Limon & PowerQUICC II, Booting the kernel

Limon & PowerQUICC II, Booting the kernel

[Ruedi.Hofer]

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Hi

Sorry for my 1st mail. The kernel gets loaded into RAM at 0x400000.

Still, when I issue the 'run' command the target crashes.

---------------- Linux Monitor 1.4.2-SBC-8260 ----------------
limon>
limon>
limon> load
BOOTP/TFTP from server 10.1.20.2; our IP address is 10.1.20.1.
Filename '/usr/src/nfs/limonZImage'.
Loading: >.................................................................<
done.
limon>
limon> debug
limon> dw 400000
00400000   6e6a725e  00000000  0007864c  6b657230  njr^.......Lker0
00400010   00078660  48000005  7c6b1b78  7cb92b78  ...`H...|k.x|.+x
00400020   38600040  7c600124  3c800040  60840000  8`.@|`.$<..@`...
00400030   7c6802a6  3863fffc  7c681b78  7c032000  |h..8c..|h.x|. .
00400040   40820028  3c800040  60840000  3ca00040  @..(<..@`...<..@
00400050   60a5b274  38a50003  7ca42850  54a5f0be  `..t8...|.(PT...
00400060   7ca72b78  48000060  7c6802a6  3863fffc  |.+xH..`|h..8c..
00400070   7c681b78  3c800040  60840000  3ca00040  |h.x<..@`...<..@
limon>
limon>
limon> run
... crash


Question:

1. Do I have to strip off the elf header from my kernel file?

2. Does the run command relocate the kernel at addr 0?

3. Some data are transferred from limon to the kernel.
 - Does Limon handle this correctly?
 - Where are these data located?

4. Why does it crash?

I guess that answering 3) should solve the problem.....

Thank you for any help

Ruedi

Re: Limon & PowerQUICC II, Booting the kernel

[Neil Russell]

On Tue, Sep 26, 2000 at 01:49:46PM +0100, Ruedi.Hofer@ascom.ch wrote:
> Question:
>
> 1. Do I have to strip off the elf header from my kernel file?

Yes.  Call me lazy, but I haven't yet written code to handle ELF (but I will).
You need to convert the kernel to a straight binary file with something like:

	objcopy -O binary vmlinux vmlinux.bin

then encode it as you have done with something like:

	mklimon -o vmlinix.limon -k vmlinux.bin

The downloaded kernel can be 4M-1K (0x3ffc00) in size, so I don't bother
with compressing it.

The kernel size limit, load address issues and the lack of handling of ELF
will all go away in the near future (now that I have time to work on limon
again).

> 2. Does the run command relocate the kernel at addr 0?

mklimon allows several images to be combined.  The kernel get moved to 0,
and initrd gets moved to the top of memory.

> 3. Some data are transferred from limon to the kernel.
>  - Does Limon handle this correctly?
>  - Where are these data located?

limon uses an enhanced version of the bootinfo structure (not the same as
bd_info).  It is currently set up at 0x3ffe00 by the run command (this will
change in the next version).

> 4. Why does it crash?

limon doesn't handle ELF (yet).


Neil.

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Re: Limon & PowerQUICC II, Booting the kernel

[Dan Malek]

Neil Russell wrote:

> The downloaded kernel can be 4M-1K (0x3ffc00) in size, so I don't bother
> with compressing it.


Yes, please bother compressing it.  Making zImage is more than just
compressing the file.  The code in arch/ppc/mbxboot will (interactively)
create the command line, properly allocate the initial ram disk, and
most importantly creates the board information structure that is
required
by the kernel.  There is also hardware initialization expected by the
kernel that is often coordinated in the various functions found in
the arch/ppc/mbxboot files.  You can't simply boot vmlinux on an
embedded
system and expect it to work (unless your boot rom is doing exactly
the functions of arch/ppc/mbxboot).

The ELF header of the resulting zImage should be removed by just
using 'dd':
	dd if=zImage bs=64k skip=1 of=zImage.bin

Using objcopy or other generic programs on zImage will likely result
in a mess, because the file isn't really a valid ELF image.

> limon uses an enhanced version of the bootinfo structure (not the same as
> bd_info).

The kernel expects a board info that matches what it was configured to
use.  Every board is different.  You should modify
arch/ppc/mbxboot/misc.c
to know it was called by limon and properly convert or discover
information
necessary for the kernel version of the structure.


	-- Dan

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RE: Limon & PowerQUICC II, Booting the kernel

[ZHANG,HAI-TAO (Non-A-China,ex1)]

Hi,

Try the URL http://www.thinsys.com/limon.html

Haitao Zhang

> -----Original Message-----
> From: Wang Chao Feng [mailto:chfwang@sina.com.cn]
> Sent: Sunday, September 03, 2000 9:39 AM
> To: linuxppc-embedded@lists.linuxppc.org
> Subject: Re: Limon & PowerQUICC II, Booting the kernel
>
>
>
> Hi,
>
> Could somebody tell me where I can download the Linux
> Monitor( Limon )?
>
> thenk you for any help
>
> Wang Chao Feng
>
> 9.28
>
>

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Limon & PowerQUICC II, Booting the kernel

[Ruedi.Hofer]

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Hi

I have Limon up and running. I managed to set up the host in order
to serv the linux kernel.
The kernel I download is the ordinary kernel from Montavista HH1.2.
I prepared the zImage in the following way:
1. I stripped off the elf header. (dd if=zImage of=stripZImage bs=64k skip=1)
2. I run it through mklimon to add the limon specific header.

After I've loaded the kernel I can see the kernel in the RAM from addr 0.

When I issue the 'run' command the target crashes.

---------------- Linux Monitor 1.4.2-SBC-8260 ----------------
limon>
limon>
limon> load
BOOTP/TFTP from server 10.1.20.2; our IP address is 10.1.20.1.
Filename '/usr/src/nfs/limonZImage'.
Loading: >.................................................................<
done.
limon>
limon> debug
limon> dw
00000000   48000005  7c6b1b78  7cb92b78  38600040  H...|k.x|.+x8`.@
00000010   7c600124  3c800040  60840000  7c6802a6  |`.$<..@`...|h..
00000020   3863fffc  7c681b78  7c032000  40820028  8c..|h.x|. .@..(
00000030   3c800040  60840000  3ca00040  60a5b274  <..@`...<..@`..t
00000040   38a50003  7ca42850  54a5f0be  7ca72b78  8...|.(PT...|.+x
limon>
limon>
limon> run
... crash


Question:

1. Is my kernel image munging correct?

2. Is the start address 0 correct?

3. Some data are transferred from limon to the kernel.
 - Does Limon handle this correctly?
 - Where are these data located?


Thank you for any help

Ruedi

Re: Limon & PowerQUICC II, Booting the kernel

[Wang Chao Feng]

Hi,

Could somebody tell me where I can download the Linux Monitor( Limon )?

thenk you for any help

Wang Chao Feng

9.28

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Re: Limon & PowerQUICC II, Booting the kernel

[Dan Malek]

Ruedi.Hofer@ascom.ch wrote:

> After I've loaded the kernel I can see the kernel in the RAM from addr 0.

I don't know what limon does, but zImage doesn't load at address 0......

> limon> debug
> limon> dw
> 00000000   48000005  7c6b1b78  7cb92b78  38600040  H...|k.x|.+x8`.@
> 00000010   7c600124  3c800040  60840000  7c6802a6  |`.$<..@`...|h..
> 00000020   3863fffc  7c681b78  7c032000  40820028  8c..|h.x|. .@..(
> 00000030   3c800040  60840000  3ca00040  60a5b274  <..@`...<..@`..t
> 00000040   38a50003  7ca42850  54a5f0be  7ca72b78  8...|.(PT...|.+x

If this is really address zero, these instructions are left over
from the last kernel boot.

> 2. Is the start address 0 correct?

No.

> 3. Some data are transferred from limon to the kernel.
>  - Does Limon handle this correctly?
>  - Where are these data located?

I don't know.  On the PQ-II (8260), the zImage should be loaded at or
above 0x900000, then jump to that address.  The code will relocate,
uncompress and start the kernel.


	-- Dan

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