diff --git a/kernel/src/arch/x86_64/driver/ide.rs b/kernel/src/arch/x86_64/driver/ide.rs
index 475a95b..356978e 100644
--- a/kernel/src/arch/x86_64/driver/ide.rs
+++ b/kernel/src/arch/x86_64/driver/ide.rs
@@ -5,267 +5,120 @@
 use spin::Mutex;
 
 lazy_static! {
-    pub static ref DISK0: LockedIde = LockedIde(Mutex::new(DmaController::new(0)));
-    pub static ref DISK1: LockedIde = LockedIde(Mutex::new(DmaController::new(1)));
+    pub static ref DISK0: LockedIde = LockedIde(Mutex::new(IDE::new(0)));
+    pub static ref DISK1: LockedIde = LockedIde(Mutex::new(IDE::new(1)));
 }
 pub const BLOCK_SIZE: usize = 512;
 
-pub struct LockedIde(pub Mutex<DmaController>);
+pub struct LockedIde(pub Mutex<IDE>);
 
-pub struct DmaController {
+pub struct IDE {
     num: u8,
+    /// I/O Base
+    base: u16,
+    /// Control Base
+    ctrl: u16,
 }
 
-impl DmaController
-{
-    /// Read ATA DMA. Block size = 512 bytes.
-    pub fn read(&self, blockidx: u64, count: usize, dst: &mut [u32]) -> Result<usize, ()> {
-        assert_eq!(dst.len(), count * SECTOR_SIZE);
-        let dst = if count > MAX_DMA_SECTORS { &mut dst[..MAX_DMA_SECTORS * SECTOR_SIZE] } else { dst };
-        //self.do_dma(blockidx, DMABuffer::new_mut(dst, 32), disk, false);
-        self.ide_read_secs(self.num, blockidx, dst, count as u8)
-    }
-    /// Write ATA DMA. Block size = 512 bytes.
-    pub fn write(&self, blockidx: u64, count: usize, dst: &[u32]) -> Result<usize, ()> {
-        assert_eq!(dst.len(), count * SECTOR_SIZE);
-        let dst = if count > MAX_DMA_SECTORS { &dst[..MAX_DMA_SECTORS * SECTOR_SIZE] } else { dst };
-        //println!("ide_write_secs: disk={},blockidx={},count={}",disk,blockidx,count);
-        self.ide_write_secs(self.num, blockidx, dst, count as u8)
-    }
-    /// Create structure and init
-    fn new(num: u8) -> Self {
-        assert!(num < MAX_IDE as u8);
-        let ide = DmaController { num };
-        ide.ide_init();
+impl IDE {
+    pub fn new(num: u8) -> Self {
+        let ide = match num {
+            0 => IDE { num: 0, base: 0x1f0, ctrl: 0x3f4 },
+            1 => IDE { num: 1, base: 0x1f0, ctrl: 0x3f4 },
+            2 => IDE { num: 2, base: 0x170, ctrl: 0x374 },
+            3 => IDE { num: 3, base: 0x170, ctrl: 0x374 },
+            _ => panic!("ide number should be 0,1,2,3"),
+        };
+        ide.init();
         ide
     }
 
-    fn ide_wait_ready(&self, iobase: u16, check_error: usize) -> usize {
+    /// Read ATA DMA. Block size = 512 bytes.
+    pub fn read(&self, sector: u64, count: usize, data: &mut [u32]) -> Result<(), ()> {
+        assert_eq!(data.len(), count * SECTOR_SIZE);
+        self.wait();
         unsafe {
-            let mut r = port::inb(iobase + ISA_STATUS);
-            //println!("iobase:{} ready:{}",iobase,r);
-            while (r & IDE_BSY) > 0 {
-                r = port::inb(iobase + ISA_STATUS);
-                //println!("busy");
-            }
-            /* nothing */
-            if check_error == 1 && (r & (IDE_DF | IDE_ERR)) != 0 {
-                return 1;
+            self.select(sector, count as u8);
+            port::outb(self.base + ISA_COMMAND, IDE_CMD_READ);
+            for i in 0..count {
+                let ptr = &data[(i as usize) * SECTOR_SIZE];
+                if self.wait_error() {
+                    return Err(());
+                }
+                asm!("rep insl" :: "{dx}"(self.base), "{rdi}"(ptr), "{cx}"(SECTOR_SIZE) : "rdi" : "volatile");
             }
         }
-        return 0;
+        Ok(())
     }
-
-    fn ide_init(&self) {
-        //static_assert((SECTSIZE % 4) == 0);
-        let ideno = self.num;
-        //println!("ideno:{}",ideno);
-        /* assume that no device here */
-        //ide_devices[ideno].valid = 0;
-
-        //let iobase = IO_BASE(ideno);
-        let iobase = CHANNELS[if ideno > 2 { 1 } else { 0 }].0;
-
-        /* wait device ready */
-        self.ide_wait_ready(iobase, 0);
-        //println!("ide_wait_ready");
+    /// Write ATA DMA. Block size = 512 bytes.
+    pub fn write(&self, sector: u64, count: usize, data: &[u32]) -> Result<(), ()> {
+        assert_eq!(data.len(), count * SECTOR_SIZE);
+        self.wait();
         unsafe {
-            /* step1: select drive */
-            //println!("outb");
-            port::outb(iobase + ISA_SDH, (0xE0 | ((ideno & 1) << 4)) as u8);
-            self.ide_wait_ready(iobase, 0);
-
-            /* step2: send ATA identify command */
-            //println!("outb");
-            port::outb(iobase + ISA_COMMAND, IDE_CMD_IDENTIFY);
-            self.ide_wait_ready(iobase, 0);
-
-            /* step3: polling */
-            //println!("inb");
-            if port::inb(iobase + ISA_STATUS) == 0 || self.ide_wait_ready(iobase, 1) != 0 {
-                return;
-            }
-
-            //println!("insl");
-            let mut buffer: [u32; 128] = [0; 128];
-            for i in 0..buffer.len() {
-                buffer[i] = i as u32;
-                if i == 1 {
-                    //println!("{:#x}",&buffer[i] as *const u32 as usize - ::consts::KERNEL_OFFSET)
+            self.select(sector, count as u8);
+            port::outb(self.base + ISA_COMMAND, IDE_CMD_WRITE);
+            for i in 0..count {
+                let ptr = &data[(i as usize) * SECTOR_SIZE];
+                if self.wait_error() {
+                    return Err(());
                 }
-            }
-            //println!("insl {:#x}",&buffer as *const u32 as usize - ::consts::KERNEL_OFFSET);
-
-            //println!("insl {:#x}",buffer.as_ptr() as usize - ::consts::KERNEL_OFFSET);
-            //port::insl(iobase + ISA_DATA, &mut buffer);
-            let port = iobase + ISA_DATA;
-            //let buf=&mut buffer;
-            for i in 0..buffer.len() {
-                asm!("insl %dx, (%rdi)"
-                :: "{dx}"(port), "{rdi}"(&buffer[i])
-                : "rdi" : "volatile");
-            }
-            //println!("insl");
-            for i in 0..4 {
-                info!("ide init: {}", buffer[i]);
+                asm!("rep outsl" :: "{dx}"(self.base), "{rsi}"(ptr), "{cx}"(SECTOR_SIZE) : "rsi" : "volatile");
             }
         }
-        /* device is ok */
-        //ide_devices[ideno].valid = 1;
-
-        /* read identification space of the device */
-        /*let buffer[128];
-        insl(iobase + ISA_DATA, buffer, sizeof(buffer) / sizeof(unsigned int));
-
-        unsigned char *ident = (unsigned char *)buffer;
-        unsigned int sectors;
-        unsigned int cmdsets = *(unsigned int *)(ident + IDE_IDENT_CMDSETS);
-        /* device use 48-bits or 28-bits addressing */
-        if (cmdsets & (1 << 26)) {
-            sectors = *(unsigned int *)(ident + IDE_IDENT_MAX_LBA_EXT);
-        }
-        else {
-            sectors = *(unsigned int *)(ident + IDE_IDENT_MAX_LBA);
-        }
-        ide_devices[ideno].sets = cmdsets;
-        ide_devices[ideno].size = sectors;
-
-        /* check if supports LBA */
-        assert((*(unsigned short *)(ident + IDE_IDENT_CAPABILITIES) & 0x200) != 0);
-
-        unsigned char *model = ide_devices[ideno].model, *data = ident + IDE_IDENT_MODEL;
-        unsigned int i, length = 40;
-        for (i = 0; i < length; i += 2) {
-            model[i] = data[i + 1], model[i + 1] = data[i];
-        }
-        do {
-            model[i] = '\0';
-        } while (i -- > 0 && model[i] == ' ');
-
-        cprintf("ide %d: %10u(sectors), '%s'.\n", ideno, ide_devices[ideno].size, ide_devices[ideno].model);*/
+        Ok(())
+    }
 
-        // enable ide interrupt
-        //pic_enable(IRQ_IDE1);
-        //pic_enable(IRQ_IDE2);
+    fn wait(&self) {
+        while unsafe { port::inb(self.base + ISA_STATUS) } & IDE_BUSY != 0 {}
+    }
 
-        info!("ide {} init end", self.num);
+    fn wait_error(&self) -> bool {
+        self.wait();
+        let status = unsafe { port::inb(self.base + ISA_STATUS) };
+        status & (IDE_DF | IDE_ERR) != 0
     }
-    fn ide_read_secs<'a>(&'a self, ideno: u8, secno: u64, dst: &'a mut [u32], nsecs: u8) -> Result<usize, ()> {
-        //assert(nsecs <= MAX_NSECS && VALID_IDE(ideno));
-        //assert(secno < MAX_DISK_NSECS && secno + nsecs <= MAX_DISK_NSECS);
-        let iobase = CHANNELS[if ideno > 2 { 1 } else { 0 }].0;
-        let ioctrl = CHANNELS[if ideno > 2 { 1 } else { 0 }].1;
 
-        //ide_wait_ready(iobase, 0);
+    fn init(&self) {
+        self.wait();
+        unsafe {
+            // step1: select drive
+            port::outb(self.base + ISA_SDH, (0xE0 | ((self.num & 1) << 4)) as u8);
+            self.wait();
 
-        self.ide_wait_ready(iobase, 0);
+            // step2: send ATA identify command
+            port::outb(self.base + ISA_COMMAND, IDE_CMD_IDENTIFY);
+            self.wait();
 
-        let ret = 0;
-        // generate interrupt
-        unsafe {
-            port::outb(ioctrl + ISA_CTRL, 0);
-            port::outb(iobase + ISA_SECCNT, nsecs);
-            port::outb(iobase + ISA_SECTOR, (secno & 0xFF) as u8);
-            port::outb(iobase + ISA_CYL_LO, ((secno >> 8) & 0xFF) as u8);
-            port::outb(iobase + ISA_CYL_HI, ((secno >> 16) & 0xFF) as u8);
-            port::outb(iobase + ISA_SDH, 0xE0 | ((ideno & 1) << 4) | (((secno >> 24) & 0xF) as u8));
-            //port::outb(iobase + ISA_SDH, (0xE0 | ((ideno & 1) << 4)) as u8);
-            //self.ide_wait_ready(iobase, 0);
-            port::outb(iobase + ISA_COMMAND, IDE_CMD_READ);
-            //self.ide_wait_ready(iobase, 0);
-            // if port::inb(iobase + ISA_STATUS) == 0 || self.ide_wait_ready(iobase, 1) != 0 {
-            // 	println!("error?");
-            // }
-            for i in 0..nsecs {
-                //dst = dst + SECTSIZE;
-                let tmp = &mut dst[(i as usize) * SECTOR_SIZE..((i + 1) as usize) * SECTOR_SIZE];
-                if self.ide_wait_ready(iobase, 1) != 0 {
-                    println!("wait ready error");
-                }
-                //self.ide_wait_ready(iobase, 1);
-                //port::insl(iobase, tmp);
-                let port = iobase;
-                //let buf=&mut buffer;
-                for i in 0..tmp.len() {
-                    asm!("insl %dx, (%rdi)"
-					:: "{dx}"(port), "{rdi}"(&tmp[i])
-					: "rdi" : "volatile");
-                }
-                //println!("read :{}",i);
+            // step3: polling
+            if port::inb(self.base + ISA_STATUS) == 0 || self.wait_error() {
+                return;
             }
+
+            // ???
+            let mut data = [0; SECTOR_SIZE];
+            asm!("rep insl" :: "{dx}"(self.base + ISA_DATA), "{rdi}"(data.as_ptr()), "{cx}"(SECTOR_SIZE) : "rdi" : "volatile");
         }
-        Ok(ret)
     }
 
-    fn ide_write_secs<'a>(&'a self, ideno: u8, secno: u64, src: &'a [u32], nsecs: u8) -> Result<usize, ()> {
-        //assert(nsecs <= MAX_NSECS && VALID_IDE(ideno));
-        //assert(secno < MAX_DISK_NSECS && secno + nsecs <= MAX_DISK_NSECS);
-        let iobase = CHANNELS[if ideno > 2 { 1 } else { 0 }].0;
-        let ioctrl = CHANNELS[if ideno > 2 { 1 } else { 0 }].1;
-
-        //ide_wait_ready(iobase, 0);
-
-        self.ide_wait_ready(iobase, 0);
-
-        let ret = 0;
-        // generate interrupt
+    fn select(&self, sector: u64, count: u8) {
+        assert_ne!(count, 0);
+        self.wait();
         unsafe {
-            port::outb(ioctrl + ISA_CTRL, 0);
-            port::outb(iobase + ISA_SECCNT, nsecs);
-            port::outb(iobase + ISA_SECTOR, (secno & 0xFF) as u8);
-            port::outb(iobase + ISA_CYL_LO, ((secno >> 8) & 0xFF) as u8);
-            port::outb(iobase + ISA_CYL_HI, ((secno >> 16) & 0xFF) as u8);
-            port::outb(iobase + ISA_SDH, 0xE0 | ((ideno & 1) << 4) | (((secno >> 24) & 0xF) as u8));
-            port::outb(iobase + ISA_COMMAND, IDE_CMD_WRITE);
-            //println!("{}",nsecs);
-            for i in 0..nsecs {
-                //dst = dst + SECTSIZE;
-                // if ((ret = ide_wait_ready(iobase, 1)) != 0) {
-                // 	goto out;
-                // }
-                //port::insb(iobase, dst);
-                //println!("i={}",i);
-                let tmp = &src[(i as usize) * SECTOR_SIZE..((i + 1) as usize) * SECTOR_SIZE];
-                if self.ide_wait_ready(iobase, 1) != 0 {
-                    println!("wait ready error");
-                }
-                //println!("write {}:{}",i,src[i as usize]);
-                //println!("outsl");
-                //port::outsl(iobase, tmp);
-                let port = iobase;
-                //let buf=&mut buffer;
-                for i in 0..tmp.len() {
-                    asm!("outsl (%rsi), %dx"
-        			:: "{dx}"(port), "{rsi}"(&tmp[i])
-        			: "rsi");
-                }
-                //println!("write :{}",i);
-                // for i in 0..4 {
-                //  	println!("{}",src[i as usize]);
-                // }
-                //port::outb(iobase, src[i as usize]);
-            }
+            // generate interrupt
+            port::outb(self.ctrl + ISA_CTRL, 0);
+            port::outb(self.base + ISA_SECCNT, count);
+            port::outb(self.base + ISA_SECTOR, (sector & 0xFF) as u8);
+            port::outb(self.base + ISA_CYL_LO, ((sector >> 8) & 0xFF) as u8);
+            port::outb(self.base + ISA_CYL_HI, ((sector >> 16) & 0xFF) as u8);
+            port::outb(self.base + ISA_SDH, 0xE0 | ((self.num & 1) << 4) | (((sector >> 24) & 0xF) as u8));
         }
-        Ok(ret)
     }
 }
 
 const SECTOR_SIZE: usize = 128;
-//const MAX_DMA_SECTORS: usize = 0x2_0000 / SECTOR_SIZE;	// Limited by sector count (and PRDT entries)
 const MAX_DMA_SECTORS: usize = 0x1F_F000 / SECTOR_SIZE;    // Limited by sector count (and PRDT entries)
 // 512 PDRT entries, assume maximum fragmentation = 512 * 4K max = 2^21 = 2MB per transfer
 
-const HDD_PIO_W28: u8 = 0x30;
-const HDD_PIO_R28: u8 = 0x20;
-const HDD_PIO_W48: u8 = 0x34;
-const HDD_PIO_R48: u8 = 0x24;
-const HDD_IDENTIFY: u8 = 0xEC;
-
-const HDD_DMA_R28: u8 = 0xC8;
-const HDD_DMA_W28: u8 = 0xCA;
-const HDD_DMA_R48: u8 = 0x25;
-const HDD_DMA_W48: u8 = 0x35;
-
 const ISA_DATA: u16 = 0x00;
 const ISA_ERROR: u16 = 0x01;
 const ISA_PRECOMP: u16 = 0x01;
@@ -278,7 +131,7 @@ const ISA_SDH: u16 = 0x06;
 const ISA_COMMAND: u16 = 0x07;
 const ISA_STATUS: u16 = 0x07;
 
-const IDE_BSY: u8 = 0x80;
+const IDE_BUSY: u8 = 0x80;
 const IDE_DRDY: u8 = 0x40;
 const IDE_DF: u8 = 0x20;
 const IDE_DRQ: u8 = 0x08;
@@ -288,33 +141,7 @@ const IDE_CMD_READ: u8 = 0x20;
 const IDE_CMD_WRITE: u8 = 0x30;
 const IDE_CMD_IDENTIFY: u8 = 0xEC;
 
-const IDE_IDENT_SECTORS: usize = 20;
-const IDE_IDENT_MODEL: usize = 54;
-const IDE_IDENT_CAPABILITIES: usize = 98;
-const IDE_IDENT_CMDSETS: usize = 164;
-const IDE_IDENT_MAX_LBA: usize = 120;
-const IDE_IDENT_MAX_LBA_EXT: usize = 200;
-
-const IO_BASE0: u16 = 0x1F0;
-const IO_BASE1: u16 = 0x170;
-const IO_CTRL0: u16 = 0x3F4;
-const IO_CTRL1: u16 = 0x374;
-
-const MAX_IDE: usize = 4;
 const MAX_NSECS: usize = 128;
-//const MAX_DISK_NSECS          0x10000000U;
-//const VALID_IDE(ideno)        (((ideno) >= 0) && ((ideno) < MAX_IDE) && (ide_devices[ideno].valid))
-
-struct Channels {
-    base: u16,
-    // I/O Base
-    ctrl: u16,        // Control Base
-}
-
-const CHANNELS: [(u16, u16); 2] = [(IO_BASE0, IO_CTRL0), (IO_BASE1, IO_CTRL1)];
-
-//const IO_BASE(ideno)          (CHANNELS[(ideno) >> 1].base)
-//const IO_CTRL(ideno)          (CHANNELS[(ideno) >> 1].ctrl)
 
 mod port {
     use x86_64::instructions::port::Port;