[U-Boot] Executing uboot from FLASH

[U-Boot] Executing uboot from FLASH

[Mike Breneman]

Hello all,

I am working with the AMCC PPC 405Ex.  I will have very limited RAM on my production board, thus I would like u-boot to execute from FLASH rather than RAM.  Has anyone else done this?  I played with this a couple of days without much success.  Is it do-able, without too much effort?

Thanks,
Mike

[U-Boot] Executing uboot from FLASH

[Wolfgang Denk]

Dear Mike Breneman,

In message <B0A7AF226B49A14897036E9B3A68CFFECB1AB0F248@HQ-EXCH-7.corp.brocade.com> you wrote:
>
> I am working with the AMCC PPC 405Ex. I will have very limited RAM
> on my production board, thus I would like u-boot to execute from

How much is "very limited" ?

If you want to use that board for any reasonable pourposes, which
justify the use of a boot loader like U-Boot, then you probably have
more than enough RAM to run U-Boot.

> FLASH rather than RAM. Has anyone else done this? I played with this
> a couple of days with out much success. Is it do-able, without too
> much effort?

It would be significant effort. And it makes not much sense, as you
would lose a lot of basic functionality, resp. have to work around the
resulting restrictions.

It doesn't make sense to me. Rather think how to make it fit into
avilable RAM. How much RAM do you have?

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
The light at the end of the tunnel is usually a "No Exit" sign.

[U-Boot] Executing uboot from FLASH

[Mike Breneman]

Thanks for the response.  Currently the processor will have 128KB of RAM.  It will be running a small footprint RTOS.

This processor is sort of a co-processor which offloads the main CPU for certain tasks.  It is basically replacing an FPGA as it is a cheaper solution.  I will check if I can bump the RAM to 256 or 512KB.

I began to suspect it would be a sizeable effort to modify u-boot to execute from FLASH, thanks for confirming.

Regards,
Mike

-----Original Message-----
From: u-boot-bounces@lists.denx.de [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Wolfgang Denk
Sent: Monday, September 21, 2009 10:46 AM
To: Mike Breneman
Cc: u-boot at lists.denx.de
Subject: Re: [U-Boot] Executing uboot from FLASH

Dear Mike Breneman,

In message <B0A7AF226B49A14897036E9B3A68CFFECB1AB0F248@HQ-EXCH-7.corp.brocade.com> you wrote:
>
> I am working with the AMCC PPC 405Ex. I will have very limited RAM
> on my production board, thus I would like u-boot to execute from

How much is "very limited" ?

If you want to use that board for any reasonable pourposes, which
justify the use of a boot loader like U-Boot, then you probably have
more than enough RAM to run U-Boot.

> FLASH rather than RAM. Has anyone else done this? I played with this
> a couple of days with out much success. Is it do-able, without too
> much effort?

It would be significant effort. And it makes not much sense, as you
would lose a lot of basic functionality, resp. have to work around the
resulting restrictions.

It doesn't make sense to me. Rather think how to make it fit into
avilable RAM. How much RAM do you have?

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
The light at the end of the tunnel is usually a "No Exit" sign.
_______________________________________________
U-Boot mailing list
U-Boot at lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot