[ECOS] Help with booting Linux off my Redboot prompt

[Krishna Ganugapati]

Albert was correct - thanks Albert!

For the list, here is the deal.

the IXP425   has two UARTs - the first is called the high speed UART and the 
second is called the Console UART

The high speed UART is /dev/ttyS0 and the Console UART is /dev/ttyS1

Hope this helps for future reference

Krishna

----- Original Message ----- 
From: "Krishna Ganugapati" <krishnag@marakicorp.com>
To: "Alfred Wong" <alfred.wong80@gmail.com>
Cc: "Nickolay" <nickolay@protei.ru>; <ecos-discuss@ecos.sourceware.org>
Sent: Tuesday, February 22, 2005 10:26 PM
Subject: Re: [ECOS] Help with booting Linux off my Redboot prompt


> 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
>>> >
>>>
>>> --
>>> Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
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>>>
>>>
>>
>> -- 
>> 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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