/* * Copyright (C) 2012 Michael Brown . * * 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. */ /** * @file * * INT 13 emulation * */ #include #include #include "ntloader.h" #include "int13.h" #include "vdisk.h" #if defined(__i386__) || defined(__x86_64__) /** Emulated drive number */ static int vdisk_drive; /** * Initialise emulation * * @ret drive Emulated drive number */ int initialise_int13 (void) { /* Determine drive number */ vdisk_drive = (0x80 | INT13_DRIVE_COUNT++); DBG ("Emulating drive %#02x\n", vdisk_drive); return vdisk_drive; } /** * INT 13, 08 - Get drive parameters * * @ret ch Low bits of maximum cylinder number * @ret cl (bits 7:6) High bits of maximum cylinder number * @ret cl (bits 5:0) Maximum sector number * @ret dh Maximum head number * @ret dl Number of drives * @ret ah Status code */ static void int13_get_parameters (struct bootapp_callback_params *params) { unsigned int max_cylinder = (VDISK_CYLINDERS - 1); unsigned int max_head = (VDISK_HEADS - 1); unsigned int max_sector = (VDISK_SECTORS_PER_TRACK - 0 /* sic */); unsigned int num_drives; unsigned int min_num_drives; /* Calculate number of drives to report */ num_drives = INT13_DRIVE_COUNT; min_num_drives = ((vdisk_drive & 0x7f) + 1); if (num_drives < min_num_drives) num_drives = min_num_drives; /* Fill in drive parameters */ params->ch = (max_cylinder & 0xff); params->cl = (((max_cylinder >> 8) << 6) | max_sector); params->dh = max_head; params->dl = num_drives; DBG2 ("Get parameters: C/H/S = %d/%d/%d, drives = %d\n", (max_cylinder + 1), (max_head + 1), max_sector, num_drives); /* Success */ params->ah = 0; } /** * INT 13, 15 - Get disk type * * @ret cx:dx Sector count * @ret ah Type code */ static void int13_get_disk_type (struct bootapp_callback_params *params) { uint32_t sector_count = VDISK_COUNT; uint8_t drive_type = INT13_DISK_TYPE_HDD; /* Fill in disk type */ params->cx = (sector_count >> 16); params->dx = (sector_count & 0xffff); params->ah = drive_type; DBG2 ("Get disk type: sectors = %#08x, type = %d\n", sector_count, drive_type); } /** * INT 13, 41 - Extensions installation check * * @v bx 0x55aa * @ret bx 0xaa55 * @ret cx Extensions API support bitmap * @ret ah API version */ static void int13_extension_check (struct bootapp_callback_params *params) { /* Fill in extension information */ params->bx = 0xaa55; params->cx = INT13_EXTENSION_LINEAR; params->ah = INT13_EXTENSION_VER_1_X; DBG2 ("Extensions installation check\n"); } /** * INT 13, 48 - Get extended parameters * * @v ds:si Drive parameter table * @ret ah Status code */ static void int13_get_extended_parameters (struct bootapp_callback_params *params) { struct int13_disk_parameters *disk_params; /* Fill in extended parameters */ disk_params = REAL_PTR (params->ds, params->si); memset (disk_params, 0, sizeof (*disk_params)); disk_params->bufsize = sizeof (*disk_params); disk_params->flags = INT13_FL_DMA_TRANSPARENT; disk_params->cylinders = VDISK_CYLINDERS; disk_params->heads = VDISK_HEADS; disk_params->sectors_per_track = VDISK_SECTORS_PER_TRACK; disk_params->sectors = VDISK_COUNT; disk_params->sector_size = VDISK_SECTOR_SIZE; DBG2 ("Get extended parameters: C/H/S = %d/%d/%d, sectors = %#llx " "(%d bytes)\n", disk_params->cylinders, disk_params->heads, disk_params->sectors_per_track, disk_params->sectors, disk_params->sector_size); /* Success */ params->ah = 0; } /** * INT 13, 42 - Extended read * * @v ds:si Disk address packet * @ret ah Status code */ static void int13_extended_read (struct bootapp_callback_params *params) { struct int13_disk_address *disk_address; void *data; /* Read from emulated disk */ disk_address = REAL_PTR (params->ds, params->si); data = REAL_PTR (disk_address->buffer.segment, disk_address->buffer.offset); vdisk_read (disk_address->lba, disk_address->count, data); /* Success */ params->ah = 0; } /** * Emulate INT 13 drive * * @v params Parameters */ void emulate_int13 (struct bootapp_callback_params *params) { int command = params->ah; int drive = params->dl; int min_num_drives; unsigned long eflags; if (drive == vdisk_drive) { /* Emulated drive - handle internally */ /* Populate eflags with a sensible starting value */ __asm__ ("pushf\n\t" "pop %0\n\t" : "=r" (eflags)); params->eflags = (eflags & ~CF); /* Handle command */ switch (command) { case INT13_GET_PARAMETERS: int13_get_parameters (params); break; case INT13_GET_DISK_TYPE: int13_get_disk_type (params); break; case INT13_EXTENSION_CHECK: int13_extension_check (params); break; case INT13_GET_EXTENDED_PARAMETERS: int13_get_extended_parameters (params); break; case INT13_EXTENDED_READ: int13_extended_read (params); break; default: DBG ("Unrecognised INT 13,%02x\n", command); params->eflags |= CF; break; } } else { /* Pass through command to underlying INT 13 */ call_interrupt (params); /* Modify drive count, if applicable */ if (command == INT13_GET_PARAMETERS) { min_num_drives = ((vdisk_drive & 0x7f) + 1); if (params->dl < min_num_drives) params->dl = min_num_drives; } } } #endif /* defined(__i386__) || defined(__x86_64__) */