[uClinux-dev] Help with Motorola 68vz328ads eval board

Frank W. Miller fwmiller at cornfed.com
Sun Mar 16 23:16:57 EST 2003


Okie doke, I got kermit and the bbug script and they appear to be 
working.  I tried to download the stock ucdimm image (after converting 
with the Perl script to a b-record file) and no go.  I downloaded the 
init.b and that worked ok.  It appears to just set a bunch of value into 
registers that I'm assuming do some basic configuration of the system 
elements.

>before uploading and running image.bin, check your
>linux-x.x.x/System.map file, all the address there should be existing
>RAM address on your board, if not, then modify the linker script
>(xxx.ld) to locate everything in RAM.
>IMHO, the easiest way is to choose the option to run the kernel from ROM
>and to change the corresponding linker script (rom.ld probably) to map
>everything in RAM (reserve the upper part of RAM like if it were ROM...)
>for example, if you have 8MB SDRAM, set the 2 upper MB as 'rom' in the
>linker script and the first 6MB as 'ram'. recompile everything.
>
>the address to upload would be the beginning of the 'rom' section,
>and the address to start the image would be specified by the symbol
>_start (or _stext maybe) in the System.map file.
>
>  
>
I looked at System.map and it appears that all the text is being placed 
at 0x1000000 which is way beyond the end of physical memory (8 Mbytes).  
I noticed that the image.brec (converted image.bin) is 4066682 bytes.  
I'll need to probably used the upper 4 Mbytes for the kernel on this 
first pass.  I'll work on slimming it down later.  One question is how 
much of the b-record file actually ends up in memory, maybe I'll need 
less.  Anyway, I went to 
linux-2.4.X/arch/m68knommu/platform/68VZ328/ucdimm and found rom.ld.  I 
hope this is the file that you are referring to for my initial 
platform?  So, now to the question.  To do what you suggest, how do I 
change this file?  It looks like this:

MEMORY
    {
    romvec: ORIGIN = 0x10c10000, LENGTH = 0x00000400
    flash: ORIGIN = 0x10c10400, LENGTH = 0x001fec00
    eflash: ORIGIN = 0x10d00000, LENGTH = 0
    ramvec: ORIGIN = 0x00000000, LENGTH = 1024
    ram: ORIGIN = 0x00020000, LENGTH = 0x00800000 - 0x00020000
    eram: ORIGIN = 0x00800000, LENGTH = 0
    }

INCLUDE arch/m68knommu/platform/68VZ328/ucdimm/fixed.ld

Do I shift romvec and ram?

FM


Frank W. Miller
fwmiller at cornfed.com





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