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Diffstat (limited to 'arch/x86/cpu/cpu.c')
| -rw-r--r-- | arch/x86/cpu/cpu.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c new file mode 100644 index 000000000..0c5d7c3d5 --- /dev/null +++ b/arch/x86/cpu/cpu.c @@ -0,0 +1,157 @@ +/* + * (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> + +/* + * 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; +} __attribute__((packed)); + +static void reload_gdt(void) +{ + /* + * 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[] __attribute__((aligned(16))) = { + /* CS: code, read/execute, 4 GB, base 0 */ + [GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff), + /* DS: data, read/write, 4 GB, base 0 */ + [GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff), + /* 16-bit CS: code, read/execute, 64 kB, base 0 */ + [GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff), + /* 16-bit DS: data, read/write, 64 kB, base 0 */ + [GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff), + }; + static struct gdt_ptr gdt; + + gdt.len = sizeof(boot_gdt)-1; + gdt.ptr = (u32)&boot_gdt; + + asm volatile("lgdtl %0\n" \ + "movl $((2+1)*8), %%ecx\n" \ + "movl %%ecx, %%ds\n" \ + "movl %%ecx, %%es\n" \ + "movl %%ecx, %%fs\n" \ + "movl %%ecx, %%gs\n" \ + "movl %%ecx, %%ss" \ + : : "m" (gdt) : "ecx"); +} + +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"); + + reload_gdt(); + + /* 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"))); |