1 /* 2 * (C) Copyright 2008-2011 3 * Graeme Russ, <graeme.russ@gmail.com> 4 * 5 * (C) Copyright 2002 6 * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se> 7 * 8 * (C) Copyright 2002 9 * Sysgo Real-Time Solutions, GmbH <www.elinos.com> 10 * Marius Groeger <mgroeger@sysgo.de> 11 * 12 * (C) Copyright 2002 13 * Sysgo Real-Time Solutions, GmbH <www.elinos.com> 14 * Alex Zuepke <azu@sysgo.de> 15 * 16 * See file CREDITS for list of people who contributed to this 17 * project. 18 * 19 * This program is free software; you can redistribute it and/or 20 * modify it under the terms of the GNU General Public License as 21 * published by the Free Software Foundation; either version 2 of 22 * the License, or (at your option) any later version. 23 * 24 * This program is distributed in the hope that it will be useful, 25 * but WITHOUT ANY WARRANTY; without even the implied warranty of 26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 27 * GNU General Public License for more details. 28 * 29 * You should have received a copy of the GNU General Public License 30 * along with this program; if not, write to the Free Software 31 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 32 * MA 02111-1307 USA 33 */ 34 35 #include <common.h> 36 #include <command.h> 37 #include <asm/processor.h> 38 #include <asm/processor-flags.h> 39 #include <asm/interrupt.h> 40 #include <linux/compiler.h> 41 42 /* 43 * Constructor for a conventional segment GDT (or LDT) entry 44 * This is a macro so it can be used in initialisers 45 */ 46 #define GDT_ENTRY(flags, base, limit) \ 47 ((((base) & 0xff000000ULL) << (56-24)) | \ 48 (((flags) & 0x0000f0ffULL) << 40) | \ 49 (((limit) & 0x000f0000ULL) << (48-16)) | \ 50 (((base) & 0x00ffffffULL) << 16) | \ 51 (((limit) & 0x0000ffffULL))) 52 53 struct gdt_ptr { 54 u16 len; 55 u32 ptr; 56 } __packed; 57 58 static void load_ds(u32 segment) 59 { 60 asm volatile("movl %0, %%ds" : : "r" (segment * X86_GDT_ENTRY_SIZE)); 61 } 62 63 static void load_es(u32 segment) 64 { 65 asm volatile("movl %0, %%es" : : "r" (segment * X86_GDT_ENTRY_SIZE)); 66 } 67 68 static void load_fs(u32 segment) 69 { 70 asm volatile("movl %0, %%fs" : : "r" (segment * X86_GDT_ENTRY_SIZE)); 71 } 72 73 static void load_gs(u32 segment) 74 { 75 asm volatile("movl %0, %%gs" : : "r" (segment * X86_GDT_ENTRY_SIZE)); 76 } 77 78 static void load_ss(u32 segment) 79 { 80 asm volatile("movl %0, %%ss" : : "r" (segment * X86_GDT_ENTRY_SIZE)); 81 } 82 83 static void load_gdt(const u64 *boot_gdt, u16 num_entries) 84 { 85 struct gdt_ptr gdt; 86 87 gdt.len = (num_entries * 8) - 1; 88 gdt.ptr = (u32)boot_gdt; 89 90 asm volatile("lgdtl %0\n" : : "m" (gdt)); 91 } 92 93 void init_gd(gd_t *id, u64 *gdt_addr) 94 { 95 id->gd_addr = (ulong)id; 96 setup_gdt(id, gdt_addr); 97 } 98 99 void setup_gdt(gd_t *id, u64 *gdt_addr) 100 { 101 /* CS: code, read/execute, 4 GB, base 0 */ 102 gdt_addr[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff); 103 104 /* DS: data, read/write, 4 GB, base 0 */ 105 gdt_addr[X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff); 106 107 /* FS: data, read/write, 4 GB, base (Global Data Pointer) */ 108 gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093, (ulong)id, 0xfffff); 109 110 /* 16-bit CS: code, read/execute, 64 kB, base 0 */ 111 gdt_addr[X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff); 112 113 /* 16-bit DS: data, read/write, 64 kB, base 0 */ 114 gdt_addr[X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff); 115 116 load_gdt(gdt_addr, X86_GDT_NUM_ENTRIES); 117 load_ds(X86_GDT_ENTRY_32BIT_DS); 118 load_es(X86_GDT_ENTRY_32BIT_DS); 119 load_gs(X86_GDT_ENTRY_32BIT_DS); 120 load_ss(X86_GDT_ENTRY_32BIT_DS); 121 load_fs(X86_GDT_ENTRY_32BIT_FS); 122 } 123 124 int x86_cpu_init_f(void) 125 { 126 const u32 em_rst = ~X86_CR0_EM; 127 const u32 mp_ne_set = X86_CR0_MP | X86_CR0_NE; 128 129 /* initialize FPU, reset EM, set MP and NE */ 130 asm ("fninit\n" \ 131 "movl %%cr0, %%eax\n" \ 132 "andl %0, %%eax\n" \ 133 "orl %1, %%eax\n" \ 134 "movl %%eax, %%cr0\n" \ 135 : : "i" (em_rst), "i" (mp_ne_set) : "eax"); 136 137 return 0; 138 } 139 int cpu_init_f(void) __attribute__((weak, alias("x86_cpu_init_f"))); 140 141 int x86_cpu_init_r(void) 142 { 143 /* Initialize core interrupt and exception functionality of CPU */ 144 cpu_init_interrupts(); 145 return 0; 146 } 147 int cpu_init_r(void) __attribute__((weak, alias("x86_cpu_init_r"))); 148 149 void x86_enable_caches(void) 150 { 151 const u32 nw_cd_rst = ~(X86_CR0_NW | X86_CR0_CD); 152 153 /* turn on the cache and disable write through */ 154 asm("movl %%cr0, %%eax\n" 155 "andl %0, %%eax\n" 156 "movl %%eax, %%cr0\n" 157 "wbinvd\n" : : "i" (nw_cd_rst) : "eax"); 158 } 159 void enable_caches(void) __attribute__((weak, alias("x86_enable_caches"))); 160 161 int x86_init_cache(void) 162 { 163 enable_caches(); 164 165 return 0; 166 } 167 int init_cache(void) __attribute__((weak, alias("x86_init_cache"))); 168 169 int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) 170 { 171 printf("resetting ...\n"); 172 173 /* wait 50 ms */ 174 udelay(50000); 175 disable_interrupts(); 176 reset_cpu(0); 177 178 /*NOTREACHED*/ 179 return 0; 180 } 181 182 void flush_cache(unsigned long dummy1, unsigned long dummy2) 183 { 184 asm("wbinvd\n"); 185 } 186 187 void __attribute__ ((regparm(0))) generate_gpf(void); 188 189 /* segment 0x70 is an arbitrary segment which does not exist */ 190 asm(".globl generate_gpf\n" 191 ".hidden generate_gpf\n" 192 ".type generate_gpf, @function\n" 193 "generate_gpf:\n" 194 "ljmp $0x70, $0x47114711\n"); 195 196 void __reset_cpu(ulong addr) 197 { 198 printf("Resetting using x86 Triple Fault\n"); 199 set_vector(13, generate_gpf); /* general protection fault handler */ 200 set_vector(8, generate_gpf); /* double fault handler */ 201 generate_gpf(); /* start the show */ 202 } 203 void reset_cpu(ulong addr) __attribute__((weak, alias("__reset_cpu"))); 204