[ECOS] Help with booting Linux off my Redboot prompt

[Krishna Ganugapati]

Thanks I'll try this.  A couple of questions

a) How does the kernel know where to find the  rootfs - is it preconfigured 
and if so can someone tell me where that information is located

b) How does the exec know that the kernel is loaded at 0x01600000? 
Internally, I've found that there is a ecos setting that defines where the 
kernel is supposed to be executed from  0x00600000.

I do understand that exec takes in parameters where you can specify the 
physical address of where zImage is loaded and the length of zImage and 
physical address of the initrd, but in the absence of providing these 
parameters how does it work?

c) Can someone provide a tutorial about how redboot "execs" a kernel?

d)   A question for Alfred:   I would think that UART0 is /dev/ttyS1 and 
UART1 is /dev/ttyS0 -  Alfred do you have two UARTs on your board or a 
single UART -  and if so  do you have UART1 or UART0 enabled... I set mine 
to /dev/ttyS0 because I'm using UART0 ...

Thanks!

Krishna
----- Original Message ----- 
From: "Alfred Wong" <alfred.wong80@gmail.com>
To: "Krishna Ganugapati" <krishnag@marakicorp.com>
Cc: "Nickolay" <nickolay@protei.ru>; <ecos-discuss@ecos.sourceware.org>
Sent: Tuesday, February 22, 2005 7:59 PM
Subject: Re: [ECOS] Help with booting Linux off my Redboot prompt


> You could try this :
> exec -c "console=ttyS1,115200 root=/dev/mtdblock4 rw, mem=64M@0x00000000"
>
> works for me on ixp425 based board.
>
> Cheers,
> Alfred
>
>
>
> On Tue, 22 Feb 2005 09:56:06 -0800, Krishna Ganugapati
> <krishnag@marakicorp.com> wrote:
>> Thanks Nickolay
>>
>> I did specify all four parameters to "exec" and while things do not dump
>> core or anything -- it looks like its hanging somewhere in the Linux
>> startup. I understand this may be the wrong place to pose the question, 
>> but
>> has anyone used the BDI2000 to debug a Linux target after it has been
>> invoked from Redboot using exec.
>>
>> The BDI2000 documentation is pretty sparse.
>>
>> I also discovered that the base address for the IXDP425 is 0x00600000 
>> after
>> greping through the sources.
>>
>> My board only has UART 0 and I'm suspecting that it has something to do 
>> with
>> how the Linux console works. I get no output to my console window once I
>> invoke exec...
>>
>> I need to figure out how to debug a Linux target under Redboot using a
>> BDI2000
>>
>> Thanks
>>
>> Krishna
>>
>> ----- Original Message -----
>> From: "Nickolay" <nickolay@protei.ru>
>> To: "Krishna Ganugapati" <krishnag@marakicorp.com>
>> Cc: <ecos-discuss@ecos.sourceware.org>
>> Sent: Tuesday, February 22, 2005 3:18 AM
>> Subject: Re: [ECOS] Help with booting Linux off my Redboot prompt
>>
>> > Krishna Ganugapati wrote:
>> >
>> >> I have successfully built redboot for my IXP425 - can load redboot 
>> >> image
>> >> store it in flash, npe's work fine and I can successfully tftp images
>> >> down to my board from by RedHat9 Linux box.
>> >>
>> >> I've built Linux kernels and a rootfs.
>> >>
>> >> My compressed Linux kernel is zImage
>> >>
>> >> and  my compressed rootfs is rootfs.gz
>> >>
>> >> I execute the following commands at my Redboot console
>> >>
>> >> a) load -r -v -b 0x00800000 rootfs.gz  ; load the rootfs.gz image @
>> >> 0x0800000
>> >>
>> >> b) load -r -v -v 0x01600000 zImage  ;  load the compressed kernel 
>> >> zImage
>> >> @ 0x01600000
>> >>
>> >> c) exec
>> >>
>> >> The resulting output is
>> >> Using base address 0x01600000 and length 0x000b73c0 (which is the 
>> >> correct
>> >> size of the image)
>> >>
>> >> However following that, I get nothing....
>> >>
>> >> Any ideas how I can debug further... or should I be taking this to
>> >> another alias...
>> >>
>> >>
>> >> Thanks!
>> >>
>> >> Krishna
>> >
>> > Try explicitly indicate what you want load from.
>> > exec -b 0x01600000 -l 0 0x01600000
>> >
>> >
>> >
>> > --
>> > Before posting, please read the FAQ: 
>> > http://ecos.sourceware.org/fom/ecos
>> > and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
>> >
>>
>> --
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>>
>>
>
> -- 
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> 


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