[U-Boot-Users] Running U-boot on RAM

Wolfgang Denk wd at denx.de
Tue Dec 19 22:12:30 CET 2006

In message <20061219181035.71719.qmail at web7909.mail.in.yahoo.com> you wrote:
>     - If we want use u-boot in embedded system, The initial part of u-boot runs from the Flash.So Flash is mandatory.

Not really. It depends on your architecture, i. e. which features are
supported by your processor, and how your baord was  designed.  There
are  systems  completely  without  any flash. There are other systems
without any NOR flash (using NAND flash only).  There  are  ...  many

>   My goal is :
>      On my embedded platform, the flash is not yet ready.So i wanted to load u-boot on DDRAM/SRAM by changing the TEXT address and set PC to start of start () using JTAG debugger.

Yes, I understood this when you asked the fist time.

>   could you please clarify Is it possible to boot from RAM as i mentioned above.

I pointed you to the FAQ entry, which explains the situation.

>   Any environment variables are access from the Flash during u-boot bootup time.

Maybe, maybe not. This depends on your configuration and the  changes
you made to support booting from RAM.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Minds are like parachutes - they only function when open.

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