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
Implement opcode group 0x0F, 0x01 (SGDT, SIDT, LGDT, LIDT, SMSW and LMSW).
Only INVLPG is not implemented yet.
svn path=/branches/ntvdm/; revision=60824
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
In real mode, the value in the IVT is a far pointer, not an IDT entry.
Fix the case when MemReadCallback is NULL.
svn path=/branches/ntvdm/; revision=60813
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
- The DosErrorLevel is stored as a WORD: its LOWORD is the return code and the HIWORD is the termination code.
- When copying CurrentDirectories[...], be sure that we copy maximum DOS_DIR_LENGTH chars.
- Implement (or stubplement) bunch of INT 21h functions: 0x03, 0x04, 0x05, 0x0C, 0x0D, 0x26, 0x37, 0x47, 0x4D and 0x50. Functions 0x18, 0x1D, 0x1E and 0x20 are NULL functions present in DOS for CP/M compatibility only.
- Fix DOS version querying.
- Use set/getAX() instead of EmulatorSet/GetRegister, and use setCF instead of EmulatorSetFlag.
svn path=/branches/ntvdm/; revision=60790
Improve performance by computing the resolution required by the PIT,
and then using the standard tick count instead of performance counters
when that resolution is low.
svn path=/branches/ntvdm/; revision=60783
- DOS: the DOS file attributes are one byte.
- BIOS: don't use hardcoded values; use the SEG_OFF_TO_PTR macro introduced earlier; use get/setAX instead of EmulatorGet/SetRegister.
svn path=/branches/ntvdm/; revision=60781
