46 lines
1.0 KiB
Rust
46 lines
1.0 KiB
Rust
use crate::util;
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use core::cell::Cell;
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use libtock_core::{callback, syscalls};
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const DRIVER_NUMBER: usize = 0x40001;
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mod command_nr {
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pub const REQUEST_RNG: usize = 1;
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}
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mod subscribe_nr {
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pub const BUFFER_FILLED: usize = 0;
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}
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mod allow_nr {
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pub const SHARE_BUFFER: usize = 0;
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}
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pub fn fill_buffer(buf: &mut [u8]) -> bool {
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let buf_len = buf.len();
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let result = syscalls::allow(DRIVER_NUMBER, allow_nr::SHARE_BUFFER, buf);
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if result.is_err() {
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return false;
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}
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let is_filled = Cell::new(false);
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let mut is_filled_alarm = || is_filled.set(true);
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let subscription = syscalls::subscribe::<callback::Identity0Consumer, _>(
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DRIVER_NUMBER,
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subscribe_nr::BUFFER_FILLED,
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&mut is_filled_alarm,
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);
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if subscription.is_err() {
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return false;
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}
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let result_code = syscalls::command(DRIVER_NUMBER, command_nr::REQUEST_RNG, buf_len, 0);
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if result_code.is_err() {
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return false;
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}
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util::yieldk_for(|| is_filled.get());
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true
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}
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