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RE: [microblaze-uclinux] Booting uClinux
Hi John,
It is an interesting point - does a bitstream and software download
always produce the same result...? the answer is yes or no, depending on
some key points.
(1) Is the software download deterministic and synchronous to the
processor system ?
(2) Are there any external asynchronous events that can change the flow
of the software?
If the software download is from an external source, for example over a
network, through your PC, through XMD, through System ACE, via morse
code.. it is very unlikely that the download will start on the same
clock cycle for the MicroBlaze system. Why does this matter? It
doesn't - for a working system.
However, on a system that has quirks we can easily see scenarios such as
"it works 4 out of 5 times", or "the results are different each time".
If all processes are synchronous, and there are no external events, the
same behaviour will be seen each time. However, as soon as asynchronous
events kick in, the flow from software to ISR could be different each
time. (I could go into the 'why's ', but for now just be aware that this
can be the case).
Best regards
Kris
--
------------------------------------------------------------------------
----
/ /\/ Kris Chaplin
\ \ Application Engineer - Embedded Processors
/ / Xilinx Europe
\_\/\ +44 (0)870-7356-563
-----Original Message-----
From: owner-microblaze-uclinux@itee.uq.edu.au
[mailto:owner-microblaze-uclinux@itee.uq.edu.au] On Behalf Of John
McGrath
Sent: 07 April 2005 13:06
To: microblaze-uclinux@itee.uq.edu.au
Subject: Re: [microblaze-uclinux] Booting uClinux
Hi,
Weird.
Now, the same bitstream, same image file is hanging at a different point
- the "calibrating delay loop". This is strange!!!! I would imagine a
fresh download of bitstream/image should always yield the same results.
This has me totally puzzled...
Any help would be much apreciated!
Cheers,
John
John McGrath wrote:
> Oh My God!
> Well what would you know? Linux Booted....to a point!
> I got as far as:
>
> --snip---
> Xilinx GPIO registered
> RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize
> MBVanilla flash probe(0xff000000,8388608,4): 800000 at ff000000
> CFI: Found no Flash device at location zero
> Search for id:(00 00) interleave(2) type(2)
> Search for id:(00 00) interleave(2) type(2)
> Search for id:(00 00) interleave(2) type(2)
> Search for id:(00 00) interleave(2) type(1)
> Search for id:(00 00) interleave(2) type(1)
> Search for id:(00 00) interleave(2) type(1)
> Search for id:(00 00) interleave(4) type(2)
> Search for id:(00 00) interleave(4) type(2)
> Search for id:(00 00) interleave(4) type(2)
> Search for id:(00 00) interleave(4) type(1)
> Search for id:(00 00) interleave(4) type(1)
> Search for id:(00 00) interleave(4) type(1)
> JEDEC: Found no Flash device at location zero
> MBVanilla ram probe(0x818c58fc,729088,4): b2000 at 818c58fc
> Creating 1 MTD partitions on "RAM":
> 0x00000000-0x000b2000 : "Romfs"
> VFS: Mounted root (romfs filesystem) readonly.
> Freeing init memory: 32K
>
>
> and thats where it ended. Dont know how "good" this is..but its a
> start....
> Any idea what is wrong? from GDB it seems to be "stuck" in block_dev.c
> which is in a directory called fs. Im guessing this has something to
> do with the ROMFS.
>
> I have 8MB ram, and the .bin file is only about 1.3 megs, but I dont
> beleive I have explicitly told uClinux the memory size (I assume
> uclinux-auto does this?)
>
> Any help would be much appreciated!
>
> Cheers
> John
>
>
> John McGrath wrote:
>
>> Hi All,
>> Well It's come time to boot my system (I've not been able to work on
>> it the the past while)...
>> My board is very basic. 8 LED's, a UART and 8MB RAM. (note, as my
>> chip has few reources, had to reduce the size of the ICACHES/DCACHES
>> - does uclinux-auto pick up on this? Is it possible to run uClinx
>> without these at all, and if so, will uclinux-auto pick up on this,
>> and make the apropriate modifications to the auto-config.in?)
>>
>> The question is, how do I boot it? Is it enough to simply do the
>> following:
>>
>> run XMD
>> > connect mb mdm
>> > force_use_fsl_dow
>> > dow -data image.bin 0x81800000 (note, does the image.elf
>> contain the romfs? when I download it it seems to download a .romfs
>> section, but I remember reading this is not the case..what is the
>> truth?)
>> >con 0x81800000
>>
>> The last step simply jumps to the start of the RAM. Is this the
>> correct way to "boot"?
>> If so, do I have to type anything into the hyperterminal to get the
>> system kicked into gear, or will it just immediatly begin to boot?
>> (I'm not having much luck..so far)
>>
>> Cheers,
>> John
>>
>> ___________________________
>> microblaze-uclinux mailing list
>> microblaze-uclinux@itee.uq.edu.au
>> Project Home Page :
http://www.itee.uq.edu.au/~jwilliams/mblaze-uclinux
>> Mailing List Archive :
>> http://www.itee.uq.edu.au/~listarch/microblaze-uclinux/
>>
>>
>>
>
> ___________________________
> microblaze-uclinux mailing list
> microblaze-uclinux@itee.uq.edu.au
> Project Home Page :
http://www.itee.uq.edu.au/~jwilliams/mblaze-uclinux
> Mailing List Archive :
> http://www.itee.uq.edu.au/~listarch/microblaze-uclinux/
>
>
>
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