According to the Intel manuals:
The LOCK prefix can be prepended only to the following instructions
and only to those forms of the instructions where the destination
operand is a memory operand: ADD, ADC, AND, BTC, BTR, BTS, CMPXCHG,
CMPXCH8B, DEC, INC, NEG, NOT, OR, SBB, SUB, XOR, XADD, and XCHG. If
the LOCK prefix is used with one of these instructions and the source
operand is a memory operand, an undefined opcode exception (#UD) will
be generated. An undefined opcode exception will also be generated if
the LOCK prefix is used with any instruction not in the above list.
Checking of the LOCK prefix done in fetchDecode state and not overloads
Bochs's execution.
* renamed CPU_ID to BX_CPU_ID.
with this new name there is no possibility for name contentions and BX_CPU_ID
definition could be moved out to NEED_CPU_REG_SHORTCUTS block
* returned back `unsigned BX_CPU::which_cpu(void)` function
* added BX_CPU_ID parameter for
BX_INSTR_PHY_READ(a20addr, len);
BX_INSTR_PHY_WRITE(a20addr, len);
now it will be
BX_INSTR_PHY_READ(cpu_id, a20addr, len);
BX_INSTR_PHY_WRITE(cpu_id, a20addr, len);
sash to run.
1) fixed fetchdecode64.cc to fix the operand size at 64 bits in long mode for moves
to/from CRx
2) minor patches to sse2.cc to fix unimplemented and 64 bit variants of sse2
instructions.
Because source files were added/removed it would require an update
of the windows and macos project files, so I want to wait until after 2.0.
M Makefile.in 1.51 back to 1.50
M cpu.h 1.121 back to 1.120
M fetchdecode.cc 1.37 back to 1.36
M fetchdecode64.cc 1.33 back to 1.32
M sse.cc 1.17 back to 1.16
A sse2.cc 1.27 back to 1.26 (added back)
R sse_move.cc removed
R sse_pfp.cc removed
- to bring these changes back again, all we have to do is
"cvs update -j tmp-before1 -j tmp-after1"
sse.cc -> general SSE stuff and SSE integer (MMX extensions)
sse_move.cc -> memory transfer and shuffle opcodes
sse_pfp.cc -> packed floating point operations
For a whole lot of configure options, I put #if...#endif around code that
is specific to the option, even in files which are normally only compiled
when the option is on. This allows me to create a MS Visual C++ 6.0
workspace that supports many of these options. The workspace will basically
compile every file all the time, but the code for disabled options will
be commented out by the #if...#endif.
This may one day lead to simplification of the Makefiles and configure
scripts, but for the moment I'm leaving Makefiles and configure scripts
alone.
Affected options:
BX_SUPPORT_APIC (cpu/apic.cc)
BX_SUPPORT_X86_64 (cpu/*64.cc)
BX_DEBUGGER (debug/*)
BX_DISASM (disasm/*)
BX_WITH_nameofgui (gui/*)
BX_SUPPORT_CDROM (iodev/cdrom.cc)
BX_NE2K_SUPPORT (iodev/eth*.cc, iodev/ne2k.cc)
BX_SUPPORT_APIC (iodev/ioapic.cc)
BX_IODEBUG_SUPPORT (iodev/iodebug.cc)
BX_PCI_SUPPORT (iodev/pci*.cc)
BX_SUPPORT_SB16 (iodev/sb*.cc)
Modified Files:
cpu/apic.cc cpu/arith64.cc cpu/ctrl_xfer64.cc
cpu/data_xfer64.cc cpu/fetchdecode64.cc cpu/logical64.cc
cpu/mult64.cc cpu/resolve64.cc cpu/shift64.cc cpu/stack64.cc
debug/Makefile.in debug/crc.cc debug/dbg_main.cc debug/lexer.l
debug/linux.cc debug/parser.c debug/parser.y
disasm/dis_decode.cc disasm/dis_groups.cc gui/amigaos.cc
gui/beos.cc gui/carbon.cc gui/macintosh.cc gui/rfb.cc
gui/sdl.cc gui/term.cc gui/win32.cc gui/wx.cc gui/wxdialog.cc
gui/wxmain.cc gui/x.cc iodev/cdrom.cc iodev/eth.cc
iodev/eth_arpback.cc iodev/eth_fbsd.cc iodev/eth_linux.cc
iodev/eth_null.cc iodev/eth_packetmaker.cc iodev/eth_tap.cc
iodev/eth_tuntap.cc iodev/eth_win32.cc iodev/ioapic.cc
iodev/iodebug.cc iodev/ne2k.cc iodev/pci.cc iodev/pci2isa.cc
iodev/sb16.cc iodev/soundlnx.cc iodev/soundwin.cc
This is an interim update to allow others to test.
We have userland code running!!! (up to a point)
Able to start executing "sash" as /sbin/init in userland from linux 64 bit
kernel until it crashes trying to access a null pointer. No kernel panics
though, just a segfault loop.
These seem to be working better, are a more simple design,
easier to understand, and AFAIK don't have race conditions
in them like the old ones do.
Re-coded the apic timer, to return cycle accurate values
which vary with each iteration of a read from a guest OS.
The previous implementation had very poor resolution. It
also didn't check the mask bit to see if an apic timer
interrupt should occur on countdown to 0. The apic timer
now calls its own bochs timer, rather than tag on the
one in iodev/devices.cc.
I needed to use one new function which is an inline in
pc_sytem.h. That would have to be added to the old pc_system.h if
we have to back-out to it.
Linux/x86-64 now boots until it hits two undefined opcodes:
FXRSTOR (0f ae). This restores FPU, MMX, XMM and MXCSR registers
from a 512-byte region of memory. We don't implement this yet.
MOVNTDQ (66 0f e7). This is a move involving an XMM register.
The 0x66 prefix is used so it's a double quadword, rather than
MOVNTQ (0f e7) which operates on a single quadword.
The Linux kernel panic is on the MOVNTQD opcodes. Perhaps that's
because that opcode is used in exception handling of the 1st?
Looks like we need to implement some new instructions.
Some things changed in the ctrl_xfer*.cc, fetchdecode*.cc,
and cpu.cc since the original patches, so I did some patch
integration by hand. Check the placement of the
macros BX_INSTR_FETCH_DECODE_COMPLETED() and BX_INSTR_OPCODE()
in cpu.cc to make sure I go them right. Also, I changed the
parameters to BX_INSTR_OPCODE() to update them to the new code.
I put some comments before each of these to help determine if
the placement is right.
These macros are only compiled in if you are gathering instrumentation
data from bochs, so they shouldn't effect others.
Created 64-bit versions of some branch instructions and
changed fetchdecode64.cc to use them instead. This keeps the
#ifdef pollution down for 32-bit code and made fixing them
easier. They needed to clear the upper bits of RIP for
16-bit operand sizes. They also should not have had a protection
limit check in them, especially since that field is still
32-bit in cpu.h, so there's no way to set nominal 64-bit values.
The 32-bit versions were also not honoring the upper 32-bits
of RIP.
LOOPNE64_Jb
LOOPE64_Jb
LOOP64_Jb
JCXZ64_Jb
Changed all occurances of JCC_Jw/JCC_Jd in fetchdecode64.cc to
use JCC_Jq, which was coded already. Both JMP_Jq and JCC_Jq are
now fixed w.r.t. 16-bit opsizes and upper RIP bit clearing.
fetching 64-bit address opcode info, which was incorrect.
Fixed. Got rid of BxImmediate_Oq. fetchdecode64.cc now
uses BxImmediateO, like the fetch routine does. Addresses which
are embedded in the opcode, have a size which depends on
the current addressing size. For long-mode, this is
either 64 (default) or 32 (AddrSize over-ride). BxImmediate_O
now conditionally fetches based on AddrSize.
64-bit bug#2: In JMP_Jq(), when the current operand size is
16-bits, the upper dword of RIP was not being cleared. The
semantics with this case are weird - one would think the
top 48 bits would be cleared, but apparently only the top
32 bits are. Anyways, I fixed this.
Replaced some of the messy immediate fetching (byte-by-byte) in
fetchdecode64.cc with ReadHost{Q,D}WordFromLittleEndian() calls
for cleanliness. Should do this for all the cases, plus
the 32-bit stuff.
Since the SYSCALL replaces the LOADALL instruction, it is incompatible with
earlier CPU types.
At moment, the SYSCALL is only enabled by x86-64 emulation, but the code
can be incorporated in IA32 only emulations.
Instructions added:
0F 05 SYSCALL (replaces LOADALL)
0F 07 SYSRET (new)
TODO: restructure #if ... so that it can be used by non x86-64 emulations.
of (1 & (val32>>N)), and added a getB_?F() accessor for special
cases which need a strict binary value (exactly 0 or 1). Most
code only needed a value for logical comparison. I modified the
special cases which do need a binary number for shifting and
comparison between flags, to use the special getB_?F() accessor.
Cleaned up memory.cc functions a little, now that all accesses
are within a single page.
Fixed a (not very likely encountered) bug in fetchdecode.cc (and
fetchdecode64.cc) where a 2-byte opcode starting with a prefix
starts at the last offset on a page. There were no checks
on the segment overrides for a boundary condition. I added them.
The eflags enhancements added just a tiny bit of performance.
also extended by the REX.B field on Hammer) is passed to instructions.
I rearranged the bxInstruction_c to free up a field to be used
to pass this info when mod-rm bytes are not used. This got rid
of the ugly ((i->b1 & 7) + i->rex_b) code.
Probably shaved just a very little run time off Hammer emulation,
and even less on x86-32. The resultant is a little cleaner anyways.
in cpu.cc out of the main loop, and into the asynchronous
events handling. I went through all the code paths, and
there doesn't seem to be any reason for that code to be
in the hot loop.
Added another accessor for getting instruction data, called
modC0(). A lot of instructions test whether the mod field
of mod-nnn-rm is 0xc0 or not, ie., it's a register operation
and not memory. So I flag this in fetchdecode{,64}.cc.
This added on the order of 1% performance improvement for
a Win95 boot.
Macroized a few leftover calls to Write_RMV_virtual_xyz()
that didn't get modified in the x86-64 merge. Really, they
just call the real function for now, but I want to have them
available to do direct writes with the guest2host TLB pointers.
but if you hand edit cpu/cpu.h, and change BxICacheEntries,
you can try different sizes. I'll make this more flexible
with configure. For now, use "--enable-icache" with no parameters.
- Modified fetchdecode.cc/fetchdecode64.cc just enough so that
instructions which encode a direct address now use a memory
resolution function which just sticks the immediate address
into rm_addr. With cached instructions we need this.
to bitfields. bxInstruction_c is now 24 bytes, including 4 for
the memory addr resolution function pointer, and 4 for the
execution function pointer (16 + 4 + 4).
Coded more accessors, to abstract access from most code.
with accessors. Had to touch a number of files to update the
access using the new accessors.
Moved rm_addr to the CPU structure, to slim down bxInstruction_c
and to prevent future instruction caching from getting sprayed
with writes to individual rm_addr fields. There only needs to
be one. Though need to deal with instructions which have
static non-modrm addresses, but which are using rm_addr since
that will change.
bxInstruction_c is down to about 40 bytes now. Trying to
get down to 24 bytes.
use accessors. This lets me work on compressing the
size of fetch-decode structure (now called bxInstruction_c).
I've reduced it down to about 76 bytes. We should be able
to do much better soon. I needed the abstraction of the
accessors, so I have a lot of freedom to re-arrange things
without making massive future changes.
Lost a few percent of performance in these mods, but my
main focus was to get the abstraction.
no longer used. Also rearranged that struct a little
to be more compressed. Over time, I'm going to reduce
it further, for use with future accelerations.
