81 lines
2.0 KiB
Rust
81 lines
2.0 KiB
Rust
//! How to use the heap and a dynamic memory allocator
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//!
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//! To compile this example you'll need to build the collections crate as part
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//! of the Xargo sysroot. To do that change the Xargo.toml file to look like
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//! this:
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//!
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//! ``` text
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//! [dependencies.core]
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//! stage = 0
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//!
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//! [dependencies.collections] # NEW
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//! stage = 0
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//!
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//! [dependencies.compiler_builtins]
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//! git = "https://github.com/rust-lang-nursery/compiler-builtins"
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//! stage = 1
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//! ```
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//!
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//! This example depends on the alloc-cortex-m crate so you'll have to add it
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//! to your Cargo.toml:
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//!
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//! ``` text
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//! # or edit the Cargo.toml file manually
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//! $ cargo add alloc-cortex-m
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//! ```
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//!
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//! ---
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#[allow(deprecated)]
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#![feature(collections)]
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#![feature(used)]
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#![no_std]
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// This is the allocator crate; you can use a different one
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extern crate alloc_cortex_m;
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#[macro_use]
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extern crate collections;
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extern crate cortex_m;
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extern crate cortex_m_rt;
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extern crate cortex_m_semihosting;
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use core::fmt::Write;
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use cortex_m::asm;
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use cortex_m_semihosting::hio;
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fn main() {
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// Initialize the allocator
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unsafe {
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extern "C" {
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// Start of the heap
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static mut _sheap: usize;
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}
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// Size of the heap in words (1 word = 4 bytes)
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// NOTE The bigger the heap the greater the chance to run into a stack
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// overflow (collision between the stack and the heap)
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const SIZE: isize = 256;
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// End of the heap
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let _eheap = (&mut _sheap as *mut _).offset(SIZE);
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alloc_cortex_m::init(&mut _sheap, _eheap);
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}
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// Growable array allocated on the heap
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let xs = vec![0, 1, 2];
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let mut stdout = hio::hstdout().unwrap();
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writeln!(stdout, "{:?}", xs).unwrap();
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}
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// As we are not using interrupts, we just register a dummy catch all handler
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#[link_section = ".vector_table.interrupts"]
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#[used]
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static INTERRUPTS: [extern "C" fn(); 240] = [default_handler; 240];
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extern "C" fn default_handler() {
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asm::bkpt();
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}
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