Subject: Maximum bootable kernel size in current ARM linux

From: [email-masked] (Bruce M. Penrod)
Date: Mon, 13 Sep 2010 12:43:59 -0700

Russell King - ARM Linux wrote:
> On Mon, Sep 13, 2010 at 12:40:56AM -0700, Bruce M. Penrod wrote:
>> This seems like a pretty straightforward question, but extensive web  
>> searching hasn't shown a really clear, up-to-date answer.  The most  
>> recent info is circa 2004 and states that 4MB is the largest  
>> uncompressed ARM kernel that may be loaded.  Not being an ARM assembly  
>> guru (head.S baffles me), I'd like to know if that is still true in  
>> 2010, and if it is, why?
> 
> It is no longer true; the only limit now is the size of contiguous RAM
> to fit the kernel image into.
> 

Interesting.  I finally was able to get an uncompressed kernel a little 
below 4MB, and now it boots.  I'm working with 2.6.35rc6 on an OpenRD 
Ultimate (Marvell Kirkwood) with Slackware, doing native compiles.  I'm 
wondering if there could be any problem with U-Boot for larger kernels 
than 4MB, but it doesn't complain and says that it is copying the image. 
  The symptom I had with a much larger kernel (~15MB) is a total hang, 
not even "Uncompressing linux".

I'll add some innocuous stuff back in until I get above 4MB again and 
see if it breaks again.
-- 
Bruce