Difference between revisions of "NAND flash boot rootfs"
From ElphelWiki
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ubiformat /dev/mtd4 -f rootfs.ubi -s 2048 -O 2048 | ubiformat /dev/mtd4 -f rootfs.ubi -s 2048 -O 2048 | ||
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− | '''Note:''' Considering to store the u-boot, device tree and kernel on | + | '''Note:''' Considering to store the u-boot (probably not, because 192K-max-boot.bin might not fit UBIFS driver), device tree and kernel on UBIFS partitions in future. |
[[Category:Elphel393]] | [[Category:Elphel393]] |
Revision as of 14:56, 4 August 2016
Boot from NAND flash (rootfs)
- The default boot option - power on.
- A UBIFS image of rootfs is written to /dev/mtd4 (ubi0:elphel393-rootfs in bootargs in the device tree) - mounted as /
Reflash factory image
Notes
- Update software/firmware or corrupt flash partition
- To update u-boot images, device tree and kernel - booting from micro SD card is not required.
- To update rootfs - boot from micro SD card otherwise a mounted flash partition will be rewritten, get corrupt and the camera won't boot - boot from micro SD card and reflash rootfs partition to recover.
- boot.bin, u-boot-dtb.img - most likely won't need updating at all. Only if their partitions get corrupt
- As Zynq's BootROM performs 32KB jumps within the first 128MiB of flash in the search of a boot.bin header with a correct checksum it is possible to flash a few backup images to the 1st flash partition (mtd0) in the device tree. The partition size is 1MB, boot.bin size is normally around 100KB (<192KB - Zynq OCM requirement)
Instructions
- Use files from .../poky/build/tmp/deploy/images/elphel393/nand/
- boot.bin
- u-boot-dtb.img
- devicetree.dtb
- uImage
- rootfs.ubifs (recommended), rootfs.ubi (radical)
- Copy all of the image files to a micro SD card (or boot first from the card then copy over network)
- Boot from micro SD card (important for rootfs updates)
- Reflash what is needed:
- Reflash SPL (boot.bin, /dev/mtd0)
cd <path-to-image-files> # boot.bin # mtd0 is 1MB (8 eraseblocks,128K = 1 block, there are 64 pages of 2048 per block) # erase only first 2 blocks, other block are reserved for copies flash_unlock /dev/mtd0 flash_erase /dev/mtd0 0 2 nandwrite -n /dev/mtd0 -p boot.bin
- Reflash u-boot (u-boot-dtb.img, /dev/mtd1)
cd <path-to-image-files> # u-boot-dtb.img # mtd1 is 4M (32 eraseblocks,128K = 1 block, there are 64 pages of 2048 per block) # erase only the 1st 8 blocks as image is <1M, leave unused area for backup copies flash_unlock /dev/mtd1 flash_erase /dev/mtd1 0 8 nandwrite -n /dev/mtd1 -p u-boot-dtb.img
- Reflash devicetree (devicetree.dtb, /dev/mtd2)
cd <path-to-image-files> # u-boot-dtb.img # mtd2 is 1M (8 eraseblocks,128K = 1 block, there are 64 pages of 2048 per block) flash_unlock /dev/mtd2 flash_erase /dev/mtd2 0 8 nandwrite -n /dev/mtd2 -p devicetree.dtb
- Reflash kernel (uImage, /dev/mtd3)
cd <path-to-image-files> # uImage # mtd3 is 16M (128 eraseblocks,128K = 1 block, there are 64 pages of 2048 per block) flash_unlock /dev/mtd3 flash_erase /dev/mtd3 0 128 nandwrite -n /dev/mtd3 -p uImage
- For rootfs there are 2 options:
- update - recommended, rootfs.ubifs
- reflash - radical, rootfs.ubi
- For rootfs there are 2 options:
Update:
flash_unlock /dev/mtd4 ubiattach /dev/ubi_ctrl -m 4 # NOT NEEDED: ubimkvol /dev/ubi0 -N elphel393-rootfs -s 256MiB ubiupdatevol /dev/ubi0_0 rootfs.ubifs # # read: http://www.linux-mtd.infradead.org/faq/ubifs.html # read: http://free-electrons.com/blog/creating-flashing-ubi-ubifs-images/ # read: http://www.linux-mtd.infradead.org/doc/ubi.html#L_volupdate # read: http://comments.gmane.org/gmane.linux.drivers.mtd/39415
Reflash:
cd <path-to-image-files> flash_unlock /dev/mtd4 flash_erase /dev/mtd4 0 2048 ubiformat /dev/mtd4 -f rootfs.ubi -s 2048 -O 2048
Note: Considering to store the u-boot (probably not, because 192K-max-boot.bin might not fit UBIFS driver), device tree and kernel on UBIFS partitions in future.