bios.c File Reference

#include "ntvdm.h"
#include <debug.h>
#include "emulator.h"
#include "int32.h"
#include "../dem.h"
#include "dos.h"
#include "dosfiles.h"
#include "handle.h"
#include "memory.h"
#include "bios/bios.h"

Include dependency graph for bios.c:

Go to the source code of this file.

Macros
#define	NDEBUG
#define	FreeEnvironmentStrings   FreeEnvironmentStringsA

Functions
VOID	DosEchoCharacter (CHAR Character)
CHAR	DosReadCharacter (WORD FileHandle, BOOLEAN Echo)
BOOLEAN	DosCheckInput (VOID)
VOID	DosPrintCharacter (WORD FileHandle, CHAR Character)
BOOLEAN	DosBuildSysEnvBlock (VOID)
BOOLEAN	DosBIOSInitialize (VOID)

Variables
PBIOS_DATA	BiosData

Macro Definition Documentation

FreeEnvironmentStrings

#define FreeEnvironmentStrings   FreeEnvironmentStringsA

Definition at line 35 of file bios.c.

NDEBUG

#define NDEBUG

Definition at line 13 of file bios.c.

Function Documentation

DosBIOSInitialize()

BOOLEAN DosBIOSInitialize

(

VOID

)

setBP(0x091E); // DOS base stack pointer relic value

Definition at line 221 of file bios.c.

{
    FILE *Stream;
    WCHAR Buffer[256];
 
    /* Set the data segment */
    setDS(BIOS_DATA_SEGMENT);
 
    /* Initialize the global DOS BIOS data area */
    BiosData = (PBIOS_DATA)SEG_OFF_TO_PTR(BIOS_DATA_SEGMENT, 0x0000);
 
    /* Initialize the DOS BIOS stack */
    // FIXME: Add a block of fixed size for the stack in BIOS/DOS_DATA instead!
    setSS(0x0F00);
    setSP(0x0FF0);
 
    /*
     * Initialize the INT 13h (BIOS Disk Services) handler chain support.
     *
     * The INT 13h handler chain is some functionality that allows DOS
     * to insert disk filter drivers in between the (hooked) INT 13h handler
     * and its original handler.
     * Typically, those are:
     * - filter for detecting disk changes (for floppy disks),
     * - filter for tracking formatting calls and correcting DMA boundary errors,
     * - a possible filter to work around a bug in a particular version of PC-AT's
     *   IBM's ROM BIOS (on systems with model byte FCh and BIOS date "01/10/84" only)
     * (see http://www.ctyme.com/intr/rb-4453.htm for more details).
     *
     * This functionality is known to be used by some legitimate programs,
     * by Windows 3.x, as well as some illegitimate ones (aka. virii).
     *
     * See extra information about this support in dos.h
     */
    // FIXME: Should be done by the DOS BIOS
    BiosData->RomBiosInt13 = ((PULONG)BaseAddress)[0x13];
    BiosData->PrevInt13    = BiosData->RomBiosInt13;
//  RegisterDosInt32(0x13, DosInt13h); // Unused at the moment!
 
    //
    // HERE: Do all hardware initialization needed for DOS
    //
 
    /*
     * SysInit part...
     */
 
    /* Initialize the DOS kernel (DosInit) */
    if (!DosKRNLInitialize())
    {
        BiosDisplayMessage("Failed to load the DOS kernel! Exiting...\n");
        return FALSE;
    }
 
    /* DOS kernel loading succeeded, we can finish the initialization */
 
    /* Build the system master (pre-) environment block (inherited by the shell) */
    if (!DosBuildSysEnvBlock())
    {
        DosDisplayMessage("An error occurred when setting up the system environment block.\n");
    }
 
    /* TODO: Read CONFIG.NT/SYS */
    Stream = _wfopen(DOS_CONFIG_PATH, L"r");
    if (Stream != NULL)
    {
        while (fgetws(Buffer, ARRAYSIZE(Buffer), Stream))
        {
            // TODO: Parse the line
        }
        fclose(Stream);
    }
 
    return TRUE;
}

Referenced by DosStart().

DosBuildSysEnvBlock()

BOOLEAN DosBuildSysEnvBlock

(

VOID

)

Definition at line 165 of file bios.c.

{
    LPSTR SourcePtr, Environment;
    LPSTR DestPtr = (LPSTR)SEG_OFF_TO_PTR(SYSTEM_ENV_BLOCK, 0);
 
    /*
     * Get the environment strings
     *
     * NOTE: On non-STANDALONE builds, this corresponds to the VDM environment
     * as created by BaseVDM for NTVDM. On STANDALONE builds this is the Win32
     * environment. In this last case we need to convert it to a proper VDM env.
     */
    SourcePtr = Environment = GetEnvironmentStrings();
    if (Environment == NULL) return FALSE;
 
    /* Fill the DOS system environment block */
    while (*SourcePtr)
    {
        /*
         * - Ignore environment strings starting with a '=',
         *   they describe current directories.
         * - Ignore also the WINDIR environment variable since
         *   DOS apps should ignore that we started from ReactOS.
         * - Upper-case the environment names, not their values.
         */
        if (*SourcePtr != '=' && _strnicmp(SourcePtr, "WINDIR", 6) != 0)
        {
            PCHAR Delim = NULL;
 
            /* Copy the environment string */
            strcpy(DestPtr, SourcePtr);
 
            /* Upper-case the environment name */
            Delim = strchr(DestPtr, '='); // Find the '=' delimiter
            if (Delim) *Delim = '\0';     // Temporarily replace it by NULL
            _strupr(DestPtr);             // Upper-case
            if (Delim) *Delim = '=';      // Restore the delimiter
 
            DestPtr += strlen(SourcePtr);
 
            /* NULL-terminate the environment string */
            *(DestPtr++) = '\0';
        }
 
        /* Move to the next string */
        SourcePtr += strlen(SourcePtr) + 1;
    }
    /* NULL-terminate the environment block */
    *DestPtr = '\0';
 
    /* Free the memory allocated for environment strings */
    FreeEnvironmentStrings(Environment);
 
    return TRUE;
}

Referenced by DosBIOSInitialize().

DosCheckInput()

BOOLEAN DosCheckInput

(

VOID

)

Definition at line 120 of file bios.c.

{
    PDOS_FILE_DESCRIPTOR Descriptor = DosGetHandleFileDescriptor(DOS_INPUT_HANDLE);
 
    if (Descriptor == NULL)
    {
        /* Invalid handle */
        Sda->LastErrorCode = ERROR_INVALID_HANDLE; // ERROR_FILE_NOT_FOUND
        return FALSE;
    }
 
    if (Descriptor->DeviceInfo & FILE_INFO_DEVICE)
    {
        WORD Result;
        PDOS_DEVICE_NODE Node = DosGetDriverNode(Descriptor->DevicePointer);
 
        if (!Node->InputStatusRoutine) return FALSE;
 
        Result = Node->InputStatusRoutine(Node);
        return !(Result & DOS_DEVSTAT_BUSY);
    }
    else
    {
        DWORD FileSizeHigh;
        DWORD FileSize = GetFileSize(Descriptor->Win32Handle, &FileSizeHigh);
        LONG LocationHigh = 0;
        DWORD Location = SetFilePointer(Descriptor->Win32Handle, 0, &LocationHigh, FILE_CURRENT);
 
        return ((Location != FileSize) || (LocationHigh != FileSizeHigh));
    }
}

Referenced by DosInt21h().

DosEchoCharacter()

VOID DosEchoCharacter

(

CHAR

Character

)

Definition at line 48 of file bios.c.

{
    switch (Character)
    {
        case '\0':
        {
            /* Nothing */
            break;
        }
 
        case '\b':
        {
            /* Erase the character */
            DosPrintCharacter(DOS_OUTPUT_HANDLE, '\b');
            DosPrintCharacter(DOS_OUTPUT_HANDLE, ' ');
            DosPrintCharacter(DOS_OUTPUT_HANDLE, '\b');
            break;
        }
 
        default:
        {
            /*
             * Check if this is a special character
             * NOTE: \r and \n are handled by the underlying driver!
             */
            if (Character < 0x20 && Character != '\r' && Character != '\n')
            {
                DosPrintCharacter(DOS_OUTPUT_HANDLE, '^');
                Character += 'A' - 1;
            }
 
            /* Echo the character */
            DosPrintCharacter(DOS_OUTPUT_HANDLE, Character);
        }
    }
}

Referenced by DosReadCharacter(), DosReadFile(), and DosReadLineBuffered().

DosPrintCharacter()

VOID DosPrintCharacter	(	WORD	FileHandle,
		CHAR	Character
	)

Definition at line 152 of file bios.c.

{
    WORD BytesWritten;
 
    Sda->ByteBuffer = Character;
 
    /* Use the file writing function */
    DosWriteFile(FileHandle,
                 MAKELONG(DOS_DATA_OFFSET(Sda.ByteBuffer), DOS_DATA_SEGMENT),
                 1,
                 &BytesWritten);
}

Referenced by DosCharPrint(), DosControlBreak(), DosEchoCharacter(), and DosInt21h().

DosReadCharacter()

CHAR DosReadCharacter	(	WORD	FileHandle,
		BOOLEAN	Echo
	)

Definition at line 85 of file bios.c.

{
    WORD BytesRead;
    PDOS_FILE_DESCRIPTOR Descriptor = NULL;
    WORD OldDeviceInfo;
 
    /* Find the standard input descriptor and switch it to binary mode */
    Descriptor = DosGetHandleFileDescriptor(FileHandle);
    if (Descriptor)
    {
        OldDeviceInfo = Descriptor->DeviceInfo;
        Descriptor->DeviceInfo |= FILE_INFO_BINARY;
    }
 
    Sda->ByteBuffer = '\0';
    DPRINT("DosReadCharacter\n");
 
    /* Use the file reading function */
    DosReadFile(FileHandle,
                MAKELONG(DOS_DATA_OFFSET(Sda.ByteBuffer), DOS_DATA_SEGMENT),
                1,
                &BytesRead);
 
    /* Check if we should echo and the file is actually the CON device */
    if (Echo && Descriptor && Descriptor->DeviceInfo & FILE_INFO_DEVICE)
    {
        /* Echo the character */
        DosEchoCharacter(Sda->ByteBuffer);
    }
 
    /* Restore the old mode and return the character */
    if (Descriptor) Descriptor->DeviceInfo = OldDeviceInfo;
    return Sda->ByteBuffer;
}

Referenced by DosInt21h().

Variable Documentation

BiosData

PBIOS_DATA BiosData

Definition at line 42 of file bios.c.

Referenced by DosBIOSInitialize(), DosInt2Fh(), PciScanBus(), and PPBridge_SaveCurrentSettings().