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| author | Michael Brown | 2011-03-01 17:03:44 +0100 |
|---|---|---|
| committer | Michael Brown | 2011-03-01 17:09:09 +0100 |
| commit | 90563f69be960d3b6fd9021445aa9ecdf6eb5db7 (patch) | |
| tree | cd2e99c81035a24177e23aff6bb5dc5bb819e9e5 /src | |
| parent | [prefix] Add rudimentary debugging messages to libprefix (diff) | |
| download | ipxe-90563f69be960d3b6fd9021445aa9ecdf6eb5db7.tar.gz ipxe-90563f69be960d3b6fd9021445aa9ecdf6eb5db7.tar.xz ipxe-90563f69be960d3b6fd9021445aa9ecdf6eb5db7.zip | |
[prefix] Set the "size" bit in the GDT entry for the flat data segment
The "size" bit (aka the D/B) bit should (as far as I can tell) be
irrelevant for accesses to a non-code, non-stack, expand-upwards
segment. However, VirtualBox fails on some accesses via this segment
if this bit is not set.
This change allows iPXE to boot under VirtualBox without having to
disable VT-x/AMD-V support.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src')
| -rw-r--r-- | src/arch/i386/prefix/libprefix.S | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/arch/i386/prefix/libprefix.S b/src/arch/i386/prefix/libprefix.S index b67798e5d..76f455862 100644 --- a/src/arch/i386/prefix/libprefix.S +++ b/src/arch/i386/prefix/libprefix.S @@ -332,7 +332,7 @@ process_bytes: /* Construct GDT on stack (since .prefix may not be writable) */ .equ PM_DS, 0x18 /* Flat data segment */ - pushl $0x008f9300 + pushl $0x00cf9300 pushl $0x0000ffff .equ PM_SS, 0x10 /* Stack segment based at %ss:0000 */ pushl $0x008f0930 |