- When accessing memory using ESP, make the SS segment default.
- The INT instructions always pushes 16-bit values in real mode, regardless
of the operand/address size attributes.
svn path=/branches/ntvdm/; revision=61000
- Fix the privilege checks.
- Store the CPL in a special field, so that it doesn't get mixed up
with the lowest 2 bits of real mode selectors while switching
into protected mode.
- Reset the exception count after a successful ISR call.
- In Fast486OpcodeGroup0F01, check for prefix overrides after parsing
the Mod-Reg-R/M, which might add a SS: prefix override in some cases.
svn path=/branches/ntvdm/; revision=60995
XADD: Fix the order of operations.
POP <modrm>: The value must be popped from the stack before parsing the
Mod-Reg-R/M, because of the "POP DWORD [ESP]" case.
svn path=/branches/ntvdm/; revision=60984
Fix the Mod-Reg-R/M parser. EBP cannot be used as a SIB byte base,
instead it's used to mark that the base is an immediate operand.
svn path=/branches/ntvdm/; revision=60944
Give the virtual machine 16 MB of memory, for DOS extenders,
protected mode programs, etc...
EMS is still not implemented.
svn path=/branches/ntvdm/; revision=60937
To make debugging easier, put the interrupt handlers at offset 0x1000,
and reserve 16 bytes for each. Also, move the common stub to offset
0x2000. That way the entry point of, for example, INT 0x21 is at
F000:1210.
svn path=/branches/ntvdm/; revision=60933
We don't support in-circuit emulation opcodes such as USERMOV.
The 486 does not have the JMPE or POPCNT instructions.
svn path=/branches/ntvdm/; revision=60932
Modularize linear memory access by adding two new functions:
Fast486ReadLinearMemory and Fast486WriteLinearMemory.
Implement Fast486GetPageTableEntry.
svn path=/branches/ntvdm/; revision=60923
Instead of reassembling each time the very same common stub code for each interrupt, do it once, and then assemble just a little part for each interrupt and jump to the common stub.
Now the 4DOS Ctrl-C exception bug changes, but I have an idea what's happening in there...
svn path=/branches/ntvdm/; revision=60917
- BIOS: Reorganize a bit the header, and close the input thread before closing the input handle (and not after).
- INT32: Fix a comment.
- CMOS: Put CMOS data into a structure called CMOS_MEMORY, introduce READ/WRITE_CMOS_DATA macros for simplifying code. Save CMOS memory into a file (à la Windows' NTVDM), which is loaded at startup.
svn path=/branches/ntvdm/; revision=60913
The number of bit places in a shift operation is ANDed by the width of the type
when it is in a register, so (1 << c), when c is 32, is actually 1, and not 0.
Fix the calculation of MaxValue by using SignFlag | (SignFlag - 1) instead.
svn path=/branches/ntvdm/; revision=60912
Don't enable interrupts unless it's necessary in the interrupt handler.
[FAST486]
When handling interrupt signals, make sure at least one instruction is executed,
to prevent the CPU from being completely blocked by interrupt signals.
svn path=/branches/ntvdm/; revision=60910
