Writing the USRP File System Disk Image to a SD Card
- 1 Application Note Number
- 2 Abstract
- 3 Required Tools
- 4 Downloading the File System Image
- 5 Identifying UHD Installation Prefix
- 6 Writing the File System Image with Linux
Application Note Number
This application note will provide step-by-step instructions on writing a file system disk image to a SD card using Linux.
- Computer with USB2/3 Interface
- UHD Installation
- microSD card to USB Adapter
Downloading the File System Image
To obtain the file system SD card image for your USRP device, run the command in the next step on the host computer with UHD installed and Internet access.
$ sudo uhd_images_downloader -t sdimg -t n3xx
$ sudo uhd_images_downloader -t sdimg -t n3xx [INFO] Images destination: /usr/local/share/uhd/images [INFO] No inventory file found at /usr/local/share/uhd/images/inventory.json. Creating an empty one. 845962 kB / 845962 kB (100%) n3xx_common_sdimg_default-v184.108.40.206.zip [INFO] Images download complete.
$ sudo uhd_images_downloader -t sdimg -t e320
$ sudo uhd_images_downloader -t sdimg -t e320 [INFO] Images destination: /usr/local/share/uhd/images [INFO] No inventory file found at /usr/local/share/uhd/images/inventory.json. Creating an empty one. 795674 kB / 795674 kB (100%) e3xx_e320_sdimg_default-v220.127.116.11.zip [INFO] Images download complete.
Identifying UHD Installation Prefix
In the output of the
uhd_images_downloader command above, the folder destination where the images are saved is printed out.
An alternative method to identify your installation prefix is to run the command:
$ uhd_config_info --install-prefix
Install prefix: /usr/local
The default folder location for FPGA and SD card images is:
Writing the File System Image with Linux
Identifying SD Card Mount Location
Insert the microSD card into the host computer.
To identify the device where the microSD card is, run the command:
dmesg | tail
Example Output (partially truncated for readability):
[21265.575488] usb-storage 1-2:1.0: USB Mass Storage device detected [21266.586983] scsi 0:0:0:0: Direct-Access Generic Mass-Storage 1.11 PQ: 0 ANSI: 2 [21266.588024] sd 0:0:0:0: Attached scsi generic sg0 type 0 [21267.299812] sd 0:0:0:0: [sdb] 31116288 512-byte logical blocks: (15.9 Gb/14.8 GiB) [21267.302687] sdb: sdb1 sdb2 sdb3 sdb4
NOTE: In this specific example configuration, the SD card has been attached to
Another method to finding the device node the disk is attached at is to use the Linux utility
$ lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sdb 8:16 1 14.9G 0 disk ├─sdb1 8:17 1 16M 0 part /media/user/boot ├─sdb2 8:18 1 1.9G 0 part /media/user/primary ├─sdb3 8:19 1 1.9G 0 part /media/user/secondary └─sdb4 8:20 1 11G 0 part /media/user/data
Unmount Auto-mounted Partitions
Some operating systems by default will auto-mount the partitions on a block device when it is attached. Before writing a new disk image to the SD card, you should first unmount any mounted partitions. This can be done with the Linux utility
umount as shown below:
$ sudo umount /media/user/data $ sudo umount /media/user/primary $ sudo umount /media/user/secondary $ sudo umount /media/user/boot
Running the command
lsblk again will show these partitions have been unmounted:
$ lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sdb 8:16 1 14.9G 0 disk ├─sdb1 8:17 1 16M 0 part ├─sdb2 8:18 1 1.9G 0 part ├─sdb3 8:19 1 1.9G 0 part └─sdb4 8:20 1 11G 0 part
Writing the SD Card Image
Using dd to write the disk image
WARNING: The Linux utility
dd can cause unrecoverable data loss if the incorrect disk is selected, or if the parameters are input incorrectly. Ensure you have selected the correct input and output parameters for your system configuration.
NOTE: You must use a 16 Gb or larger SD card for the N3xx and E320 file system images.
<SD_CARD_DEV_NAME> device node depends on your operating system and which other devices are plugged in. Typical values are
<IMAGE> value will depend upon which file system image you're writing. Examples for the N300/N310 and E320 are listed below:
Write the disk image with the command:
$ sudo dd if=<IMAGE> of=<SD_CARD_DEV_NAME> bs=1M
This step of writing the disk image to the SD card can take several minutes to complete.
$ sudo dd if=/usr/local/share/uhd/images/usrp_<deivce>_fs.sdimg of=/dev/sdb bs=1M 15160+0 records in 15160+0 records out 15896412160 bytes (16 Gb, 15 GiB) copied, 1160.93 s, 13.7 MB/s
To ensure the disk is synchronized, run the
You can now remove the microSD card from your host computer and insert it into the USRP.
Using bmaptool to write the disk image
The Linux utility
bmaptool can be used in place of the utility
dd, and will generally write the SD card image faster.
bmaptool is not a standard Linux utility and must be installed on your host system; some OSs provide this tool via their system package manager.
Typical usage in this context is as follows:
$ sudo bmaptool copy <IMAGE> <SD_CARD_DEV_NAME> --bmap <IMAGE BMAP (*.sdimg.bmap)>
lsblk is available on most Linux OSs to show the
SD_CARD_DEV_NAME noted above.
USRP filesystem images are located in the UHD images directory, which is by default either
/usr/local/share/uhd/images/, and the files will have the extension
.sdimg. The full filename will be
usrp_<device>_fs.sdimg, for the desired USRP
device such as the
Thus, for example, for the
/dev/sdb and for the E320 USRP, the command and resulting output could be:
$ sudo bmaptool copy /usr/local/share/uhd/images/usrp_e320_fs.sdimg /dev/sdb --bmap /usr/local/share/uhd/images/usrp_e320_fs.sdimg.bmap bmaptool: info: block map format version 2.0 bmaptool: info: 3875840 blocks of size 4096 (14.8 GiB), mapped 596649 blocks (2.3 GiB or 15.4%) bmaptool: info: copying image ‘/usr/local/share/uhd/images/usrp_e320_fs.sdimg' to block device '/dev/sdb' using bmap file '/usr/local/share/uhd/images/usrp_e320_fs.sdimg.bmap' bmaptool: info: 100% copied bmaptool: info: synchronizing '/dev/sdb' bmaptool: info: copying time: 4m 10.3s, copying speed 9.3 MiB/sec