[coreboot] Convert Assembly JMP to C

Jordan Crouse jordan.crouse at amd.com
Fri Sep 12 00:21:03 CEST 2008


On 11/09/08 18:05 -0400, Joseph Smith wrote:
> 
> 
> 
> On Thu, 11 Sep 2008 16:03:04 -0600, Jordan Crouse <jordan.crouse at amd.com>
> wrote:
> > On 11/09/08 17:49 -0400, Joseph Smith wrote:
> >>
> >> OK,
> >> My JMP question is about copying a drives mbr to memory 0x7c00 and or
> >> 0x0600 at 512 byte
> >> blocks. Which is doable. I haven't decided wetheir to try Ron's
> > suggestion
> >> and try to execute the mbr (hence the JMP question) OR we could even
> > write
> >> code to translate the mbr and JMP/execute directly to the active
> > bootable
> >> partition OR even better we could write code translate the mbr, goto the
> >> active bootable partition and translate it, and JMP/execute right to the
> >> boot manager, thus bypassing a whole bunch of real mode interrupts. What
> > do
> >> you think?
> > 
> > You won't be successful.  Any executable code in any MBR is going to use
> > real mode software interrupts.  You can't get around that, you shouldn't
> > try.  We have very intellegent payloads that can boot any operating
> system
> > imaginable.  Use that.
> > 
> Ah, Jordan you speak to soon. I have learn a way to setup a simple real
> mode interrupt handler, capable of sending generic/dummy responses back to
> the software....

Well, if you do that well enough to boot an arbitrary bootloader (say,
syslinux), then you have ended up implementing SeaBIOS all over again.  
If you are going to implement real-mode calls, then please, lets consolidate
our energies into a single project.

Jordan

-- 
Jordan Crouse
Systems Software Development Engineer 
Advanced Micro Devices, Inc.





More information about the coreboot mailing list