Custom ramdisk

Tim Komarov happycorsair at yandex.ru
Tue Apr 1 00:17:29 CEST 2014


Hello, Adam!
Thanks for yor answer.


01.04.2014, 02:03, "Adam Lackorzynski" <adam at os.inf.tu-dresden.de>:
> Hi,
>
> On Mon Mar 31, 2014 at 20:07:34 +0400, Tim Komarov wrote:
>
>>  I use Pandaboard for my practising with Fiasco.OC and L4Linux.
>>
>>  1) I got a problem with booting L4Linux with my own ramdisk. When I use 18 mb ramdisk, I got the following error:
>>
>>  reading image.elf ЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪ
>>
>>  24691072 bytes read ЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪ
>>  ## Starting application at 0x81000000 ...
>>  ...
>>  ,,,[Everything is usual]
>>  ,,,
>>
>>  NET: Registered protocol family 17
>>  List of all partitions:
>>  No filesystem could mount root, tried:  ext3 ext2 ext4 cramfs
>>  Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(1,0)
>>  CPU: 0 PID: 1 Comm: swapper Not tainted 3.13.0-l4 #1
>>  [<0200c624>] (unwind_backtrace+0x0/0xec) from [<020054c0>] (show_stack+0x10/0x14)
>>  [<020054c0>] (show_stack+0x10/0x14) from [<0222e63c>] (panic+0x7c/0x1b8)
>>  [<0222e63c>] (panic+0x7c/0x1b8) from [<022f2c40>] (mount_block_root+0x25c/0x29c)
>>  [<022f2c40>] (mount_block_root+0x25c/0x29c) from [<022f2f44>] (prepare_namespace+0x160/0)
>>  [<022f2f44>] (prepare_namespace+0x160/0x1b4) from [<022f2894>] (kernel_init_freeable+0x1)
>>  [<022f2894>] (kernel_init_freeable+0x174/0x1b8) from [<0222ccf0>] (kernel_init+0x8/0x118)
>>  [<0222ccf0>] (kernel_init+0x8/0x118) from [<020077d4>] (ret_from_fork+0x14/0x20)
>>  [<020077d4>] (ret_from_fork+0x14/0x20) from [<00000000>] (  (null))
>>  panic: going to sleep forever, bye
>>
>>  To make ramdisk I simply create a file, write 18 Mb of zeroes to it
>>  (with dd), create in that file ext2 partition and copy there files
>>  from ramdisk-arm.rd
>>
>>  So, what should I do to get a proper working ramdisk?
>
> Hmm, is the expected ramdisk size big enough? I.e. a ramdisk_size=18500
> on the cmdline could help here. (On the other side the according error
> message is missing, so maybe not.)

Yes, in this case in lua configuration file I put 19000. So, that's not the reason of my problem. Would you be so kind to write an example ( with particular commands ) of making suitable ramdisk for l4linux? May be I am wrong with it... If you did, I would be happy!

>>  2) Even more. If I create 20 mb ramdisk, I got this:
>>
>>  reading image.elf ЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪ
>>
>>  26788224 bytes read ЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪЪ
>>  ## Starting application at 0x00000000 ... Ъ
>>
>>  Than the booting hangs. Why so?
>
> Just guessing, loading the ramdisk has overwritten u-boot? So you could
> try changing the load address in u-boot a bit and see if it changes something?
> bootstrap will start from anywhere, so you can use the same binary.
>
   I'm going to play with it a bit. Thanks for this idea.

And once again thanks for your answer!

> Adam
> --
> Adam                 adam at os.inf.tu-dresden.de
>   Lackorzynski         http://os.inf.tu-dresden.de/~adam/
>
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