diff options
Diffstat (limited to 'contrib/syslinux/syslinux-4.03/memdisk/dskprobe.c')
| -rw-r--r-- | contrib/syslinux/syslinux-4.03/memdisk/dskprobe.c | 114 |
1 files changed, 0 insertions, 114 deletions
diff --git a/contrib/syslinux/syslinux-4.03/memdisk/dskprobe.c b/contrib/syslinux/syslinux-4.03/memdisk/dskprobe.c deleted file mode 100644 index de858bb..0000000 --- a/contrib/syslinux/syslinux-4.03/memdisk/dskprobe.c +++ /dev/null @@ -1,114 +0,0 @@ -/* ----------------------------------------------------------------------- * - * - * Copyright 2009 Shao Miller - All Rights Reserved - * - * 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, Inc., 53 Temple Place Ste 330, - * Boston MA 02111-1307, USA; either version 2 of the License, or - * (at your option) any later version; incorporated herein by reference. - * - * ----------------------------------------------------------------------- */ - -/* - * dskprobe.c - * - * Routines for probing BIOS disk drives - */ - -/* - * Uncomment for debugging - * - * #define DBG_DSKPROBE 1 - */ - -#include <stdint.h> -#include "memdisk.h" -#include "bda.h" -#include "conio.h" - -/* - * We will probe a BIOS drive numer using INT 13h, AH=probe - * and will pass along that call's success or failure - */ -int probe_int13_ah(uint8_t drive, uint8_t probe) -{ - int err; - com32sys_t regs; - - memset(®s, 0, sizeof regs); - - regs.eax.b[1] = probe; /* AH = probe */ - regs.edx.b[0] = drive; /* DL = drive number to probe */ - intcall(0x13, ®s, ®s); - - err = !(regs.eflags.l & 1); -#ifdef DBG_DSKPROBE - printf("probe_int13_ah(0x%02x, 0x%02x) == %d\n", drive, probe, err); -#endif - return err; -} - -/* - * We will probe the BIOS Data Area and count the drives found there. - * This heuristic then assumes that all drives of 'drive's type are - * found in a contiguous range, and returns 1 if the probed drive - * is less than or equal to the BDA count. - * This particular function's code is derived from code in setup.c by - * H. Peter Anvin. Please respect that file's copyright for this function - */ -int probe_bda_drive(uint8_t drive) -{ - int bios_drives; - int err; - - if (drive & 0x80) { - bios_drives = rdz_8(BIOS_HD_COUNT); /* HDD count */ - } else { - uint8_t equip = rdz_8(BIOS_EQUIP); - if (equip & 1) - bios_drives = (equip >> 6) + 1; /* Floppy count */ - else - bios_drives = 0; - } - err = (drive - (drive & 0x80)) >= bios_drives ? 0 : 1; -#ifdef DBG_DSKPROBE - printf("probe_bda_drive(0x%02x) == %d, count: %d\n", - drive, err, bios_drives); -#endif - return err; -} - -/* - * We will probe a drive with a few different methods, returning - * the count of succesful probes - */ -int probe_drive(uint8_t drive) -{ - int c = 0; - /* Only probe the BDA for floppies */ - if (drive & 0x80) { - c += probe_int13_ah(drive, 0x08); - c += probe_int13_ah(drive, 0x15); - c += probe_int13_ah(drive, 0x41); - } - c += probe_bda_drive(drive); - return c; -} - -/* - * We will probe a contiguous range of BIOS drive, starting with drive - * number 'start'. We probe with a few different methods, and return - * the first drive which doesn't respond to any of the probes. - */ -uint8_t probe_drive_range(uint8_t start) -{ - uint8_t drive = start; - while (probe_drive(drive)) { - drive++; - /* Check for passing the floppy/HDD boundary */ - if ((drive & 0x7F) == 0) - break; - } - return drive; -} |