[U-Boot] U-Boot load and run via NAND flash - ARM926EJ-S

[Thomas Jackson]

Hi List,
I understand NOR-based flash memory devices have traditionally been used for
non-volatile storage for a bootloader and other various advantages including
support for execute-in-place code, random access to memory, and zero error
rate, etc. However, we have a project that we would like to have U-Boot
bootloader run via NAND Flash memory device on a ARM926EJ-S based board. I
searched the mailing list for this and didn't see anything. I only found a
question posted in 2006 where it was asked if the kernel based on ARM926EJ-S
can boot from NAND flash. Which I know is ok. Does the community know of
any existing mechanisms for this type of configuration to enable U-Boot load
and run via NAND flash?

Thanks in advance!
TJ

[N Cheung]

I presume you system will have SDRAM and execution is from SDRAM. I did a
port to an Atmel 9260 with only NAND flash (for bootstrap, bootloader, RFS).
The only issue with NAND is dealing with bad blocks. There are many ways to
work this. One example:
1. bootstrap - I put it in the first block as it guarantees good by
manufacturer. ATmel's bootstrap will skip to next block when reading u-boot
into SDRAM for execution
2. RFS - Initially I tried read/writeable FS with bad block management like
JFFS2 but performance was bad. I end up using CRAMFS on top of UBI in a
read only RFS partition and a small JFFS2 for RW.

Hope this helps.
Norman

Post by Thomas Jackson
Hi List,
I understand NOR-based flash memory devices have traditionally been used
for non-volatile storage for a bootloader and other various advantages
including support for execute-in-place code, random access to memory, and
zero error rate, etc. However, we have a project that we would like to
have U-Boot bootloader run via NAND Flash memory device on a ARM926EJ-S
based board. I searched the mailing list for this and didn't see
anything. I only found a question posted in 2006 where it was asked if
the kernel based on ARM926EJ-S can boot from NAND flash. Which I know is
ok. Does the community know of any existing mechanisms for this type of
configuration to enable U-Boot load and run via NAND flash?
Thanks in advance!
TJ

[Wolfgang Denk]

Dear Thomas Jackson,

Post by Thomas Jackson
I understand NOR-based flash memory devices have traditionally been used for
non-volatile storage for a bootloader and other various advantages including
support for execute-in-place code, random access to memory, and zero error
rate, etc. However, we have a project that we would like to have U-Boot
bootloader run via NAND Flash memory device on a ARM926EJ-S based board. I
searched the mailing list for this and didn't see anything. I only found a

I have no idea how you performed that search, but it seems you have a
special aptitude to avoid all the obvious hits.

Post by Thomas Jackson
question posted in 2006 where it was asked if the kernel based on ARM926EJ-S
can boot from NAND flash. Which I know is ok. Does the community know of
any existing mechanisms for this type of configuration to enable U-Boot load
and run via NAND flash?

It's a standard feature and available on many (most?) boards that
support booting from NAND. Dunno if this includes AT91 boards.

Jean-Christophe should be able to answer this, but he is currently
off this planet.

Best regards,

Wolfgang Denk

[Prafulla Wadaskar]

-----Original Message-----
From: u-boot-bounces at lists.denx.de
[mailto:u-boot-bounces at lists.denx.de] On Behalf Of Wolfgang Denk
Sent: Thursday, September 17, 2009 1:14 PM
To: Thomas Jackson
Cc: u-boot at lists.denx.de
Subject: Re: [U-Boot] U-Boot load and run via NAND flash - ARM926EJ-S
Dear Thomas Jackson,

Post by Thomas Jackson
I understand NOR-based flash memory devices have

traditionally been used for

Post by Thomas Jackson
non-volatile storage for a bootloader and other various

advantages including

Post by Thomas Jackson
support for execute-in-place code, random access to memory,

and zero error

Post by Thomas Jackson
rate, etc. However, we have a project that we would like

to have U-Boot

Post by Thomas Jackson
bootloader run via NAND Flash memory device on a ARM926EJ-S

based board. I

Post by Thomas Jackson
searched the mailing list for this and didn't see anything.

I only found a
I have no idea how you performed that search, but it seems you have a
special aptitude to avoid all the obvious hits.

Post by Thomas Jackson
question posted in 2006 where it was asked if the kernel

based on ARM926EJ-S

Post by Thomas Jackson
can boot from NAND flash. Which I know is ok. Does the

community know of

Post by Thomas Jackson
any existing mechanisms for this type of configuration to

enable U-Boot load

Post by Thomas Jackson
and run via NAND flash?

It's a standard feature and available on many (most?) boards that
support booting from NAND. Dunno if this includes AT91 boards.

On Kirkwood there is internal BootROM which takes care of this.
In this case you need to add some header on the top of u-boot binary
Pls go through doc/README.kwbimage

On Nomadik platforms there is intermediate binary sits on the very first sector which does DRAM initialization ,some other basic system setup and loads u-boot into DRAM.

I am not familiar with AT91, but there must be similar approach.
May be new mkimage structure may find useful for you

Regards..

Prafulla . .

Jean-Christophe should be able to answer this, but he is currently
off this planet.
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: [phone] Fax: [phone] Email: wd at denx.de
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