Subject: Re: [U-Boot-Users] booting linux from u-boot - help!
From: "My-Hong Vuong" <[email-masked]>
To: <[email-masked]>
Date: Tue, 17 Dec 2002 14:17:50 +1100

Thanks for the prompt response.

The board I'm working with does not utilise SDRAM, rather SRAM - Samsung
K1S321615M, which does not utilise burst access - our ORx has Burst
Inhibit turned on - it does not support burst accesses.  This shouldn't
pose a problem then, should it?

We have CPU6 turned off as we're using an MPC860T Rev.D.4.  Switching
the Copyback on and off seem to have no effect.

also, for the console, we have it set at SMC1, standard/generic
serial... 

i'm unclear as to what you mean by:
you must have a virtual memory mapping set up once the mmu is turned on
- the head.S file sets one up for the IMMR and the first 8M of RAM until
the kernel takes over.

Do you mean that BRx and ORx need to be set up again? (btw, i'm a newbie
at this stuff)

thanks again, 
My Hong Vuong

<<< Murray Jensen <[email-masked]> 12/17 11:57a >>>
On Tue, 17 Dec 2002 11:23:15 +1100, My-Hong Vuong
<[email-masked]> writes:
>it appears that the system crashes after the "rfi", which
>enables our mmu.

I think this is the first time the cache, and hence burst-mode
transfers,
will be used (u-boot runs with cache disabled). Check that the UPM
programs
for your SDRAM actually work in burst mode.

Otherwise, check the CPU6 and COPYBACK config options - you may need to
run
with either or both of these, depending on the Rev of your CPU.

Finally, are you sure the system is crashing? or maybe you just haven't
set
up your console correctly and therefore see no output?

Hope this helps. Cheers!
        Murray...

PS: be careful writing to things like LEDs during early startup - you
must
have a virtual memory mapping set up once the mmu is turned on - the
head.S
file sets one up for the IMMR and the first 8M of RAM until the kernel
takes
over.
--
Murray Jensen, CSIRO Manufacturing & Infra. Tech.      Phone: +61 3 9662
7763
Locked Bag No. 9, Preston, Vic, 3072, Australia.         Fax: +61 3 9662
7853
Internet: [email-masked]

Hymod project: http://www.msa.cmst.csiro.au/projects/Hymod/

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