| /* |
| * Copyright (C) 2009 Juergen Beisert, Pengutronix |
| * |
| * Mostly stolen from the GRUB2 project |
| * Copyright (C) 1999,2000,2001,2002,2003,2004,2005,2006,2007,2008 Free Software Foundation, Inc. |
| * |
| * 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., 59 Temple Place, Suite 330, Boston, |
| * MA 02111-1307 USA |
| * |
| */ |
| |
| /** |
| * @file |
| * @brief Do BIOS calls to load or save data from disks |
| * |
| * @note These functions are running in flat and real mode. Due to some |
| * other restrictions these routines must running from an address |
| * space below 0x10000 |
| */ |
| |
| #ifndef DOXYGEN_SHOULD_SKIP_THIS |
| /* |
| * int bios_disk_rw_int13_extensions (int ah, int drive, void *dap) |
| * |
| * Call IBM/MS INT13 Extensions (int 13 %ah=AH) for DRIVE. DAP |
| * is passed for disk address packet. If an error occurs, return |
| * non-zero, otherwise zero. |
| */ |
| .section .boot.text.bios_disk_rw_int13_extensions, "ax" |
| .code32 |
| .globl bios_disk_rw_int13_extensions |
| .type bios_disk_rw_int13_extensions, @function |
| |
| .extern prot_to_real |
| .extern real_to_prot |
| |
| bios_disk_rw_int13_extensions: |
| pushl %ebp |
| pushl %esi |
| |
| /* compute the address of disk_address_packet */ |
| movw %cx, %si |
| xorw %cx, %cx |
| shrl $4, %ecx /* save the segment to cx */ |
| |
| movb %al, %dh |
| call prot_to_real /* enter real mode right now */ |
| |
| .code16 |
| movb %dh, %ah |
| movw %cx, %ds |
| int $0x13 /* do the operation */ |
| movb %ah, %dl /* save return value */ |
| /* back to protected mode */ |
| DATA32 call real_to_prot |
| |
| .code32 |
| movb %dl, %al /* return value in %eax */ |
| |
| popl %esi |
| popl %ebp |
| |
| ret |
| |
| #endif |
