Implement Heap allocation (#3)

* Implement Maloc

* Implement Dealloc

* Migrate to a struct based heap implementation

src/main.rs

@@ -1,18 +1,20 @@
 #![no_main]
 #![no_std]
 #![feature(asm_experimental_arch)]
-
+#![allow(static_mut_refs)]
 use core::{
     arch::{asm, global_asm},
     panic::PanicInfo,
     ptr::write_volatile,
 };
 
+extern crate alloc;
+
 use nova::{
-    framebuffer::{print_display_resolution, FrameBuffer, BLUE, GREEN, ORANGE, RED, YELLOW},
+    framebuffer::{FrameBuffer, BLUE, GREEN, RED},
+    heap::{init_global_heap, HEAP},
     irq_interrupt::enable_irq_source,
     mailbox::mb_read_soc_temp,
-    math::polar_to_cartesian,
     peripherals::{
         gpio::{
             blink_gpio, gpio_pull_up, set_falling_edge_detect, set_gpio_function, GPIOFunction,
@@ -44,7 +46,7 @@ fn panic(_panic: &PanicInfo) -> ! {
 pub unsafe extern "C" fn _start() {
     // Set the stack pointer
     asm!(
-        "ldr x0, =0x8008000",
+        "ldr x0, =__stack_end",
         "mov sp, x0",
         "b main",
         options(noreturn)
@@ -61,8 +63,6 @@ pub extern "C" fn main() -> ! {
     // Set ACT Led to Outout
     let _ = set_gpio_function(21, GPIOFunction::Output);
 
-    print_current_el_str();
-
     // Delay so clock speed can stabilize
     delay_nops(50000);
     println!("Hello World!");
@@ -86,7 +86,9 @@ unsafe fn zero_bss() {
 
 #[no_mangle]
 pub extern "C" fn kernel_main() -> ! {
-    print_current_el_str();
+    println!("EL: {}", get_current_el());
+
+    heap_test();
 
     sleep_us(500_000);
 
@@ -96,20 +98,7 @@ pub extern "C" fn kernel_main() -> ! {
     gpio_pull_up(26);
     set_falling_edge_detect(26, true);
 
-    print_display_resolution();
     let fb = FrameBuffer::new();
-    print_display_resolution();
-
-    for a in 0..360 {
-        let (x, y) = polar_to_cartesian(100.0, a as f32);
-        fb.draw_line(
-            150,
-            150,
-            (150.0 + x) as u32,
-            (150.0 + y) as u32,
-            a * (0x00FFFFFF / 360),
-        );
-    }
 
     fb.draw_square(500, 500, 600, 700, RED);
     fb.draw_square_fill(800, 800, 900, 900, GREEN);
@@ -118,10 +107,6 @@ pub extern "C" fn kernel_main() -> ! {
     fb.draw_string("Hello World! :D\nTest next Line", 500, 5, 3, BLUE);
 
     fb.draw_function(cos, 100, 101, RED);
-    fb.draw_function(cos, 100, 102, ORANGE);
-    fb.draw_function(cos, 100, 103, YELLOW);
-    fb.draw_function(cos, 100, 104, GREEN);
-    fb.draw_function(cos, 100, 105, BLUE);
 
     loop {
         let temp = mb_read_soc_temp([0]).unwrap();
@@ -131,11 +116,28 @@ pub extern "C" fn kernel_main() -> ! {
     }
 }
 
+fn heap_test() {
+    unsafe {
+        init_global_heap();
+        let a = HEAP.malloc(32).unwrap();
+        let b = HEAP.malloc(64).unwrap();
+        let c = HEAP.malloc(128).unwrap();
+        let _ = HEAP.malloc(256).unwrap();
+        HEAP.traverse_heap();
+        HEAP.free(b).unwrap();
+        HEAP.traverse_heap();
+        HEAP.free(a).unwrap();
+        HEAP.traverse_heap();
+        HEAP.free(c).unwrap();
+        HEAP.traverse_heap();
+    }
+}
+
 fn cos(x: u32) -> f64 {
     libm::cos(x as f64 * 0.1) * 20.0
 }
 
-pub fn get_current_el() -> u64 {
+fn get_current_el() -> u64 {
     let el: u64;
     unsafe {
         asm!(
@@ -153,16 +155,3 @@ fn enable_uart() {
     let _ = set_gpio_function(14, GPIOFunction::Alternative0);
     let _ = set_gpio_function(15, GPIOFunction::Alternative0);
 }
-
-fn print_current_el_str() {
-    let el = get_current_el();
-    let el_str = match el {
-        0b11 => "Level 3",
-        0b10 => "Level 2",
-        0b01 => "Level 1",
-        0b00 => "Level 0",
-        _ => "Unknown EL",
-    };
-
-    println!("{}", el_str);
-}