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 setup_gdt(gd_t *id, u64 *gdt_addr) 94 { 95 /* CS: code, read/execute, 4 GB, base 0 */ 96 gdt_addr[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff); 97 98 /* DS: data, read/write, 4 GB, base 0 */ 99 gdt_addr[X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff); 100 101 /* FS: data, read/write, 4 GB, base (Global Data Pointer) */ 102 gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093, (ulong)id, 0xfffff); 103 104 /* 16-bit CS: code, read/execute, 64 kB, base 0 */ 105 gdt_addr[X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff); 106 107 /* 16-bit DS: data, read/write, 64 kB, base 0 */ 108 gdt_addr[X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff); 109 110 load_gdt(gdt_addr, X86_GDT_NUM_ENTRIES); 111 load_ds(X86_GDT_ENTRY_32BIT_DS); 112 load_es(X86_GDT_ENTRY_32BIT_DS); 113 load_gs(X86_GDT_ENTRY_32BIT_DS); 114 load_ss(X86_GDT_ENTRY_32BIT_DS); 115 load_fs(X86_GDT_ENTRY_32BIT_FS); 116 } 117 118 int __weak x86_cleanup_before_linux(void) 119 { 120 return 0; 121 } 122 123 int x86_cpu_init_f(void) 124 { 125 const u32 em_rst = ~X86_CR0_EM; 126 const u32 mp_ne_set = X86_CR0_MP | X86_CR0_NE; 127 128 /* initialize FPU, reset EM, set MP and NE */ 129 asm ("fninit\n" \ 130 "movl %%cr0, %%eax\n" \ 131 "andl %0, %%eax\n" \ 132 "orl %1, %%eax\n" \ 133 "movl %%eax, %%cr0\n" \ 134 : : "i" (em_rst), "i" (mp_ne_set) : "eax"); 135 136 return 0; 137 } 138 int cpu_init_f(void) __attribute__((weak, alias("x86_cpu_init_f"))); 139 140 int x86_cpu_init_r(void) 141 { 142 /* Initialize core interrupt and exception functionality of CPU */ 143 cpu_init_interrupts(); 144 return 0; 145 } 146 int cpu_init_r(void) __attribute__((weak, alias("x86_cpu_init_r"))); 147 148 void x86_enable_caches(void) 149 { 150 const u32 nw_cd_rst = ~(X86_CR0_NW | X86_CR0_CD); 151 152 /* turn on the cache and disable write through */ 153 asm("movl %%cr0, %%eax\n" 154 "andl %0, %%eax\n" 155 "movl %%eax, %%cr0\n" 156 "wbinvd\n" : : "i" (nw_cd_rst) : "eax"); 157 } 158 void enable_caches(void) __attribute__((weak, alias("x86_enable_caches"))); 159 160 int x86_init_cache(void) 161 { 162 enable_caches(); 163 164 return 0; 165 } 166 int init_cache(void) __attribute__((weak, alias("x86_init_cache"))); 167 168 int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) 169 { 170 printf("resetting ...\n"); 171 172 /* wait 50 ms */ 173 udelay(50000); 174 disable_interrupts(); 175 reset_cpu(0); 176 177 /*NOTREACHED*/ 178 return 0; 179 } 180 181 void flush_cache(unsigned long dummy1, unsigned long dummy2) 182 { 183 asm("wbinvd\n"); 184 } 185 186 void __attribute__ ((regparm(0))) generate_gpf(void); 187 188 /* segment 0x70 is an arbitrary segment which does not exist */ 189 asm(".globl generate_gpf\n" 190 ".hidden generate_gpf\n" 191 ".type generate_gpf, @function\n" 192 "generate_gpf:\n" 193 "ljmp $0x70, $0x47114711\n"); 194 195 void __reset_cpu(ulong addr) 196 { 197 printf("Resetting using x86 Triple Fault\n"); 198 set_vector(13, generate_gpf); /* general protection fault handler */ 199 set_vector(8, generate_gpf); /* double fault handler */ 200 generate_gpf(); /* start the show */ 201 } 202 void reset_cpu(ulong addr) __attribute__((weak, alias("__reset_cpu"))); 203