unsafe {
+        if cfg!(feature = "pimoroni2w") {
+            crate::heap::HEAP.dealloc(ptr, layout.into())
+        } else {
+            alloc::alloc::dealloc(ptr, layout.into())
+        }
+    }
+}
+
 const _: PrintAbi = print;
 pub extern "C" fn print(ptr: *const u8, len: usize) {
     // SAFETY: caller guarantees `ptr` is valid for `len` bytes
@@ -48,19 +73,16 @@ pub extern "C" fn get_ms() -> u64 {
         .as_millis()
 }
 
-const _: LockDisplay = lock_display;
-pub extern "C" fn lock_display(lock: bool) {
-    FB_PAUSED.store(lock, Ordering::Relaxed);
-}
-
 const _: DrawIterAbi = draw_iter;
-// TODO: maybe return result
 pub extern "C" fn draw_iter(cpixels: *const CPixel, len: usize) {
     // SAFETY: caller guarantees `ptr` is valid for `len` bytes
     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() }
+
+    FB_PAUSED.store(true, Ordering::Release);
+    unsafe { FRAMEBUFFER.as_mut().unwrap().draw_iter(iter).unwrap() }
+    FB_PAUSED.store(false, Ordering::Release);
 }
 
 pub static mut KEY_CACHE: Queue<KeyEvent, 32> = Queue::new();
@@ -94,11 +116,27 @@ pub extern "C" fn gen_rand(req: &mut RngRequest) {
     }
 }
 
-fn get_dir_entries(dir: &Dir, files: &mut [Option<DirEntry>]) -> usize {
+unsafe fn copy_entry_to_user_buf(name: &[u8], dest: *mut c_char, max_str_len: usize) {
+    if !dest.is_null() {
+        let len = name.len().min(max_str_len - 1);
+        unsafe {
+            ptr::copy_nonoverlapping(name.as_ptr(), dest as *mut u8, len);
+            *dest.add(len) = 0; // nul terminator
+        }
+    }
+}
+
+unsafe fn get_dir_entries(dir: &Dir, entries: &mut [*mut c_char], max_str_len: usize) -> usize {
+    let mut b = [0; 25];
+    let mut buf = LfnBuffer::new(&mut b);
     let mut i = 0;
-    dir.iterate_dir(|entry| {
+    dir.iterate_dir_lfn(&mut buf, |entry, lfn_name| {
-        if i < files.len() {
+        if i < entries.len() {
-            files[i] = Some(entry.clone());
+            if let Some(name) = lfn_name {
+                unsafe { copy_entry_to_user_buf(name.as_bytes(), entries[i], max_str_len) };
+            } else {
+                unsafe { copy_entry_to_user_buf(entry.name.base_name(), entries[i], max_str_len) };
+            }
             i += 1;
         }
     })
@@ -106,24 +144,30 @@ fn get_dir_entries(dir: &Dir, files: &mut [Option<DirEntry>]) -> usize {
     i
 }
 
-fn recurse_dir(dir: &Dir, dirs: &[&str], files: &mut [Option<DirEntry>]) -> usize {
+unsafe fn recurse_dir(
+    dir: &Dir,
+    dirs: &[&str],
+    entries: &mut [*mut c_char],
+    max_str_len: usize,
+) -> usize {
     if dirs.is_empty() {
-        return get_dir_entries(dir, files);
+        return unsafe { get_dir_entries(dir, entries, max_str_len) };
     }
 
     let dir = dir.open_dir(dirs[0]).unwrap();
-    recurse_dir(&dir, &dirs[1..], files)
+    unsafe { recurse_dir(&dir, &dirs[1..], entries, max_str_len) }
 }
 
 const _: ListDir = list_dir;
 pub extern "C" fn list_dir(
     dir: *const u8,
     len: usize,
-    files: *mut Option<DirEntry>,
+    entries: *mut *mut c_char,
     files_len: usize,
+    max_entry_str_len: usize,
 ) -> usize {
     // SAFETY: caller guarantees `ptr` is valid for `len` bytes
-    let files = unsafe { core::slice::from_raw_parts_mut(files, files_len) };
+    let files = unsafe { core::slice::from_raw_parts_mut(entries, files_len) };
     // SAFETY: caller guarantees `ptr` is valid for `len` bytes
     let dir = unsafe { core::str::from_raw_parts(dir, len) };
     let dirs: Vec<&str> = dir.split('/').collect();
@@ -134,10 +178,12 @@ pub extern "C" fn list_dir(
     let mut wrote = 0;
     sd.access_root_dir(|root| {
         if dirs[0] == "" && dirs.len() >= 2 {
-            if dir == "/" {
+            unsafe {
-                wrote = get_dir_entries(&root, files);
+                if dir == "/" {
-            } else {
+                    wrote = get_dir_entries(&root, files, max_entry_str_len);
-                wrote = recurse_dir(&root, &dirs[1..], files);
+                } else {
+                    wrote = recurse_dir(&root, &dirs[1..], files, max_entry_str_len);
+                }
             }
         }
     });

kernel/src/display.rs

@@ -1,6 +1,6 @@
-use core::sync::atomic::{AtomicBool, Ordering};
+use crate::framebuffer::{self, AtomicFrameBuffer, FB_PAUSED};
-
+use core::alloc::{GlobalAlloc, Layout};
-use crate::framebuffer::AtomicFrameBuffer;
+use core::sync::atomic::Ordering;
 use embassy_rp::{
     Peri,
     gpio::{Level, Output},
@@ -8,6 +8,10 @@ use embassy_rp::{
     spi::{Async, Spi},
 };
 use embassy_time::{Delay, Timer};
+use embedded_graphics::{
+    pixelcolor::Rgb565,
+    prelude::{DrawTarget, RgbColor},
+};
 use embedded_hal_bus::spi::ExclusiveDevice;
 use st7365p_lcd::ST7365P;
 
@@ -21,8 +25,24 @@ type DISPLAY = ST7365P<
 pub const SCREEN_WIDTH: usize = 320;
 pub const SCREEN_HEIGHT: usize = 320;
 
-pub static mut FRAMEBUFFER: AtomicFrameBuffer = AtomicFrameBuffer::new();
+pub static mut FRAMEBUFFER: Option<AtomicFrameBuffer> = None;
-pub static FB_PAUSED: AtomicBool = AtomicBool::new(false);
+
+fn init_fb() {
+    unsafe {
+        FRAMEBUFFER = Some(if cfg!(not(feature = "pimoroni2w")) {
+            static mut BUF: [u16; framebuffer::SIZE] = [0; framebuffer::SIZE];
+            AtomicFrameBuffer::new(&mut BUF)
+        } else {
+            let slab = crate::heap::HEAP.alloc(Layout::array::<u16>(framebuffer::SIZE).unwrap())
+                as *mut u16;
+            let buf = core::slice::from_raw_parts_mut(slab, framebuffer::SIZE);
+
+            let mut fb = AtomicFrameBuffer::new(buf);
+            fb.clear(Rgb565::BLACK).unwrap();
+            fb
+        });
+    }
+}
 
 pub async fn init_display(
     spi: Spi<'static, SPI1, Async>,
@@ -30,6 +50,8 @@ pub async fn init_display(
     data: Peri<'static, PIN_14>,
     reset: Peri<'static, PIN_15>,
 ) -> DISPLAY {
+    init_fb();
+
     let spi_device = ExclusiveDevice::new(spi, Output::new(cs, Level::Low), Delay).unwrap();
     let mut display = ST7365P::new(
         spi_device,
@@ -41,7 +63,14 @@ pub async fn init_display(
     );
     display.init().await.unwrap();
     display.set_custom_orientation(0x40).await.unwrap();
-    unsafe { FRAMEBUFFER.draw(&mut display).await.unwrap() }
+    unsafe {
+        FRAMEBUFFER
+            .as_mut()
+            .unwrap()
+            .draw(&mut display)
+            .await
+            .unwrap()
+    }
     display.set_on().await.unwrap();
 
     display
@@ -53,12 +82,15 @@ pub async fn display_handler(mut display: DISPLAY) {
         if !FB_PAUSED.load(Ordering::Acquire) {
             unsafe {
                 FRAMEBUFFER
-                    .partial_draw_batched(&mut display)
+                    .as_mut()
+                    .unwrap()
+                    .partial_draw(&mut display)
                     .await
                     .unwrap()
-            }
+            };
         }
 
-        Timer::after_millis(10).await;
+        // small yield to allow other tasks to run
+        Timer::after_nanos(500).await;
     }
 }

kernel/src/elf.rs

@@ -2,7 +2,7 @@ use crate::{
     abi,
     storage::{File, SDCARD},
 };
-use abi_sys::CallAbiTable;
+use abi_sys::CallTable;
 use abi_sys::EntryFn;
 use alloc::{vec, vec::Vec};
 use bumpalo::Bump;
@@ -194,18 +194,19 @@ fn patch_abi(
                         unsafe { base.add((sym.st_value as usize) - min_vaddr as usize) }
                             as *mut usize;
 
-                    for (idx, call) in CallAbiTable::iter().enumerate() {
+                    for (idx, call) in CallTable::iter().enumerate() {
                         let ptr = match call {
-                            CallAbiTable::PrintString => abi::print as usize,
+                            CallTable::Alloc => abi::alloc as usize,
-                            CallAbiTable::SleepMs => abi::sleep as usize,
+                            CallTable::Dealloc => abi::dealloc as usize,
-                            CallAbiTable::GetMs => abi::get_ms as usize,
+                            CallTable::PrintString => abi::print as usize,
-                            CallAbiTable::LockDisplay => abi::lock_display as usize,
+                            CallTable::SleepMs => abi::sleep as usize,
-                            CallAbiTable::DrawIter => abi::draw_iter as usize,
+                            CallTable::GetMs => abi::get_ms as usize,
-                            CallAbiTable::GetKey => abi::get_key as usize,
+                            CallTable::DrawIter => abi::draw_iter as usize,
-                            CallAbiTable::GenRand => abi::gen_rand as usize,
+                            CallTable::GetKey => abi::get_key as usize,
-                            CallAbiTable::ListDir => abi::list_dir as usize,
+                            CallTable::GenRand => abi::gen_rand as usize,
-                            CallAbiTable::ReadFile => abi::read_file as usize,
+                            CallTable::ListDir => abi::list_dir as usize,
-                            CallAbiTable::FileLen => abi::file_len as usize,
+                            CallTable::ReadFile => abi::read_file as usize,
+                            CallTable::FileLen => abi::file_len as usize,
                         };
                         unsafe {
                             table_base.add(idx as usize).write(ptr);

kernel/src/framebuffer.rs

@@ -1,6 +1,5 @@
 use crate::display::{SCREEN_HEIGHT, SCREEN_WIDTH};
 use core::sync::atomic::{AtomicBool, Ordering};
-use embassy_sync::lazy_lock::LazyLock;
 use embedded_graphics::{
     draw_target::DrawTarget,
     pixelcolor::{
@@ -12,34 +11,35 @@ use embedded_graphics::{
 };
 use embedded_hal_2::digital::OutputPin;
 use embedded_hal_async::{delay::DelayNs, spi::SpiDevice};
-use heapless::Vec;
 use st7365p_lcd::ST7365P;
 
-pub const TILE_SIZE: usize = 16; // 16x16 tile
+const TILE_SIZE: usize = 16; // 16x16 tile
-pub const TILE_COUNT: usize = (SCREEN_WIDTH / TILE_SIZE) * (SCREEN_HEIGHT / TILE_SIZE); // 400 tiles
+const TILE_COUNT: usize = (SCREEN_WIDTH / TILE_SIZE) * (SCREEN_HEIGHT / TILE_SIZE); // 400 tiles
+const NUM_TILE_ROWS: usize = SCREEN_WIDTH / TILE_SIZE;
+const NUM_TILE_COLS: usize = SCREEN_WIDTH / TILE_SIZE;
 
-// Group of tiles for batching
+const MAX_BATCH_TILES: usize = (SCREEN_WIDTH / TILE_SIZE) * 2;
-pub const MAX_META_TILES: usize = SCREEN_WIDTH / TILE_SIZE; // max number of meta tiles in buffer
+type BatchTileBuf = [u16; MAX_BATCH_TILES * TILE_SIZE * TILE_SIZE];
-type MetaTileVec = heapless::Vec<Rectangle, { TILE_COUNT / MAX_META_TILES }>;
 
-const SIZE: usize = SCREEN_HEIGHT * SCREEN_WIDTH;
+pub const SIZE: usize = SCREEN_HEIGHT * SCREEN_WIDTH;
 
-static mut BUFFER: [u16; SIZE] = [0; SIZE];
+pub static FB_PAUSED: AtomicBool = AtomicBool::new(false);
-
-static mut DIRTY_TILES: LazyLock<heapless::Vec<AtomicBool, TILE_COUNT>> = LazyLock::new(|| {
-    let mut tiles = Vec::new();
-    for _ in 0..TILE_COUNT {
-        tiles.push(AtomicBool::new(true)).unwrap();
-    }
-    tiles
-});
 
 #[allow(dead_code)]
-pub struct AtomicFrameBuffer;
+pub struct AtomicFrameBuffer<'a> {
+    fb: &'a mut [u16],
+    dirty_tiles: [AtomicBool; TILE_COUNT],
+    batch_tile_buf: BatchTileBuf,
+}
 
-impl AtomicFrameBuffer {
+impl<'a> AtomicFrameBuffer<'a> {
-    pub const fn new() -> Self {
+    pub fn new(buffer: &'a mut [u16]) -> Self {
-        Self
+        assert!(buffer.len() == SIZE);
+        Self {
+            fb: buffer,
+            dirty_tiles: core::array::from_fn(|_| AtomicBool::new(true)),
+            batch_tile_buf: [0; MAX_BATCH_TILES * TILE_SIZE * TILE_SIZE],
+        }
     }
 
     fn mark_tiles_dirty(&mut self, rect: Rectangle) {
@@ -52,18 +52,12 @@ impl AtomicFrameBuffer {
         for ty in start_ty..=end_ty {
             for tx in start_tx..=end_tx {
                 let tile_idx = ty * tiles_x + tx;
-                unsafe { DIRTY_TILES.get_mut()[tile_idx].store(true, Ordering::Relaxed) };
+                self.dirty_tiles[tile_idx].store(true, Ordering::Release);
             }
         }
     }
 
-    fn set_pixel(&mut self, x: u16, y: u16, color: u16) -> Result<(), ()> {
+    fn set_pixels<P: IntoIterator<Item = u16>>(
-        unsafe { BUFFER[(y as usize * SCREEN_WIDTH) + x as usize] = color };
-
-        Ok(())
-    }
-
-    fn set_pixels_buffered<P: IntoIterator<Item = u16>>(
         &mut self,
         sx: u16,
         sy: u16,
@@ -84,7 +78,7 @@ impl AtomicFrameBuffer {
         for y in sy..=ey {
             for x in sx..=ex {
                 if let Some(color) = color_iter.next() {
-                    unsafe { BUFFER[(y as usize * SCREEN_WIDTH) + x as usize] = color };
+                    self.fb[(y as usize * SCREEN_WIDTH) + x as usize] = color;
                 } else {
                     return Err(()); // Not enough data
                 }
@@ -99,60 +93,17 @@ impl AtomicFrameBuffer {
         Ok(())
     }
 
-    // walk the dirty tiles and mark groups of tiles(meta-tiles) for batched updates
+    // Checks if a full draw would be faster than individual tile batches
-    fn find_meta_tiles(&mut self, tiles_x: usize, tiles_y: usize) -> MetaTileVec {
+    fn should_full_draw(&self) -> bool {
-        let mut meta_tiles: MetaTileVec = heapless::Vec::new();
+        let threshold_pixels = SIZE * 80 / 100;
+        let mut dirty_pixels = 0;
 
-        for ty in 0..tiles_y {
+        self.dirty_tiles.iter().any(|tile| {
-            let mut tx = 0;
+            if tile.load(Ordering::Acquire) {
-            while tx < tiles_x {
+                dirty_pixels += TILE_SIZE * TILE_SIZE;
-                let idx = ty * tiles_x + tx;
-                if !unsafe { DIRTY_TILES.get()[idx].load(Ordering::Acquire) } {
-                    tx += 1;
-                    continue;
-                }
-
-                // Start meta-tile at this tile
-                let mut width_tiles = 1;
-                let height_tiles = 1;
-
-                // Grow horizontally, but keep under MAX_TILES_PER_METATILE
-                while tx + width_tiles < tiles_x
-                    && unsafe {
-                        DIRTY_TILES.get()[ty * tiles_x + tx + width_tiles].load(Ordering::Relaxed)
-                    }
-                    && (width_tiles + height_tiles) <= MAX_META_TILES
-                {
-                    width_tiles += 1;
-                }
-
-                // TODO: for simplicity, skipped vertical growth
-
-                for x_off in 0..width_tiles {
-                    unsafe {
-                        DIRTY_TILES.get()[ty * tiles_x + tx + x_off]
-                            .store(false, Ordering::Release);
-                    };
-                }
-
-                // new meta-tile pos
-                let rect = Rectangle::new(
-                    Point::new((tx * TILE_SIZE) as i32, (ty * TILE_SIZE) as i32),
-                    Size::new(
-                        (width_tiles * TILE_SIZE) as u32,
-                        (height_tiles * TILE_SIZE) as u32,
-                    ),
-                );
-
-                if meta_tiles.push(rect).is_err() {
-                    return meta_tiles;
-                };
-
-                tx += width_tiles;
             }
-        }
+            dirty_pixels >= threshold_pixels
-
+        })
-        meta_tiles
     }
 
     /// Sends the entire framebuffer to the display
@@ -171,21 +122,41 @@ impl AtomicFrameBuffer {
                 0,
                 self.size().width as u16 - 1,
                 self.size().height as u16 - 1,
-                unsafe { &BUFFER },
+                &self.fb[..],
             )
             .await?;
 
-        unsafe {
+        for tile in self.dirty_tiles.iter() {
-            for tile in DIRTY_TILES.get_mut().iter() {
+            tile.store(false, Ordering::Release);
-                tile.store(false, Ordering::Release);
+        }
-            }
-        };
 
         Ok(())
     }
 
-    /// Sends only dirty tiles (16x16px) in batches to the display
+    // copy N tiles horizontally to the right into batch tile buf
-    pub async fn partial_draw_batched<SPI, DC, RST, DELAY>(
+    fn append_tiles_to_batch(
+        &mut self,
+        tile_x: u16,
+        tile_y: u16,
+        total_tiles: u16, // number of tiles being written to buf
+    ) {
+        debug_assert!(total_tiles as usize <= NUM_TILE_COLS);
+        for batch_row_num in 0..TILE_SIZE {
+            let batch_row_offset = batch_row_num * total_tiles as usize * TILE_SIZE;
+            let batch_row = &mut self.batch_tile_buf
+                [batch_row_offset..batch_row_offset + (total_tiles as usize * TILE_SIZE)];
+
+            let fb_row_offset = (tile_y as usize * TILE_SIZE + batch_row_num) * SCREEN_WIDTH
+                + tile_x as usize * TILE_SIZE;
+            let fb_row =
+                &self.fb[fb_row_offset..fb_row_offset + (total_tiles as usize * TILE_SIZE)];
+
+            batch_row.copy_from_slice(fb_row);
+        }
+    }
+
+    // Pushes tiles to the display in batches to avoid full frame pushes (unless needed)
+    pub async fn partial_draw<SPI, DC, RST, DELAY>(
         &mut self,
         display: &mut ST7365P<SPI, DC, RST, DELAY>,
     ) -> Result<(), ()>
@@ -195,57 +166,53 @@ impl AtomicFrameBuffer {
         RST: OutputPin,
         DELAY: DelayNs,
     {
-        if unsafe { DIRTY_TILES.get().iter().any(|p| p.load(Ordering::Acquire)) } {
+        if self.should_full_draw() {
-            let tiles_x = (SCREEN_WIDTH + TILE_SIZE - 1) / TILE_SIZE;
+            return self.draw(display).await;
-            let tiles_y = (SCREEN_HEIGHT + TILE_SIZE - 1) / TILE_SIZE;
+        }
 
-            let meta_tiles = self.find_meta_tiles(tiles_x, tiles_y);
+        for tile_row in 0..NUM_TILE_ROWS {
+            let row_start_idx = tile_row * NUM_TILE_COLS;
+            let mut col = 0;
 
-            // buffer for copying meta tiles before sending to display
+            while col < NUM_TILE_COLS {
-            let mut pixel_buffer: heapless::Vec<u16, { MAX_META_TILES * TILE_SIZE * TILE_SIZE }> =
+                // Check for dirty tile
-                Vec::new();
+                if self.dirty_tiles[row_start_idx + col].swap(false, Ordering::Acquire) {
+                    let run_start = col;
+                    let mut run_len = 1;
 
-            for rect in meta_tiles {
+                    // Extend run while contiguous dirty tiles and within MAX_BATCH_TILES
-                let rect_width = rect.size.width as usize;
+                    while col + 1 < NUM_TILE_COLS
-                let rect_height = rect.size.height as usize;
+                        && self.dirty_tiles[row_start_idx + col + 1].load(Ordering::Acquire)
-                let rect_x = rect.top_left.x as usize;
+                        && run_len < MAX_BATCH_TILES
-                let rect_y = rect.top_left.y as usize;
+                    {
-
+                        col += 1;
-                pixel_buffer.clear();
+                        run_len += 1;
-
-                for row in 0..rect_height {
-                    let y = rect_y + row;
-                    let start = y * SCREEN_WIDTH + rect_x;
-                    let end = start + rect_width;
-
-                    // Safe: we guarantee buffer will not exceed MAX_META_TILE_PIXELS
-                    pixel_buffer
-                        .extend_from_slice(unsafe { &BUFFER[start..end] })
-                        .unwrap();
-                }
-
-                display
-                    .set_pixels_buffered(
-                        rect_x as u16,
-                        rect_y as u16,
-                        (rect_x + rect_width - 1) as u16,
-                        (rect_y + rect_height - 1) as u16,
-                        &pixel_buffer,
-                    )
-                    .await?;
-
-                // walk the meta-tile and set as clean
-                let start_tx = rect_x / TILE_SIZE;
-                let start_ty = rect_y / TILE_SIZE;
-                let end_tx = (rect_x + rect_width - 1) / TILE_SIZE;
-                let end_ty = (rect_y + rect_height - 1) / TILE_SIZE;
-
-                for ty in start_ty..=end_ty {
-                    for tx in start_tx..=end_tx {
-                        let tile_idx = ty * tiles_x + tx;
-                        unsafe { DIRTY_TILES.get_mut()[tile_idx].store(false, Ordering::Release) };
                     }
+
+                    // Copy the whole horizontal run into the batch buffer in one call
+                    let tile_x = run_start;
+                    let tile_y = tile_row;
+                    self.append_tiles_to_batch(tile_x as u16, tile_y as u16, run_len as u16);
+
+                    // Compute coordinates for display write
+                    let start_x = tile_x * TILE_SIZE;
+                    let end_x = start_x + run_len * TILE_SIZE - 1;
+                    let start_y = tile_y * TILE_SIZE;
+                    let end_y = start_y + TILE_SIZE - 1;
+
+                    // Send batch to display
+                    display
+                        .set_pixels_buffered(
+                            start_x as u16,
+                            start_y as u16,
+                            end_x as u16,
+                            end_y as u16,
+                            &self.batch_tile_buf[..run_len * TILE_SIZE * TILE_SIZE],
+                        )
+                        .await?;
                 }
+
+                col += 1;
             }
         }
 
@@ -253,7 +220,7 @@ impl AtomicFrameBuffer {
     }
 }
 
-impl DrawTarget for AtomicFrameBuffer {
+impl<'a> DrawTarget for AtomicFrameBuffer<'a> {
     type Error = ();
     type Color = Rgb565;
 
@@ -262,17 +229,20 @@ impl DrawTarget for AtomicFrameBuffer {
         I: IntoIterator<Item = Pixel<Self::Color>>,
     {
         let mut dirty_rect: Option<Rectangle> = None;
+        let mut changed = false;
 
         for Pixel(coord, color) in pixels {
             if coord.x >= 0 && coord.y >= 0 {
-                let x = coord.x as i32;
+                let x = coord.x;
-                let y = coord.y as i32;
+                let y = coord.y;
 
                 if (x as usize) < SCREEN_WIDTH && (y as usize) < SCREEN_HEIGHT {
-                    unsafe {
+                    let idx = (y as usize) * SCREEN_WIDTH + (x as usize);
-                        BUFFER[(y as usize) * SCREEN_WIDTH + (x as usize)] =
+                    let raw_color = RawU16::from(color).into_inner();
-                            RawU16::from(color).into_inner()
+                    if self.fb[idx] != raw_color {
-                    };
+                        self.fb[idx] = raw_color;
+                        changed = true;
+                    }
 
                     if let Some(ref mut rect) = dirty_rect {
                         rect.top_left.x = rect.top_left.x.min(x);
@@ -288,8 +258,10 @@ impl DrawTarget for AtomicFrameBuffer {
             }
         }
 
-        if let Some(rect) = dirty_rect {
+        if changed {
-            self.mark_tiles_dirty(rect);
+            if let Some(rect) = dirty_rect {
+                self.mark_tiles_dirty(rect);
+            }
         }
 
         Ok(())
@@ -307,6 +279,7 @@ impl DrawTarget for AtomicFrameBuffer {
             let area_width = area.size.width;
             let area_height = area.size.height;
             let mut colors = colors.into_iter();
+            let mut changed = false;
 
             for y in 0..area_height {
                 for x in 0..area_width {
@@ -314,11 +287,12 @@ impl DrawTarget for AtomicFrameBuffer {
 
                     if drawable_area.contains(p) {
                         if let Some(color) = colors.next() {
-                            self.set_pixel(
+                            let idx = (p.y as usize * SCREEN_WIDTH) + (p.x as usize);
-                                p.x as u16,
+                            let raw_color = RawU16::from(color).into_inner();
-                                p.y as u16,
+                            if self.fb[idx] != raw_color {
-                                RawU16::from(color).into_inner(),
+                                self.fb[idx] = raw_color;
-                            )?;
+                                changed = true;
+                            }
                         } else {
                             break;
                         }
@@ -329,7 +303,9 @@ impl DrawTarget for AtomicFrameBuffer {
                 }
             }
 
-            self.mark_tiles_dirty(*area);
+            if changed {
+                self.mark_tiles_dirty(*area);
+            }
         }
 
         Ok(())
@@ -343,7 +319,7 @@ impl DrawTarget for AtomicFrameBuffer {
     }
 
     fn clear(&mut self, color: Self::Color) -> Result<(), Self::Error> {
-        self.set_pixels_buffered(
+        self.set_pixels(
             0,
             0,
             self.size().width as u16 - 1,
@@ -352,7 +328,7 @@ impl DrawTarget for AtomicFrameBuffer {
                 .take((self.size().width * self.size().height) as usize),
         )?;
 
-        for tile in unsafe { DIRTY_TILES.get_mut() }.iter() {
+        for tile in self.dirty_tiles.iter() {
             tile.store(true, Ordering::Release);
         }
 
@@ -360,7 +336,7 @@ impl DrawTarget for AtomicFrameBuffer {
     }
 }
 
-impl OriginDimensions for AtomicFrameBuffer {
+impl<'a> OriginDimensions for AtomicFrameBuffer<'a> {
     fn size(&self) -> Size {
         Size::new(SCREEN_WIDTH as u32, SCREEN_HEIGHT as u32)
     }

kernel/src/heap.rs

@@ -2,14 +2,10 @@
 // https://github.com/wezterm/picocalc-wezterm/blob/main/src/heap.rs
 
 use core::alloc::{GlobalAlloc, Layout};
-use core::mem::MaybeUninit;
 use core::sync::atomic::{AtomicUsize, Ordering};
 use embedded_alloc::LlffHeap as Heap;
 
-#[global_allocator]
+pub static mut HEAP: PsramHeap = PsramHeap::empty();
-pub static HEAP: DualHeap = DualHeap::empty();
-const HEAP_SIZE: usize = 64 * 1024;
-static mut HEAP_MEM: [MaybeUninit<u8>; HEAP_SIZE] = [MaybeUninit::uninit(); HEAP_SIZE];
 
 struct Region {
     start: AtomicUsize,
@@ -38,95 +34,62 @@ impl Region {
     }
 }
 
-/// This is an allocator that combines two regions of memory.
-/// The intent is to use some of the directly connected RAM
-/// for this, and if we find some XIP capable PSRAM, add that
-/// as a secondary region.
-/// Allocation from the primary region is always preferred,
-/// as it is expected to be a bit faster than PSRAM.
 /// FIXME: PSRAM-allocated memory isn't compatible with
 /// CAS atomics, so we might need a bit of a think about this!
-pub struct DualHeap {
+pub struct PsramHeap {
-    primary: Heap,
+    heap: Heap,
-    primary_region: Region,
+    region: Region,
-    secondary: Heap,
 }
 
-impl DualHeap {
+impl PsramHeap {
     pub const fn empty() -> Self {
         Self {
-            primary: Heap::empty(),
+            heap: Heap::empty(),
-            primary_region: Region::default(),
+            region: Region::default(),
-            secondary: Heap::empty(),
         }
     }
 
-    unsafe fn add_primary(&self, region: Region) {
+    unsafe fn add_psram(&self, region: Region) {
         let start = region.start.load(Ordering::SeqCst);
         let size = region.size.load(Ordering::SeqCst);
         unsafe {
-            self.primary.init(start, size);
+            self.heap.init(start, size);
-        }
-        self.primary_region.start.store(start, Ordering::SeqCst);
-        self.primary_region.size.store(size, Ordering::SeqCst);
-    }
-
-    unsafe fn add_secondary(&self, region: Region) {
-        let start = region.start.load(Ordering::SeqCst);
-        let size = region.size.load(Ordering::SeqCst);
-        unsafe {
-            self.secondary.init(start, size);
         }
+        self.region.start.store(start, Ordering::SeqCst);
+        self.region.size.store(size, Ordering::SeqCst);
     }
 
     pub fn used(&self) -> usize {
-        self.primary.used() + self.secondary.used()
+        self.heap.used()
     }
 
     pub fn free(&self) -> usize {
-        self.primary.free() + self.secondary.free()
+        self.heap.free()
     }
 }
 
-unsafe impl GlobalAlloc for DualHeap {
+unsafe impl GlobalAlloc for PsramHeap {
     unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
         unsafe {
-            let ptr = self.primary.alloc(layout);
+            let ptr = self.heap.alloc(layout);
             if !ptr.is_null() {
                 return ptr;
+            } else {
+                panic!("HEAP FULL");
             }
-            // start using secondary area when primary heap is full
-            self.secondary.alloc(layout)
         }
     }
 
     unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
         unsafe {
             let ptr_usize = ptr as usize;
-            if self.primary_region.contains(ptr_usize) {
+            if self.region.contains(ptr_usize) {
-                self.primary.dealloc(ptr, layout);
+                self.heap.dealloc(ptr, layout);
-            } else {
-                self.secondary.dealloc(ptr, layout);
             }
         }
     }
 }
 
-pub fn init_heap() {
-    let primary_start = &raw mut HEAP_MEM as usize;
-    unsafe { HEAP.add_primary(Region::new(primary_start, HEAP_SIZE)) }
-}
-
 pub fn init_qmi_psram_heap(size: u32) {
-    unsafe { HEAP.add_secondary(Region::new(0x11000000, size as usize)) }
+    unsafe { HEAP.add_psram(Region::new(0x11000000, size as usize)) }
-}
-
-pub async fn free_command(_args: &[&str]) {
-    let ram_used = HEAP.primary.used();
-    let ram_free = HEAP.primary.free();
-    let ram_total = ram_used + ram_free;
-
-    let qmi_used = HEAP.secondary.used();
-    let qmi_free = HEAP.secondary.free();
-    let qmi_total = qmi_used + qmi_free;
 }

kernel/src/main.rs

@@ -3,6 +3,8 @@
 #![cfg_attr(not(test), no_std)]
 #![cfg_attr(not(test), no_main)]
 #![allow(static_mut_refs)]
+#![feature(allocator_api)]
+#![feature(slice_ptr_get)]
 
 extern crate alloc;
 
@@ -10,9 +12,10 @@ mod abi;
 mod display;
 mod elf;
 mod framebuffer;
-#[cfg(feature = "pimoroni2w")]
+#[allow(unused)]
 mod heap;
 mod peripherals;
+#[allow(unused)]
 mod psram;
 mod scsi;
 mod storage;
@@ -26,6 +29,7 @@ use crate::{heap::init_qmi_psram_heap, psram::init_psram_qmi};
 use crate::{
     abi::{KEY_CACHE, MS_SINCE_LAUNCH},
     display::{FRAMEBUFFER, display_handler, init_display},
+    heap::HEAP,
     peripherals::{
         conf_peripherals,
         keyboard::{KeyState, read_keyboard_fifo},
@@ -37,13 +41,6 @@ use crate::{
 };
 use abi_sys::EntryFn;
 use bumpalo::Bump;
-use embedded_graphics::{
-    pixelcolor::Rgb565,
-    prelude::{DrawTarget, RgbColor},
-};
-
-use {defmt_rtt as _, panic_probe as _};
-
 use core::sync::atomic::{AtomicBool, Ordering};
 use embassy_executor::{Executor, Spawner};
 use embassy_futures::{join::join, select::select};
@@ -55,20 +52,26 @@ use embassy_rp::{
     peripherals::{
         DMA_CH0, DMA_CH1, DMA_CH3, DMA_CH4, I2C1, PIN_2, PIN_3, PIN_6, PIN_7, PIN_10, PIN_11,
         PIN_12, PIN_13, PIN_14, PIN_15, PIN_16, PIN_17, PIN_18, PIN_19, PIN_20, PIN_21, PIN_22,
-        PIO0, SPI0, SPI1, USB,
+        PIO0, SPI0, SPI1, USB, WATCHDOG,
     },
     pio,
     spi::{self, Spi},
     usb as embassy_rp_usb,
+    watchdog::{ResetReason, Watchdog},
 };
 use embassy_sync::{
     blocking_mutex::raw::CriticalSectionRawMutex, channel::Channel, signal::Signal,
 };
-use embassy_time::{Delay, Instant, Timer};
+use embassy_time::{Delay, Duration, Instant, Ticker, Timer};
+use embedded_graphics::{
+    pixelcolor::Rgb565,
+    prelude::{DrawTarget, RgbColor},
+};
 use embedded_hal_bus::spi::ExclusiveDevice;
 use embedded_sdmmc::SdCard as SdmmcSdCard;
 use static_cell::StaticCell;
 use talc::*;
+use {defmt_rtt as _, panic_probe as _};
 
 embassy_rp::bind_interrupts!(struct Irqs {
     I2C1_IRQ => i2c::InterruptHandler<I2C1>;
@@ -81,14 +84,35 @@ static EXECUTOR0: StaticCell<Executor> = StaticCell::new();
 static EXECUTOR1: StaticCell<Executor> = StaticCell::new();
 
 #[cfg(not(feature = "pimoroni2w"))]
-static mut ARENA: [u8; 200 * 1024] = [0; 200 * 1024];
+static mut ARENA: [u8; 250 * 1024] = [0; 250 * 1024];
+#[cfg(feature = "pimoroni2w")]
+static mut ARENA: [u8; 400 * 1024] = [0; 400 * 1024];
 
-#[cfg(not(feature = "pimoroni2w"))]
 #[global_allocator]
 static ALLOCATOR: Talck<spin::Mutex<()>, ClaimOnOom> =
     Talc::new(unsafe { ClaimOnOom::new(Span::from_array(core::ptr::addr_of!(ARENA).cast_mut())) })
         .lock();
 
+#[embassy_executor::task]
+async fn watchdog_task(mut watchdog: Watchdog) {
+    if let Some(reason) = watchdog.reset_reason() {
+        let _reason = match reason {
+            ResetReason::Forced => "forced",
+            ResetReason::TimedOut => "timed out",
+        };
+        #[cfg(feature = "debug")]
+        defmt::error!("Watchdog reset reason: {}", _reason);
+    }
+
+    watchdog.start(Duration::from_secs(3));
+
+    let mut ticker = Ticker::every(Duration::from_secs(2));
+    loop {
+        watchdog.feed();
+        ticker.next().await;
+    }
+}
+
 static ENABLE_UI: AtomicBool = AtomicBool::new(true);
 static UI_CHANGE: Signal<CriticalSectionRawMutex, ()> = Signal::new();
 
@@ -141,7 +165,9 @@ async fn main(_spawner: Spawner) {
     let executor0 = EXECUTOR0.init(Executor::new());
     executor0.run(|spawner| {
         spawner
-            .spawn(kernel_task(spawner, display, sd, psram, mcu, p.USB))
+            .spawn(kernel_task(
+                spawner, p.WATCHDOG, display, sd, psram, mcu, p.USB,
+            ))
             .unwrap()
     });
 }
@@ -175,7 +201,7 @@ async fn userland_task() {
         {
             ENABLE_UI.store(true, Ordering::Release);
             UI_CHANGE.signal(());
-            unsafe { FRAMEBUFFER.clear(Rgb565::BLACK).unwrap() };
+            unsafe { FRAMEBUFFER.as_mut().unwrap().clear(Rgb565::BLACK).unwrap() };
 
             let mut selections = SELECTIONS.lock().await;
             selections.set_changed(true);
@@ -202,6 +228,7 @@ struct Sd {
     cs: Peri<'static, PIN_17>,
     det: Peri<'static, PIN_22>,
 }
+#[allow(dead_code)]
 struct Psram {
     pio: Peri<'static, PIO0>,
     sclk: Peri<'static, PIN_21>,
@@ -227,7 +254,7 @@ async fn setup_mcu(mcu: Mcu) {
 
 async fn setup_display(display: Display, spawner: Spawner) {
     let mut config = spi::Config::default();
-    config.frequency = 16_000_000;
+    config.frequency = 64_000_000;
     let spi = Spi::new(
         display.spi,
         display.clk,
@@ -241,6 +268,8 @@ async fn setup_display(display: Display, spawner: Spawner) {
     spawner.spawn(display_handler(display)).unwrap();
 }
 
+// psram is kind of useless on the pico calc
+// ive opted to use the pimoroni with on onboard xip psram instead
 async fn setup_psram(psram: Psram) {
     let psram = init_psram(
         psram.pio, psram.sclk, psram.mosi, psram.miso, psram.cs, psram.dma1, psram.dma2,
@@ -254,13 +283,21 @@ async fn setup_psram(psram: Psram) {
         #[cfg(feature = "defmt")]
         defmt::info!("\u{1b}[1mExternal PSRAM was NOT found!\u{1b}[0m");
     }
+}
 
-    #[cfg(feature = "pimoroni2w")]
+#[cfg(feature = "pimoroni2w")]
-    {
+async fn setup_qmi_psram() {
-        let psram_qmi_size = init_psram_qmi(&embassy_rp::pac::QMI, &embassy_rp::pac::XIP_CTRL);
+    Timer::after_millis(250).await;
-        if psram_qmi_size > 0 {
+    let psram_qmi_size = init_psram_qmi(&embassy_rp::pac::QMI, &embassy_rp::pac::XIP_CTRL);
-            init_qmi_psram_heap(psram_qmi_size);
+    #[cfg(feature = "debug")]
-        }
+    defmt::info!("size:  {}", psram_qmi_size);
+    Timer::after_millis(100).await;
+
+    if psram_qmi_size > 0 {
+        init_qmi_psram_heap(psram_qmi_size);
+        return;
+    } else {
+        panic!("qmi psram not initialized");
     }
 }
 
@@ -282,16 +319,28 @@ async fn setup_sd(sd: Sd) {
 #[embassy_executor::task]
 async fn kernel_task(
     spawner: Spawner,
+    watchdog: Peri<'static, WATCHDOG>,
     display: Display,
     sd: Sd,
     psram: Psram,
     mcu: Mcu,
     usb: Peri<'static, USB>,
 ) {
+    spawner
+        .spawn(watchdog_task(Watchdog::new(watchdog)))
+        .unwrap();
+
     setup_mcu(mcu).await;
-    Timer::after_millis(250).await;
+
+    defmt::info!("setting up psram");
+    Timer::after_millis(100).await;
+
+    // setup_psram(psram).await;
+    #[cfg(feature = "pimoroni2w")]
+    setup_qmi_psram().await;
+
+    Timer::after_millis(100).await;
     setup_display(display, spawner).await;
-    setup_psram(psram).await;
     setup_sd(sd).await;
 
     let _usb = embassy_rp_usb::Driver::new(usb, Irqs);

kernel/src/psram.rs

@@ -526,16 +526,11 @@ pub fn init_psram_qmi(
     let psram_size = detect_psram_qmi(qmi);
 
     if psram_size == 0 {
+        #[cfg(feature = "debug")]
+        defmt::error!("qmi psram size 0");
         return 0;
     }
 
-    // Set PSRAM timing for APS6404
-    //
-    // Using an rxdelay equal to the divisor isn't enough when running the APS6404 close to 133MHz.
-    // So: don't allow running at divisor 1 above 100MHz (because delay of 2 would be too late),
-    // and add an extra 1 to the rxdelay if the divided clock is > 100MHz (i.e. sys clock > 200MHz).
-    const MAX_PSRAM_FREQ: u32 = 133_000_000;
-
     let clock_hz = clk_peri_freq();
 
     let mut divisor: u32 = (clock_hz + MAX_PSRAM_FREQ - 1) / MAX_PSRAM_FREQ;
@@ -554,13 +549,13 @@ pub fn init_psram_qmi(
     let min_deselect: u32 = ((18 * 1_000_000 + (clock_period_fs - 1)) / clock_period_fs
         - u64::from(divisor + 1) / 2) as u32;
 
-    #[cfg(feature = "defmt")]
+    // #[cfg(feature = "defmt")]
-    defmt::info!(
+    // defmt::info!(
-        "clock_period_fs={} max_select={} min_deselect={}",
+    //     "clock_period_fs={} max_select={} min_deselect={}",
-        clock_period_fs,
+    //     clock_period_fs,
-        max_select,
+    //     max_select,
-        min_deselect
+    //     min_deselect
-    );
+    // );
 
     qmi.direct_csr().write(|w| {
         w.set_clkdiv(10);

kernel/src/ui.rs

@@ -1,9 +1,6 @@
 use crate::{
-    BINARY_CH,
+    BINARY_CH, display::FRAMEBUFFER, elf::load_binary, framebuffer::FB_PAUSED,
-    display::{FB_PAUSED, FRAMEBUFFER},
+    peripherals::keyboard, storage::FileName,
-    elf::load_binary,
-    peripherals::keyboard,
-    storage::FileName,
 };
 use abi_sys::keyboard::{KeyCode, KeyState};
 use alloc::{str::FromStr, string::String, vec::Vec};
@@ -71,7 +68,7 @@ pub async fn clear_selection() {
     if let Some(area) = sel.last_bounds {
         Rectangle::new(area.top_left, area.size)
             .into_styled(PrimitiveStyle::with_fill(Rgb565::BLACK))
-            .draw(unsafe { &mut FRAMEBUFFER })
+            .draw(unsafe { &mut *FRAMEBUFFER.as_mut().unwrap() })
             .unwrap();
     }
 }
@@ -81,7 +78,7 @@ async fn draw_selection() {
     let file_names = &guard.selections.clone();
 
     let text_style = MonoTextStyle::new(&FONT_10X20, Rgb565::WHITE);
-    let display_area = unsafe { FRAMEBUFFER.bounding_box() };
+    let display_area = unsafe { FRAMEBUFFER.as_mut().unwrap().bounding_box() };
 
     const NO_BINS: &str = "No Programs found on SD Card. Ensure programs end with '.bin', and are located in the root directory";
     let no_bins = String::from_str(NO_BINS).unwrap();
@@ -97,7 +94,7 @@ async fn draw_selection() {
             ),
             text_style,
         )
-        .draw(unsafe { &mut FRAMEBUFFER })
+        .draw(unsafe { &mut *FRAMEBUFFER.as_mut().unwrap() })
         .unwrap();
     } else {
         let mut views: alloc::vec::Vec<Text<MonoTextStyle<Rgb565>>> = Vec::new();
@@ -122,12 +119,14 @@ async fn draw_selection() {
             .bounding_box();
         Rectangle::new(selected_bounds.top_left, selected_bounds.size)
             .into_styled(PrimitiveStyle::with_stroke(Rgb565::WHITE, 1))
-            .draw(unsafe { &mut FRAMEBUFFER })
+            .draw(unsafe { &mut *FRAMEBUFFER.as_mut().unwrap() })
             .unwrap();
 
         guard.last_bounds = Some(layout.bounds());
 
-        layout.draw(unsafe { &mut FRAMEBUFFER }).unwrap();
+        layout
+            .draw(unsafe { &mut *FRAMEBUFFER.as_mut().unwrap() })
+            .unwrap();
     }
 
     guard.changed = false;

selection_ui/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "selection_ui"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+abi = { path = "../abi" }
+embedded-graphics = "0.8.1"
+embedded-layout = "0.4.2"
+embedded-text = "0.7.3"

selection_ui/src/lib.rs

@@ -0,0 +1,119 @@
+#![no_std]
+
+extern crate alloc;
+
+use abi::{
+    display::Display,
+    get_key,
+    keyboard::{KeyCode, KeyState},
+    print, sleep,
+};
+use alloc::vec::Vec;
+use embedded_graphics::{
+    Drawable,
+    mono_font::{MonoTextStyle, ascii::FONT_10X20},
+    pixelcolor::Rgb565,
+    prelude::{Dimensions, Point, Primitive, RgbColor, Size},
+    primitives::{PrimitiveStyle, Rectangle},
+    text::Text,
+};
+use embedded_layout::{
+    align::{horizontal, vertical},
+    layout::linear::{FixedMargin, LinearLayout},
+    prelude::*,
+};
+use embedded_text::TextBox;
+
+pub struct SelectionUi<'a> {
+    selection: usize,
+    items: &'a [&'a str],
+    error: &'a str,
+    last_bounds: Option<Rectangle>,
+}
+
+impl<'a> SelectionUi<'a> {
+    pub fn new(items: &'a [&'a str], error: &'a str) -> Self {
+        Self {
+            selection: 0,
+            items,
+            error,
+            last_bounds: None,
+        }
+    }
+
+    pub fn run_selection_ui(&mut self, display: &mut Display) -> Result<Option<usize>, ()> {
+        self.draw(display)?;
+        let selection;
+        loop {
+            let key = get_key();
+            if key.state == KeyState::Pressed {
+                print!("Got Key press: {:?}", key.key);
+                if let Some(s) = self.update(display, key.key)? {
+                    selection = Some(s);
+                    break;
+                }
+            }
+        }
+        Ok(selection)
+    }
+
+    /// updates the display with a new keypress.
+    /// returns selection idx if selected
+    pub fn update(&mut self, display: &mut Display, key: KeyCode) -> Result<Option<usize>, ()> {
+        match key {
+            KeyCode::JoyUp => {
+                self.selection = self.selection.saturating_sub(1);
+            }
+            KeyCode::JoyDown => {
+                self.selection = self.selection.saturating_add(1);
+            }
+            KeyCode::Enter | KeyCode::JoyRight => return Ok(Some(self.selection)),
+            _ => return Ok(Some(self.selection)),
+        };
+        self.draw(display)?;
+        Ok(None)
+    }
+
+    fn draw(&mut self, display: &mut Display) -> Result<(), ()> {
+        let text_style = MonoTextStyle::new(&FONT_10X20, Rgb565::WHITE);
+        let display_area = display.bounding_box();
+
+        if self.items.is_empty() {
+            TextBox::new(
+                &self.error,
+                Rectangle::new(
+                    Point::new(25, 25),
+                    Size::new(display_area.size.width - 50, display_area.size.width - 50),
+                ),
+                text_style,
+            )
+            .draw(display)
+            .unwrap();
+        }
+
+        let mut views: Vec<Text<MonoTextStyle<Rgb565>>> = Vec::new();
+
+        for i in self.items {
+            views.push(Text::new(i, Point::zero(), text_style));
+        }
+
+        let views_group = Views::new(views.as_mut_slice());
+
+        let layout = LinearLayout::vertical(views_group)
+            .with_alignment(horizontal::Center)
+            .with_spacing(FixedMargin(5))
+            .arrange()
+            .align_to(&display_area, horizontal::Center, vertical::Center);
+
+        // draw selected box
+        let selected_bounds = layout.inner().get(self.selection).ok_or(())?.bounding_box();
+        Rectangle::new(selected_bounds.top_left, selected_bounds.size)
+            .into_styled(PrimitiveStyle::with_stroke(Rgb565::WHITE, 1))
+            .draw(display)?;
+
+        self.last_bounds = Some(layout.bounds());
+
+        layout.draw(display)?;
+        Ok(())
+    }
+}

user-apps/calculator/src/main.rs

@@ -3,7 +3,7 @@
 
 extern crate alloc;
 use abi::{
-    display::{Display, lock_display},
+    display::Display,
     get_key,
     keyboard::{KeyCode, KeyState},
     print,
@@ -28,11 +28,7 @@ use embedded_layout::{
 
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {
-    print(&format!(
+    print!("user panic: {} @ {:?}", info.message(), info.location(),);
-        "user panic: {} @ {:?}",
-        info.message(),
-        info.location(),
-    ));
     loop {}
 }
 
@@ -42,7 +38,7 @@ pub extern "Rust" fn _start() {
 }
 
 pub fn main() {
-    print("Starting Calculator app");
+    print!("Starting Calculator app");
     let mut display = Display;
 
     let mut input = vec!['e', 'x', 'p', 'r', ':', ' '];
@@ -62,8 +58,6 @@ pub fn main() {
 
     loop {
         if dirty {
-            lock_display(true);
-
             let style = PrimitiveStyle::with_fill(Rgb565::BLACK);
             if let Some(area) = last_area {
                 Rectangle::new(area.0.top_left, area.0.size)
@@ -107,7 +101,6 @@ pub fn main() {
             eq_layout.draw(&mut display).unwrap();
 
             dirty = false;
-            lock_display(false);
         }
 
         let event = get_key();

user-apps/gallery/src/main.rs

@@ -4,13 +4,13 @@
 
 extern crate alloc;
 use abi::{
-    display::{Display, SCREEN_HEIGHT, SCREEN_WIDTH, lock_display},
+    display::{Display, SCREEN_HEIGHT, SCREEN_WIDTH},
-    fs::{list_dir, read_file},
+    fs::{Entries, list_dir, read_file},
     get_key,
     keyboard::{KeyCode, KeyState},
     print,
 };
-use alloc::{format, string::ToString};
+use alloc::{format, vec};
 use core::panic::PanicInfo;
 use embedded_graphics::{
     Drawable, image::Image, mono_font::MonoTextStyle, mono_font::ascii::FONT_6X10,
@@ -20,11 +20,7 @@ use tinybmp::Bmp;
 
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {
-    print(&format!(
+    print!("user panic: {} @ {:?}", info.message(), info.location());
-        "user panic: {} @ {:?}",
-        info.message(),
-        info.location(),
-    ));
     loop {}
 }
 
@@ -34,11 +30,10 @@ pub extern "Rust" fn _start() {
 }
 
 pub fn main() {
-    print("Starting Gallery app");
+    print!("Starting Gallery app");
-    static mut BMP_BUF: [u8; 100_000] = [0_u8; 100_000];
+    let mut bmp_buf = vec![0_u8; 100_000];
     let mut display = Display;
 
-    // Grid parameters
     let grid_cols = 3;
     let grid_rows = 3;
     let cell_width = SCREEN_WIDTH as i32 / grid_cols;
@@ -46,53 +41,44 @@ pub fn main() {
 
     let mut images_drawn = 0;
 
-    let mut files = [const { None }; 18];
+    let mut entries = Entries::new();
-    let files_num = list_dir("/images", &mut files);
+    let files_num = list_dir("/images", &mut entries);
 
-    for file in &files[2..files_num] {
+    for file in &entries.entries()[2..files_num] {
         if images_drawn >= grid_cols * grid_rows {
             break; // only draw 3x3
         }
 
-        if let Some(f) = file {
+        print!("file: {}", file);
-            print(&format!("file: {}", f.name));
+        if file.extension().unwrap_or("") == "bmp" || file.extension().unwrap_or("") == "BMP" {
-            if f.name.extension() == b"bmp" || f.name.extension() == b"BMP" {
+            let file_path = format!("/images/{}", file);
-                let file = format!("/images/{}", f.name);
 
-                let read = read_file(&file, 0, &mut unsafe { &mut BMP_BUF[..] });
+            let read = read_file(&file_path, 0, &mut &mut bmp_buf[..]);
-                if read > 0 {
+            if read > 0 {
-                    let bmp = Bmp::from_slice(unsafe { &BMP_BUF }).expect("failed to parse bmp");
+                let bmp = Bmp::from_slice(&bmp_buf).expect("failed to parse bmp");
 
-                    let row = images_drawn / grid_cols;
+                let row = images_drawn / grid_cols;
-                    let col = images_drawn % grid_cols;
+                let col = images_drawn % grid_cols;
-                    let cell_x = col * cell_width;
+                let cell_x = col * cell_width;
-                    let cell_y = row * cell_height;
+                let cell_y = row * cell_height;
 
-                    // Center image inside cell
+                // Center image inside cell
-                    let bmp_w = bmp.size().width as i32;
+                let bmp_w = bmp.size().width as i32;
-                    let bmp_h = bmp.size().height as i32;
+                let bmp_h = bmp.size().height as i32;
-                    let x = cell_x + (cell_width - bmp_w) / 2;
+                let x = cell_x + (cell_width - bmp_w) / 2;
-                    let y = cell_y + 5; // 5px top margin
+                let y = cell_y + 5; // 5px top margin
 
-                    lock_display(true);
+                Image::new(&bmp, Point::new(x, y))
-                    Image::new(&bmp, Point::new(x, y))
-                        .draw(&mut display)
-                        .unwrap();
-
-                    let text_style = MonoTextStyle::new(&FONT_6X10, Rgb565::WHITE);
-                    let text_y = y + bmp_h + 2; // 2px gap under image
-                    Text::new(
-                        f.name.to_string().as_str(),
-                        Point::new(cell_x + 2, text_y),
-                        text_style,
-                    )
                     .draw(&mut display)
                     .unwrap();
 
-                    lock_display(false);
+                let text_style = MonoTextStyle::new(&FONT_6X10, Rgb565::WHITE);
+                let text_y = y + bmp_h + 2; // 2px gap under image
+                Text::new(&file.base(), Point::new(cell_x + 2, text_y), text_style)
+                    .draw(&mut display)
+                    .unwrap();
 
-                    images_drawn += 1;
+                images_drawn += 1;
-                }
             }
         }
     }

user-apps/gif/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "gif"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+abi = { path = "../../abi" }
+embedded-graphics = "0.8.1"
+selection_ui = { path = "../../selection_ui" }
+tinygif = { git = "https://github.com/LegitCamper/tinygif" }

user-apps/gif/build.rs

@@ -0,0 +1,28 @@
+//! This build script copies the `memory.x` file from the crate root into
+//! a directory where the linker can always find it at build time.
+//! For many projects this is optional, as the linker always searches the
+//! project root directory -- wherever `Cargo.toml` is. However, if you
+//! are using a workspace or have a more complicated build setup, this
+//! build script becomes required. Additionally, by requesting that
+//! Cargo re-run the build script whenever `memory.x` is changed,
+//! updating `memory.x` ensures a rebuild of the application with the
+//! new memory settings.
+
+use std::env;
+use std::fs::File;
+use std::io::Write;
+use std::path::PathBuf;
+
+fn main() {
+    // Put `memory.x` in our output directory and ensure it's
+    // on the linker search path.
+    let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    File::create(out.join("memory.x"))
+        .unwrap()
+        .write_all(include_bytes!("../memory.x"))
+        .unwrap();
+    println!("cargo:rustc-link-search={}", out.display());
+
+    println!("cargo:rerun-if-changed=memory.x");
+    println!("cargo:rustc-link-arg-bins=-Tmemory.x");
+}

user-apps/gif/src/main.rs

@@ -0,0 +1,84 @@
+#![no_std]
+#![no_main]
+
+extern crate alloc;
+use abi::{
+    display::Display,
+    fs::{Entries, file_len, list_dir, read_file},
+    get_key, get_ms,
+    keyboard::{KeyCode, KeyState},
+    print, sleep,
+};
+use alloc::{format, vec, vec::Vec};
+use core::panic::PanicInfo;
+use embedded_graphics::{
+    image::ImageDrawable, pixelcolor::Rgb565, prelude::Point, transform::Transform,
+};
+use selection_ui::SelectionUi;
+use tinygif::Gif;
+
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    print!("user panic: {} @ {:?}", info.message(), info.location(),);
+    loop {}
+}
+
+#[unsafe(no_mangle)]
+pub extern "Rust" fn _start() {
+    main()
+}
+
+pub fn main() {
+    print!("Starting Gif app");
+    let mut display = Display;
+
+    let mut entries = Entries::new();
+    list_dir("/gifs", &mut entries);
+
+    let mut files = entries.entries();
+    files.retain(|e| e.extension().unwrap_or("") == "gif");
+    let gifs = &files.iter().map(|e| e.full_name()).collect::<Vec<&str>>();
+
+    let mut selection_ui = SelectionUi::new(&gifs, "No Gif files found in /gifs");
+    let selection = selection_ui
+        .run_selection_ui(&mut display)
+        .expect("failed to draw")
+        .expect("Failed to get user selection");
+
+    let file_name = format!("/gifs/{}", gifs[selection]);
+    let size = file_len(&file_name);
+    let mut buf = vec![0_u8; size];
+    let read = read_file(&file_name, 0, &mut buf);
+    print!("read: {}, file size: {}", read, size);
+    assert!(read == size);
+
+    let gif = Gif::<Rgb565>::from_slice(&buf).expect("Failed to parse gif");
+    let height = gif.height();
+
+    let mut frame_num = 0;
+    loop {
+        for mut frame in gif.frames() {
+            let start = get_ms();
+
+            frame
+                .translate_mut(Point::new(0, (320 - height as i32) / 2))
+                .draw(&mut display)
+                .unwrap();
+            frame_num += 1;
+
+            if frame_num % 5 == 0 {
+                let event = get_key();
+                if event.state != KeyState::Idle {
+                    match event.key {
+                        KeyCode::Esc => {
+                            drop(buf);
+                            return;
+                        }
+                        _ => (),
+                    };
+                };
+            }
+            sleep(((frame.delay_centis as u64) * 10).saturating_sub(start));
+        }
+    }
+}

user-apps/memory.x

@@ -1,6 +1,6 @@
 MEMORY
 {
-  RAM : ORIGIN = 0x0, LENGTH = 150K
+  RAM : ORIGIN = 0x0, LENGTH = 250K
 }
 
 SECTIONS

user-apps/snake/Cargo.toml

@@ -6,5 +6,5 @@ edition = "2024"
 [dependencies]
 abi = { path = "../../abi" }
 embedded-graphics = "0.8.1"
-embedded-snake = { path = "../../../embedded-snake-rs" }
+embedded-snake = { git = "https://github.com/LegitCamper/embedded-snake-rs" }
 rand = { version = "0.9.0", default-features = false }

user-apps/snake/src/main.rs

@@ -4,23 +4,18 @@
 extern crate alloc;
 use abi::{
     Rng,
-    display::{Display, SCREEN_HEIGHT, SCREEN_WIDTH, lock_display},
+    display::{Display, SCREEN_HEIGHT, SCREEN_WIDTH},
     get_key,
     keyboard::{KeyCode, KeyState},
     print, sleep,
 };
-use alloc::format;
 use core::panic::PanicInfo;
 use embedded_graphics::{pixelcolor::Rgb565, prelude::RgbColor};
 use embedded_snake::{Direction, SnakeGame};
 
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {
-    print(&format!(
+    print!("user panic: {} @ {:?}", info.message(), info.location(),);
-        "user panic: {} @ {:?}",
-        info.message(),
-        info.location(),
-    ));
     loop {}
 }
 
@@ -32,7 +27,7 @@ pub extern "Rust" fn _start() {
 const CELL_SIZE: usize = 8;
 
 pub fn main() {
-    print("Starting Snake app");
+    print!("Starting Snake app");
     let mut display = Display;
 
     let mut game = SnakeGame::<100, Rgb565, Rng>::new(
@@ -62,10 +57,8 @@ pub fn main() {
         };
 
         // ensure all draws show up at once
-        lock_display(true);
         game.pre_draw(&mut display);
         game.draw(&mut display);
-        lock_display(false);
 
         sleep(15);
     }