[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm
From: |
Avi Kivity |
Subject: |
Re: [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm |
Date: |
Tue, 08 Sep 2009 23:00:34 +0300 |
User-agent: |
Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.1) Gecko/20090814 Fedora/3.0-2.6.b3.fc11 Lightning/1.0pre Thunderbird/3.0b3 |
On 09/08/2009 10:46 PM, Anthony Liguori wrote:
Avi Kivity wrote:
The bios exports the "bios drives". You can tell grub to load a
kernel from the first partition of the second disk: (hd1,0) or even
chain-load another boot loaded from another disk.
The whole point of device.map is that grub doesn't intrinsically know
how to map from bios drives to real drives.
device.map is a wonderful thing, but unrelated to the bios exposing
drive 0x81.
In fact, when you chain-load with grub, you often have to "swap"
device mappings which has the effect of hooking int13 and faking the
primary drive for another OS. See
http://www.gnu.org/software/grub/manual/html_node/DOS_002fWindows.html
But grub still has to issue a real int 13 for drive 0x81. If we don't
expose it, it can't. Until a real OS is loaded, the only way to access
a drive is through int 13 and if we don't expose it, it's invisible.
All else aside, from a BIOS perspective, you can usually only boot
from 0x80 and that can be mapped to different drives via BCV.
There things you can do with a drive other than boot it. For example,
access it via int 13.
How will you access D:\ from DOS?
--
Do not meddle in the internals of kernels, for they are subtle and quick to
panic.
- [Qemu-devel] [PATCH 2/2] extboot: qemu code., (continued)
- [Qemu-devel] [PATCH 2/2] extboot: qemu code., Gerd Hoffmann, 2009/09/08
- [Qemu-devel] [PATCH 1/2] extboot: add option rom., Gerd Hoffmann, 2009/09/08
- Re: [Qemu-devel] [PATCH 0/2] port over extboot from kvm, Gerd Hoffmann, 2009/09/08
- [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm, Jan Kiszka, 2009/09/08
- [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm, Gerd Hoffmann, 2009/09/08
- Re: [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm, Anthony Liguori, 2009/09/08
- Re: [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm, Avi Kivity, 2009/09/08
- Re: [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm, Anthony Liguori, 2009/09/08
- Re: [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm, Avi Kivity, 2009/09/08
- Re: [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm, Anthony Liguori, 2009/09/08
- Re: [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm,
Avi Kivity <=
- Re: [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm, Anthony Liguori, 2009/09/08
- Re: [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm, Kevin O'Connor, 2009/09/12
- [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm, Jan Kiszka, 2009/09/08
- [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm, Gerd Hoffmann, 2009/09/08
- [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm, Jan Kiszka, 2009/09/08
- Re: [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm, Anthony Liguori, 2009/09/08
- Re: [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm, Gerd Hoffmann, 2009/09/08
- Re: [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm, Anthony Liguori, 2009/09/08
- Re: [Qemu-devel] Re: [PATCH 0/2] port over extboot from kvm, Kevin O'Connor, 2009/09/12
Re: [Qemu-devel] [PATCH 0/2] port over extboot from kvm, Anthony Liguori, 2009/09/08