Macros for more convenient usage (#16)

* Macros for more convenient usage

* Remove unnecessary< fn, hide statics

src/lib.rs

@@ -6,6 +6,8 @@
 
 #![no_std]
 
+pub mod macros;
+
 use core::{
     alloc::{GlobalAlloc, Layout},
     cell::RefCell,

src/macros.rs

@@ -0,0 +1,40 @@
+//! Macros provided for convenience
+
+/// Create a heap allocator providing a heap of the given size in bytes
+///
+/// You can only have ONE allocator at most
+#[macro_export]
+macro_rules! heap_allocator {
+    ($size:expr) => {{
+        #[global_allocator]
+        static ALLOCATOR: $crate::EspHeap = $crate::EspHeap::empty();
+        static mut HEAP: core::mem::MaybeUninit<[u8; $size]> = core::mem::MaybeUninit::uninit();
+
+        unsafe {
+            ALLOCATOR.init(HEAP.as_mut_ptr() as *mut u8, $size);
+        }
+    }};
+}
+
+/// Create a heap allocator backed by PSRAM
+///
+/// You can only have ONE allocator at most. You need a SoC which supports PSRAM and activate the feature to enable it.
+/// You need to pass the PSRAM peripheral and the psram module path.
+///
+/// # Usage
+/// ```no_run
+/// esp_alloc::psram_allocator!(peripherals.PSRAM, hal::psram);
+/// ```
+#[macro_export]
+macro_rules! psram_allocator {
+    ($peripheral:expr,$psram_module:path) => {{
+        #[global_allocator]
+        static ALLOCATOR: $crate::EspHeap = $crate::EspHeap::empty();
+
+        use $psram_module as _psram;
+        _psram::init_psram($peripheral);
+        unsafe {
+            ALLOCATOR.init(_psram::psram_vaddr_start() as *mut u8, _psram::PSRAM_BYTES);
+        }
+    }};
+}