Re: clean patch for i386-qemu port (Re: [PATCH] i386-qemu port)

[Robert Millan]

On Tue, Jun 23, 2009 at 01:38:50PM +0200, Robert Millan wrote:
> > If I use all modules, the image is too big:
> > grub-mkimage: error: Core image is too big (0xa8200 > 0xa0000)
> 
> Strange, with all modules I get 0x88200.  Anyway, GRUB_MEMORY_MACHINE_UPPER
> can be increased up to GRUB_BOOT_MACHINE_LINK_ADDR, this was just copied
> from the coreboot port.
> 
> With GRUB_BOOT_MACHINE_LINK_ADDR (0xffe00) you should be able to fit all
> of GRUB in.
> 
> Increasing it further would involve either compression or breaking the
> 0x100000 barrier (imposed by the Linux loader).  I think compression for
> qemu is just silly, but fixing the Linux loader is not trivial (Vladimir's
> memory management proposal could help on this).

Actually, you can't step after 0xa0000 because there are I/O maps there
(there's 0xb8000 and I think other VGA stuff).

I think I'll just change the link address to 0x100000.  Then our limit is
almost 2 GiB, which gives plenty of room for a big memdisk in case user
wants that.

As for the Linux loader, I'll have to disable it on this port untill it
doesn't require that we reserve a hardcoded address for it.

-- 
Robert Millan

  The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
  how) you may access your data; but nobody's threatening your freedom: we
  still allow you to remove your data and not access it at all."