Vybrid NAND flash repartitioning

[JaclynM]

I'm using a Phytec PCM052 board with ARM DS-5 and Timesys toolchain.
Due to an update of U-Boot I need to repartition the flash mem.


Is there a step by step guide available from NXP using the tools from Linux-Busybox ?

I've found two reserved partitions.
According to the VybridRM the start partition holds the Firmware Configuration Block (FCB) containing primary/secondary U-Boot addresses.
Which program writes the initial values into flash ?

What is the second partition at the end of the flash used for ? Bad Block Marking Table ?

[kef2]

• Due to an update of U-Boot I need to repartition the flash mem.

Why? You need to "nand erase.part <u-boot-partition>" or "nand erase <offset> <size>" the same U-Boot locations and nand write there new U-boot. Why repartition? 

NAND partitioning is done defining U-Boot default mtdparts variable. You may temporarily edit this variable to repartition NAND, but in case U-Boot environment settings are lost, default mtdparts shouldn't lead to disasters on rootfs or othe partitions.

• According to the VybridRM the start partition holds the Firmware Configuration Block (FCB) containing primary/secondary U-Boot addresses.
  Which program writes the initial values into flash ?

Toradex U-Boot had writebcb command, which was used to create BCB taking primary and optional secondary U-boot offsets in NAND and write created BCB to start of NAND. Alternatively you may create BCB file on PC, deliver somehow to U-Boot on target and nand write it. 

• What is the second partition at the end of the flash used for ? Bad Block Marking Table ?

It is up to you or your SOM vendor. Minimally mtdparts should include 3 partitions, one reserved for BCB, one or two for U-Boot copies, one for UBI (which may include several UBI volumes) or any other kind for partition(s) for rootfs, device tree and kernel.

[Bio_TICFSL]

Hello,

You can put in second partition the rootfs or bad block marking table but remember that the flash must be completely erase before burn. NXP don;t have any document about it.

Regards