2 * (C) Copyright 2008-2011
3 * Graeme Russ, <graeme.russ@gmail.com>
6 * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
9 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
10 * Marius Groeger <mgroeger@sysgo.de>
13 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
14 * Alex Zuepke <azu@sysgo.de>
16 * See file CREDITS for list of people who contributed to this
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.
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.
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,
37 #include <asm/control_regs.h>
38 #include <asm/processor.h>
39 #include <asm/processor-flags.h>
40 #include <asm/interrupt.h>
41 #include <linux/compiler.h>
44 * Constructor for a conventional segment GDT (or LDT) entry
45 * This is a macro so it can be used in initialisers
47 #define GDT_ENTRY(flags, base, limit) \
48 ((((base) & 0xff000000ULL) << (56-24)) | \
49 (((flags) & 0x0000f0ffULL) << 40) | \
50 (((limit) & 0x000f0000ULL) << (48-16)) | \
51 (((base) & 0x00ffffffULL) << 16) | \
52 (((limit) & 0x0000ffffULL)))
59 static void load_ds(u32 segment)
61 asm volatile("movl %0, %%ds" : : "r" (segment * X86_GDT_ENTRY_SIZE));
64 static void load_es(u32 segment)
66 asm volatile("movl %0, %%es" : : "r" (segment * X86_GDT_ENTRY_SIZE));
69 static void load_fs(u32 segment)
71 asm volatile("movl %0, %%fs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
74 static void load_gs(u32 segment)
76 asm volatile("movl %0, %%gs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
79 static void load_ss(u32 segment)
81 asm volatile("movl %0, %%ss" : : "r" (segment * X86_GDT_ENTRY_SIZE));
84 static void load_gdt(const u64 *boot_gdt, u16 num_entries)
88 gdt.len = (num_entries * 8) - 1;
89 gdt.ptr = (u32)boot_gdt;
91 asm volatile("lgdtl %0\n" : : "m" (gdt));
94 void setup_gdt(gd_t *id, u64 *gdt_addr)
96 /* CS: code, read/execute, 4 GB, base 0 */
97 gdt_addr[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff);
99 /* DS: data, read/write, 4 GB, base 0 */
100 gdt_addr[X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff);
102 /* FS: data, read/write, 4 GB, base (Global Data Pointer) */
103 id->arch.gd_addr = id;
104 gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093,
105 (ulong)&id->arch.gd_addr, 0xfffff);
107 /* 16-bit CS: code, read/execute, 64 kB, base 0 */
108 gdt_addr[X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff);
110 /* 16-bit DS: data, read/write, 64 kB, base 0 */
111 gdt_addr[X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff);
113 load_gdt(gdt_addr, X86_GDT_NUM_ENTRIES);
114 load_ds(X86_GDT_ENTRY_32BIT_DS);
115 load_es(X86_GDT_ENTRY_32BIT_DS);
116 load_gs(X86_GDT_ENTRY_32BIT_DS);
117 load_ss(X86_GDT_ENTRY_32BIT_DS);
118 load_fs(X86_GDT_ENTRY_32BIT_FS);
121 int __weak x86_cleanup_before_linux(void)
123 #ifdef CONFIG_BOOTSTAGE_STASH
124 bootstage_stash((void *)CONFIG_BOOTSTAGE_STASH,
125 CONFIG_BOOTSTAGE_STASH_SIZE);
131 int x86_cpu_init_f(void)
133 const u32 em_rst = ~X86_CR0_EM;
134 const u32 mp_ne_set = X86_CR0_MP | X86_CR0_NE;
136 /* initialize FPU, reset EM, set MP and NE */
138 "movl %%cr0, %%eax\n" \
141 "movl %%eax, %%cr0\n" \
142 : : "i" (em_rst), "i" (mp_ne_set) : "eax");
146 int cpu_init_f(void) __attribute__((weak, alias("x86_cpu_init_f")));
148 int x86_cpu_init_r(void)
150 /* Initialize core interrupt and exception functionality of CPU */
151 cpu_init_interrupts();
154 int cpu_init_r(void) __attribute__((weak, alias("x86_cpu_init_r")));
156 void x86_enable_caches(void)
161 cr0 &= ~(X86_CR0_NW | X86_CR0_CD);
165 void enable_caches(void) __attribute__((weak, alias("x86_enable_caches")));
167 void x86_disable_caches(void)
172 cr0 |= X86_CR0_NW | X86_CR0_CD;
177 void disable_caches(void) __attribute__((weak, alias("x86_disable_caches")));
179 int x86_init_cache(void)
185 int init_cache(void) __attribute__((weak, alias("x86_init_cache")));
187 int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
189 printf("resetting ...\n");
193 disable_interrupts();
200 void flush_cache(unsigned long dummy1, unsigned long dummy2)
205 void __attribute__ ((regparm(0))) generate_gpf(void);
207 /* segment 0x70 is an arbitrary segment which does not exist */
208 asm(".globl generate_gpf\n"
209 ".hidden generate_gpf\n"
210 ".type generate_gpf, @function\n"
212 "ljmp $0x70, $0x47114711\n");
214 void __reset_cpu(ulong addr)
216 printf("Resetting using x86 Triple Fault\n");
217 set_vector(13, generate_gpf); /* general protection fault handler */
218 set_vector(8, generate_gpf); /* double fault handler */
219 generate_gpf(); /* start the show */
221 void reset_cpu(ulong addr) __attribute__((weak, alias("__reset_cpu")));
223 int dcache_status(void)
225 return !(read_cr0() & 0x40000000);
228 /* Define these functions to allow ehch-hcd to function */
229 void flush_dcache_range(unsigned long start, unsigned long stop)
233 void invalidate_dcache_range(unsigned long start, unsigned long stop)
237 void dcache_enable(void)
242 void dcache_disable(void)
247 void icache_enable(void)
251 void icache_disable(void)
255 int icache_status(void)