Thread: Introducing ubiboot N9 (multiboot OS loader)
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fejd is offline fejd
2013-12-30 , 22:46
Posts: 12 | Thanked: 5 times | Joined on Dec 2013
#1027
Originally Posted by juiceme View Post
Kernel is not flashed on your mmcblk0 flash, there's a differnt flash filesystem on the device that consists of the parts of device which hold for example the factory calibration data.

The location for kernel is the MTD2 partition of the system NAND.
You can get some information with mtdinfo command, for example on my device it says:
~ # /usr/sbin/mtdinfo -m 2
mtd2
Name: kernel
Type: nand
Eraseblock size: 262144 bytes, 256.0 KiB
Amount of eraseblocks: 64 (16777216 bytes, 16.0 MiB)
Minimum input/output unit size: 4096 bytes
Sub-page size: 1024 bytes
OOB size: 128 bytes
Character device major/minor: 90:4
Bad blocks are allowed: true
Device is writable: true
mtdinfo for partition 2 shows:

~ # /usr/sbin/mtdinfo -m 2
mtd2
Name: kernel
Type: nand
Eraseblock size: 131072 bytes, 128.0 KiB
Amount of eraseblocks: 64 (8388608 bytes, 8.0 MiB)
Minimum input/output unit size: 2048 bytes
Sub-page size: 512 bytes
OOB size: 64 bytes
Character device major/minor: 90:4
Bad blocks are allowed: true
Device is writable: true


mtd_debug gives me:


~ # /usr/sbin/mtd_debug info /dev/mtd2
mtd.type = MTD_NANDFLASH
mtd.flags = MTD_CAP_NANDFLASH
mtd.size = 8388608 (8M)
mtd.erasesize = 131072 (128K)
mtd.writesize = 2048 (2K)
mtd.oobsize = 64
regions = 0


So it looks like the size is set to 8M. Is this a factory setting or is it set during flashing? Could it be a result of damaged sectors? I've flashed two different variants with the same result:
059H2M6_RM-696 NDT 64GB ROW BLACK
059L7N6_N9 RM-696 Country Variant Sweden SE Black 64GB

If I print the MTD info for Moslo, its size is set to 16M:

~ # /usr/sbin/mtd_debug info /dev/mtd5
mtd.type = MTD_NANDFLASH
mtd.flags = MTD_CAP_NANDFLASH
mtd.size = 16777216 (16M)
mtd.erasesize = 131072 (128K)
mtd.writesize = 2048 (2K)
mtd.oobsize = 64
regions = 0