3 * Daniel Engström, Omicron Ceti AB, daniel@omicron.se.
6 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
7 * Marius Groeger <mgroeger@sysgo.de>
10 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
11 * Alex Zuepke <azu@sysgo.de>
13 * See file CREDITS for list of people who contributed to this
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License as
18 * published by the Free Software Foundation; either version 2 of
19 * the License, or (at your option) any later version.
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 * GNU General Public License for more details.
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, write to the Free Software
28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
38 #include <asm/interrupt.h>
40 /* Constructor for a conventional segment GDT (or LDT) entry */
41 /* This is a macro so it can be used in initializers */
42 #define GDT_ENTRY(flags, base, limit) \
43 ((((base) & 0xff000000ULL) << (56-24)) | \
44 (((flags) & 0x0000f0ffULL) << 40) | \
45 (((limit) & 0x000f0000ULL) << (48-16)) | \
46 (((base) & 0x00ffffffULL) << 16) | \
47 (((limit) & 0x0000ffffULL)))
49 /* Simple and small GDT entries for booting only */
51 #define GDT_ENTRY_32BIT_CS 2
52 #define GDT_ENTRY_32BIT_DS (GDT_ENTRY_32BIT_CS + 1)
53 #define GDT_ENTRY_16BIT_CS (GDT_ENTRY_32BIT_DS + 1)
54 #define GDT_ENTRY_16BIT_DS (GDT_ENTRY_16BIT_CS + 1)
63 } __attribute__((packed));
65 static void reload_gdt(void)
67 /* There are machines which are known to not boot with the GDT
68 being 8-byte unaligned. Intel recommends 16 byte alignment. */
69 static const u64 boot_gdt[] __attribute__((aligned(16))) = {
70 /* CS: code, read/execute, 4 GB, base 0 */
71 [GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff),
72 /* DS: data, read/write, 4 GB, base 0 */
73 [GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff),
74 /* 16-bit CS: code, read/execute, 64 kB, base 0 */
75 [GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff),
76 /* 16-bit DS: data, read/write, 64 kB, base 0 */
77 [GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff),
79 static struct gdt_ptr gdt;
81 gdt.len = sizeof(boot_gdt)-1;
82 gdt.ptr = (u32)&boot_gdt;
84 asm volatile("lgdtl %0\n" \
85 "movl $((2+1)*8), %%ecx\n" \
86 "movl %%ecx, %%ds\n" \
87 "movl %%ecx, %%es\n" \
88 "movl %%ecx, %%fs\n" \
89 "movl %%ecx, %%gs\n" \
91 : : "m" (gdt) : "ecx");
97 /* initialize FPU, reset EM, set MP and NE */
100 "andl $~0x4, %eax\n" \
101 "orl $0x22, %eax\n" \
102 "movl %eax, %cr0\n" );
111 /* Initialize core interrupt and exception functionality of CPU */
112 cpu_init_interrupts ();
116 int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
118 printf ("resetting ...\n");
119 udelay(50000); /* wait 50 ms */
120 disable_interrupts();
127 void flush_cache (unsigned long dummy1, unsigned long dummy2)
133 void __attribute__ ((regparm(0))) generate_gpf(void);
135 /* segment 0x70 is an arbitrary segment which does not exist */
136 asm(".globl generate_gpf\n"
137 ".hidden generate_gpf\n"
138 ".type generate_gpf, @function\n"
140 "ljmp $0x70, $0x47114711\n");
142 void __reset_cpu(ulong addr)
144 printf("Resetting using i386 Triple Fault\n");
145 set_vector(13, generate_gpf); /* general protection fault handler */
146 set_vector(8, generate_gpf); /* double fault handler */
147 generate_gpf(); /* start the show */
149 void reset_cpu(ulong addr) __attribute__((weak, alias("__reset_cpu")));