diff options
Diffstat (limited to 'src/VBox/Devices/PC/BIOS/floppyt.c')
| -rw-r--r-- | src/VBox/Devices/PC/BIOS/floppyt.c | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/src/VBox/Devices/PC/BIOS/floppyt.c b/src/VBox/Devices/PC/BIOS/floppyt.c new file mode 100644 index 00000000..114a0300 --- /dev/null +++ b/src/VBox/Devices/PC/BIOS/floppyt.c @@ -0,0 +1,114 @@ +/* $Id: floppyt.c $ */ +/** @file + * Floppy drive tables. + */ + +/* + * Copyright (C) 2011-2023 Oracle and/or its affiliates. + * + * This file is part of VirtualBox base platform packages, as + * available from https://www.virtualbox.org. + * + * 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, in version 3 of the + * License. + * + * 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, see <https://www.gnu.org/licenses>. + * + * SPDX-License-Identifier: GPL-3.0-only + */ + +#include <stdint.h> +#include <string.h> +#include "biosint.h" +#include "inlines.h" + +/** + * Extended DPT (Disk Parameter Table) structure. + */ +typedef struct +{ + uint8_t spec1; /* First SPECIFY byte. */ + uint8_t spec2; /* Second SPECIFY byte. */ + uint8_t mot_wait; /* Motor wait time after operation. */ + uint8_t ss_code; /* Sector size code. */ + uint8_t eot; /* End of Track (ID of last sector). */ + uint8_t gap; /* Gap length. */ + uint8_t dtl; /* Data length. */ + uint8_t fmt_gap; /* Gap length for format. */ + uint8_t fmt_fill; /* Format fill byte. */ + uint8_t hd_settle; /* Head settle time (msec). */ + uint8_t mot_start; /* Motor start time (1/8 sec units). */ + uint8_t max_trk; /* Maximum track number. */ + uint8_t rate; /* Data transfer rate code. */ +} dpt_ext; + +ct_assert(sizeof(dpt_ext) == 13); + +/* Motor spin-up wait time in BIOS ticks (~2 seconds). */ +#define MOTOR_WAIT 0x25 + +/* Data rates as stored in the DPT */ +#define RATE_250K 0x80 +#define RATE_300K 0x40 +#define RATE_500K 0x00 +#define RATE_1M 0xC0 + +/* In the 13-entry DPT, 7 entries are constant. Use a macro to set those. */ +#define MAKE_DPT_ENTRY(sp1, eot, gap, fgp, mxt, dtr) \ + { sp1, 2, MOTOR_WAIT, 2, eot, gap, 0xFF, fgp, 0xF6, 15, 8, mxt, dtr } + +dpt_ext fd_parm[] = { + MAKE_DPT_ENTRY(0xDF, 9, 0x2A, 0x50, 39, RATE_250K), /* 360K disk/360K drive */ + MAKE_DPT_ENTRY(0xDF, 9, 0x2A, 0x50, 39, RATE_300K), /* 360K disk/1.2M drive */ + MAKE_DPT_ENTRY(0xDF, 15, 0x1B, 0x54, 79, RATE_500K), /* 1.2M disk */ + MAKE_DPT_ENTRY(0xDF, 9, 0x2A, 0x50, 79, RATE_250K), /* 720K disk */ + MAKE_DPT_ENTRY(0xAF, 18, 0x1B, 0x6C, 79, RATE_500K), /* 1.44M disk */ + MAKE_DPT_ENTRY(0xAF, 36, 0x1B, 0x54, 79, RATE_1M), /* 2.88M disk */ + MAKE_DPT_ENTRY(0xAF, 255, 0x1B, 0x54, 255, RATE_500K) /* Fake mega-disk */ +}; + +typedef struct { + uint8_t type; /* Drive type. */ + uint8_t dpt_entry; /* Index of entry in fd_parm. */ +} fd_map_entry; + +/* Drive types as stored in the CMOS. Must match DevPCBios! */ +#define FDRV_360K 1 +#define FDRV_1_2M 2 +#define FDRV_720K 3 +#define FDRV_1_44M 4 +#define FDRV_2_88M 5 +#define FDRV_15M 14 +#define FDRV_63M 15 + +/* A table mapping (CMOS) drive types to DPT entries. */ +fd_map_entry fd_map[] = { + { FDRV_360K, 0 }, + { FDRV_1_2M, 2 }, + { FDRV_720K, 3 }, + { FDRV_1_44M, 4 }, + { FDRV_2_88M, 5 }, + { FDRV_15M, 6 }, + { FDRV_63M, 6 } +}; + +/* Find a DPT corresponding to the given drive type. */ +dpt_ext *get_floppy_dpt(uint8_t drv_typ) +{ + int i; + + for (i = 0; i < sizeof(fd_map) / sizeof(fd_map[0]); ++i) + if (fd_map[i].type == drv_typ) + return &fd_parm[fd_map[i].dpt_entry]; + + /* As a fallback, return the 1.44M DPT. */ + return &fd_parm[5]; +} |