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
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
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 the type of a variable.
[NTVDM]
Introduce a BOP handler table for the 256 possible BOP functions and use it.
svn path=/branches/ntvdm/; revision=60818
Revert a previous incorrect fix for the PIT.
Modify the PitDecrementCount function to take a parameter instead
of it being called multiple times (which is slower).
svn path=/branches/ntvdm/; revision=60816
- Introduce a Fast486Initialize which is used to set up the CPU callbacks (and use default ones if some of the given callbacks are NULL), and to reset it the first time. Now Fast486Reset is meant to be used for only resetting the CPU to a safe state.
- Hence we are now sure that State->WhateverCallback is never NULL (and is theoretically valid), so don't do NULL-checks when calling them, but call them directly. The default cases for those checks become the default calls for the default callbacks.
- Remove the now-unneeded EmulatorIdle function.
svn path=/branches/ntvdm/; revision=60814
BOP numbers are 1 byte and map to a function (over 255). But one can pass additional "parameters" to those functions by adding extra bytes, however such functions must advance "by hand" the instruction pointer.
[NTVDM]
- Take into account our previous remark for the BIOS interrupt stubs, and comment them.
- Rework EmulatorBiosOperation (move almost all of its existing code into subfunctions in bop.c) so that one can call many other BOP functions in the future (WIP). The BOP number (still called) EMULATOR_INT_BOP (of value 0xFF) is used for internal 16 --> 32 bit switching for our 32bit bios.
- It appears that the IoRead/WriteCallback and IdleCallback must not be NULL for using fast486. I'm committing a temporary fix that I will definitely fix in a subsequent commit.
svn path=/branches/ntvdm/; revision=60812
