sw/host/opentitanlib/src/transport/common/fpga.rs

// Copyright lowRISC contributors.
// Licensed under the Apache License, Version 2.0, see LICENSE for details.
// SPDX-License-Identifier: Apache-2.0

use anyhow::Result;
use std::time::Duration;

use crate::io::gpio::GpioPin;
use crate::io::uart::Uart;
use crate::util::rom_detect::{RomDetect, RomKind};

/// Command for Transport::dispatch().
pub struct FpgaProgram<'a> {
    /// The bitstream content to load into the FPGA.
    pub bitstream: Vec<u8>,
    /// What type of ROM to expect.
    pub rom_kind: Option<RomKind>,
    /// How long of a reset pulse to send to the device.
    pub rom_reset_pulse: Duration,
    /// How long to wait for the ROM to print its type and version.
    pub rom_timeout: Duration,
    /// A progress function to provide user feedback.
    /// Will be called with the address and length of each chunk sent to the target device.
    pub progress: Option<Box<dyn Fn(u32, u32) + 'a>>,
}

impl FpgaProgram<'_> {
    pub fn check_correct_version(&self, uart: &dyn Uart, reset_pin: &dyn GpioPin) -> Result<bool> {
        if let Some(rom_kind) = &self.rom_kind {
            let mut rd = RomDetect::new(*rom_kind, &self.bitstream, Some(self.rom_timeout))?;

            // Send a reset pulse so the ROM will print the FPGA version.
            // Reset is active low, sleep, then drive high.
            reset_pin.write(false)?;
            std::thread::sleep(self.rom_reset_pulse);
            // Also clear the UART RX buffer for improved robustness.
            uart.clear_rx_buffer()?;
            reset_pin.write(true)?;

            // Now read the uart until the ROM prints it's version.
            if rd.detect(&*uart)? {
                log::info!("Already running the correct bitstream.  Skip loading bitstream.");
                // If we're already running the right ROM+bitstream,
                // then we can skip bootstrap.
                return Ok(true);
            }
        }
        Ok(false)
    }

    pub fn skip(&self) -> bool {
        self.bitstream.starts_with(b"__skip__")
    }
}

/// Command for Transport::dispatch().
pub struct ClearBitstream;