xCAT/xNBA
2
0
Fork 0
mirror of https://github.com/xcat2/xNBA.git synced 2024-11-22 01:21:45 +00:00
Code Issues Projects Releases Wiki Activity
xCAT Network Boot Agent
3,221 Commits 4 Branches 0 Tags 13 MiB
C 94.5%
Objective-C 2.1%
Assembly 1.3%
Perl 0.9%
Makefile 0.4%
Other 0.7%
cb43056809
Go to file
Michael Brown cb43056809 [prefix] Use flat real mode instead of real mode 
When returning to real mode, set 4GB segment limits instead of 64kB
limits.  This change improves our chances of successfully returning to
a PMM-capable BIOS aftering entering iPXE during POST; the BIOS will
have set up flat real mode before calling our initialisation point,
and may be disconcerted if we then return in genuine real mode.

This change is unlikely to break anything, since any code that might
potentially access beyond 64kB must use addr32 prefixes to do so; if
this is the case then it is almost certainly code written to expect
flat real mode anyway.

Note that it is not possible to restore the real-mode segment limits
to their original values, since it is not possible to know which
protected-mode segment descriptor was originally used to initialise
the limit portion of the segment register.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2010-04-19 23:43:48 +01:00
contrib [build] Rename gPXE to iPXE 2010-04-19 23:43:39 +01:00
src [prefix] Use flat real mode instead of real mode 2010-04-19 23:43:48 +01:00
COPYING Initial revision 2005-05-17 16:44:57 +00:00
COPYRIGHTS [build] Rename gPXE to iPXE 2010-04-19 23:43:39 +01:00
README [build] Rename gPXE to iPXE 2010-04-19 23:43:39 +01:00

README 

iPXE README File

Quick start guide:

   cd src
   make

For any more detailed instructions, see http://ipxe.org