diff options
author | Michael Brown | 2008-09-24 19:33:31 +0200 |
---|---|---|
committer | Michael Brown | 2008-09-24 19:33:31 +0200 |
commit | 887d77c27ac6ccdb13892ab05e50281e63df6bbf (patch) | |
tree | 195dc9a42cd1e4eee891641b19411877aa5b0c3c /README | |
parent | [settings] Add the uristring setting type (diff) | |
download | ipxe-887d77c27ac6ccdb13892ab05e50281e63df6bbf.tar.gz ipxe-887d77c27ac6ccdb13892ab05e50281e63df6bbf.tar.xz ipxe-887d77c27ac6ccdb13892ab05e50281e63df6bbf.zip |
[pcbios] Inhibit INT 15 memory map hiding on brain-dead BIOSes
Some really moronic BIOSes bring up the PXE stack via the UNDI loader
entry point during POST, and then don't bother to unload it before
overwriting the code and data segments. If this happens, we really
don't want to leave INT 15 hooked, because that will cause any loaded
OS to die horribly as soon as it attempts to fetch the system memory
map.
We use a heuristic to detect whether or not we are being loaded at the
top of free base memory. If we determine that we are being loaded at
some other arbitrary location in base memory, then we assume that it's
not safe to hook INT 15.
Diffstat (limited to 'README')
0 files changed, 0 insertions, 0 deletions