TS-4720 eMMC: Difference between revisions
(Created page with "This board includes an onboard 4GB eMMC disk. The datasheet for this Micron part can be accessed [http://www.micron.com/parts/nand-flash/managed-nand/n2m400fdb311a3ce here]. ...") |
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This board includes an onboard 4GB eMMC disk. | This board includes an onboard 4GB eMMC disk. This disk is accessed very similar to an SD card and is also supported with the sdctl driver. This eMMC supports read and write speeds at approximately 10MB/s. The kernel provides access to the flash at /dev/nbd1 for the entire block device. The kernel also includes a module that will break this up into partitions. Our default software image contains 2 partitions: | ||
{|class=wikitable | {|class=wikitable | ||
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| Full Linux Root | | Full Linux Root | ||
|} | |} | ||
Pre 11/2/2014 release TS-4720 eMMC by default uses [[#Doublestore|Single card doublestore]]. To access the Linux partition of the SD card while booted to eMMC, you can use the mount command as expected: | |||
<source lang=bash> | |||
mkdir /mnt/sd | |||
mount /dev/nbd1p2 /mnt/sd | |||
</source> | |||
Post 11/2/2014 release TS-4720 eMMC uses Enhanced SLC mode eMMC, allowing for even greater reliability and longer lifespan. To access the Linux partition of the SD Card while using this eMMC, read the device partition table, and then mount as normal: | |||
<source lang=bash> | |||
busybox blockdev --rereadpt /dev/nbd1 | |||
mkdir /mnt/sd | |||
mount /dev/nbd1p2 /mnt/sd | |||
</source> | |||
A useful script for this device read activity has been included in the <code> ts.subr </code> definitions file for use within custom startup scripts: | |||
<source lang=bash> | |||
# excpecting "source ts.subr" is already done | |||
scan_lun <lun number> | |||
mkdir /dev/sd | |||
mount /dev/nbd1p2 /mnt/sd | |||
</source> | |||
Latest revision as of 11:28, 11 January 2021
This board includes an onboard 4GB eMMC disk. This disk is accessed very similar to an SD card and is also supported with the sdctl driver. This eMMC supports read and write speeds at approximately 10MB/s. The kernel provides access to the flash at /dev/nbd1 for the entire block device. The kernel also includes a module that will break this up into partitions. Our default software image contains 2 partitions:
| Device | Contents |
|---|---|
| /dev/nbd1 | eMMC block device |
| /dev/nbd1p1 | Kernel and initramfs |
| /dev/nbd1p2 | Full Linux Root |
Pre 11/2/2014 release TS-4720 eMMC by default uses Single card doublestore. To access the Linux partition of the SD card while booted to eMMC, you can use the mount command as expected:
mkdir /mnt/sd
mount /dev/nbd1p2 /mnt/sd
Post 11/2/2014 release TS-4720 eMMC uses Enhanced SLC mode eMMC, allowing for even greater reliability and longer lifespan. To access the Linux partition of the SD Card while using this eMMC, read the device partition table, and then mount as normal:
busybox blockdev --rereadpt /dev/nbd1
mkdir /mnt/sd
mount /dev/nbd1p2 /mnt/sd
A useful script for this device read activity has been included in the ts.subr definitions file for use within custom startup scripts:
# excpecting "source ts.subr" is already done
scan_lun <lun number>
mkdir /dev/sd
mount /dev/nbd1p2 /mnt/sd