add atapi helpers

Signed-off-by: Julien CLEMENT <julien.clement@epita.fr>

src/drivers/atapi/mod.rs

@@ -1,52 +1,117 @@
+use x86_64::instructions::port::Port;
+
 const CD_SECTOR_SIZE: usize = 2048;
 
-
+// Data buses
 const ATA_BUS_PRIMARY: u16= 0x1f0;
 const ATA_BUS_SECONDARY: u16 = 0x170;
 
-const ATA_DRIVE_MASTER: u16 = 0xa0;
-const ATA_DRIVE_SLAVE: u16 = 0xb0;
+// Drives
+const ATA_DRIVE_MASTER: u8 = 0xa0;
+const ATA_DRIVE_SLAVE: u8 = 0xb0;
 
-macro_rules! ATA_DATA {
-    ($reg:expr) => (reg);
+// Status bits
+const ATA_ERR: u8 = 1 << 0;
+const ATA_DRQ: u8 = 1 << 3;
+const ATA_SRV: u8 = 1 << 4;
+const ATA_DF: u8 = 1 << 5;
+const ATA_RDY: u8 = 1 << 6;
+const ATA_BSY: u8 = 1 << 7;
+
+// ATAPI signature
+const ATAPI_SIG_SC: u8 = 0x01;
+const ATAPI_SIG_LBA_LO: u8 = 0x01;
+const ATAPI_SIG_LBA_MI: u8 = 0x14;
+const ATAPI_SIG_LBA_HI: u8 = 0xeb;
+
+static ATAPI_SIG: [u8; 4] = [
+    ATAPI_SIG_SC,
+    ATAPI_SIG_LBA_LO,
+    ATAPI_SIG_LBA_MI,
+    ATAPI_SIG_LBA_HI
+];
+
+struct ATABus {
+    // IO ports
+    data: Port<u8>,
+    features: Port<u8>, // write
+    error: Port<u8>, // read
+    sector_count: Port<u8>,
+    address1: Port<u8>,
+    address2: Port<u8>,
+    address3: Port<u8>,
+    drive_select: Port<u8>,
+    command: Port<u8>, // write
+    status: Port<u8>, // read
+    dcr: Port<u8>,
+
+    current_drive: u8,
 }
 
-macro_rules! ATA_ERROR {
-    ($reg:expr) => (reg + 1); // read
-}
+impl ATABus {
+    pub fn new(port: u16) -> Self {
+        ATABus {
+            data: Port::new(port),
+            features: Port::new(port + 1), // write
+            error: Port::new(port + 1), // read
+            sector_count: Port::new(port + 2),
+            address1: Port::new(port + 3),
+            address2: Port::new(port + 4),
+            address3: Port::new(port + 5),
+            drive_select: Port::new(port + 6),
+            command: Port::new(port + 7), // write
+            status: Port::new(port + 7), // read
+            dcr: Port::new(port + 0x206),
 
-macro_rules! ATA_FEATURES {
-    ($reg:expr) => (reg + 1); // write
-}
+            current_drive: 0,
+        }
+    }
 
-macro_rules! ATA_SECTOR_COUNT {
-    ($reg:expr) => (reg + 2);
-}
+    fn select_drive(&mut self, drive: u8) {
+        unsafe {
+            self.drive_select.write(drive);
+        }
+        self.select_delay();
+        self.current_drive = drive;
+    }
 
-macro_rules! ATA_ADDRESS1 {
-    ($reg:expr) => (reg + 3);
-}
+    fn is_atapi(&mut self) -> bool {
 
-macro_rules! ATA_ADDRESS2 {
-    ($reg:expr) => (reg + 4);
-}
+        let mut sig: [u8; 4] = [0, 0, 0, 0];
+        unsafe {
+            sig[0] = self.sector_count.read();
+            sig[1] = self.address1.read();
+            sig[2] = self.address2.read();
+            sig[3] = self.address3.read();
+        }
 
-macro_rules! ATA_ADDRESS3 {
-    ($reg:expr) => (reg + 5);
-}
+        ATAPI_SIG == sig
+    }
 
-macro_rules! ATA_DRIVE_SELECT {
-    ($reg:expr) => (reg + 6);
-}
+    fn wait_busy(&mut self) {
+        let mut status = ATA_BSY;
+        while (status & ATA_BSY) != 0 {
+            unsafe {
+                status = self.status.read();
+            }
+        }
+    }
 
-macro_rules! ATA_STATUS {
-    ($reg:expr) => (reg + 7); // read
-}
+    fn select_delay(&mut self) {
+        unsafe {
+            self.dcr.read();
+            self.dcr.read();
+            self.dcr.read();
+            self.dcr.read();
+        }
+    }
 
-macro_rules! ATA_COMMAND {
-    ($reg:expr) => (reg + 7); // write
-}
-
-macro_rules! ATA_DCR {
-    ($reg:expr) => (reg + 0x206);
+    fn wait_packet_request(&mut self) {
+        let mut status = ATA_BSY;
+        while (status & ATA_BSY) != 0 && (status & ATA_DRQ) == 0 {
+            unsafe {
+                status = self.status.read();
+            }
+        }
+    }
 }