75XX XNAND: Difference between revisions
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The [[XNAND]] access is implemented in userspace in conjunction with NBD (network block device). You may want to refer to the [[nandctl]] page which will show more advanced usage, but by default the linuxrc script will mount the sd card with the following layout | The [[XNAND]] is our layer of software and an FPGA core which is designed to vastly increase the reliability of NAND access. This board includes a 512MB flash chip, but the XNAND algorithm will limit this to a usable 256MB from redundancy. The software layer to access the XNAND is implemented in userspace in conjunction with NBD (network block device). You may want to refer to the [[nandctl]] page which will show more advanced usage, but by default the linuxrc script will mount the sd card with the following layout: | ||
/dev/nbd0 - whole disk device of XNAND drive | /dev/nbd0 - whole disk device of XNAND drive | ||
/dev/nbd1 - 1st partition (kernel partition) | /dev/nbd1 - 1st partition (kernel partition) | ||
/dev/nbd2 - 2nd partition (EXT2 initrd) | /dev/nbd2 - 2nd partition (EXT2 initrd) | ||
/dev/nbd3 - 3rd partition (252MByte mini Debian EXT3 filesystem) | /dev/nbd3 - 3rd partition (~252MByte mini Debian EXT3 filesystem) | ||
/dev/nbd4 - 4th partition (unused) | /dev/nbd4 - 4th partition (unused) | ||
{{Note|NBD devices do not report size correctly. If you are formatting a partition or using dd you will need to specify the size.}} | {{Note|NBD devices do not report size correctly. If you are formatting a partition or using dd you will need to specify the size.}} | ||
For more information on the [[XNAND]] layer, see [[XNAND|this]] page. | |||
Revision as of 15:47, 29 August 2012
The XNAND is our layer of software and an FPGA core which is designed to vastly increase the reliability of NAND access. This board includes a 512MB flash chip, but the XNAND algorithm will limit this to a usable 256MB from redundancy. The software layer to access the XNAND is implemented in userspace in conjunction with NBD (network block device). You may want to refer to the nandctl page which will show more advanced usage, but by default the linuxrc script will mount the sd card with the following layout:
/dev/nbd0 - whole disk device of XNAND drive /dev/nbd1 - 1st partition (kernel partition) /dev/nbd2 - 2nd partition (EXT2 initrd) /dev/nbd3 - 3rd partition (~252MByte mini Debian EXT3 filesystem) /dev/nbd4 - 4th partition (unused)
| Note: | NBD devices do not report size correctly. If you are formatting a partition or using dd you will need to specify the size. |