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/*
* VBSF - VirtualBox shared folders for DOS, resident interface
* Copyright (C) 2022 Javier S. Pedro
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#ifndef SFTSR_H
#define SFTSR_H
#include <stdbool.h>
#include <stdint.h>
#include "vbox.h"
#include "int21dos.h"
/** Trace all int2F calls into dlog */
#define TRACE_CALLS 0
#define LASTDRIVE 'Z'
#define NUM_DRIVES ((LASTDRIVE - 'A') + 1)
/** Maximum number of open files and open directories (being enumerated). */
#define NUM_FILES 60
/** Parameters used for returning disk geometry.
* For compatibility, better if sector_per_cluster * bytes_per_sector <= 32K. */
#define SECTORS_PER_CLUSTER 8
#define BYTES_PER_SECTOR 4096
#define BYTES_PER_CLUSTER (SECTORS_PER_CLUSTER * BYTES_PER_SECTOR)
/** Size of the VBox buffer. The maximum message length that may be sent.
* Enough to fit an HGCM connect call, which is actually larger than most other calls we use ( <= 7 args ). */
#define VBOX_BUFFER_SIZE (200)
#define INVALID_OPENFILE (-1)
typedef struct {
uint32_t root;
uint64_t handle;
} OPENFILE;
// TODO: Technically we could reduce the size of the above struct to save a bit of mem
// In the current implementation the max handle virtualbox can give is < 4K,
// but we still waste a full uint64_t to store a value that is always < 4K.
// Similarly, at most 64 roots are supported, but we waste a uint32_t.
typedef struct {
// TSR installation data
/** Previous int2f ISR, storing it for uninstall. */
void (__interrupt __far *prev_int2f_handler)();
/** Stored pointer for the DOS SDA. */
DOSSDA __far *dossda;
// TSR configuration
/** Offset (in seconds/2) of the current timezone.
* As per tradition, a negative offset means east of GMT; while positive means west. */
int32_t tz_offset;
/** NLS support tables. */
uint8_t __far *file_upper_case;
FCHAR __far *file_char;
/** Codepage to unicode lookup table. */
uint16_t unicode_table[128];
// Current status
/** Array of all possible DOS drives. */
struct {
/** VirtualBox "root" for this drive, or NIL if unmounted. */
uint32_t root;
} drives[NUM_DRIVES];
/** All currently open files. */
OPENFILE files[NUM_FILES];
// VirtualBox communication
struct vboxcomm vb;
char vbbuf[VBOX_BUFFER_SIZE];
uint32_t hgcm_client_id;
} TSRDATA;
typedef TSRDATA * PTSRDATA;
typedef TSRDATA __far * LPTSRDATA;
extern void __declspec(naked) __far int2f_isr(void);
extern LPTSRDATA __far get_tsr_data(bool installed);
/** This symbol is always at the end of the TSR segment */
extern int resident_end;
/** This is not just data, but the entire segment. */
static inline unsigned get_resident_size(void)
{
return FP_OFF(&resident_end);
}
#endif // SFTSR_H
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