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77 lines
2.5 KiB
Rust

// SPDX-License-Identifier: MIT OR Apache-2.0
//
// Copyright (c) 2018-2021 Andre Richter <andre.o.richter@gmail.com>
//! BSP Memory Management.
use core::{cell::UnsafeCell, ops::RangeInclusive};
//--------------------------------------------------------------------------------------------------
// Private Definitions
//--------------------------------------------------------------------------------------------------
// Symbols from the linker script.
extern "Rust" {
static __bss_start: UnsafeCell<u64>;
static __bss_end_inclusive: UnsafeCell<u64>;
}
//--------------------------------------------------------------------------------------------------
// Public Definitions
//--------------------------------------------------------------------------------------------------
/// The board's physical memory map.
#[rustfmt::skip]
pub(super) mod map {
pub const BOARD_DEFAULT_LOAD_ADDRESS: usize = 0x8_0000;
pub const GPIO_OFFSET: usize = 0x0020_0000;
pub const UART_OFFSET: usize = 0x0020_1000;
/// Physical devices.
#[cfg(feature = "bsp_rpi3")]
pub mod mmio {
use super::*;
pub const START: usize = 0x3F00_0000;
pub const GPIO_START: usize = START + GPIO_OFFSET;
pub const PL011_UART_START: usize = START + UART_OFFSET;
}
/// Physical devices.
#[cfg(feature = "bsp_rpi4")]
pub mod mmio {
use super::*;
pub const START: usize = 0xFE00_0000;
pub const GPIO_START: usize = START + GPIO_OFFSET;
pub const PL011_UART_START: usize = START + UART_OFFSET;
}
}
//--------------------------------------------------------------------------------------------------
// Public Code
//--------------------------------------------------------------------------------------------------
/// The address on which the Raspberry firmware loads every binary by default.
#[inline(always)]
pub fn board_default_load_addr() -> *const u64 {
map::BOARD_DEFAULT_LOAD_ADDRESS as _
}
/// Return the inclusive range spanning the relocated .bss section.
///
/// # Safety
///
/// - Values are provided by the linker script and must be trusted as-is.
/// - The linker-provided addresses must be u64 aligned.
pub fn bss_range_inclusive() -> RangeInclusive<*mut u64> {
let range;
unsafe {
range = RangeInclusive::new(__bss_start.get(), __bss_end_inclusive.get());
}
assert!(!range.is_empty());
range
}