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64 lines
1.8 KiB
Rust
64 lines
1.8 KiB
Rust
// SPDX-License-Identifier: MIT OR Apache-2.0
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//
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// Copyright (c) 2018-2020 Andre Richter <andre.o.richter@gmail.com>
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//! Rust runtime initialization code.
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use crate::{bsp, memory};
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//--------------------------------------------------------------------------------------------------
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// Private Code
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//--------------------------------------------------------------------------------------------------
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/// Zero out the .bss section.
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///
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/// # Safety
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///
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/// - Must only be called pre `kernel_init()`.
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#[inline(always)]
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unsafe fn zero_bss() {
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memory::zero_volatile(bsp::memory::bss_range());
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}
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//--------------------------------------------------------------------------------------------------
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// Public Code
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//--------------------------------------------------------------------------------------------------
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/// Equivalent to `crt0` or `c0` code in C/C++ world. Clears the `bss` section, then jumps to kernel
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/// init code.
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///
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/// # Safety
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///
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/// - Only a single core must be active and running this function.
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pub unsafe fn runtime_init() -> ! {
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extern "Rust" {
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fn kernel_init() -> !;
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}
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zero_bss();
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kernel_init()
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}
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//--------------------------------------------------------------------------------------------------
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// Testing
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//--------------------------------------------------------------------------------------------------
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#[cfg(test)]
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mod tests {
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use super::*;
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use test_macros::kernel_test;
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/// Check `bss` section layout.
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#[kernel_test]
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fn bss_section_is_sane() {
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use core::mem;
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let start = bsp::memory::bss_range().start as *const _ as usize;
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let end = bsp::memory::bss_range().end as *const _ as usize;
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assert_eq!(start % mem::size_of::<usize>(), 0);
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assert_eq!(end % mem::size_of::<usize>(), 0);
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assert!(end >= start);
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}
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}
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