[U-Boot-Users] U-boot with IBM-PPC440GP - questions

Wolfgang Denk wd at denx.de
Mon Jul 19 20:43:40 CEST 2004

In message <40FBFF16.50003 at cyclades.com> you wrote:
> (please answer with copy to me, because I am not subscribed to the 
> mailing list)

This is a one-time exception. You ask here, so we reply here.

> (1) - Did anyone use the U-boot with the IBM-440GP? If so, could you 
> give me an idea of the boot time, both with the default configuration 
> and with an optimized configuration?

I did such measurements lately, but on a slower system (405EP at  133
MHz);  in  this application it was critical how long it takes until a
certain Linux device driver  starts  running  to  empty  some  FIFOs.
Without  any modifications to the code the driver started running not
more than 600 milliseconds after Power-on; the  Linux  kernel  starts
loading  about  175  ms after power-on. Approx. 110ms of this time is
spent for the PCI initialization; if you omit this, you can  probably
start the Linux kernel 65 ms after power-on.

> (2) - The binary file (u-boot.bin) generated was too big for me (almost 
> half Mbytes). Could it be smaller, how? Is it already compressed?

The image is mostly empty. The size is determined by the link address
in flash and the faxt that the reset vector is the last word in flash
- there is a huge gap. The actual code is MUCH scmaller:

	Configuring for EBONY board...
	   text    data     bss     dec     hex filename
         163772   24316   23948  212036   33c44 u-boot

As you can see, the real size is 212036 bytes = 207 kB.

> (3) - My board uses the LXT972 as the Ethernet transceiver (PHY). Does 
> the boot loader support it?


> (4) - I will use the Montavista Linux as operating system. Have anyone 
> done that already? How hard is it to integrate the U-boot with it?

Zero effort.

> (5) - Will I have to publish the changes which are specific to my board, 
> if I use the u-boot?

If you distribute the board with your modified U-Boot, yes. U-Boot is
covered by the GPL.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
An age is called Dark not because  the  light  fails  to  shine,  but
because people refuse to see it.           -- James Michener, "Space"

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