topic Re: Vybrid NAND flash repartitioning in Vybrid Processors

Vybrid NAND flash repartitioning

JaclynM — Mon, 20 Nov 2023 17:11:41 GMT

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 ?

Re: Vybrid NAND flash repartitioning

Bio_TICFSL — Wed, 22 Nov 2023 14:27:13 GMT

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

Re: Vybrid NAND flash repartitioning

kef2 — Wed, 22 Nov 2023 15:37:32 GMT

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.