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
Finish my Interruption revamp.
- Move interrupt-related code from bop.c to int32.c
- Introduce InitializeInt32 helper so that one can initialize all the needed 16-bit stubs for the 32-bit interrupts.
- Remove unneeded defines in emulator.h and an exported variable in ntvdm.h.
svn path=/branches/ntvdm/; revision=60908
Start my work on modularizing registration of "32-bit" interrupts, i.e.
interrupts that are implemented in 32-bit mode, but are stubbed with 16-bit
code (so that 16-bit apps can call them).
The 16-bit stub code uses a BOP call to our Control BOP function (BOP 0xFF) which
can handle in theory many sub-functions (as the BOP 0x58 documented here: http://www.ragestorm.net/tutorial?id=27)
specified as an additional BYTE in the call:
0xC4 0xC4 bop_code <optional_bop_subfunction>
Here, for calling 32-bit interrupts we use our BOP 0xFF, subfunction 0xFF.
The final aim would be to generate the 16-bit stub code when one calls the RegisterInt32 helper function
(contrary to what's happening now, that is, the 16-bit stub code is generated for all of the interrupts
at BIOS initialization time, and we use it for BIOS and DOS interrupts).
svn path=/branches/ntvdm/; revision=60907
- Make usage of MAKEWORD;
- Introduce BiosGetCursorPosition and use it in BiosPrintCharacter;
- Use EmulatorWriteMemory instead of VgaWriteMemory somewhere in BiosPrintCharacter;
- Add support for tabs in BiosPrintCharacter (taken from DosBox).
svn path=/branches/ntvdm/; revision=60906
Make the emulator callbacks non-static.
In BiosPrintCallback, use EmulatorWriteMemory instead of VgaWriteMemory, because
VgaWriteMemory does not do any input validation.
Improve EmulatorWriteMemory input validation and bound checking.
svn path=/branches/ntvdm/; revision=60903
The behavior of the I/O port bus depends on the data width. In the case
of 16-bit/32-bit access, two/four adjacent ports will be accessed.
svn path=/branches/ntvdm/; revision=60891
- BIOS: Implement INT 12h (BiosGetMemorySize)
- BOP/DOS: Add some DPRINTs for INT 25h, 2Fh and for unimplemented functions of INT 21h. It's for helping in testing 4DOS.COM
svn path=/branches/ntvdm/; revision=60889
Implement the use of palettes for text mode. Adapted from a patch by Hermes Belusca-Maito.
Reset the palette during every BIOS video mode switch.
svn path=/branches/ntvdm/; revision=60886
- Add a missing "goto Cleanup;"
- Add DPRINT1s at the beginning and the end of ntvdm, so that one can easily localize in debug logs where one started it. Suggested by Vampyre ;)
svn path=/branches/ntvdm/; revision=60860
Implement the CMOS and Real Time Clock (RTC).
Improve the performance of the PIT and RTC (correctly this time).
svn path=/branches/ntvdm/; revision=60854
Fix segment initialization. The cached descriptors must have valid values
during the switch to protected mode.
For some odd reason, GCC makes the FAST486_GDT_ENTRY structure 12 bytes
instead of 8 if there is a bit field with more than 16 bits, so split
the Base field into Base and BaseMid.
Add size checks below important structure declarations.
svn path=/branches/ntvdm/; revision=60825
