1 /* -----------------------------------------------------------------------
2 *
3 * Copyright 1999-2008 H. Peter Anvin - All Rights Reserved
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
8 * Boston MA 02110-1301, USA; either version 2 of the License, or
9 * (at your option) any later version; incorporated herein by reference.
10 *
11 * -----------------------------------------------------------------------
12 */
13 #include <sys/cpu.h>
14 #include <sys/io.h>
15 #include <string.h>
16 #include <core.h>
17 #include <fs.h>
18 #include <bios.h>
19 #include <syslinux/video.h>
20
21 /*
22 * localboot.c
23 *
24 * Boot from a local disk, or invoke INT 18h.
25 */
26
27 #define LOCALBOOT_MSG "Booting from local disk..."
28
29 #define retry_count 16
30
31 extern void local_boot16(void);
32
33 /*
34 * Boot a specified local disk. AX specifies the BIOS disk number; or
35 * -1 in case we should execute INT 18h ("next device.")
36 */
local_boot(int16_t ax)37 __export void local_boot(int16_t ax)
38 {
39 com32sys_t ireg, oreg;
40 int i;
41
42 memset(&ireg, 0, sizeof(ireg));
43 syslinux_force_text_mode();
44
45 writestr(LOCALBOOT_MSG);
46 crlf();
47 cleanup_hardware();
48
49 if (ax == -1) {
50 /* Hope this does the right thing */
51 __intcall(0x18, &zero_regs, NULL);
52
53 /* If we returned, oh boy... */
54 kaboom();
55 }
56
57 /*
58 * Load boot sector from the specified BIOS device and jump to
59 * it.
60 */
61 memset(&ireg, 0, sizeof ireg);
62 ireg.edx.b[0] = ax & 0xff;
63 ireg.eax.w[0] = 0; /* Reset drive */
64 __intcall(0x13, &ireg, NULL);
65
66 memset(&ireg, 0, sizeof(ireg));
67 ireg.eax.w[0] = 0x0201; /* Read one sector */
68 ireg.ecx.w[0] = 0x0001; /* C/H/S = 0/0/1 (first sector) */
69 ireg.ebx.w[0] = OFFS(trackbuf);
70 ireg.es = SEG(trackbuf);
71
72 for (i = 0; i < retry_count; i++) {
73 __intcall(0x13, &ireg, &oreg);
74
75 if (!(oreg.eflags.l & EFLAGS_CF))
76 break;
77 }
78
79 if (i == retry_count)
80 kaboom();
81
82 cli(); /* Abandon hope, ye who enter here */
83 memcpy((void *)0x07C00, trackbuf, 512);
84
85 ireg.esi.w[0] = OFFS(trackbuf);
86 ireg.edi.w[0] = 0x07C00;
87 ireg.edx.w[0] = ax;
88 call16(local_boot16, &ireg, NULL);
89 }
90
pm_local_boot(com32sys_t * regs)91 void pm_local_boot(com32sys_t *regs)
92 {
93 local_boot(regs->eax.w[0]);
94 }
95