Re: [ECOS] Redboot customization for DOCMP?

[Iztok Zupet <iz at elsis dot si>]

On Wed, 2004-02-25 at 04:28, Deya wrote:
> Hi,
>       My embedded device is based on Intel's xscale
> PXA255 processor(ARM compatible). I want to have my
> firmware, linux OS and filesystem in diskonchip
> millennium plus.

>       I planeed as follows. Write a IPL code to bring
> the SPL(Redboot) into SDRAM and give it control.
> Redboot shall brng the OS into SDRAm and give it
> control.

My patch brings only the RedBoot into RAM and starts it. It gets started
by BIOS as all so called bios extensions, and installs the appropriate
int 19 handler.
On int 19 it copies RedBoot from Doc to RAM and starts it.


>       Seeing the patch i stood that it is for x86
> systems, with int 19h handler we can load the SPL...
>       I dont know how to do with arm? Does redboot
> knows how to bring the OS from diskonchip millennium
> plus into sdram or should I provide support for it?
> Can u correct me if I have a wrong idea somewhare and
> make me proceed in the right direction?

Since I doubt that the DoC on Your target platform is bootable, i
suggest:

Put RedBoot into some kind of normal bootable flash. Since RedBoot
supports normal flash, You can also put Linux image inthere (By means of
RedBoot itself) and leave the DoC to be used by Linux MTD driver as the
filesystem.

If You wanted RedBoot to manage the DiskOnChip, You would have to port
the entire NFTL support from Linux (which is fully GPL-ed) to RedBoot
itself. I've solved that problem by linking the original Msys linux
driver object for x86 with RedBoot (You are free to use the Msys flobj.o
anywhere as long it is used on original DoC HW), BUT on x86.

Iztok

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