Re: Using reblob to load another blob from ram

[Klaus F. <k.f...@fe...>]

Hello,

>Hello.
>
>I'm not sure if i'm wrong here, because this is cvs-commit list and
>not discussion.
>
>I'm writing here becuase the lart ml seems to be broken for at least 3
>weeks. BTW, lart ml archive and anon cvs access to blob cvs is broken,
>too. So no really good starting point for hacking on blob.
>
>OK, back to my main problem. I'm one of the developer behind the
>http://openezx.org/ project. EZX is the name of the Motorola Linux
>smartphone architecture based on pxa27x. On this phones they use blob
>as bootloader. But we like to extend blob to choose the kernel to boot
>and booting kernel from MicroSD/SD card. This would help us a lot in
>kernel and userspace development because we don't need to touch the
>pre-installed system.
>
>In some small talk with Tim Riker on IRC he suggested me to load
>the extended blob into ram and do a reblob. Sounds great, but 
>unfortunately i get it not working.
>
>Some more words about the setup. Motorola had modified blob. After
>some discussion i was able to get the source. You can find it here:
>
>http://www.datenfreihafen.org/~stefan/EZX/a780-blob.tar.bz2
>
>It based on blob-2.0.5-pre2 .
>
>We are able to communicate with the bootloader over usb. Harald Welte
>wrote some kind of bootloader client which is called boot_usb.
>
>http://svn.gnumonks.org/trunk/a780/src/boot_usb/
>
>It loads the code into ram, exactly to KERNEL_RAM_BASE, and afterwards
>JUMP to it. This works fine for selfcompiled kernels. But it does not
>work for the blob binary at the moment.
>
>A compile of the modified blob source give me the the following
>interesting binaries:
>
>blob
>blob-chain
>blob-rest
>blob-rest-elf32
>blob-start
>blob-start-chain
>blob-start-chain-elf32
>blob-start-elf32
>
>I tried all of them load to KERNEL_RAM_BASE and also to BLOB_RAM_BASE
>as defined inside the blob code.
>
>If i load blob or blob-start-elf32 the display goes blank and thats
>it. For blob-start at KERNEL_RAM_BASE it goes blank, too. On all the
>other tests exactly nothing happens.
>
>I just changed the version string displayed to confirm if i see the
>new blob on the screen.
>
>So perhaps anybody here can help me at this point. The most
>interesting questions are the following:
>
>- Is there some good doc about blob? I don't find anything.
>- Which binary i had to use for reblob?
>- Which place i had to load into ram? BLOB_RAM_BASE or
>  
>

BLOB_RAM_BASE : This is the destination address for the first stage of Blob, where the rest of blob is copied from flash to RAM.

>  ?
>  
>

KERNEL_RAM_BASE : This is the destination address, where the second stage of Blob the kernel copies from flash to RAM.



>- Tim Riker mentoined there are flying some SD card patches around.
>  Where can i find it?
>
>  
>
Klaus