Averything that required cpu.h include now has it explicitly and there are a lot of files not dependant by CPU at all which will compile a lot faster now ...
2. Fixed bug
[ 989478 ] I-Cache and undefined Instruktions
The L4 microkernel uses an undefined instruction to
trap for a special requests into the kernel (LOCK NOP).
The handler fixes this up and gives the user a special
code page with syscall stubs. If you're not using the
I-Cache optimization everthing works find on bochs. But
if you enable the I-Cache (--enable-icache), then the
undefined opcode exception is thrown only once for ever
virtual address it occurs. See the demodisk of the
L4KA::pistachio
(http://www.l4ka.org/projects/pistachio/download.php).
In this case the pingpong benchmark of this demo is of
interest. Everything runs fine until the program tries
to spawn a new task for its measurements. This new task
shares the code of the creating program. But the new
task stops executing at the undefined instruction
explained above and no exception is thrown.
memory handling in memory.cc removed)
- CRTC write protection implemented
- 16-bit read access to some VGA registers added
- memory handler code now conciders the status of the A20 line
bochs.h already not include iodev.h which reduces compilation dependences for almost all cpu and fpu files, now cpu files will not be recompiled if iodev includes was changed
- it works only on x86 with gcc2.95+
- uses the GCC function atribute "regparm(n)" to declare that certain
functions use the register calling convention
- performance improvement is about 6%
* 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);
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.
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.
mode uses the notion of the guest-to-host TLB. This has the
benefit of allowing more uniform and streamlined acceleration
code in access.cc which does not have to check if CR0.PG
is set, eliminating a few instructions per guest access.
Shaved just a little off execution time, as expected.
Also, access_linear now breaks accesses which span two pages,
into two calls the the physical memory routines, when paging
is off, just like it always has for paging on. Besides
being more uniform, this allows the physical memory access
routines to known the complete data item is contained
within a single physical page, and stop reapplying the
A20ADDR() macro to pointers as it increments them.
Perhaps things can be optimized a little more now there too...
I renamed the routines to {read,write}PhysicalPage() as
a reminder that these routines now operate on data
solely within one page.
I also added a little code so that the paging module is
notified when the A20 line is tweaked, so it can dump
whatever mappings it wants to.
