[hbelusca] 67601: [NTVDM]: Implement PC reset handling in the BIOS. Used by some apps for switching from protected mode back to real mode the 286 way (see: http://www.rcollins.org/articles/pmbasics...
Author: hbelusca Date: Fri May 8 19:26:46 2015 New Revision: 67601
URL: http://svn.reactos.org/svn/reactos?rev=67601&view=rev Log: [NTVDM]: Implement PC reset handling in the BIOS. Used by some apps for switching from protected mode back to real mode the 286 way (see: http://www.rcollins.org/articles/pmbasics/ for more details).
Modified: trunk/reactos/subsystems/mvdm/ntvdm/bios/bios.h trunk/reactos/subsystems/mvdm/ntvdm/bios/bios32/bios32.c
Modified: trunk/reactos/subsystems/mvdm/ntvdm/bios/bios.h URL: http://svn.reactos.org/svn/reactos/trunk/reactos/subsystems/mvdm/ntvdm/bios/... ============================================================================== --- trunk/reactos/subsystems/mvdm/ntvdm/bios/bios.h [iso-8859-1] (original) +++ trunk/reactos/subsystems/mvdm/ntvdm/bios/bios.h [iso-8859-1] Fri May 8 19:26:46 2015 @@ -74,7 +74,13 @@ WORD CrtBasePort; // 0x63 BYTE CrtModeControl; // 0x65 BYTE CrtColorPaletteMask; // 0x66 - BYTE CassetteData[5]; // 0x67 + + union // 0x67 + { + BYTE CassetteData[5]; // Cassette tape control (unused) + DWORD ResumeEntryPoint; // CS:IP for 286 return from Protected Mode + }; + DWORD TickCounter; // 0x6c BYTE MidnightPassed; // 0x70 BYTE BreakFlag; // 0x71
Modified: trunk/reactos/subsystems/mvdm/ntvdm/bios/bios32/bios32.c URL: http://svn.reactos.org/svn/reactos/trunk/reactos/subsystems/mvdm/ntvdm/bios/... ============================================================================== --- trunk/reactos/subsystems/mvdm/ntvdm/bios/bios32/bios32.c [iso-8859-1] (original) +++ trunk/reactos/subsystems/mvdm/ntvdm/bios/bios32/bios32.c [iso-8859-1] Fri May 8 19:26:46 2015 @@ -31,6 +31,7 @@ #include "hardware/cmos.h" #include "hardware/pic.h" #include "hardware/pit.h" +#include "hardware/ps2.h"
/* PRIVATE VARIABLES **********************************************************/
@@ -131,7 +132,7 @@ static BYTE PostCode[] = { LOBYTE(EMULATOR_BOP), HIBYTE(EMULATOR_BOP), BOP_RESET, // Call BIOS POST - 0xCD, 0x19, // INT 0x19, the bootstrap loader interrupt + 0xCD, BIOS_BOOTSTRAP_LOADER, // INT 0x19 // LOBYTE(EMULATOR_BOP), HIBYTE(EMULATOR_BOP), BOP_UNSIMULATE };
@@ -233,9 +234,9 @@ * Return the (usable) extended memory (after 1 MB) * size in kB from CMOS. */ - IOWriteB(CMOS_ADDRESS_PORT, CMOS_REG_ACTUAL_EXT_MEMORY_LOW); + IOWriteB(CMOS_ADDRESS_PORT, CMOS_REG_ACTUAL_EXT_MEMORY_LOW | CMOS_DISABLE_NMI); Low = IOReadB(CMOS_DATA_PORT); - IOWriteB(CMOS_ADDRESS_PORT, CMOS_REG_ACTUAL_EXT_MEMORY_HIGH); + IOWriteB(CMOS_ADDRESS_PORT, CMOS_REG_ACTUAL_EXT_MEMORY_HIGH | CMOS_DISABLE_NMI); High = IOReadB(CMOS_DATA_PORT); setAX(MAKEWORD(Low, High));
@@ -607,9 +608,9 @@ * Retrieve the conventional memory size * in kB from CMOS, typically 640 kB. */ - IOWriteB(CMOS_ADDRESS_PORT, CMOS_REG_BASE_MEMORY_LOW); + IOWriteB(CMOS_ADDRESS_PORT, CMOS_REG_BASE_MEMORY_LOW | CMOS_DISABLE_NMI); Low = IOReadB(CMOS_DATA_PORT); - IOWriteB(CMOS_ADDRESS_PORT, CMOS_REG_BASE_MEMORY_HIGH); + IOWriteB(CMOS_ADDRESS_PORT, CMOS_REG_BASE_MEMORY_HIGH | CMOS_DISABLE_NMI); High = IOReadB(CMOS_DATA_PORT); Bda->MemorySize = MAKEWORD(Low, High); } @@ -640,6 +641,7 @@ #if 0 BOOLEAN Success; #endif + BYTE ShutdownStatus;
DPRINT("Bios32Post\n");
@@ -654,12 +656,80 @@ setDS(BDA_SEGMENT);
/* + * Perform early CMOS shutdown status checks + */ + + /* Read the CMOS shutdown status byte and reset it */ + IOWriteB(CMOS_ADDRESS_PORT, CMOS_REG_SHUTDOWN_STATUS | CMOS_DISABLE_NMI); + ShutdownStatus = IOReadB(CMOS_DATA_PORT); + IOWriteB(CMOS_ADDRESS_PORT, CMOS_REG_SHUTDOWN_STATUS | CMOS_DISABLE_NMI); + IOWriteB(CMOS_DATA_PORT, 0x00); + + DPRINT1("Bda->SoftReset = 0x%04X ; ShutdownStatus = 0x%02X\n", + Bda->SoftReset, ShutdownStatus); + + switch (ShutdownStatus) + { + /* Shutdown after Memory Tests (unsupported) */ + case 0x01: case 0x02: case 0x03: + /* Shutdown after Protected Mode Tests (unsupported) */ + case 0x06: case 0x07: case 0x08: + /* Shutdown after Block Move Test (unsupported) */ + case 0x09: + { + DisplayMessage(L"Unsupported CMOS Shutdown Status value 0x%02X. The VDM is stopping...", ShutdownStatus); + EmulatorTerminate(); + return; + } + + /* Shutdown to Boot Loader */ + case 0x04: + { + DPRINT1("Fast restart to Bootstrap Loader...\n"); + return; + } + + /* Flush keyboard, issue an EOI... */ + case 0x05: + { + IOReadB(PS2_DATA_PORT); + + /* Send EOI */ + IOWriteB(PIC_SLAVE_CMD , PIC_OCW2_EOI); + IOWriteB(PIC_MASTER_CMD, PIC_OCW2_EOI); + + // Fall back + } + + /* + * ... and far JMP to user-specified location at 0040:0067 + * (Bda->ResumeEntryPoint) with interrupts and NMI disabled. + */ + case 0x0A: + { + DPRINT1("Bda->ResumeEntryPoint = %04X:%04X\n", + HIWORD(Bda->ResumeEntryPoint), + LOWORD(Bda->ResumeEntryPoint)); + + /* Position execution pointers to Bda->ResumeEntryPoint and return */ + setCS(HIWORD(Bda->ResumeEntryPoint)); + setIP(LOWORD(Bda->ResumeEntryPoint)); + return; + } + + /* Soft reset or unexpected shutdown... */ + case 0x00: + /* ... or other possible shutdown codes: just continue the POST */ + default: + break; + } + + /* + * FIXME: UNIMPLEMENTED! * Check the word at 0040h:0072h (Bda->SoftReset) and do one of the * following actions: * - if the word is 0000h, perform a cold reboot (aka. Reset). Everything gets initialized. * - if the word is 1234h, perform a warm reboot (aka. Ctrl-Alt-Del). Some stuff is skipped. - * In case we do a warm reboot, we need to check for the CMOS shutdown flag - * and take a suitable action. */
// FIXME: This is a debug temporary check:
-
hbelusca＠svn.reactos.org