[U-Boot] u-boot didn't mount ramdisk ...

[mike xu]

Hi Wolfgang,

Thank you for your quick response.
Actually I need to get one image which composed by the kernel ramdisk
image. I'd like to use the ramdisk as root file system. The combined
imageg is made by `mkimage -T multi...` command...
And I found that the image can not startup successfully (kernel is ok
but cannot mount the rootfs). Then I tried to bootup the kernel and
ramdisk separately as I describe in the previous email.

Do you have any suggestion on how to bootup a multiple type image via u-boot?

Best regards & Thanks again,
Mike

On Wed, Dec 17, 2008 at 11:35 PM, Wolfgang Denk <wd at denx.de> wrote:
> Dear "mike xu",
>
> In message <7103aeea0812170706p3e1fa7cby7093a87d4d01eb6f at mail.gmail.com> you wrote:
>>
>> I am using u-boot 1.2.0 and tried to boot kernel with one ramdisk, but
>> it seems the u-boot doesn't load my ramdisk image at all. Please view
>
> This is correct. U-Boot does not load the RAMdisk image - why  should
> it?  If  the image is stored in NOR flash memory, the kernel can read
> it there as well, so copying it to RAM before starting Linux would be
> just a waste of boot time.
>
> U-Boot just passes tha ramdisk address to the Linux kernel - assuming
> your ports of U-Boot and Linux  for  your  MIPS  board  support  this
> correctly.
>
>> Are there any special requirement of the ramdisk format for u-boot? I
>> used mips mkimage command as below and both of the ramdisk.gz in ext2
>> or cramfs format are all failed.
>> mkimage -O linux -A mips  -T ramdisk -C gzip -n 'Test Ramdisk Image'
>> -d ramdisk.gz uRamdisk
>
> This is OK. Maybe you are using a kernel version that  cannot  use  a
> ramdisk  image  from  flash  (i. e. it finds it only in RAM, like the
> vanilla ARM kernel does, too).
>
> Patche sto fix that (for ARM) have been posted several timers before,
> search the archives if needed.
>
> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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>