target-m68k/helper.c

   1 /*
   2  *  m68k op helpers
   3  *
   4  *  Copyright (c) 2006-2007 CodeSourcery
   5  *  Written by Paul Brook
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include <stdio.h>
  23 #include <string.h>
  24
  25 #include "config.h"
  26 #include "cpu.h"
  27 #include "exec-all.h"
  28
  29 enum m68k_cpuid {
  30     M68K_CPUID_M5206,
  31     M68K_CPUID_CFV4E,
  32     M68K_CPUID_ANY,
  33 };
  34
  35 struct m68k_def_t {
  36     const char * name;
  37     enum m68k_cpuid id;
  38 };
  39
  40 static m68k_def_t m68k_cpu_defs[] = {
  41     {"m5206", M68K_CPUID_M5206},
  42     {"cfv4e", M68K_CPUID_CFV4E},
  43     {"any", M68K_CPUID_ANY},
  44     {NULL, 0},
  45 };
  46
  47 static void m68k_set_feature(CPUM68KState *env, int feature)
  48 {
  49     env->features |= (1u << feature);
  50 }
  51
  52 int cpu_m68k_set_model(CPUM68KState *env, const char * name)
  53 {
  54     m68k_def_t *def;
  55
  56     for (def = m68k_cpu_defs; def->name; def++) {
  57         if (strcmp(def->name, name) == 0)
  58             break;
  59     }
  60     if (!def->name)
  61         return 1;
  62
  63     switch (def->id) {
  64     case M68K_CPUID_M5206:
  65         m68k_set_feature(env, M68K_FEATURE_CF_ISA_A);
  66         break;
  67     case M68K_CPUID_CFV4E:
  68         m68k_set_feature(env, M68K_FEATURE_CF_ISA_A);
  69         m68k_set_feature(env, M68K_FEATURE_CF_ISA_B);
  70         m68k_set_feature(env, M68K_FEATURE_CF_ISA_C);
  71         m68k_set_feature(env, M68K_FEATURE_CF_FPU);
  72         m68k_set_feature(env, M68K_FEATURE_CF_MAC);
  73         m68k_set_feature(env, M68K_FEATURE_CF_EMAC);
  74         break;
  75     case M68K_CPUID_ANY:
  76         m68k_set_feature(env, M68K_FEATURE_CF_ISA_A);
  77         m68k_set_feature(env, M68K_FEATURE_CF_ISA_B);
  78         m68k_set_feature(env, M68K_FEATURE_CF_ISA_C);
  79         m68k_set_feature(env, M68K_FEATURE_CF_FPU);
  80         m68k_set_feature(env, M68K_FEATURE_CF_MAC);
  81         m68k_set_feature(env, M68K_FEATURE_CF_EMAC);
  82         m68k_set_feature(env, M68K_FEATURE_EXT_FULL);
  83         break;
  84     }
  85
  86     register_m68k_insns(env);
  87
  88     return 0;
  89 }
  90
  91 void cpu_m68k_flush_flags(CPUM68KState *env, int cc_op)
  92 {
  93     int flags;
  94     uint32_t src;
  95     uint32_t dest;
  96     uint32_t tmp;
  97
  98 #define HIGHBIT 0x80000000u
  99
 100 #define SET_NZ(x) do { \
 101     if ((x) == 0) \
 102         flags |= CCF_Z; \
 103     else if ((int32_t)(x) < 0) \
 104         flags |= CCF_N; \
 105     } while (0)
 106
 107 #define SET_FLAGS_SUB(type, utype) do { \
 108     SET_NZ((type)dest); \
 109     tmp = dest + src; \
 110     if ((utype) tmp < (utype) src) \
 111         flags |= CCF_C; \
 112     if ((1u << (sizeof(type) * 8 - 1)) & (tmp ^ dest) & (tmp ^ src)) \
 113         flags |= CCF_V; \
 114     } while (0)
 115
 116     flags = 0;
 117     src = env->cc_src;
 118     dest = env->cc_dest;
 119     switch (cc_op) {
 120     case CC_OP_FLAGS:
 121         flags = dest;
 122         break;
 123     case CC_OP_LOGIC:
 124         SET_NZ(dest);
 125         break;
 126     case CC_OP_ADD:
 127         SET_NZ(dest);
 128         if (dest < src)
 129             flags |= CCF_C;
 130         tmp = dest - src;
 131         if (HIGHBIT & (src ^ dest) & ~(tmp ^ src))
 132             flags |= CCF_V;
 133         break;
 134     case CC_OP_SUB:
 135         SET_FLAGS_SUB(int32_t, uint32_t);
 136         break;
 137     case CC_OP_CMPB:
 138         SET_FLAGS_SUB(int8_t, uint8_t);
 139         break;
 140     case CC_OP_CMPW:
 141         SET_FLAGS_SUB(int16_t, uint16_t);
 142         break;
 143     case CC_OP_ADDX:
 144         SET_NZ(dest);
 145         if (dest <= src)
 146             flags |= CCF_C;
 147         tmp = dest - src - 1;
 148         if (HIGHBIT & (src ^ dest) & ~(tmp ^ src))
 149             flags |= CCF_V;
 150         break;
 151     case CC_OP_SUBX:
 152         SET_NZ(dest);
 153         tmp = dest + src + 1;
 154         if (tmp <= src)
 155             flags |= CCF_C;
 156         if (HIGHBIT & (tmp ^ dest) & (tmp ^ src))
 157             flags |= CCF_V;
 158         break;
 159     case CC_OP_SHL:
 160         if (src >= 32) {
 161             SET_NZ(0);
 162         } else {
 163             tmp = dest << src;
 164             SET_NZ(tmp);
 165         }
 166         if (src && src <= 32 && (dest & (1 << (32 - src))))
 167             flags |= CCF_C;
 168         break;
 169     case CC_OP_SHR:
 170         if (src >= 32) {
 171             SET_NZ(0);
 172         } else {
 173             tmp = dest >> src;
 174             SET_NZ(tmp);
 175         }
 176         if (src && src <= 32 && ((dest >> (src - 1)) & 1))
 177             flags |= CCF_C;
 178         break;
 179     case CC_OP_SAR:
 180         if (src >= 32) {
 181             SET_NZ(-1);
 182         } else {
 183             tmp = (int32_t)dest >> src;
 184             SET_NZ(tmp);
 185         }
 186         if (src && src <= 32 && (((int32_t)dest >> (src - 1)) & 1))
 187             flags |= CCF_C;
 188         break;
 189     default:
 190         cpu_abort(env, "Bad CC_OP %d", cc_op);
 191     }
 192     env->cc_op = CC_OP_FLAGS;
 193     env->cc_dest = flags;
 194 }
 195
 196 float64 helper_sub_cmpf64(CPUM68KState *env, float64 src0, float64 src1)
 197 {
 198     /* ??? This may incorrectly raise exceptions.  */
 199     /* ??? Should flush denormals to zero.  */
 200     float64 res;
 201     res = float64_sub(src0, src1, &env->fp_status);
 202     if (float64_is_nan(res)) {
 203         /* +/-inf compares equal against itself, but sub returns nan.  */
 204         if (!float64_is_nan(src0)
 205             && !float64_is_nan(src1)) {
 206             res = 0;
 207             if (float64_lt_quiet(src0, res, &env->fp_status))
 208                 res = float64_chs(res);
 209         }
 210     }
 211     return res;
 212 }
 213
 214 void helper_movec(CPUM68KState *env, int reg, uint32_t val)
 215 {
 216     switch (reg) {
 217     case 0x02: /* CACR */
 218         /* Ignored.  */
 219         break;
 220     case 0x801: /* VBR */
 221         env->vbr = val;
 222         break;
 223     /* TODO: Implement control registers.  */
 224     default:
 225         cpu_abort(env, "Unimplemented control register write 0x%x = 0x%x\n",
 226                   reg, val);
 227     }
 228 }
 229
 230 /* MMU */
 231
 232 /* TODO: This will need fixing once the MMU is implemented.  */
 233 target_phys_addr_t cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
 234 {
 235     return addr;
 236 }
 237
 238 #if defined(CONFIG_USER_ONLY)
 239
 240 int cpu_m68k_handle_mmu_fault (CPUState *env, target_ulong address, int rw,
 241                                int is_user, int is_softmmu)
 242 {
 243     env->exception_index = EXCP_ACCESS;
 244     env->mmu.ar = address;
 245     return 1;
 246 }
 247
 248 #else
 249
 250 int cpu_m68k_handle_mmu_fault (CPUState *env, target_ulong address, int rw,
 251                                int is_user, int is_softmmu)
 252 {
 253     int prot;
 254
 255     address &= TARGET_PAGE_MASK;
 256     prot = PAGE_READ | PAGE_WRITE;
 257     return tlb_set_page(env, address, address, prot, is_user, is_softmmu);
 258 }
 259
 260 /* Notify CPU of a pending interrupt.  Prioritization and vectoring should
 261    be handled by the interrupt controller.  Real hardware only requests
 262    the vector when the interrupt is acknowledged by the CPU.  For
 263    simplicitly we calculate it when the interrupt is signalled.  */
 264 void m68k_set_irq_level(CPUM68KState *env, int level, uint8_t vector)
 265 {
 266     env->pending_level = level;
 267     env->pending_vector = vector;
 268     if (level)
 269         cpu_interrupt(env, CPU_INTERRUPT_HARD);
 270     else
 271         cpu_reset_interrupt(env, CPU_INTERRUPT_HARD);
 272 }
 273
 274 #endif