xref: /netbsd-src/external/gpl3/gdb/dist/sim/ft32/interp.c (revision c38e7cc395b1472a774ff828e46123de44c628e9)
1 /* Simulator for the FT32 processor
2 
3    Copyright (C) 2008-2017 Free Software Foundation, Inc.
4    Contributed by FTDI <support@ftdichip.com>
5 
6    This file is part of simulators.
7 
8    This program is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 3 of the License, or
11    (at your option) any later version.
12 
13    This program is distributed in the hope that it will be useful,
14    but WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16    GNU General Public License for more details.
17 
18    You should have received a copy of the GNU General Public License
19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
20 
21 #include "config.h"
22 #include <fcntl.h>
23 #include <signal.h>
24 #include <stdlib.h>
25 #include <stdint.h>
26 
27 #include "bfd.h"
28 #include "gdb/callback.h"
29 #include "libiberty.h"
30 #include "gdb/remote-sim.h"
31 
32 #include "sim-main.h"
33 #include "sim-options.h"
34 
35 #include "opcode/ft32.h"
36 
37 /*
38  * FT32 is a Harvard architecture: RAM and code occupy
39  * different address spaces.
40  *
41  * sim and gdb model FT32 memory by adding 0x800000 to RAM
42  * addresses. This means that sim/gdb can treat all addresses
43  * similarly.
44  *
45  * The address space looks like:
46  *
47  *    00000   start of code memory
48  *    3ffff   end of code memory
49  *   800000   start of RAM
50  *   80ffff   end of RAM
51  */
52 
53 #define RAM_BIAS  0x800000  /* Bias added to RAM addresses.  */
54 
55 static unsigned long
56 ft32_extract_unsigned_integer (unsigned char *addr, int len)
57 {
58   unsigned long retval;
59   unsigned char *p;
60   unsigned char *startaddr = (unsigned char *) addr;
61   unsigned char *endaddr = startaddr + len;
62 
63   /* Start at the most significant end of the integer, and work towards
64      the least significant.  */
65   retval = 0;
66 
67   for (p = endaddr; p > startaddr;)
68     retval = (retval << 8) | * -- p;
69 
70   return retval;
71 }
72 
73 static void
74 ft32_store_unsigned_integer (unsigned char *addr, int len, unsigned long val)
75 {
76   unsigned char *p;
77   unsigned char *startaddr = (unsigned char *)addr;
78   unsigned char *endaddr = startaddr + len;
79 
80   for (p = startaddr; p < endaddr; p++)
81     {
82       *p = val & 0xff;
83       val >>= 8;
84     }
85 }
86 
87 /*
88  * Align EA according to its size DW.
89  * The FT32 ignores the low bit of a 16-bit addresss,
90  * and the low two bits of a 32-bit address.
91  */
92 static uint32_t ft32_align (uint32_t dw, uint32_t ea)
93 {
94   switch (dw)
95     {
96     case 1:
97       ea &= ~1;
98       break;
99     case 2:
100       ea &= ~3;
101       break;
102     default:
103       break;
104     }
105   return ea;
106 }
107 
108 /* Read an item from memory address EA, sized DW.  */
109 static uint32_t
110 ft32_read_item (SIM_DESC sd, int dw, uint32_t ea)
111 {
112   sim_cpu *cpu = STATE_CPU (sd, 0);
113   address_word cia = CPU_PC_GET (cpu);
114   uint8_t byte[4];
115   uint32_t r;
116 
117   ea = ft32_align (dw, ea);
118 
119   switch (dw) {
120     case 0:
121       return sim_core_read_aligned_1 (cpu, cia, read_map, ea);
122     case 1:
123       return sim_core_read_aligned_2 (cpu, cia, read_map, ea);
124     case 2:
125       return sim_core_read_aligned_4 (cpu, cia, read_map, ea);
126     default:
127       abort ();
128   }
129 }
130 
131 /* Write item V to memory address EA, sized DW.  */
132 static void
133 ft32_write_item (SIM_DESC sd, int dw, uint32_t ea, uint32_t v)
134 {
135   sim_cpu *cpu = STATE_CPU (sd, 0);
136   address_word cia = CPU_PC_GET (cpu);
137   uint8_t byte[4];
138 
139   ea = ft32_align (dw, ea);
140 
141   switch (dw) {
142     case 0:
143       sim_core_write_aligned_1 (cpu, cia, write_map, ea, v);
144       break;
145     case 1:
146       sim_core_write_aligned_2 (cpu, cia, write_map, ea, v);
147       break;
148     case 2:
149       sim_core_write_aligned_4 (cpu, cia, write_map, ea, v);
150       break;
151     default:
152       abort ();
153   }
154 }
155 
156 #define ILLEGAL() \
157   sim_engine_halt (sd, cpu, NULL, insnpc, sim_signalled, SIM_SIGILL)
158 
159 static uint32_t cpu_mem_read (SIM_DESC sd, uint32_t dw, uint32_t ea)
160 {
161   sim_cpu *cpu = STATE_CPU (sd, 0);
162   uint32_t insnpc = cpu->state.pc;
163   uint32_t r;
164   uint8_t byte[4];
165 
166   ea &= 0x1ffff;
167   if (ea & ~0xffff)
168     {
169       /* Simulate some IO devices */
170       switch (ea)
171 	{
172 	case 0x10000:
173 	  return getchar ();
174 	case 0x1fff4:
175 	  /* Read the simulator cycle timer.  */
176 	  return cpu->state.cycles / 100;
177 	default:
178 	  sim_io_eprintf (sd, "Illegal IO read address %08x, pc %#x\n",
179 			  ea, insnpc);
180 	  ILLEGAL ();
181 	}
182     }
183   return ft32_read_item (sd, dw, RAM_BIAS + ea);
184 }
185 
186 static void cpu_mem_write (SIM_DESC sd, uint32_t dw, uint32_t ea, uint32_t d)
187 {
188   sim_cpu *cpu = STATE_CPU (sd, 0);
189   ea &= 0x1ffff;
190   if (ea & 0x10000)
191     {
192       /* Simulate some IO devices */
193       switch (ea)
194 	{
195 	case 0x10000:
196 	  /* Console output */
197 	  putchar (d & 0xff);
198 	  break;
199 	case 0x1fc80:
200 	  /* Unlock the PM write port */
201 	  cpu->state.pm_unlock = (d == 0x1337f7d1);
202 	  break;
203 	case 0x1fc84:
204 	  /* Set the PM write address register */
205 	  cpu->state.pm_addr = d;
206 	  break;
207 	case 0x1fc88:
208 	  if (cpu->state.pm_unlock)
209 	    {
210 	      /* Write to PM.  */
211 	      ft32_write_item (sd, dw, cpu->state.pm_addr, d);
212 	      cpu->state.pm_addr += 4;
213 	    }
214 	  break;
215 	case 0x1fffc:
216 	  /* Normal exit.  */
217 	  sim_engine_halt (sd, cpu, NULL, cpu->state.pc, sim_exited, cpu->state.regs[0]);
218 	  break;
219 	case 0x1fff8:
220 	  sim_io_printf (sd, "Debug write %08x\n", d);
221 	  break;
222 	default:
223 	  sim_io_eprintf (sd, "Unknown IO write %08x to to %08x\n", d, ea);
224 	}
225     }
226   else
227     ft32_write_item (sd, dw, RAM_BIAS + ea, d);
228 }
229 
230 #define GET_BYTE(ea)    cpu_mem_read (sd, 0, (ea))
231 #define PUT_BYTE(ea, d) cpu_mem_write (sd, 0, (ea), (d))
232 
233 /* LSBS (n) is a mask of the least significant N bits.  */
234 #define LSBS(n) ((1U << (n)) - 1)
235 
236 static void ft32_push (SIM_DESC sd, uint32_t v)
237 {
238   sim_cpu *cpu = STATE_CPU (sd, 0);
239   cpu->state.regs[FT32_HARD_SP] -= 4;
240   cpu->state.regs[FT32_HARD_SP] &= 0xffff;
241   cpu_mem_write (sd, 2, cpu->state.regs[FT32_HARD_SP], v);
242 }
243 
244 static uint32_t ft32_pop (SIM_DESC sd)
245 {
246   sim_cpu *cpu = STATE_CPU (sd, 0);
247   uint32_t r = cpu_mem_read (sd, 2, cpu->state.regs[FT32_HARD_SP]);
248   cpu->state.regs[FT32_HARD_SP] += 4;
249   cpu->state.regs[FT32_HARD_SP] &= 0xffff;
250   return r;
251 }
252 
253 /* Extract the low SIZ bits of N as an unsigned number.  */
254 static int nunsigned (int siz, int n)
255 {
256   return n & LSBS (siz);
257 }
258 
259 /* Extract the low SIZ bits of N as a signed number.  */
260 static int nsigned (int siz, int n)
261 {
262   int shift = (sizeof (int) * 8) - siz;
263   return (n << shift) >> shift;
264 }
265 
266 /* Signed division N / D, matching hw behavior for (MIN_INT, -1).  */
267 static uint32_t ft32sdiv (uint32_t n, uint32_t d)
268 {
269   if (n == 0x80000000UL && d == 0xffffffffUL)
270     return 0x80000000UL;
271   else
272     return (uint32_t)((int)n / (int)d);
273 }
274 
275 /* Signed modulus N % D, matching hw behavior for (MIN_INT, -1).  */
276 static uint32_t ft32smod (uint32_t n, uint32_t d)
277 {
278   if (n == 0x80000000UL && d == 0xffffffffUL)
279     return 0;
280   else
281     return (uint32_t)((int)n % (int)d);
282 }
283 
284 /* Circular rotate right N by B bits.  */
285 static uint32_t ror (uint32_t n, uint32_t b)
286 {
287   b &= 31;
288   return (n >> b) | (n << (32 - b));
289 }
290 
291 /* Implement the BINS machine instruction.
292    See FT32 Programmer's Reference for details.  */
293 static uint32_t bins (uint32_t d, uint32_t f, uint32_t len, uint32_t pos)
294 {
295   uint32_t bitmask = LSBS (len) << pos;
296   return (d & ~bitmask) | ((f << pos) & bitmask);
297 }
298 
299 /* Implement the FLIP machine instruction.
300    See FT32 Programmer's Reference for details.  */
301 static uint32_t flip (uint32_t x, uint32_t b)
302 {
303   if (b & 1)
304     x = (x & 0x55555555) <<  1 | (x & 0xAAAAAAAA) >>  1;
305   if (b & 2)
306     x = (x & 0x33333333) <<  2 | (x & 0xCCCCCCCC) >>  2;
307   if (b & 4)
308     x = (x & 0x0F0F0F0F) <<  4 | (x & 0xF0F0F0F0) >>  4;
309   if (b & 8)
310     x = (x & 0x00FF00FF) <<  8 | (x & 0xFF00FF00) >>  8;
311   if (b & 16)
312     x = (x & 0x0000FFFF) << 16 | (x & 0xFFFF0000) >> 16;
313   return x;
314 }
315 
316 static void
317 step_once (SIM_DESC sd)
318 {
319   sim_cpu *cpu = STATE_CPU (sd, 0);
320   address_word cia = CPU_PC_GET (cpu);
321   uint32_t inst;
322   uint32_t dw;
323   uint32_t cb;
324   uint32_t r_d;
325   uint32_t cr;
326   uint32_t cv;
327   uint32_t bt;
328   uint32_t r_1;
329   uint32_t rimm;
330   uint32_t r_2;
331   uint32_t k20;
332   uint32_t pa;
333   uint32_t aa;
334   uint32_t k16;
335   uint32_t k8;
336   uint32_t al;
337   uint32_t r_1v;
338   uint32_t rimmv;
339   uint32_t bit_pos;
340   uint32_t bit_len;
341   uint32_t upper;
342   uint32_t insnpc;
343 
344   if (cpu->state.cycles >= cpu->state.next_tick_cycle)
345     {
346       cpu->state.next_tick_cycle += 100000;
347       ft32_push (sd, cpu->state.pc);
348       cpu->state.pc = 12;  /* interrupt 1.  */
349     }
350   inst = ft32_read_item (sd, 2, cpu->state.pc);
351   cpu->state.cycles += 1;
352 
353   /* Handle "call 8" (which is FT32's "break" equivalent) here.  */
354   if (inst == 0x00340002)
355     {
356       sim_engine_halt (sd, cpu, NULL,
357 		       cpu->state.pc,
358 		       sim_stopped, SIM_SIGTRAP);
359       goto escape;
360     }
361 
362   dw   =              (inst >> FT32_FLD_DW_BIT) & LSBS (FT32_FLD_DW_SIZ);
363   cb   =              (inst >> FT32_FLD_CB_BIT) & LSBS (FT32_FLD_CB_SIZ);
364   r_d  =              (inst >> FT32_FLD_R_D_BIT) & LSBS (FT32_FLD_R_D_SIZ);
365   cr   =              (inst >> FT32_FLD_CR_BIT) & LSBS (FT32_FLD_CR_SIZ);
366   cv   =              (inst >> FT32_FLD_CV_BIT) & LSBS (FT32_FLD_CV_SIZ);
367   bt   =              (inst >> FT32_FLD_BT_BIT) & LSBS (FT32_FLD_BT_SIZ);
368   r_1  =              (inst >> FT32_FLD_R_1_BIT) & LSBS (FT32_FLD_R_1_SIZ);
369   rimm =              (inst >> FT32_FLD_RIMM_BIT) & LSBS (FT32_FLD_RIMM_SIZ);
370   r_2  =              (inst >> FT32_FLD_R_2_BIT) & LSBS (FT32_FLD_R_2_SIZ);
371   k20  = nsigned (20, (inst >> FT32_FLD_K20_BIT) & LSBS (FT32_FLD_K20_SIZ));
372   pa   =              (inst >> FT32_FLD_PA_BIT) & LSBS (FT32_FLD_PA_SIZ);
373   aa   =              (inst >> FT32_FLD_AA_BIT) & LSBS (FT32_FLD_AA_SIZ);
374   k16  =              (inst >> FT32_FLD_K16_BIT) & LSBS (FT32_FLD_K16_SIZ);
375   k8   = nsigned (8,  (inst >> FT32_FLD_K8_BIT) & LSBS (FT32_FLD_K8_SIZ));
376   al   =              (inst >> FT32_FLD_AL_BIT) & LSBS (FT32_FLD_AL_SIZ);
377 
378   r_1v = cpu->state.regs[r_1];
379   rimmv = (rimm & 0x400) ? nsigned (10, rimm) : cpu->state.regs[rimm & 0x1f];
380 
381   bit_pos = rimmv & 31;
382   bit_len = 0xf & (rimmv >> 5);
383   if (bit_len == 0)
384     bit_len = 16;
385 
386   upper = (inst >> 27);
387 
388   insnpc = cpu->state.pc;
389   cpu->state.pc += 4;
390   switch (upper)
391     {
392     case FT32_PAT_TOC:
393     case FT32_PAT_TOCI:
394       {
395 	int take = (cr == 3) || ((1 & (cpu->state.regs[28 + cr] >> cb)) == cv);
396 	if (take)
397 	  {
398 	    cpu->state.cycles += 1;
399 	    if (bt)
400 	      ft32_push (sd, cpu->state.pc); /* this is a call.  */
401 	    if (upper == FT32_PAT_TOC)
402 	      cpu->state.pc = pa << 2;
403 	    else
404 	      cpu->state.pc = cpu->state.regs[r_2];
405 	    if (cpu->state.pc == 0x8)
406 		goto escape;
407 	  }
408       }
409       break;
410 
411     case FT32_PAT_ALUOP:
412     case FT32_PAT_CMPOP:
413       {
414 	uint32_t result;
415 	switch (al)
416 	  {
417 	  case 0x0: result = r_1v + rimmv; break;
418 	  case 0x1: result = ror (r_1v, rimmv); break;
419 	  case 0x2: result = r_1v - rimmv; break;
420 	  case 0x3: result = (r_1v << 10) | (1023 & rimmv); break;
421 	  case 0x4: result = r_1v & rimmv; break;
422 	  case 0x5: result = r_1v | rimmv; break;
423 	  case 0x6: result = r_1v ^ rimmv; break;
424 	  case 0x7: result = ~(r_1v ^ rimmv); break;
425 	  case 0x8: result = r_1v << rimmv; break;
426 	  case 0x9: result = r_1v >> rimmv; break;
427 	  case 0xa: result = (int32_t)r_1v >> rimmv; break;
428 	  case 0xb: result = bins (r_1v, rimmv >> 10, bit_len, bit_pos); break;
429 	  case 0xc: result = nsigned (bit_len, r_1v >> bit_pos); break;
430 	  case 0xd: result = nunsigned (bit_len, r_1v >> bit_pos); break;
431 	  case 0xe: result = flip (r_1v, rimmv); break;
432 	  default:
433 	    sim_io_eprintf (sd, "Unhandled alu %#x\n", al);
434 	    ILLEGAL ();
435 	  }
436 	if (upper == FT32_PAT_ALUOP)
437 	  cpu->state.regs[r_d] = result;
438 	else
439 	  {
440 	    uint32_t dwmask = 0;
441 	    int dwsiz = 0;
442 	    int zero;
443 	    int sign;
444 	    int ahi;
445 	    int bhi;
446 	    int overflow;
447 	    int carry;
448 	    int bit;
449 	    uint64_t ra;
450 	    uint64_t rb;
451 	    int above;
452 	    int greater;
453 	    int greatereq;
454 
455 	    switch (dw)
456 	      {
457 	      case 0: dwsiz = 7;  dwmask = 0xffU; break;
458 	      case 1: dwsiz = 15; dwmask = 0xffffU; break;
459 	      case 2: dwsiz = 31; dwmask = 0xffffffffU; break;
460 	      }
461 
462 	    zero = (0 == (result & dwmask));
463 	    sign = 1 & (result >> dwsiz);
464 	    ahi = 1 & (r_1v >> dwsiz);
465 	    bhi = 1 & (rimmv >> dwsiz);
466 	    overflow = (sign != ahi) & (ahi == !bhi);
467 	    bit = (dwsiz + 1);
468 	    ra = r_1v & dwmask;
469 	    rb = rimmv & dwmask;
470 	    switch (al)
471 	      {
472 	      case 0x0: carry = 1 & ((ra + rb) >> bit); break;
473 	      case 0x2: carry = 1 & ((ra - rb) >> bit); break;
474 	      default:  carry = 0; break;
475 	      }
476 	    above = (!carry & !zero);
477 	    greater = (sign == overflow) & !zero;
478 	    greatereq = (sign == overflow);
479 
480 	    cpu->state.regs[r_d] = (
481 	      (above << 6) |
482 	      (greater << 5) |
483 	      (greatereq << 4) |
484 	      (sign << 3) |
485 	      (overflow << 2) |
486 	      (carry << 1) |
487 	      (zero << 0));
488 	  }
489       }
490       break;
491 
492     case FT32_PAT_LDK:
493       cpu->state.regs[r_d] = k20;
494       break;
495 
496     case FT32_PAT_LPM:
497       cpu->state.regs[r_d] = ft32_read_item (sd, dw, pa << 2);
498       cpu->state.cycles += 1;
499       break;
500 
501     case FT32_PAT_LPMI:
502       cpu->state.regs[r_d] = ft32_read_item (sd, dw, cpu->state.regs[r_1] + k8);
503       cpu->state.cycles += 1;
504       break;
505 
506     case FT32_PAT_STA:
507       cpu_mem_write (sd, dw, aa, cpu->state.regs[r_d]);
508       break;
509 
510     case FT32_PAT_STI:
511       cpu_mem_write (sd, dw, cpu->state.regs[r_d] + k8, cpu->state.regs[r_1]);
512       break;
513 
514     case FT32_PAT_LDA:
515       cpu->state.regs[r_d] = cpu_mem_read (sd, dw, aa);
516       cpu->state.cycles += 1;
517       break;
518 
519     case FT32_PAT_LDI:
520       cpu->state.regs[r_d] = cpu_mem_read (sd, dw, cpu->state.regs[r_1] + k8);
521       cpu->state.cycles += 1;
522       break;
523 
524     case FT32_PAT_EXA:
525       {
526 	uint32_t tmp;
527 	tmp = cpu_mem_read (sd, dw, aa);
528 	cpu_mem_write (sd, dw, aa, cpu->state.regs[r_d]);
529 	cpu->state.regs[r_d] = tmp;
530 	cpu->state.cycles += 1;
531       }
532       break;
533 
534     case FT32_PAT_EXI:
535       {
536 	uint32_t tmp;
537 	tmp = cpu_mem_read (sd, dw, cpu->state.regs[r_1] + k8);
538 	cpu_mem_write (sd, dw, cpu->state.regs[r_1] + k8, cpu->state.regs[r_d]);
539 	cpu->state.regs[r_d] = tmp;
540 	cpu->state.cycles += 1;
541       }
542       break;
543 
544     case FT32_PAT_PUSH:
545       ft32_push (sd, r_1v);
546       break;
547 
548     case FT32_PAT_LINK:
549       ft32_push (sd, cpu->state.regs[r_d]);
550       cpu->state.regs[r_d] = cpu->state.regs[FT32_HARD_SP];
551       cpu->state.regs[FT32_HARD_SP] -= k16;
552       cpu->state.regs[FT32_HARD_SP] &= 0xffff;
553       break;
554 
555     case FT32_PAT_UNLINK:
556       cpu->state.regs[FT32_HARD_SP] = cpu->state.regs[r_d];
557       cpu->state.regs[FT32_HARD_SP] &= 0xffff;
558       cpu->state.regs[r_d] = ft32_pop (sd);
559       break;
560 
561     case FT32_PAT_POP:
562       cpu->state.cycles += 1;
563       cpu->state.regs[r_d] = ft32_pop (sd);
564       break;
565 
566     case FT32_PAT_RETURN:
567       cpu->state.pc = ft32_pop (sd);
568       break;
569 
570     case FT32_PAT_FFUOP:
571       switch (al)
572 	{
573 	case 0x0:
574 	  cpu->state.regs[r_d] = r_1v / rimmv;
575 	  break;
576 	case 0x1:
577 	  cpu->state.regs[r_d] = r_1v % rimmv;
578 	  break;
579 	case 0x2:
580 	  cpu->state.regs[r_d] = ft32sdiv (r_1v, rimmv);
581 	  break;
582 	case 0x3:
583 	  cpu->state.regs[r_d] = ft32smod (r_1v, rimmv);
584 	  break;
585 
586 	case 0x4:
587 	  {
588 	    /* strcmp instruction.  */
589 	    uint32_t a = r_1v;
590 	    uint32_t b = rimmv;
591 	    uint32_t i = 0;
592 	    while ((GET_BYTE (a + i) != 0) &&
593 		   (GET_BYTE (a + i) == GET_BYTE (b + i)))
594 	      i++;
595 	    cpu->state.regs[r_d] = GET_BYTE (a + i) - GET_BYTE (b + i);
596 	  }
597 	  break;
598 
599 	case 0x5:
600 	  {
601 	    /* memcpy instruction.  */
602 	    uint32_t src = r_1v;
603 	    uint32_t dst = cpu->state.regs[r_d];
604 	    uint32_t i;
605 	    for (i = 0; i < (rimmv & 0x7fff); i++)
606 	      PUT_BYTE (dst + i, GET_BYTE (src + i));
607 	  }
608 	  break;
609 	case 0x6:
610 	  {
611 	    /* strlen instruction.  */
612 	    uint32_t src = r_1v;
613 	    uint32_t i;
614 	    for (i = 0; GET_BYTE (src + i) != 0; i++)
615 	      ;
616 	    cpu->state.regs[r_d] = i;
617 	  }
618 	  break;
619 	case 0x7:
620 	  {
621 	    /* memset instruction.  */
622 	    uint32_t dst = cpu->state.regs[r_d];
623 	    uint32_t i;
624 	    for (i = 0; i < (rimmv & 0x7fff); i++)
625 	      PUT_BYTE (dst + i, r_1v);
626 	  }
627 	  break;
628 	case 0x8:
629 	  cpu->state.regs[r_d] = r_1v * rimmv;
630 	  break;
631 	case 0x9:
632 	  cpu->state.regs[r_d] = ((uint64_t)r_1v * (uint64_t)rimmv) >> 32;
633 	  break;
634 	case 0xa:
635 	  {
636 	    /* stpcpy instruction.  */
637 	    uint32_t src = r_1v;
638 	    uint32_t dst = cpu->state.regs[r_d];
639 	    uint32_t i;
640 	    for (i = 0; GET_BYTE (src + i) != 0; i++)
641 	      PUT_BYTE (dst + i, GET_BYTE (src + i));
642 	    PUT_BYTE (dst + i, 0);
643 	    cpu->state.regs[r_d] = dst + i;
644 	  }
645 	  break;
646 	case 0xe:
647 	  {
648 	    /* streamout instruction.  */
649 	    uint32_t i;
650 	    uint32_t src = cpu->state.regs[r_1];
651 	    for (i = 0; i < rimmv; i += (1 << dw))
652 	      {
653 		cpu_mem_write (sd,
654 			       dw,
655 			       cpu->state.regs[r_d],
656 			       cpu_mem_read (sd, dw, src));
657 		src += (1 << dw);
658 	      }
659 	  }
660 	  break;
661 	default:
662 	  sim_io_eprintf (sd, "Unhandled ffu %#x at %08x\n", al, insnpc);
663 	  ILLEGAL ();
664 	}
665       break;
666 
667     default:
668       sim_io_eprintf (sd, "Unhandled pattern %d at %08x\n", upper, insnpc);
669       ILLEGAL ();
670     }
671   cpu->state.num_i++;
672 
673 escape:
674   ;
675 }
676 
677 void
678 sim_engine_run (SIM_DESC sd,
679 		int next_cpu_nr,  /* ignore  */
680 		int nr_cpus,      /* ignore  */
681 		int siggnal)      /* ignore  */
682 {
683   sim_cpu *cpu;
684 
685   SIM_ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
686 
687   cpu = STATE_CPU (sd, 0);
688 
689   while (1)
690     {
691       step_once (sd);
692       if (sim_events_tick (sd))
693 	sim_events_process (sd);
694     }
695 }
696 
697 static uint32_t *
698 ft32_lookup_register (SIM_CPU *cpu, int nr)
699 {
700   /* Handle the register number translation here.
701    * Sim registers are 0-31.
702    * Other tools (gcc, gdb) use:
703    * 0 - fp
704    * 1 - sp
705    * 2 - r0
706    * 31 - cc
707    */
708 
709   if ((nr < 0) || (nr > 32))
710     {
711       sim_io_eprintf (CPU_STATE (cpu), "unknown register %i\n", nr);
712       abort ();
713     }
714 
715   switch (nr)
716     {
717     case FT32_FP_REGNUM:
718       return &cpu->state.regs[FT32_HARD_FP];
719     case FT32_SP_REGNUM:
720       return &cpu->state.regs[FT32_HARD_SP];
721     case FT32_CC_REGNUM:
722       return &cpu->state.regs[FT32_HARD_CC];
723     case FT32_PC_REGNUM:
724       return &cpu->state.pc;
725     default:
726       return &cpu->state.regs[nr - 2];
727     }
728 }
729 
730 static int
731 ft32_reg_store (SIM_CPU *cpu,
732 		int rn,
733 		unsigned char *memory,
734 		int length)
735 {
736   if (0 <= rn && rn <= 32)
737     {
738       if (length == 4)
739 	*ft32_lookup_register (cpu, rn) = ft32_extract_unsigned_integer (memory, 4);
740 
741       return 4;
742     }
743   else
744     return 0;
745 }
746 
747 static int
748 ft32_reg_fetch (SIM_CPU *cpu,
749 		int rn,
750 		unsigned char *memory,
751 		int length)
752 {
753   if (0 <= rn && rn <= 32)
754     {
755       if (length == 4)
756 	ft32_store_unsigned_integer (memory, 4, *ft32_lookup_register (cpu, rn));
757 
758       return 4;
759     }
760   else
761     return 0;
762 }
763 
764 static sim_cia
765 ft32_pc_get (SIM_CPU *cpu)
766 {
767   return cpu->state.pc;
768 }
769 
770 static void
771 ft32_pc_set (SIM_CPU *cpu, sim_cia newpc)
772 {
773   cpu->state.pc = newpc;
774 }
775 
776 /* Cover function of sim_state_free to free the cpu buffers as well.  */
777 
778 static void
779 free_state (SIM_DESC sd)
780 {
781   if (STATE_MODULES (sd) != NULL)
782     sim_module_uninstall (sd);
783   sim_cpu_free_all (sd);
784   sim_state_free (sd);
785 }
786 
787 SIM_DESC
788 sim_open (SIM_OPEN_KIND kind,
789 	  host_callback *cb,
790 	  struct bfd *abfd,
791 	  char * const *argv)
792 {
793   char c;
794   size_t i;
795   SIM_DESC sd = sim_state_alloc (kind, cb);
796 
797   /* The cpu data is kept in a separately allocated chunk of memory.  */
798   if (sim_cpu_alloc_all (sd, 1, /*cgen_cpu_max_extra_bytes ()*/0) != SIM_RC_OK)
799     {
800       free_state (sd);
801       return 0;
802     }
803 
804   if (sim_pre_argv_init (sd, argv[0]) != SIM_RC_OK)
805     {
806       free_state (sd);
807       return 0;
808     }
809 
810   /* The parser will print an error message for us, so we silently return.  */
811   if (sim_parse_args (sd, argv) != SIM_RC_OK)
812     {
813       free_state (sd);
814       return 0;
815     }
816 
817   /* Allocate external memory if none specified by user.
818      Use address 4 here in case the user wanted address 0 unmapped.  */
819   if (sim_core_read_buffer (sd, NULL, read_map, &c, 4, 1) == 0)
820     {
821       sim_do_command (sd, "memory region 0x00000000,0x40000");
822       sim_do_command (sd, "memory region 0x800000,0x10000");
823     }
824 
825   /* Check for/establish the reference program image.  */
826   if (sim_analyze_program (sd,
827 			   (STATE_PROG_ARGV (sd) != NULL
828 			    ? *STATE_PROG_ARGV (sd)
829 			    : NULL), abfd) != SIM_RC_OK)
830     {
831       free_state (sd);
832       return 0;
833     }
834 
835   /* Configure/verify the target byte order and other runtime
836      configuration options.  */
837   if (sim_config (sd) != SIM_RC_OK)
838     {
839       free_state (sd);
840       return 0;
841     }
842 
843   if (sim_post_argv_init (sd) != SIM_RC_OK)
844     {
845       free_state (sd);
846       return 0;
847     }
848 
849   /* CPU specific initialization.  */
850   for (i = 0; i < MAX_NR_PROCESSORS; ++i)
851     {
852       SIM_CPU *cpu = STATE_CPU (sd, i);
853 
854       CPU_REG_FETCH (cpu) = ft32_reg_fetch;
855       CPU_REG_STORE (cpu) = ft32_reg_store;
856       CPU_PC_FETCH (cpu) = ft32_pc_get;
857       CPU_PC_STORE (cpu) = ft32_pc_set;
858     }
859 
860   return sd;
861 }
862 
863 SIM_RC
864 sim_create_inferior (SIM_DESC sd,
865 		     struct bfd *abfd,
866 		     char * const *argv,
867 		     char * const *env)
868 {
869   uint32_t addr;
870   sim_cpu *cpu = STATE_CPU (sd, 0);
871 
872   /* Set the PC.  */
873   if (abfd != NULL)
874     addr = bfd_get_start_address (abfd);
875   else
876     addr = 0;
877 
878   /* Standalone mode (i.e. `run`) will take care of the argv for us in
879      sim_open() -> sim_parse_args().  But in debug mode (i.e. 'target sim'
880      with `gdb`), we need to handle it because the user can change the
881      argv on the fly via gdb's 'run'.  */
882   if (STATE_PROG_ARGV (sd) != argv)
883     {
884       freeargv (STATE_PROG_ARGV (sd));
885       STATE_PROG_ARGV (sd) = dupargv (argv);
886     }
887   cpu->state.regs[FT32_HARD_SP] = addr;
888   cpu->state.num_i = 0;
889   cpu->state.cycles = 0;
890   cpu->state.next_tick_cycle = 100000;
891 
892   return SIM_RC_OK;
893 }
894