You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
47 lines
1.7 KiB
Rust
47 lines
1.7 KiB
Rust
// SPDX-License-Identifier: MIT OR Apache-2.0
|
|
//
|
|
// Copyright (c) 2018-2019 Andre Richter <andre.o.richter@gmail.com>
|
|
|
|
//! Relocation code.
|
|
|
|
/// Relocates the own binary from `bsp::BOARD_DEFAULT_LOAD_ADDRESS` to the `__binary_start` address
|
|
/// from the linker script.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// - Only a single core must be active and running this function.
|
|
/// - Function must not use the `bss` section.
|
|
pub unsafe fn relocate_self<T>() -> ! {
|
|
extern "C" {
|
|
static __binary_start: usize;
|
|
static __binary_end: usize;
|
|
}
|
|
|
|
let binary_start_addr: usize = &__binary_start as *const _ as _;
|
|
let binary_end_addr: usize = &__binary_end as *const _ as _;
|
|
let binary_size_in_byte: usize = binary_end_addr - binary_start_addr;
|
|
|
|
// Get the relocation destination address from the linker symbol.
|
|
let mut reloc_dst_addr: *mut T = binary_start_addr as *mut T;
|
|
|
|
// The address of where the previous firmware loaded us.
|
|
let mut src_addr: *const T = crate::bsp::BOARD_DEFAULT_LOAD_ADDRESS as *const _;
|
|
|
|
// Copy the whole binary.
|
|
//
|
|
// This is essentially a `memcpy()` optimized for throughput by transferring in chunks of T.
|
|
let n = binary_size_in_byte / core::mem::size_of::<T>();
|
|
for _ in 0..n {
|
|
use core::ptr;
|
|
|
|
ptr::write_volatile::<T>(reloc_dst_addr, ptr::read_volatile::<T>(src_addr));
|
|
reloc_dst_addr = reloc_dst_addr.offset(1);
|
|
src_addr = src_addr.offset(1);
|
|
}
|
|
|
|
// Call `init()` through a trait object, causing the jump to use an absolute address to reach
|
|
// the relocated binary. An elaborate explanation can be found in the runtime_init.rs source
|
|
// comments.
|
|
crate::runtime_init::get().init()
|
|
}
|