From memory the limit is around 3M

-----Message d'origine-----
De : Lewis Donzis [mailto:community-noreply@qnx.com] 
Envoyé : 23 juillet 2010 14:21
À : ostech-core_os
Objet : maximum boot image size

We're trying to build a rather large boot image on an x86 platform and running into some problems.  The reason the image
 is so large is because its purpose is to format and initialize an entire target system, so it contains a rather large .
tgz file that will be un-tar'ed onto the target.

However, some of the executables don't run properly, for example, tar exits with "Memory fault".  Reducing the size of 
the image file allows tar to run correctly.

I noticed in the mkifs documentation, under the image= attribute, there is the following description:

-----
,maxsize
    A comma followed by a number represents the maximum allowed size of the image. If the output image becomes larger 
than this value, an error is reported. The default is no limit. The maximum image size depends on your configuration; 
for example, it may be limited on an x86 system with a BIOS. 
-----

I tried to see what the limit might be on an x86 system with a BIOS and have not been able to find it anywhere.

So my question is: what are the maximum size limits for a boot image on an x86 system with a BIOS?

Given that, we can decide whether we can fit what we need in the image, or go another route.

Thanks,
lew



_______________________________________________

OSTech
http://community.qnx.com/sf/go/post60470

The following may help...

FAE:HowTo-Create QNX-bootable IFS Greater than 3M-64K
From Sales

By default, the IDE will create an IFS file with maximum size of 3M less 64K. This value comes from the default "RAM 
Address" subtracted from the default "Image Address".... 0x400000 - 0x110000

The "RAM Address" cannot be changed from 0x110000 - if you want to use the standard disk loaders. However, the "Image 
Address" can be moved upward - the disk loaders will adjust to "Image Address" found in the startup header!

So, changing the "Image Address" allows you to 'make room' for any size IFS file. For example, changing "Image Address" 
from "Default" to "0x800000" will change the largest IFS size to 7M less 64K... 0x800000 - 0x110000.

Of course you do not want to reserve more space than you need since the reserved RAM may be unavailable to the kernel...
?