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Index: seabios/optionrom/extboot.S
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===================================================================
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--- /dev/null 1970-01-01 00:00:00.000000000 +0000
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+++ seabios/optionrom/extboot.S 2011-11-24 10:30:35.984542155 -0800
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+ * Extended Boot Option ROM
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+ * This program is free software; you can redistribute it and/or modify
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+ * it under the terms of the GNU General Public License as published by
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+ * the Free Software Foundation; either version 2 of the License, or
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+ * (at your option) any later version.
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+ * This program is distributed in the hope that it will be useful,
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+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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+ * GNU General Public License for more details.
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+ * You should have received a copy of the GNU General Public License
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+ * along with this program; if not, write to the Free Software
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+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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+ * Copyright IBM Corporation, 2007
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+ * Authors: Anthony Liguori <aliguori@us.ibm.com>
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+#define OLD_INT19 (0x80 * 4) /* re-use INT 0x80 BASIC vector */
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+#define OLD_INT13 (0x81 * 4) /* re-use INT 0x81 BASIC vector */
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+ .byte (_end - _start) / 512
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+ /* setup ds so we can access the IVT */
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+ /* there is one more bootable HD */
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+ /* save old int 19 */
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+ mov %eax, (OLD_INT19)
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+ /* install out int 19 handler */
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+ movw $int19_handler, (0x19*4)
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+ push %eax /* reserve space for lret */
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+ /* setup ds to access IVT */
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+ /* save old int 13 to int 2c */
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+ mov %eax, (OLD_INT13)
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+ /* install our int 13 handler */
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+ movw $int13_handler, (0x13*4)
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+ /* restore previous int $0x19 handler */
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+ mov (OLD_INT19),%eax
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+ /* write old handler as return address onto stack */
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+#define FLAGS_CF 0x01
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+/* The two macro below clear/set the carry flag to indicate the status
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+ * of the interrupt execution. It is not enough to issue a clc/stc instruction,
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+ * since the value of the flags register will be overwritten by whatever is
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+ * in the stack frame
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+ /* 8 = 2 (bp, just pushed) + 2 (ip) + 3 (real mode interrupt frame) */
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+ and $(~FLAGS_CF), 8(%bp)
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+ /* 8 = 2 (bp, just pushed) + 2 (ip) + 3 (real mode interrupt frame) */
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+ or $(FLAGS_CF), 8(%bp)
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+/* we clobber %bx */
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+ mov %sp, %bp /* remember the current stack position */
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+/* we clobber %bp */
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+.macro allocbpa size
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+ mov %sp, %bp /* remember the current stack position */
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+.macro callout value
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+ mov %ax, 0(%bx) /* ax */
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+ mov 0(%bp), %ax /* bx */
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+ mov %cx, 4(%bx) /* cx */
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+ mov %dx, 6(%bx) /* dx */
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+ mov %si, 8(%bx) /* si */
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+ mov %ds, 10(%bx) /* ds */
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+ mov %es, 12(%bx) /* ds */
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+ movw \value, 14(%bx) /* value */
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+add32: /* lo, hi, lo, hi */
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+ movw 4(%bp), %cx /* hi */
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+ movw 6(%bp), %dx /* lo */
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+mul32: /* lo, hi, lo, hi */
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+ /* 10(%bp), 8(%bp), 6(%bp), 4(%bp) */
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+ /* for (i = 0; i < 16;) */
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+/* this really should be a function, not a macro but i'm lazy */
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+.macro read_write_disk_sectors cmd
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+ /* save nb_sectors */
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+ movw $0, 0(%bx) /* read c,h,s */
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+ mov 6(%bx), %ax /* total_sectors */
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+ mov 2(%bp), %si /* *= heads */
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+ add 4(%bp), %ax /* += sectors - 1 */
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+ push 4(%bx) /* total_heads */
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+ push 6(%bx) /* total_sectors */
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+ push 0(%bp) /* cylinders */
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+ movw \cmd, 0(%bx) /* read */
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+ movw 6(%bp), %ax /* nb_sectors */
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+ movw %es, 4(%bx) /* segment */
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+ movw 8(%bp), %ax /* offset */
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+ movw %dx, 8(%bx) /* sector */
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+ read_write_disk_sectors $0x01
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+ read_write_disk_sectors $0x02
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+read_disk_drive_parameters:
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+ /* allocate memory for packet, pointer gets returned in bx */
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+ /* issue command */
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+ movw $0, 0(%bx) /* cmd = 0, read c,h,s */
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+ /* normalize sector value */
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+ /* normalize cylinders */
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+ /* normalize heads */
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+ /* do this last since it's the most sensitive */
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+alternate_disk_reset:
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+read_disk_drive_size:
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+ movw $0, 0(%bx) /* cmd = 0, read c,h,s */
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+ /* cylinders - 1 to cx:dx */
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+check_if_extensions_present:
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+.macro extended_read_write_sectors cmd
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+ movw \cmd, 0(%bp) /* read */
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+ movw 2(%si), %ax /* nb_sectors */
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+ movw 4(%si), %ax /* offset */
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+ movw 6(%si), %ax /* segment */
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+ movw 8(%si), %ax /* block */
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+extended_read_sectors:
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+ extended_read_write_sectors $0x01
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+extended_write_sectors:
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+ extended_read_write_sectors $0x02
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+get_extended_drive_parameters:
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+ movw $0, 0(%bp) /* read c,h,s */
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+ /* set flags to 2 */
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+ /* set total number of sectors */
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+ /* number of bytes per sector */
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+terminate_disk_emulation:
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+ /* write old handler as return address onto stack */
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+ mov (OLD_INT13), %eax
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+ call read_disk_sectors
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+ call read_disk_drive_parameters
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+ call read_disk_drive_size
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+ call check_if_extensions_present
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+ call extended_read_sectors
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+ call get_extended_drive_parameters
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+ call terminate_disk_emulation
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+ call alternate_disk_reset
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+ call write_disk_sectors
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+ call extended_write_sectors
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+ int $0x18 /* boot failed */
added
removed
debian/patches/01_optionrom_extboot.patch
