Sansa Express Rockbox Development

---

See also SansaExpressPort.

---

PCB Scans

Scans are now attached on this page. They're courtesy of "kape" from the ABI forums.

-- SiloSpen - 27 Jun 2008

---

Here is the relevant info from fisk -l with Linux:

Disk /dev/sda: 1022 MB, 1022623744 bytes
24 heads, 23 sectors/track, 3618 cylinders
Units = cylinders of 552 * 512 = 282624 bytes
Disk identifier: 0x00000000

Device Boot Start End Blocks Id System
/dev/sda1 * 1 3619 998532+ 6 FAT16

Conclusion: It looks like the partition that is visible to Linux is the boot partition and there is a 23M hidden partition.

Connecting the Sansa express while holding down "-" button enters some form of direct chip, possibly recovery mode. fdisk -l shows nothing in this mode.

---

lsusb Output

lsusb -v output:

Bus 002 Device 022: ID 0781:7460 SanDisk Corp. 
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  idVendor           0x0781 SanDisk Corp.
  idProduct          0x7460 
  bcdDevice            0.01
  iManufacturer           1 Sandisk
  iProduct                2 Sansa Express
  iSerial                 5 XXXXXXXXXXXXXXXXXXXXXXXXX
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           39
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          3 USB/Sansa Express
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              500mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           3
      bInterfaceClass         8 Mass Storage
      bInterfaceSubClass      6 SCSI
      bInterfaceProtocol     80 Bulk (Zip)
      iInterface              4 USB/Sansa Express
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x02  EP 2 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x83  EP 3 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval              16
Device Qualifier (for other device speed):
  bLength                10
  bDescriptorType         6
  bcdUSB               2.00
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  bNumConfigurations      1
Device Status:     0x0000
  (Bus Powered)

I have usbmount installed, and it sees /dev/sdb but cannot actually read from it to mount it. From what I've read on sandisk's forums, it seems that "drive" (partition) is an "OS/2 Hidden" partition, and that's where the firmware and bootloader are hosted, would be my guess.

usbmount[7657]: cannot read from /dev/sdb

Mine's formatted a bit differently:

Disk /dev/sda: 1023 MB, 1023002624 bytes
4 heads, 7 sectors/track, 71359 cylinders
Units = cylinders of 28 * 512 = 14336 bytes
Disk identifier: 0x000b3697

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           9       71359      998902+   6  FAT16

-- SimonRaven - 22 Jan 2008

Connecting the Sansa express while holding down "-" button enters some form of direct chip, possibly recovery mode.

lsusb -v shows:

Bus 001 Device 004: ID 066f:3600 SigmaTel, Inc. 
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  idVendor           0x066f SigmaTel, Inc.
  idProduct          0x3600 
  bcdDevice            0.01
  iManufacturer           1 Sigmatel, Inc.
  iProduct                2 STMP3600
  iSerial                 0 
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           32
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          3 USB Boot Class-c
    bmAttributes         0xc0
      Self Powered
    MaxPower              100mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass      0 
      bInterfaceProtocol    255 
      iInterface              4 USB Boot Class-i
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x01  EP 1 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               0
Device Status:     0x0000
  (Bus Powered)

The device itself has nothing on the screen.

-- Main.SiloSpen - 27 Jun 2008