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Re: redboot memory map.


max wrote:
> 
> > -----Original Message-----
> > From: jlarmour@cambridge.redhat.com
> > [mailto:jlarmour@cambridge.redhat.com]On Behalf Of
> Jonathan Larmour
> > Sent: Tuesday, April 09, 2002 12:06 PM
> > To: Max
> > Cc: ecos
> > Subject: Re: [ECOS] redboot memory map.
> >
> >
> > Max wrote:
> > >
> > > target PC 386.
> > > redboot image: got binary file from redboot site.
> > >
> > > I just notice something from the redboot bootup
> message.
> > > "
> > > RedBoot(tm) bootstrap and debug environment -
> built 05:37:52,
> > Jun  8 2001
> > > Platform: PC (I386)
> > > Copyright (C) 2000, 2001, Red Hat, Inc.
> > > RAM: 0x00000000-0x000a0000, 0x0007c080-0x000a0000
> available
> > > "
> > > Q1: look available RAM range, it can not be right?
> Overlapped.
> > > Where can I find related code?
> > > Besides the Redboot Manual says that Redboot will
> use 2000 ro a0000, and
> > > a000 to
> > > 100000 is reserved for ROM  and BIOS. Tha
> application should be
> > load from
> > > 0x100000 upwards.
> >
> > Yes, we know about this problem. What RedBoot prints
> for the RAM area is
> > misleading. The documentation is correct.
> 
> Any one there familair with this part of code?

Yes. The problem is that RedBoot only has knowledge of the single "RAM"
memory region defined in the platform files, and assumes that dictates the
location and size of all of RAM. Whereas in the PC HAL, there will be two
regions: one from 0x0 to 0xa0000, and then from 0x100000 upwards (assuming
more than 64K is fitted :-)).

The MLT files for the FLOPPY startup type have the RAM region from 0x0 to
0xa0000, and the RAM startup type has the RAM region from 0x100000 upwards.

Jifl
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