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/*
* (C) Copyright 2008-2011
* Graeme Russ, <graeme.russ@gmail.com>
*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Alex Zuepke <azu@sysgo.de>
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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
*/
#include <common.h>
#include <command.h>
#include <asm/processor.h>
#include <asm/processor-flags.h>
#include <asm/interrupt.h>
#include <linux/compiler.h>
/*
* Constructor for a conventional segment GDT (or LDT) entry
* This is a macro so it can be used in initialisers
*/
#define GDT_ENTRY(flags, base, limit) \
((((base) & 0xff000000ULL) << (56-24)) | \
(((flags) & 0x0000f0ffULL) << 40) | \
(((limit) & 0x000f0000ULL) << (48-16)) | \
(((base) & 0x00ffffffULL) << 16) | \
(((limit) & 0x0000ffffULL)))
struct gdt_ptr {
u16 len;
u32 ptr;
} __packed;
static void load_ds(u32 segment)
{
asm volatile("movl %0, %%ds" : : "r" (segment * X86_GDT_ENTRY_SIZE));
}
static void load_es(u32 segment)
{
asm volatile("movl %0, %%es" : : "r" (segment * X86_GDT_ENTRY_SIZE));
}
static void load_fs(u32 segment)
{
asm volatile("movl %0, %%fs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
}
static void load_gs(u32 segment)
{
asm volatile("movl %0, %%gs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
}
static void load_ss(u32 segment)
{
asm volatile("movl %0, %%ss" : : "r" (segment * X86_GDT_ENTRY_SIZE));
}
static void load_gdt(const u64 *boot_gdt, u16 num_entries)
{
struct gdt_ptr gdt;
gdt.len = (num_entries * 8) - 1;
gdt.ptr = (u32)boot_gdt;
asm volatile("lgdtl %0\n" : : "m" (gdt));
}
int x86_cpu_init_f(void)
{
const u32 em_rst = ~X86_CR0_EM;
const u32 mp_ne_set = X86_CR0_MP | X86_CR0_NE;
/* initialize FPU, reset EM, set MP and NE */
asm ("fninit\n" \
"movl %%cr0, %%eax\n" \
"andl %0, %%eax\n" \
"orl %1, %%eax\n" \
"movl %%eax, %%cr0\n" \
: : "i" (em_rst), "i" (mp_ne_set) : "eax");
return 0;
}
int cpu_init_f(void) __attribute__((weak, alias("x86_cpu_init_f")));
int x86_cpu_init_r(void)
{
const u32 nw_cd_rst = ~(X86_CR0_NW | X86_CR0_CD);
/* turn on the cache and disable write through */
asm("movl %%cr0, %%eax\n"
"andl %0, %%eax\n"
"movl %%eax, %%cr0\n"
"wbinvd\n" : : "i" (nw_cd_rst) : "eax");
/*
* There are machines which are known to not boot with the GDT
* being 8-byte unaligned. Intel recommends 16 byte alignment
*/
static const u64 boot_gdt[] __aligned(16) = {
/* CS: code, read/execute, 4 GB, base 0 */
[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff),
/* DS: data, read/write, 4 GB, base 0 */
[X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff),
/* 16-bit CS: code, read/execute, 64 kB, base 0 */
[X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff),
/* 16-bit DS: data, read/write, 64 kB, base 0 */
[X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff),
};
load_gdt(boot_gdt, X86_GDT_NUM_ENTRIES);
load_ds(X86_GDT_ENTRY_32BIT_DS);
load_es(X86_GDT_ENTRY_32BIT_DS);
load_fs(X86_GDT_ENTRY_32BIT_DS);
load_gs(X86_GDT_ENTRY_32BIT_DS);
load_ss(X86_GDT_ENTRY_32BIT_DS);
/* Initialize core interrupt and exception functionality of CPU */
cpu_init_interrupts();
return 0;
}
int cpu_init_r(void) __attribute__((weak, alias("x86_cpu_init_r")));
int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
printf("resetting ...\n");
/* wait 50 ms */
udelay(50000);
disable_interrupts();
reset_cpu(0);
/*NOTREACHED*/
return 0;
}
void flush_cache(unsigned long dummy1, unsigned long dummy2)
{
asm("wbinvd\n");
}
void __attribute__ ((regparm(0))) generate_gpf(void);
/* segment 0x70 is an arbitrary segment which does not exist */
asm(".globl generate_gpf\n"
".hidden generate_gpf\n"
".type generate_gpf, @function\n"
"generate_gpf:\n"
"ljmp $0x70, $0x47114711\n");
void __reset_cpu(ulong addr)
{
printf("Resetting using x86 Triple Fault\n");
set_vector(13, generate_gpf); /* general protection fault handler */
set_vector(8, generate_gpf); /* double fault handler */
generate_gpf(); /* start the show */
}
void reset_cpu(ulong addr) __attribute__((weak, alias("__reset_cpu")));
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