Files
picocalc-os-rs/src/scsi/mod.rs

331 lines
13 KiB
Rust

use crate::format;
use embassy_usb::driver::{Driver, EndpointIn, EndpointOut};
use embassy_usb::types::StringIndex;
use embassy_usb::{Builder, Config};
use embedded_sdmmc::{Block, BlockIdx};
use heapless::Vec;
mod scsi_types;
use scsi_types::*;
use crate::storage::SdCard;
const BULK_ENDPOINT_PACKET_SIZE: usize = 64;
#[derive(PartialEq, Eq)]
enum State {
Ready,
Ejected,
}
pub struct MassStorageClass<'d, D: Driver<'d>> {
sdcard: SdCard,
state: State,
bulk_out: D::EndpointOut,
bulk_in: D::EndpointIn,
last_sense: Option<ScsiError>,
}
impl<'d, D: Driver<'d>> MassStorageClass<'d, D> {
pub fn new(builder: &mut Builder<'d, D>, sdcard: SdCard) -> Self {
let mut function = builder.function(0x08, SUBCLASS_SCSI, 0x50); // Mass Storage class
let mut interface = function.interface();
let mut alt = interface.alt_setting(0x08, SUBCLASS_SCSI, 0x50, None);
let bulk_out = alt.endpoint_bulk_out(BULK_ENDPOINT_PACKET_SIZE as u16);
let bulk_in = alt.endpoint_bulk_in(BULK_ENDPOINT_PACKET_SIZE as u16);
Self {
bulk_out,
bulk_in,
sdcard,
state: State::Ready,
last_sense: None,
}
}
pub async fn poll(&mut self) {
loop {
let mut cbw_buf = [0u8; 31];
if let Ok(n) = self.bulk_out.read(&mut cbw_buf).await {
if n == 31 {
if let Some(cbw) = CommandBlockWrapper::parse(&cbw_buf[..n]) {
if self.state == State::Ejected {
self.last_sense = Some(ScsiError::NotReady);
self.send_csw_fail(cbw.dCBWTag).await;
continue;
}
// TODO: validate cbw
if self.handle_command(&cbw.CBWCB).await.is_ok() {
self.send_csw_success(cbw.dCBWTag).await
} else {
self.send_csw_fail(cbw.dCBWTag).await
}
}
}
}
}
}
async fn handle_command(&mut self, cbw: &[u8]) -> Result<(), ()> {
let mut response: Vec<u8, BULK_ENDPOINT_PACKET_SIZE> = Vec::new();
let mut block = [Block::new(); 1];
match parse_cb(cbw) {
ScsiCommand::Unknown => {
#[cfg(feature = "defmt")]
defmt::warn!("Got unexpected scsi command: {}", cbw);
Err(())
}
ScsiCommand::Inquiry {
evpd,
page_code,
alloc_len,
} => {
if !evpd {
response.push(0x00).map_err(|_| ())?; // Direct-access block device
response.push(0x80).map_err(|_| ())?; // Removable
response.push(0x05).map_err(|_| ())?; // SPC-3 compliance
response.push(0x02).map_err(|_| ())?; // Response data format
response.push(0x00).map_err(|_| ())?; // Additional length - edited later
response.push(0x00).map_err(|_| ())?; // FLAGS
response.push(0x00).map_err(|_| ())?; // FLAGS
response.push(0).map_err(|_| ())?; // FLAGS
assert!(response.len() == 8);
let vendor = b"LEGTCMPR";
assert!(vendor.len() == 8);
response.extend_from_slice(vendor)?;
let product = b"Pico Calc Sdcard";
assert!(product.len() == 16);
response.extend_from_slice(product)?;
let version = b"1.00";
assert!(version.len() == 4);
response.extend_from_slice(version)?; // 4-byte firmware version
let addl_len = response.len() - 5;
response[4] = addl_len as u8;
assert!(response.len() == 36);
} else {
match page_code {
0x00 => {
response
.extend_from_slice(&[
0x00, // Peripheral Qualifier + Peripheral Device Type (0x00 = Direct-access block device)
0x00, // Page Code (same as requested: 0x00)
0x00, 0x03, // Page Length: 3 bytes follow
0x00, // Supported VPD Page: 0x00 (this one — the "Supported VPD Pages" page itself)
0x80, // Supported VPD Page: 0x80 (Unit Serial Number)
0x83, // Supported VPD Page: 0x83 (Device Identification)
])
.map_err(|_| ())?
}
0x80 => {
let serial = b"Pico Calc";
response.extend_from_slice(&[
0x00, // Peripheral Qualifier & Device Type
0x80, // Page Code = 0x80 (Unit Serial Number)
0x00, // Reserved
serial.len() as u8,
])?;
response.extend_from_slice(serial)?;
}
0x83 => {
let id = b"SdCard";
response.extend_from_slice(&[
0x00,
0x83, // Page code
0x00,
(4 + id.len()) as u8, // Length
0x02, // ASCII identifier
0x01, // Identifier type
0x00, // Reserved
id.len() as u8,
])?;
response.extend_from_slice(id)?;
}
_ => (),
}
};
let len = core::cmp::min(alloc_len as usize, response.len());
self.bulk_in.write(&response[..len]).await.map_err(|_| ())
}
ScsiCommand::TestUnitReady => {
if self.sdcard.is_attached() {
Ok(())
} else {
Err(())
}
}
ScsiCommand::RequestSense { desc, alloc_len } => Ok(()),
ScsiCommand::ModeSense6 {
dbd,
page_control,
page_code,
subpage_code,
alloc_len,
} => {
// DBD=0, no block descriptors; total length = 4
let response = [
0x03, // Mode data length (excluding this byte): 3
0x00, // Medium type
0x00, // Device-specific parameter
0x00, // Block descriptor length = 0 (DBD = 1)
];
let len = alloc_len.min(response.len() as u8) as usize;
self.bulk_in.write(&response[..len]).await.map_err(|_| ())
}
ScsiCommand::ModeSense10 {
dbd,
page_control,
page_code,
subpage_code,
alloc_len,
} => {
let response = [
0x00, 0x06, // Mode data length = 6
0x00, // Medium type
0x00, // Device-specific parameter
0x00, 0x00, // Reserved
0x00, 0x00, // Block descriptor length = 0
];
let len = alloc_len.min(response.len() as u16) as usize;
self.bulk_in.write(&response[..len]).await.map_err(|_| ())
}
ScsiCommand::ReadCapacity10 => {
let block_size = SdCard::BLOCK_SIZE as u64;
let total_blocks = self.sdcard.size() / block_size;
let last_lba = total_blocks.checked_sub(1).unwrap_or(0);
response.extend_from_slice(&(last_lba as u32).to_be_bytes())?;
response.extend_from_slice(&(block_size as u32).to_be_bytes())?;
self.bulk_in.write(&response).await.map_err(|_| ())
}
ScsiCommand::ReadCapacity16 { alloc_len } => {
let block_size = SdCard::BLOCK_SIZE as u64;
let total_blocks = self.sdcard.size() / block_size;
let last_lba = total_blocks.checked_sub(1).unwrap_or(0);
response.extend_from_slice(&last_lba.to_be_bytes())?; // 8 bytes last LBA
response.extend_from_slice(&(block_size as u32).to_be_bytes())?; // 4 bytes block length
response.extend_from_slice(&[0u8; 20])?; // 20 reserved bytes zeroed
let len = alloc_len.min(response.len() as u32) as usize;
self.bulk_in.write(&response[..len]).await.map_err(|_| ())
}
ScsiCommand::Read { lba, len } => {
for i in 0..len {
let block_idx = BlockIdx(lba as u32 + i as u32);
self.sdcard.read_blocks(&mut block, block_idx)?;
for chunk in block[0].contents.chunks(BULK_ENDPOINT_PACKET_SIZE.into()) {
self.bulk_in.write(chunk).await.map_err(|_| ())?;
}
}
Ok(())
}
ScsiCommand::Write { lba, len } => {
for i in 0..len {
let block_idx = BlockIdx(lba as u32 + i as u32);
for chunk in block[0]
.contents
.chunks_mut(BULK_ENDPOINT_PACKET_SIZE.into())
{
self.bulk_out.read(chunk).await.map_err(|_| ())?;
}
self.sdcard.write_blocks(&mut block, block_idx)?;
}
Ok(())
}
ScsiCommand::ReadFormatCapacities { alloc_len } => {
let block_size = SdCard::BLOCK_SIZE as u32;
let num_blocks = (self.sdcard.size() / block_size as u64) as u32;
let mut response = [0u8; 12];
// Capacity List Length (8 bytes follows)
response[3] = 8;
// Descriptor
response[4..8].copy_from_slice(&num_blocks.to_be_bytes());
response[8] = 0x03; // formatted media
response[9..12].copy_from_slice(&block_size.to_be_bytes()[1..4]); // only 3 bytes
let response_len = alloc_len.min(response.len() as u16) as usize;
self.bulk_in
.write(&response[..response_len])
.await
.map_err(|_| ())
}
ScsiCommand::PreventAllowMediumRemoval { prevent: _prevent } => Ok(()),
ScsiCommand::StartStopUnit { start, load_eject } => {
if !start && load_eject {
self.state = State::Ejected;
self.last_sense = Some(ScsiError::NotReady);
}
Ok(())
}
}
}
pub async fn send_csw_success(&mut self, tag: u32) {
self.send_csw(tag, 0x00, 0).await;
}
pub async fn send_csw_fail(&mut self, tag: u32) {
defmt::error!("Command Failed");
self.send_csw(tag, 0x01, 0).await; // 0x01 = Command Failed
}
pub async fn send_csw(&mut self, tag: u32, status: u8, residue: u32) {
let mut csw = [0u8; 13];
csw[0..4].copy_from_slice(&0x53425355u32.to_le_bytes()); // Signature "USBS"
csw[4..8].copy_from_slice(&tag.to_le_bytes());
csw[8..12].copy_from_slice(&residue.to_le_bytes());
csw[12] = status;
let _ = self.bulk_in.write(&csw).await;
}
}
#[repr(C, packed)]
struct CommandBlockWrapper {
dCBWSignature: u32,
dCBWTag: u32,
dCBWDataTransferLength: u32,
bmCBWFlags: u8,
bCBWLUN: u8,
bCBWCBLength: u8,
CBWCB: [u8; 16],
}
impl CommandBlockWrapper {
fn parse(buf: &[u8]) -> Option<Self> {
if buf.len() < 31 {
return None;
}
let dCBWSignature = u32::from_le_bytes(buf[0..4].try_into().ok()?);
if dCBWSignature != 0x43425355 {
return None; // invalid signature
}
Some(Self {
dCBWSignature,
dCBWTag: u32::from_le_bytes(buf[4..8].try_into().ok()?),
dCBWDataTransferLength: u32::from_le_bytes(buf[8..12].try_into().ok()?),
bmCBWFlags: buf[12],
bCBWLUN: buf[13],
bCBWCBLength: buf[14],
CBWCB: buf[15..31].try_into().ok()?,
})
}
}