(Sorry for double posting)
I repost this patch because I havn't got any replies from maintainers
since I posted the initial patch back in March.
Some instructions are not emulated correctly by x86emu when they
are prefixed by the 0x66 opcode.
I've identified problems in the emulation of these intructions: ret,
enter, leave, iret and some forms of call.
Most of the time, the problem is that these instructions should push or
pop 32-bit values to/from the stack, instead of 16bit, when they are
prefixed by the 0x66 special opcode.
The SeaBIOS project aims to produce a complete legacy BIOS
implementation as well as a VGA option ROM, entirely written in C and
using the GCC compiler.
In 16bit code produced by the GCC compiler, the 0x66 prefix is used
almost everywhere. This patch is necessary to allow the SeaBIOS VGA
option ROM to function with Xorg when using the vesa driver.
SeaBIOS currently use postprocessing on the ROM assembly output to
replace the affected instruction with alternative unaffected instructions.
This is obviously not very elegant, and this fix in x86emu would be
more appropriate.
v2: - Decrement BP instead of EBP in accordance with the Intel Manual
- Assign EIP instead of IP when poping the return address from the
stack in 32-bit operand size mode in ret_far_IMM, ret_far, and iret
- When poping EFLAGS from the stack in iret in 32-bit operand size
mode, apply some mask to preserve Read-only flags.
v3: - Rebase
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Julian Pidancet <julian.pidancet@gmail.com>
This gets the easy warnings, mostly constant string problems.
Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
This is strictly the application of the script 'x-indent-all.sh'
from util/modular. Compared to the patch that Daniel posted in
January, I've added a few indent flags:
-bap
-psl
-T PrivatePtr
-T pmWait
-T _XFUNCPROTOBEGIN
-T _XFUNCPROTOEND
-T _X_EXPORT
The typedefs were needed to make the output of sdksyms.sh match the
previous output, otherwise, the code is formatted badly enough that
sdksyms.sh generates incorrect output.
The generated code was compared with the previous version and found to
be essentially identical -- "assert" line numbers and BUILD_TIME were
the only differences found.
The comparison was done with this script:
dir1=$1
dir2=$2
for dir in $dir1 $dir2; do
(cd $dir && find . -name '*.o' | while read file; do
dir=`dirname $file`
base=`basename $file .o`
dump=$dir/$base.dump
objdump -d $file > $dump
done)
done
find $dir1 -name '*.dump' | while read dump; do
otherdump=`echo $dump | sed "s;$dir1;$dir2;"`
diff -u $dump $otherdump
done
Signed-off-by: Keith Packard <keithp@keithp.com>
Acked-by: Daniel Stone <daniel@fooishbar.org>
Acked-by: Alan Coopersmith <alan.coopersmith@oracle.com>
cc2c73ddcb4370a7c3ad439cda4da825156c26c9's three-cent titanium tax
doesn't go too far enough. Fix the rest of the call and jmp
instructions to handle the data prefix correctly.
Reference: Intel 64 and IA-32 Architectures Software Developer's Manual
Volume 2A: Instruction Set Reference, A-M
http://www.intel.com/Assets/PDF/manual/253666.pdf
Reviewed-by: Julien Cristau <jcristau@debian.org>
Signed-off-by: Adam Jackson <ajax@redhat.com>
Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=24348
Before (data flag ignored -> broken):
66 DATA:
e944f1 JMP 1ff6
After (fixed):
66 DATA:
e944f1ffff JMP 00001ff8
This subtle difference in the length of decoded instruction meant
that the VBE call jumped to the routine setting AX=0x14F (VBE Failed)
instead of the routine that set AX=0x4F (VBE success).
The ability to run the same code in vm86 significantly aided the
debugging of this issue. Those X.org developers who would like to drop
vm86 better take special care towards _all_ vesa bugs, as those will
expose further issues.
Patch applies easily to even xserver 1.4.2.
Signed-off-by: Luc Verhaegen <libv@skynet.be>
Tested-by: Luc Verhaegen <libv@skynet.be>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
