Subject: Re: HEADS UP: New arm32 pmap committed
To: Jason Thorpe <thorpej@wasabisystems.com>
From: John Clark <j1clark@ucsd.edu>
List: port-arm
Date: 07/13/2003 19:51:38
Am Freitag, 04.07.03, um 18:11 Uhr (US/Pacific) schrieb Jason Thorpe:

>
> On Friday, July 4, 2003, at 11:03  AM, Steve Woodford wrote:
>
>> Making use of the first chunk of SDRAM on a RedBoot system will 
>> require
>> some more work, however. Perhaps the easiest way would be to make the
>> kernel self-relocating. Note that there may be issues associated with
>> trashing the RedBoot area of SDRAM, with respect to rebooting, for
>> example.
>>
>> Of course, this would all be moot if RedBoot reserved the top 2MB of 
>> SDRAM
>> instead. ;-)
>
> It's not really RedBoot that's an issue.  Here's what the situation 
> is...
>
> The kernel needs to be loaded "somewhere out of the way" of RedBoot.  
> Fine, we do that.  There is also the "gzboot" loader which may also 
> run, which also needs to be out of the way of the kernel.
>
> To make this easy on myself, I simply used the following rule:
>
> 	1. gzboot loads at RAM+1MB.
>
> 	2. kernel loads at RAM+2MB.
>

I tend to do it the otherway for my linux initrd+kernel. I load the 
package 'anywhere', it then copies itself up to about around Megabyte
16, then 'uncompresses' itself to it's final resting place, or where it 
is expected to be.

This way I can burn a copy into flash, jump to the self-copy entry 
point in flash, copies itself up to standard place, then
further unbundles itself. Also, I can use the same package to load over 
the net via TFTP....