topic LS1046ARDB USB Console: no serial device in Layerscape

LS1046ARDB USB Console: no serial device

jepstein — Mon, 03 Aug 2020 23:58:51 GMT

Hello,

We have a fresh LS1046ARDB. When the front console USB port is plugged into another computer, the mbed device shows up, along with the BOOTLOADER drive. However, the bootloader serial port does not appear on the USB bus as expected.

What do we need to do to get the bootloader's serial port to pop up there, or anywhere for that matter?

Thanks

Re: LS1046ARDB USB Console: no serial device

yipingwang — Tue, 04 Aug 2020 03:55:40 GMT

Please download and install mbed device driver from Windows serial configuration - Handbook | Mbed .

Please refer to section "10 Booting LS1046ARDB" in the attached document.

Re: LS1046ARDB USB Console: no serial device

jepstein — Tue, 04 Aug 2020 04:47:38 GMT

Thanks, but that is not the issue. There is no serial-compatible USB device presented by the mbed controller. The storage device is presented.

Just in case the Windows driver performed some magic, we tried repeatedly to apply it with no effect.

Is there any way the mbed controller might not present the USB serial device while still functioning enough to present the storage device?

Thanks

Re: LS1046ARDB USB Console: no serial device

yipingwang — Tue, 04 Aug 2020 08:06:02 GMT

Please check whether the USB to Serial port displayed as the following in device manager.

Please check the switch setting as the following.

Re: LS1046ARDB USB Console: no serial device

jepstein — Tue, 04 Aug 2020 14:54:08 GMT

Right, that's what's happening: no USB-to-serial device shows up on the USB device tree--and thus nothing under the "Ports (COM & LPT)" gets added--and the DIP switches are all in the proper positions, including SW4[4]. Clearly the mbed device is working enough to expose the bootloader storage, but nothing else.

Thanks

Re: LS1046ARDB USB Console: no serial device

yipingwang — Thu, 06 Aug 2020 09:30:20 GMT

Would you please attach a picture to show what cable do you use to connect your target board and PC?

Re: LS1046ARDB USB Console: no serial device

jepstein — Thu, 06 Aug 2020 17:20:49 GMT

For what it's worth, the UART1 connection does work (and we did remember to put SW4[4] back), so I suspect it's an odd mbed issue.

Thanks

Re: LS1046ARDB USB Console: no serial device

yipingwang — Fri, 07 Aug 2020 07:46:18 GMT

Probably there is problem with the your serial cable, after plugin the serial cable to the PC, you should find the serial port information under ports(COM & LPT) in the device manager.

In addition, please set the switch configuration same as my target board.

SW3: 01001110

SW4: 00101011

SW5: 00100000

Re: LS1046ARDB USB Console: no serial device

jepstein — Fri, 07 Aug 2020 20:37:30 GMT

Thanks, Yiping, for your help. The cable works fine...both in other devices, and to export the mass storage function from mbed. Here's a dump of lspci -vv, so you can see that only one interface descriptor (the mass storage BOOTLOADER) is exposed by mbed. Normally, a couple other interface descriptors are exposed--most importantly, serial.

Is there a way to reset the mbed's configuration?

Joe

Bus 001 Device 019: ID 0d28:0204 NXP ARM mbed
Device Descriptor:
bLength                18
bDescriptorType         1
bcdUSB               1.10
bDeviceClass            0
bDeviceSubClass         0
bDeviceProtocol         0
bMaxPacketSize0         8
idVendor           0x0d28 NXP
idProduct          0x0204 ARM mbed
bcdDevice            1.00
iManufacturer           1 MBED
iProduct                2 MBED CMSIS-DAP
iSerial                 3 0201EA06C8715F002C7C
bNumConfigurations      1
Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x0020
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              500mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass         8 Mass Storage
      bInterfaceSubClass      6 SCSI
      bInterfaceProtocol     80 Bulk-Only
      iInterface              4 USB_MSC
      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
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x02 EP 2 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040 1x 64 bytes
        bInterval               0
Device Status:     0x0000
(Bus Powered)

Re: LS1046ARDB USB Console: no serial device

yipingwang — Mon, 10 Aug 2020 09:22:13 GMT

Please try the attached mbed WinSerial driver.

Re: LS1046ARDB USB Console: no serial device

jepstein — Mon, 10 Aug 2020 15:03:26 GMT

Sorry, Yiping, but unfortunately, that's not the issue. The mbed USB port doesn't expose a serial port to attach to, so there's nothing for the driver to find. The driver you posted--which we installed before our first post--would have worked if the mbed device was exposing a serial interface on its USB, and if it were missing, we would have seen a USB device on Windows with a missing driver, or on Linux it would have simply worked. Instead, we only see the mass storage interface and nothing else. (The USB iteration's bNumInterfaces is 1, above, not the usual 4, or not even 2.)

So, we suspect something is wrong with the firmware image on the mbed MCU and we need to reflash it.

Could you point us to the right mbed firmware image for the LS1046ARDB to reprogram it with? Per the schematic, the part is the MK22FX512VLH12, but we want to make sure we get an image for it that reflects the board properly and not try to build or scavenge an image from the web (such as mbed.org) and brick the mbed MCU entirely.

Thanks!

Re: LS1046ARDB USB Console: no serial device

yipingwang — Tue, 11 Aug 2020 05:33:09 GMT

Please refer to the attached document and firmware image.

Re: LS1046ARDB USB Console: no serial device

jepstein — Tue, 11 Aug 2020 14:32:56 GMT

Thanks! Works like a charm.