Add new driver implementations and workspace updates

drivers/0x0f_flash_rust/src/board.rs

@@ -0,0 +1,207 @@
+//! @file board.rs
+//! @brief Board-level HAL helpers for the flash driver
+//! @author Kevin Thomas
+//! @date 2025
+//!
+//! MIT License
+//!
+//! Copyright (c) 2025 Kevin Thomas
+//!
+//! Permission is hereby granted, free of charge, to any person obtaining a copy
+//! of this software and associated documentation files (the "Software"), to deal
+//! in the Software without restriction, including without limitation the rights
+//! to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//! copies of the Software, and to permit persons to whom the Software is
+//! furnished to do so, subject to the following conditions:
+//!
+//! The above copyright notice and this permission notice shall be included in
+//! all copies or substantial portions of the Software.
+//!
+//! THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//! IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//! FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//! AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//! LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//! OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//! SOFTWARE.
+
+// Flash driver pure-logic functions and constants
+use crate::flash_driver;
+// Rate extension trait for .Hz() baud rate construction
+use fugit::RateExtU32;
+// Clock trait for accessing system clock frequency
+use hal::Clock;
+// GPIO pin types and function selectors
+use hal::gpio::{FunctionNull, FunctionUart, Pin, PullDown, PullNone};
+// ROM data flash functions for low-level flash operations
+use hal::rom_data;
+// UART configuration and peripheral types
+use hal::uart::{DataBits, Enabled, StopBits, UartConfig, UartPeripheral};
+
+// Alias our HAL crate
+#[cfg(rp2350)]
+use rp235x_hal as hal;
+#[cfg(rp2040)]
+use rp2040_hal as hal;
+
+/// External crystal frequency in Hz (12 MHz).
+pub(crate) const XTAL_FREQ_HZ: u32 = 12_000_000u32;
+
+/// UART baud rate in bits per second.
+pub(crate) const UART_BAUD: u32 = 115_200;
+
+/// Type alias for the configured TX pin (GPIO 0, UART function, no pull).
+pub(crate) type TxPin = Pin<hal::gpio::bank0::Gpio0, FunctionUart, PullNone>;
+
+/// Type alias for the configured RX pin (GPIO 1, UART function, no pull).
+pub(crate) type RxPin = Pin<hal::gpio::bank0::Gpio1, FunctionUart, PullNone>;
+
+/// Type alias for the default TX pin state from `Pins::new()`.
+pub(crate) type TxPinDefault = Pin<hal::gpio::bank0::Gpio0, FunctionNull, PullDown>;
+
+/// Type alias for the default RX pin state from `Pins::new()`.
+pub(crate) type RxPinDefault = Pin<hal::gpio::bank0::Gpio1, FunctionNull, PullDown>;
+
+/// Type alias for the fully-enabled UART0 peripheral with TX/RX pins.
+pub(crate) type EnabledUart = UartPeripheral<Enabled, hal::pac::UART0, (TxPin, RxPin)>;
+
+/// Initialise system clocks and PLLs from the external 12 MHz crystal.
+///
+/// # Arguments
+///
+/// * `xosc` - XOSC peripheral singleton.
+/// * `clocks` - CLOCKS peripheral singleton.
+/// * `pll_sys` - PLL_SYS peripheral singleton.
+/// * `pll_usb` - PLL_USB peripheral singleton.
+/// * `resets` - Mutable reference to the RESETS peripheral.
+/// * `watchdog` - Mutable reference to the watchdog timer.
+///
+/// # Returns
+///
+/// Configured clocks manager.
+///
+/// # Panics
+///
+/// Panics if clock initialisation fails.
+pub(crate) fn init_clocks(
+    xosc: hal::pac::XOSC,
+    clocks: hal::pac::CLOCKS,
+    pll_sys: hal::pac::PLL_SYS,
+    pll_usb: hal::pac::PLL_USB,
+    resets: &mut hal::pac::RESETS,
+    watchdog: &mut hal::Watchdog,
+) -> hal::clocks::ClocksManager {
+    hal::clocks::init_clocks_and_plls(
+        XTAL_FREQ_HZ, xosc, clocks, pll_sys, pll_usb, resets, watchdog,
+    )
+    .unwrap()
+}
+
+/// Unlock the GPIO bank and return the pin set.
+///
+/// # Arguments
+///
+/// * `io_bank0` - IO_BANK0 peripheral singleton.
+/// * `pads_bank0` - PADS_BANK0 peripheral singleton.
+/// * `sio` - SIO peripheral singleton.
+/// * `resets` - Mutable reference to the RESETS peripheral.
+///
+/// # Returns
+///
+/// GPIO pin set for the entire bank.
+pub(crate) fn init_pins(
+    io_bank0: hal::pac::IO_BANK0,
+    pads_bank0: hal::pac::PADS_BANK0,
+    sio: hal::pac::SIO,
+    resets: &mut hal::pac::RESETS,
+) -> hal::gpio::Pins {
+    let sio = hal::Sio::new(sio);
+    hal::gpio::Pins::new(io_bank0, pads_bank0, sio.gpio_bank0, resets)
+}
+
+/// Initialise UART0 for serial output (stdio equivalent).
+///
+/// # Arguments
+///
+/// * `uart0` - PAC UART0 peripheral singleton.
+/// * `tx_pin` - GPIO pin to use as UART0 TX (GPIO 0).
+/// * `rx_pin` - GPIO pin to use as UART0 RX (GPIO 1).
+/// * `resets` - Mutable reference to the RESETS peripheral.
+/// * `clocks` - Reference to the initialised clock configuration.
+///
+/// # Returns
+///
+/// Enabled UART0 peripheral ready for blocking writes.
+///
+/// # Panics
+///
+/// Panics if the HAL cannot achieve the requested baud rate.
+pub(crate) fn init_uart(
+    uart0: hal::pac::UART0,
+    tx_pin: TxPinDefault,
+    rx_pin: RxPinDefault,
+    resets: &mut hal::pac::RESETS,
+    clocks: &hal::clocks::ClocksManager,
+) -> EnabledUart {
+    let pins = (
+        tx_pin.reconfigure::<FunctionUart, PullNone>(),
+        rx_pin.reconfigure::<FunctionUart, PullNone>(),
+    );
+    let cfg = UartConfig::new(UART_BAUD.Hz(), DataBits::Eight, None, StopBits::One);
+    UartPeripheral::new(uart0, pins, resets)
+        .enable(cfg, clocks.peripheral_clock.freq())
+        .unwrap()
+}
+
+/// Erase one 4096-byte sector and write data to on-chip flash.
+///
+/// Disables interrupts, transitions the flash device out of XIP mode,
+/// erases the sector at `flash_offset`, programs `data` into it, flushes
+/// the cache, re-enters XIP mode, and restores interrupts. This mirrors
+/// the C demo's `flash_driver_write()`.
+///
+/// # Arguments
+///
+/// * `flash_offset` - Byte offset from the start of flash (must be sector-aligned).
+/// * `data` - Data buffer to write (length must be a multiple of 256).
+///
+/// # Safety
+///
+/// Caller must ensure no other core or DMA is accessing flash/XIP during
+/// this operation.
+pub(crate) fn flash_write(flash_offset: u32, data: &[u8]) {
+    let len = data.len();
+    cortex_m::interrupt::free(|_| unsafe {
+        rom_data::connect_internal_flash();
+        rom_data::flash_exit_xip();
+        rom_data::flash_range_erase(
+            flash_offset,
+            flash_driver::FLASH_SECTOR_SIZE as usize,
+            flash_driver::FLASH_SECTOR_SIZE,
+            0x20,
+        );
+        rom_data::flash_range_program(flash_offset, data.as_ptr(), len);
+        rom_data::flash_flush_cache();
+        rom_data::flash_enter_cmd_xip();
+    });
+}
+
+/// Read bytes from on-chip flash via the XIP memory map.
+///
+/// Flash is memory-mapped starting at XIP_BASE (0x10000000). This
+/// function copies `out.len()` bytes from the XIP address corresponding
+/// to `flash_offset` into `out`, matching the C demo's
+/// `flash_driver_read()`.
+///
+/// # Arguments
+///
+/// * `flash_offset` - Byte offset from the start of flash.
+/// * `out` - Destination buffer.
+pub(crate) fn flash_read(flash_offset: u32, out: &mut [u8]) {
+    let addr = (flash_driver::XIP_BASE + flash_offset) as *const u8;
+    for (i, byte) in out.iter_mut().enumerate() {
+        *byte = unsafe { core::ptr::read_volatile(addr.add(i)) };
+    }
+}
+
+// End of file

drivers/0x0f_flash_rust/src/flash_driver.rs

@@ -0,0 +1,205 @@
+//! @file flash_driver.rs
+//! @brief Pure-logic flash driver (host-testable, no HAL)
+//! @author Kevin Thomas
+//! @date 2025
+//!
+//! MIT License
+//!
+//! Copyright (c) 2025 Kevin Thomas
+//!
+//! Permission is hereby granted, free of charge, to any person obtaining a copy
+//! of this software and associated documentation files (the "Software"), to deal
+//! in the Software without restriction, including without limitation the rights
+//! to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//! copies of the Software, and to permit persons to whom the Software is
+//! furnished to do so, subject to the following conditions:
+//!
+//! The above copyright notice and this permission notice shall be included in
+//! all copies or substantial portions of the Software.
+//!
+//! THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//! IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//! FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//! AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//! LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//! OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//! SOFTWARE.
+
+/// Total on-chip flash size in bytes (4 MB).
+pub const FLASH_SIZE_BYTES: u32 = 4 * 1024 * 1024;
+
+/// Flash sector size in bytes (4096).
+pub const FLASH_SECTOR_SIZE: u32 = 4096;
+
+/// Flash page size in bytes (256).
+pub const FLASH_PAGE_SIZE: u32 = 256;
+
+/// Flash target offset: last sector of flash.
+pub const FLASH_TARGET_OFFSET: u32 = FLASH_SIZE_BYTES - FLASH_SECTOR_SIZE;
+
+/// Write buffer length matching the C demo (one page = 256 bytes).
+pub const FLASH_WRITE_LEN: usize = FLASH_PAGE_SIZE as usize;
+
+/// XIP base address where flash is memory-mapped.
+pub const XIP_BASE: u32 = 0x1000_0000;
+
+/// Demo string written to flash, matching the C demo exactly.
+pub const DEMO_MSG: &[u8] = b"Embedded Hacking flash driver demo";
+
+/// Prepare a write buffer with 0xFF fill and the demo string at the start.
+///
+/// Mirrors the C demo's `_prepare_write_buf()` function. The buffer is
+/// filled with 0xFF (erased flash state), then the demo string including
+/// its NUL terminator is copied to the beginning.
+///
+/// # Arguments
+///
+/// * `buf` - Output buffer (should be `FLASH_WRITE_LEN` bytes).
+///
+/// # Returns
+///
+/// Number of meaningful bytes (string length + NUL terminator).
+pub fn prepare_write_buf(buf: &mut [u8]) -> usize {
+    for b in buf.iter_mut() {
+        *b = 0xFF;
+    }
+    let msg_with_nul = DEMO_MSG.len() + 1;
+    let n = msg_with_nul.min(buf.len());
+    let copy_len = DEMO_MSG.len().min(n);
+    buf[..copy_len].copy_from_slice(&DEMO_MSG[..copy_len]);
+    if copy_len < n {
+        buf[copy_len] = 0x00;
+    }
+    n
+}
+
+/// Format the "Flash readback: <string>\r\n" message into `buf`.
+///
+/// Reads from `read_data` up to the first NUL byte (or end of slice)
+/// and formats the output message matching the C demo's printf.
+///
+/// # Arguments
+///
+/// * `buf` - Output buffer (should be >= 64 bytes).
+/// * `read_data` - Data read back from flash.
+///
+/// # Returns
+///
+/// Number of bytes written to `buf`.
+pub fn format_readback(buf: &mut [u8], read_data: &[u8]) -> usize {
+    let prefix = b"Flash readback: ";
+    let suffix = b"\r\n";
+    let mut pos = 0usize;
+    // Write prefix
+    let n = prefix.len().min(buf.len());
+    buf[..n].copy_from_slice(&prefix[..n]);
+    pos += n;
+    // Find NUL terminator in read_data
+    let str_len = read_data.iter().position(|&b| b == 0).unwrap_or(read_data.len());
+    let copy_len = str_len.min(buf.len().saturating_sub(pos));
+    buf[pos..pos + copy_len].copy_from_slice(&read_data[..copy_len]);
+    pos += copy_len;
+    // Write suffix
+    let n = suffix.len().min(buf.len().saturating_sub(pos));
+    buf[pos..pos + n].copy_from_slice(&suffix[..n]);
+    pos += n;
+    pos
+}
+
+#[cfg(test)]
+mod tests {
+    // Import all parent module items
+    use super::*;
+
+    #[test]
+    fn flash_size_is_4mb() {
+        assert_eq!(FLASH_SIZE_BYTES, 4 * 1024 * 1024);
+    }
+
+    #[test]
+    fn sector_size_is_4096() {
+        assert_eq!(FLASH_SECTOR_SIZE, 4096);
+    }
+
+    #[test]
+    fn page_size_is_256() {
+        assert_eq!(FLASH_PAGE_SIZE, 256);
+    }
+
+    #[test]
+    fn target_offset_is_last_sector() {
+        assert_eq!(FLASH_TARGET_OFFSET, FLASH_SIZE_BYTES - FLASH_SECTOR_SIZE);
+    }
+
+    #[test]
+    fn write_len_matches_page_size() {
+        assert_eq!(FLASH_WRITE_LEN, 256);
+    }
+
+    #[test]
+    fn xip_base_address() {
+        assert_eq!(XIP_BASE, 0x1000_0000);
+    }
+
+    #[test]
+    fn prepare_write_buf_fills_0xff() {
+        let mut buf = [0u8; FLASH_WRITE_LEN];
+        prepare_write_buf(&mut buf);
+        // Bytes after the string + NUL should be 0xFF
+        let after = DEMO_MSG.len() + 1;
+        for &b in &buf[after..] {
+            assert_eq!(b, 0xFF);
+        }
+    }
+
+    #[test]
+    fn prepare_write_buf_has_demo_string() {
+        let mut buf = [0u8; FLASH_WRITE_LEN];
+        prepare_write_buf(&mut buf);
+        assert_eq!(&buf[..DEMO_MSG.len()], DEMO_MSG);
+    }
+
+    #[test]
+    fn prepare_write_buf_has_nul_terminator() {
+        let mut buf = [0u8; FLASH_WRITE_LEN];
+        prepare_write_buf(&mut buf);
+        assert_eq!(buf[DEMO_MSG.len()], 0x00);
+    }
+
+    #[test]
+    fn format_readback_matches_c_output() {
+        let mut read_data = [0xFFu8; FLASH_WRITE_LEN];
+        let msg = b"Embedded Hacking flash driver demo";
+        read_data[..msg.len()].copy_from_slice(msg);
+        read_data[msg.len()] = 0x00;
+        let mut buf = [0u8; 128];
+        let n = format_readback(&mut buf, &read_data);
+        assert_eq!(
+            &buf[..n],
+            b"Flash readback: Embedded Hacking flash driver demo\r\n"
+        );
+    }
+
+    #[test]
+    fn format_readback_empty_string() {
+        let read_data = [0u8; 8];
+        let mut buf = [0u8; 64];
+        let n = format_readback(&mut buf, &read_data);
+        assert_eq!(&buf[..n], b"Flash readback: \r\n");
+    }
+
+    #[test]
+    fn format_readback_no_nul() {
+        let read_data = [b'A'; 8];
+        let mut buf = [0u8; 64];
+        let n = format_readback(&mut buf, &read_data);
+        assert_eq!(&buf[..n], b"Flash readback: AAAAAAAA\r\n");
+    }
+
+    #[test]
+    fn demo_msg_matches_c_string() {
+        assert_eq!(DEMO_MSG, b"Embedded Hacking flash driver demo");
+    }
+}
+
+// End of file

drivers/0x0f_flash_rust/src/lib.rs

@@ -0,0 +1,9 @@
+//! @file lib.rs
+//! @brief Library root for the flash driver crate
+//! @author Kevin Thomas
+//! @date 2025
+
+#![no_std]
+
+// Flash driver module
+pub mod flash_driver;

drivers/0x0f_flash_rust/src/main.rs

@@ -0,0 +1,110 @@
+//! @file main.rs
+//! @brief On-chip flash write/read demo using flash_driver.rs
+//! @author Kevin Thomas
+//! @date 2025
+//!
+//! MIT License
+//!
+//! Copyright (c) 2025 Kevin Thomas
+//!
+//! Permission is hereby granted, free of charge, to any person obtaining a copy
+//! of this software and associated documentation files (the "Software"), to deal
+//! in the Software without restriction, including without limitation the rights
+//! to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//! copies of the Software, and to permit persons to whom the Software is
+//! furnished to do so, subject to the following conditions:
+//!
+//! The above copyright notice and this permission notice shall be included in
+//! all copies or substantial portions of the Software.
+//!
+//! THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//! IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//! FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//! AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//! LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//! OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//! SOFTWARE.
+//!
+//! -----------------------------------------------------------------------------
+//!
+//! Demonstrates on-chip flash read/write using the flash driver
+//! (flash_driver.rs). A string is written to the last sector of flash
+//! and then read back to verify. The result is printed over UART.
+//!
+//! Wiring:
+//!   No external wiring required
+
+#![no_std]
+#![no_main]
+
+// Board-level helpers: constants, type aliases, and init functions
+mod board;
+// Flash driver module — suppress warnings for unused public API functions
+#[allow(dead_code)]
+mod flash_driver;
+
+// Debugging output over RTT
+use defmt_rtt as _;
+// Panic handler for RISC-V targets
+#[cfg(target_arch = "riscv32")]
+use panic_halt as _;
+// Panic handler for ARM targets
+#[cfg(target_arch = "arm")]
+use panic_probe as _;
+
+// HAL entry-point macro
+use hal::entry;
+
+// Alias our HAL crate
+#[cfg(rp2350)]
+use rp235x_hal as hal;
+#[cfg(rp2040)]
+use rp2040_hal as hal;
+
+// Second-stage boot loader for RP2040
+#[unsafe(link_section = ".boot2")]
+#[used]
+#[cfg(rp2040)]
+pub static BOOT2: [u8; 256] = rp2040_boot2::BOOT_LOADER_W25Q080;
+
+// Boot metadata for the RP2350 Boot ROM
+#[unsafe(link_section = ".start_block")]
+#[used]
+#[cfg(rp2350)]
+pub static IMAGE_DEF: hal::block::ImageDef = hal::block::ImageDef::secure_exe();
+
+/// Application entry point for the on-chip flash demo.
+#[entry]
+fn main() -> ! {
+    let mut pac = hal::pac::Peripherals::take().unwrap();
+    let clocks = board::init_clocks(
+        pac.XOSC, pac.CLOCKS, pac.PLL_SYS, pac.PLL_USB, &mut pac.RESETS,
+        &mut hal::Watchdog::new(pac.WATCHDOG),
+    );
+    let pins = board::init_pins(pac.IO_BANK0, pac.PADS_BANK0, pac.SIO, &mut pac.RESETS);
+    let uart = board::init_uart(pac.UART0, pins.gpio0, pins.gpio1, &mut pac.RESETS, &clocks);
+    let mut write_buf = [0u8; flash_driver::FLASH_WRITE_LEN];
+    flash_driver::prepare_write_buf(&mut write_buf);
+    board::flash_write(flash_driver::FLASH_TARGET_OFFSET, &write_buf);
+    let mut read_buf = [0u8; flash_driver::FLASH_WRITE_LEN];
+    board::flash_read(flash_driver::FLASH_TARGET_OFFSET, &mut read_buf);
+    let mut out = [0u8; 128];
+    let n = flash_driver::format_readback(&mut out, &read_buf);
+    uart.write_full_blocking(&out[..n]);
+    loop {
+        cortex_m::asm::wfe();
+    }
+}
+
+// Picotool binary info metadata
+#[unsafe(link_section = ".bi_entries")]
+#[used]
+pub static PICOTOOL_ENTRIES: [hal::binary_info::EntryAddr; 5] = [
+    hal::binary_info::rp_cargo_bin_name!(),
+    hal::binary_info::rp_cargo_version!(),
+    hal::binary_info::rp_program_description!(c"On-chip Flash Demo"),
+    hal::binary_info::rp_cargo_homepage_url!(),
+    hal::binary_info::rp_program_build_attribute!(),
+];
+
+// End of file