xref: /netbsd-src/external/gpl3/gdb/dist/sim/ft32/interp.c (revision 71f621822dbfd5073a314948bec169b7bb05f7be)
1 /* Simulator for the FT32 processor
2 
3    Copyright (C) 2008-2024 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 /* This must come before any other includes.  */
22 #include "defs.h"
23 
24 #include <fcntl.h>
25 #include <signal.h>
26 #include <stdlib.h>
27 #include <stdint.h>
28 
29 #include "bfd.h"
30 #include "sim/callback.h"
31 #include "libiberty.h"
32 #include "sim/sim.h"
33 
34 #include "sim-main.h"
35 #include "sim-options.h"
36 #include "sim-signal.h"
37 
38 #include "opcode/ft32.h"
39 
40 #include "ft32-sim.h"
41 
42 /*
43  * FT32 is a Harvard architecture: RAM and code occupy
44  * different address spaces.
45  *
46  * sim and gdb model FT32 memory by adding 0x800000 to RAM
47  * addresses. This means that sim/gdb can treat all addresses
48  * similarly.
49  *
50  * The address space looks like:
51  *
52  *    00000   start of code memory
53  *    3ffff   end of code memory
54  *   800000   start of RAM
55  *   80ffff   end of RAM
56  */
57 
58 #define RAM_BIAS  0x800000  /* Bias added to RAM addresses.  */
59 
60 static unsigned long
61 ft32_extract_unsigned_integer (const unsigned char *addr, int len)
62 {
63   unsigned long retval;
64   unsigned char *p;
65   unsigned char *startaddr = (unsigned char *) addr;
66   unsigned char *endaddr = startaddr + len;
67 
68   /* Start at the most significant end of the integer, and work towards
69      the least significant.  */
70   retval = 0;
71 
72   for (p = endaddr; p > startaddr;)
73     retval = (retval << 8) | * -- p;
74 
75   return retval;
76 }
77 
78 static void
79 ft32_store_unsigned_integer (unsigned char *addr, int len, unsigned long val)
80 {
81   unsigned char *p;
82   unsigned char *startaddr = (unsigned char *)addr;
83   unsigned char *endaddr = startaddr + len;
84 
85   for (p = startaddr; p < endaddr; p++)
86     {
87       *p = val & 0xff;
88       val >>= 8;
89     }
90 }
91 
92 /*
93  * Align EA according to its size DW.
94  * The FT32 ignores the low bit of a 16-bit addresss,
95  * and the low two bits of a 32-bit address.
96  */
97 static uint32_t ft32_align (uint32_t dw, uint32_t ea)
98 {
99   switch (dw)
100     {
101     case 1:
102       ea &= ~1;
103       break;
104     case 2:
105       ea &= ~3;
106       break;
107     default:
108       break;
109     }
110   return ea;
111 }
112 
113 /* Read an item from memory address EA, sized DW.  */
114 static uint32_t
115 ft32_read_item (SIM_DESC sd, int dw, uint32_t ea)
116 {
117   sim_cpu *cpu = STATE_CPU (sd, 0);
118   address_word cia = CPU_PC_GET (cpu);
119 
120   ea = ft32_align (dw, ea);
121 
122   switch (dw) {
123     case 0:
124       return sim_core_read_aligned_1 (cpu, cia, read_map, ea);
125     case 1:
126       return sim_core_read_aligned_2 (cpu, cia, read_map, ea);
127     case 2:
128       return sim_core_read_aligned_4 (cpu, cia, read_map, ea);
129     default:
130       abort ();
131   }
132 }
133 
134 /* Write item V to memory address EA, sized DW.  */
135 static void
136 ft32_write_item (SIM_DESC sd, int dw, uint32_t ea, uint32_t v)
137 {
138   sim_cpu *cpu = STATE_CPU (sd, 0);
139   address_word cia = CPU_PC_GET (cpu);
140 
141   ea = ft32_align (dw, ea);
142 
143   switch (dw) {
144     case 0:
145       sim_core_write_aligned_1 (cpu, cia, write_map, ea, v);
146       break;
147     case 1:
148       sim_core_write_aligned_2 (cpu, cia, write_map, ea, v);
149       break;
150     case 2:
151       sim_core_write_aligned_4 (cpu, cia, write_map, ea, v);
152       break;
153     default:
154       abort ();
155   }
156 }
157 
158 #define ILLEGAL() \
159   sim_engine_halt (sd, cpu, NULL, insnpc, sim_signalled, SIM_SIGILL)
160 
161 static uint32_t cpu_mem_read (SIM_DESC sd, uint32_t dw, uint32_t ea)
162 {
163   sim_cpu *cpu = STATE_CPU (sd, 0);
164   struct ft32_cpu_state *ft32_cpu = FT32_SIM_CPU (cpu);
165   uint32_t insnpc = ft32_cpu->pc;
166 
167   ea &= 0x1ffff;
168   if (ea & ~0xffff)
169     {
170       /* Simulate some IO devices */
171       switch (ea)
172 	{
173 	case 0x10000:
174 	  return getchar ();
175 	case 0x1fff4:
176 	  /* Read the simulator cycle timer.  */
177 	  return ft32_cpu->cycles / 100;
178 	default:
179 	  sim_io_eprintf (sd, "Illegal IO read address %08x, pc %#x\n",
180 			  ea, insnpc);
181 	  ILLEGAL ();
182 	}
183     }
184   return ft32_read_item (sd, dw, RAM_BIAS + ea);
185 }
186 
187 static void cpu_mem_write (SIM_DESC sd, uint32_t dw, uint32_t ea, uint32_t d)
188 {
189   sim_cpu *cpu = STATE_CPU (sd, 0);
190   struct ft32_cpu_state *ft32_cpu = FT32_SIM_CPU (cpu);
191   ea &= 0x1ffff;
192   if (ea & 0x10000)
193     {
194       /* Simulate some IO devices */
195       switch (ea)
196 	{
197 	case 0x10000:
198 	  /* Console output */
199 	  putchar (d & 0xff);
200 	  break;
201 	case 0x1fc80:
202 	  /* Unlock the PM write port */
203 	  ft32_cpu->pm_unlock = (d == 0x1337f7d1);
204 	  break;
205 	case 0x1fc84:
206 	  /* Set the PM write address register */
207 	  ft32_cpu->pm_addr = d;
208 	  break;
209 	case 0x1fc88:
210 	  if (ft32_cpu->pm_unlock)
211 	    {
212 	      /* Write to PM.  */
213 	      ft32_write_item (sd, dw, ft32_cpu->pm_addr, d);
214 	      ft32_cpu->pm_addr += 4;
215 	    }
216 	  break;
217 	case 0x1fffc:
218 	  /* Normal exit.  */
219 	  sim_engine_halt (sd, cpu, NULL, ft32_cpu->pc, sim_exited, ft32_cpu->regs[0]);
220 	  break;
221 	case 0x1fff8:
222 	  sim_io_printf (sd, "Debug write %08x\n", d);
223 	  break;
224 	default:
225 	  sim_io_eprintf (sd, "Unknown IO write %08x to to %08x\n", d, ea);
226 	}
227     }
228   else
229     ft32_write_item (sd, dw, RAM_BIAS + ea, d);
230 }
231 
232 #define GET_BYTE(ea)    cpu_mem_read (sd, 0, (ea))
233 #define PUT_BYTE(ea, d) cpu_mem_write (sd, 0, (ea), (d))
234 
235 /* LSBS (n) is a mask of the least significant N bits.  */
236 #define LSBS(n) ((1U << (n)) - 1)
237 
238 static void ft32_push (SIM_DESC sd, uint32_t v)
239 {
240   sim_cpu *cpu = STATE_CPU (sd, 0);
241   struct ft32_cpu_state *ft32_cpu = FT32_SIM_CPU (cpu);
242   ft32_cpu->regs[FT32_HARD_SP] -= 4;
243   ft32_cpu->regs[FT32_HARD_SP] &= 0xffff;
244   cpu_mem_write (sd, 2, ft32_cpu->regs[FT32_HARD_SP], v);
245 }
246 
247 static uint32_t ft32_pop (SIM_DESC sd)
248 {
249   sim_cpu *cpu = STATE_CPU (sd, 0);
250   struct ft32_cpu_state *ft32_cpu = FT32_SIM_CPU (cpu);
251   uint32_t r = cpu_mem_read (sd, 2, ft32_cpu->regs[FT32_HARD_SP]);
252   ft32_cpu->regs[FT32_HARD_SP] += 4;
253   ft32_cpu->regs[FT32_HARD_SP] &= 0xffff;
254   return r;
255 }
256 
257 /* Extract the low SIZ bits of N as an unsigned number.  */
258 static int nunsigned (int siz, int n)
259 {
260   return n & LSBS (siz);
261 }
262 
263 /* Extract the low SIZ bits of N as a signed number.  */
264 static int nsigned (int siz, int n)
265 {
266   int shift = (sizeof (int) * 8) - siz;
267   return (n << shift) >> shift;
268 }
269 
270 /* Signed division N / D, matching hw behavior for (MIN_INT, -1).  */
271 static uint32_t ft32sdiv (uint32_t n, uint32_t d)
272 {
273   if (n == 0x80000000UL && d == 0xffffffffUL)
274     return 0x80000000UL;
275   else
276     return (uint32_t)((int)n / (int)d);
277 }
278 
279 /* Signed modulus N % D, matching hw behavior for (MIN_INT, -1).  */
280 static uint32_t ft32smod (uint32_t n, uint32_t d)
281 {
282   if (n == 0x80000000UL && d == 0xffffffffUL)
283     return 0;
284   else
285     return (uint32_t)((int)n % (int)d);
286 }
287 
288 /* Circular rotate right N by B bits.  */
289 static uint32_t ror (uint32_t n, uint32_t b)
290 {
291   b &= 31;
292   return (n >> b) | (n << (32 - b));
293 }
294 
295 /* Implement the BINS machine instruction.
296    See FT32 Programmer's Reference for details.  */
297 static uint32_t bins (uint32_t d, uint32_t f, uint32_t len, uint32_t pos)
298 {
299   uint32_t bitmask = LSBS (len) << pos;
300   return (d & ~bitmask) | ((f << pos) & bitmask);
301 }
302 
303 /* Implement the FLIP machine instruction.
304    See FT32 Programmer's Reference for details.  */
305 static uint32_t flip (uint32_t x, uint32_t b)
306 {
307   if (b & 1)
308     x = (x & 0x55555555) <<  1 | (x & 0xAAAAAAAA) >>  1;
309   if (b & 2)
310     x = (x & 0x33333333) <<  2 | (x & 0xCCCCCCCC) >>  2;
311   if (b & 4)
312     x = (x & 0x0F0F0F0F) <<  4 | (x & 0xF0F0F0F0) >>  4;
313   if (b & 8)
314     x = (x & 0x00FF00FF) <<  8 | (x & 0xFF00FF00) >>  8;
315   if (b & 16)
316     x = (x & 0x0000FFFF) << 16 | (x & 0xFFFF0000) >> 16;
317   return x;
318 }
319 
320 static void
321 step_once (SIM_DESC sd)
322 {
323   sim_cpu *cpu = STATE_CPU (sd, 0);
324   struct ft32_cpu_state *ft32_cpu = FT32_SIM_CPU (cpu);
325   uint32_t inst;
326   uint32_t dw;
327   uint32_t cb;
328   uint32_t r_d;
329   uint32_t cr;
330   uint32_t cv;
331   uint32_t bt;
332   uint32_t r_1;
333   uint32_t rimm;
334   uint32_t r_2;
335   uint32_t k20;
336   uint32_t pa;
337   uint32_t aa;
338   uint32_t k16;
339   uint32_t k15;
340   uint32_t al;
341   uint32_t r_1v;
342   uint32_t rimmv;
343   uint32_t bit_pos;
344   uint32_t bit_len;
345   uint32_t upper;
346   uint32_t insnpc;
347   unsigned int sc[2];
348   int isize;
349 
350   inst = ft32_read_item (sd, 2, ft32_cpu->pc);
351   ft32_cpu->cycles += 1;
352 
353   if ((STATE_ARCHITECTURE (sd)->mach == bfd_mach_ft32b)
354       && ft32_decode_shortcode (ft32_cpu->pc, inst, sc))
355     {
356       if ((ft32_cpu->pc & 3) == 0)
357         inst = sc[0];
358       else
359         inst = sc[1];
360       isize = 2;
361     }
362   else
363     isize = 4;
364 
365   /* Handle "call 8" (which is FT32's "break" equivalent) here.  */
366   if (inst == 0x00340002)
367     {
368       sim_engine_halt (sd, cpu, NULL,
369 		       ft32_cpu->pc,
370 		       sim_stopped, SIM_SIGTRAP);
371       goto escape;
372     }
373 
374   dw   =              (inst >> FT32_FLD_DW_BIT) & LSBS (FT32_FLD_DW_SIZ);
375   cb   =              (inst >> FT32_FLD_CB_BIT) & LSBS (FT32_FLD_CB_SIZ);
376   r_d  =              (inst >> FT32_FLD_R_D_BIT) & LSBS (FT32_FLD_R_D_SIZ);
377   cr   =              (inst >> FT32_FLD_CR_BIT) & LSBS (FT32_FLD_CR_SIZ);
378   cv   =              (inst >> FT32_FLD_CV_BIT) & LSBS (FT32_FLD_CV_SIZ);
379   bt   =              (inst >> FT32_FLD_BT_BIT) & LSBS (FT32_FLD_BT_SIZ);
380   r_1  =              (inst >> FT32_FLD_R_1_BIT) & LSBS (FT32_FLD_R_1_SIZ);
381   rimm =              (inst >> FT32_FLD_RIMM_BIT) & LSBS (FT32_FLD_RIMM_SIZ);
382   r_2  =              (inst >> FT32_FLD_R_2_BIT) & LSBS (FT32_FLD_R_2_SIZ);
383   k20  = nsigned (20, (inst >> FT32_FLD_K20_BIT) & LSBS (FT32_FLD_K20_SIZ));
384   pa   =              (inst >> FT32_FLD_PA_BIT) & LSBS (FT32_FLD_PA_SIZ);
385   aa   =              (inst >> FT32_FLD_AA_BIT) & LSBS (FT32_FLD_AA_SIZ);
386   k16  =              (inst >> FT32_FLD_K16_BIT) & LSBS (FT32_FLD_K16_SIZ);
387   k15  =              (inst >> FT32_FLD_K15_BIT) & LSBS (FT32_FLD_K15_SIZ);
388   if (k15 & 0x80)
389     k15 ^= 0x7f00;
390   if (k15 & 0x4000)
391     k15 -= 0x8000;
392   al   =              (inst >> FT32_FLD_AL_BIT) & LSBS (FT32_FLD_AL_SIZ);
393 
394   r_1v = ft32_cpu->regs[r_1];
395   rimmv = (rimm & 0x400) ? nsigned (10, rimm) : ft32_cpu->regs[rimm & 0x1f];
396 
397   bit_pos = rimmv & 31;
398   bit_len = 0xf & (rimmv >> 5);
399   if (bit_len == 0)
400     bit_len = 16;
401 
402   upper = (inst >> 27);
403 
404   insnpc = ft32_cpu->pc;
405   ft32_cpu->pc += isize;
406   switch (upper)
407     {
408     case FT32_PAT_TOC:
409     case FT32_PAT_TOCI:
410       {
411 	int take = (cr == 3) || ((1 & (ft32_cpu->regs[28 + cr] >> cb)) == cv);
412 	if (take)
413 	  {
414 	    ft32_cpu->cycles += 1;
415 	    if (bt)
416 	      ft32_push (sd, ft32_cpu->pc); /* this is a call.  */
417 	    if (upper == FT32_PAT_TOC)
418 	      ft32_cpu->pc = pa << 2;
419 	    else
420 	      ft32_cpu->pc = ft32_cpu->regs[r_2];
421 	    if (ft32_cpu->pc == 0x8)
422 		goto escape;
423 	  }
424       }
425       break;
426 
427     case FT32_PAT_ALUOP:
428     case FT32_PAT_CMPOP:
429       {
430 	uint32_t result;
431 	switch (al)
432 	  {
433 	  case 0x0: result = r_1v + rimmv; break;
434 	  case 0x1: result = ror (r_1v, rimmv); break;
435 	  case 0x2: result = r_1v - rimmv; break;
436 	  case 0x3: result = (r_1v << 10) | (1023 & rimmv); break;
437 	  case 0x4: result = r_1v & rimmv; break;
438 	  case 0x5: result = r_1v | rimmv; break;
439 	  case 0x6: result = r_1v ^ rimmv; break;
440 	  case 0x7: result = ~(r_1v ^ rimmv); break;
441 	  case 0x8: result = r_1v << rimmv; break;
442 	  case 0x9: result = r_1v >> rimmv; break;
443 	  case 0xa: result = (int32_t)r_1v >> rimmv; break;
444 	  case 0xb: result = bins (r_1v, rimmv >> 10, bit_len, bit_pos); break;
445 	  case 0xc: result = nsigned (bit_len, r_1v >> bit_pos); break;
446 	  case 0xd: result = nunsigned (bit_len, r_1v >> bit_pos); break;
447 	  case 0xe: result = flip (r_1v, rimmv); break;
448 	  default:
449 	    sim_io_eprintf (sd, "Unhandled alu %#x\n", al);
450 	    ILLEGAL ();
451 	  }
452 	if (upper == FT32_PAT_ALUOP)
453 	  ft32_cpu->regs[r_d] = result;
454 	else
455 	  {
456 	    uint32_t dwmask = 0;
457 	    int dwsiz = 0;
458 	    int zero;
459 	    int sign;
460 	    int ahi;
461 	    int bhi;
462 	    int overflow;
463 	    int carry;
464 	    int bit;
465 	    uint64_t ra;
466 	    uint64_t rb;
467 	    int above;
468 	    int greater;
469 	    int greatereq;
470 
471 	    switch (dw)
472 	      {
473 	      case 0: dwsiz = 7;  dwmask = 0xffU; break;
474 	      case 1: dwsiz = 15; dwmask = 0xffffU; break;
475 	      case 2: dwsiz = 31; dwmask = 0xffffffffU; break;
476 	      }
477 
478 	    zero = (0 == (result & dwmask));
479 	    sign = 1 & (result >> dwsiz);
480 	    ahi = 1 & (r_1v >> dwsiz);
481 	    bhi = 1 & (rimmv >> dwsiz);
482 	    overflow = (sign != ahi) & (ahi == !bhi);
483 	    bit = (dwsiz + 1);
484 	    ra = r_1v & dwmask;
485 	    rb = rimmv & dwmask;
486 	    switch (al)
487 	      {
488 	      case 0x0: carry = 1 & ((ra + rb) >> bit); break;
489 	      case 0x2: carry = 1 & ((ra - rb) >> bit); break;
490 	      default:  carry = 0; break;
491 	      }
492 	    above = (!carry & !zero);
493 	    greater = (sign == overflow) & !zero;
494 	    greatereq = (sign == overflow);
495 
496 	    ft32_cpu->regs[r_d] = (
497 	      (above << 6) |
498 	      (greater << 5) |
499 	      (greatereq << 4) |
500 	      (sign << 3) |
501 	      (overflow << 2) |
502 	      (carry << 1) |
503 	      (zero << 0));
504 	  }
505       }
506       break;
507 
508     case FT32_PAT_LDK:
509       ft32_cpu->regs[r_d] = k20;
510       break;
511 
512     case FT32_PAT_LPM:
513       ft32_cpu->regs[r_d] = ft32_read_item (sd, dw, pa << 2);
514       ft32_cpu->cycles += 1;
515       break;
516 
517     case FT32_PAT_LPMI:
518       ft32_cpu->regs[r_d] = ft32_read_item (sd, dw, ft32_cpu->regs[r_1] + k15);
519       ft32_cpu->cycles += 1;
520       break;
521 
522     case FT32_PAT_STA:
523       cpu_mem_write (sd, dw, aa, ft32_cpu->regs[r_d]);
524       break;
525 
526     case FT32_PAT_STI:
527       cpu_mem_write (sd, dw, ft32_cpu->regs[r_d] + k15, ft32_cpu->regs[r_1]);
528       break;
529 
530     case FT32_PAT_LDA:
531       ft32_cpu->regs[r_d] = cpu_mem_read (sd, dw, aa);
532       ft32_cpu->cycles += 1;
533       break;
534 
535     case FT32_PAT_LDI:
536       ft32_cpu->regs[r_d] = cpu_mem_read (sd, dw, ft32_cpu->regs[r_1] + k15);
537       ft32_cpu->cycles += 1;
538       break;
539 
540     case FT32_PAT_EXA:
541       {
542 	uint32_t tmp;
543 	tmp = cpu_mem_read (sd, dw, aa);
544 	cpu_mem_write (sd, dw, aa, ft32_cpu->regs[r_d]);
545 	ft32_cpu->regs[r_d] = tmp;
546 	ft32_cpu->cycles += 1;
547       }
548       break;
549 
550     case FT32_PAT_EXI:
551       {
552 	uint32_t tmp;
553 	tmp = cpu_mem_read (sd, dw, ft32_cpu->regs[r_1] + k15);
554 	cpu_mem_write (sd, dw, ft32_cpu->regs[r_1] + k15, ft32_cpu->regs[r_d]);
555 	ft32_cpu->regs[r_d] = tmp;
556 	ft32_cpu->cycles += 1;
557       }
558       break;
559 
560     case FT32_PAT_PUSH:
561       ft32_push (sd, r_1v);
562       break;
563 
564     case FT32_PAT_LINK:
565       ft32_push (sd, ft32_cpu->regs[r_d]);
566       ft32_cpu->regs[r_d] = ft32_cpu->regs[FT32_HARD_SP];
567       ft32_cpu->regs[FT32_HARD_SP] -= k16;
568       ft32_cpu->regs[FT32_HARD_SP] &= 0xffff;
569       break;
570 
571     case FT32_PAT_UNLINK:
572       ft32_cpu->regs[FT32_HARD_SP] = ft32_cpu->regs[r_d];
573       ft32_cpu->regs[FT32_HARD_SP] &= 0xffff;
574       ft32_cpu->regs[r_d] = ft32_pop (sd);
575       break;
576 
577     case FT32_PAT_POP:
578       ft32_cpu->cycles += 1;
579       ft32_cpu->regs[r_d] = ft32_pop (sd);
580       break;
581 
582     case FT32_PAT_RETURN:
583       ft32_cpu->pc = ft32_pop (sd);
584       break;
585 
586     case FT32_PAT_FFUOP:
587       switch (al)
588 	{
589 	case 0x0:
590 	  ft32_cpu->regs[r_d] = r_1v / rimmv;
591 	  break;
592 	case 0x1:
593 	  ft32_cpu->regs[r_d] = r_1v % rimmv;
594 	  break;
595 	case 0x2:
596 	  ft32_cpu->regs[r_d] = ft32sdiv (r_1v, rimmv);
597 	  break;
598 	case 0x3:
599 	  ft32_cpu->regs[r_d] = ft32smod (r_1v, rimmv);
600 	  break;
601 
602 	case 0x4:
603 	  {
604 	    /* strcmp instruction.  */
605 	    uint32_t a = r_1v;
606 	    uint32_t b = rimmv;
607 	    uint32_t i = 0;
608 	    while ((GET_BYTE (a + i) != 0) &&
609 		   (GET_BYTE (a + i) == GET_BYTE (b + i)))
610 	      i++;
611 	    ft32_cpu->regs[r_d] = GET_BYTE (a + i) - GET_BYTE (b + i);
612 	  }
613 	  break;
614 
615 	case 0x5:
616 	  {
617 	    /* memcpy instruction.  */
618 	    uint32_t src = r_1v;
619 	    uint32_t dst = ft32_cpu->regs[r_d];
620 	    uint32_t i;
621 	    for (i = 0; i < (rimmv & 0x7fff); i++)
622 	      PUT_BYTE (dst + i, GET_BYTE (src + i));
623 	  }
624 	  break;
625 	case 0x6:
626 	  {
627 	    /* strlen instruction.  */
628 	    uint32_t src = r_1v;
629 	    uint32_t i;
630 	    for (i = 0; GET_BYTE (src + i) != 0; i++)
631 	      ;
632 	    ft32_cpu->regs[r_d] = i;
633 	  }
634 	  break;
635 	case 0x7:
636 	  {
637 	    /* memset instruction.  */
638 	    uint32_t dst = ft32_cpu->regs[r_d];
639 	    uint32_t i;
640 	    for (i = 0; i < (rimmv & 0x7fff); i++)
641 	      PUT_BYTE (dst + i, r_1v);
642 	  }
643 	  break;
644 	case 0x8:
645 	  ft32_cpu->regs[r_d] = r_1v * rimmv;
646 	  break;
647 	case 0x9:
648 	  ft32_cpu->regs[r_d] = ((uint64_t)r_1v * (uint64_t)rimmv) >> 32;
649 	  break;
650 	case 0xa:
651 	  {
652 	    /* stpcpy instruction.  */
653 	    uint32_t src = r_1v;
654 	    uint32_t dst = ft32_cpu->regs[r_d];
655 	    uint32_t i;
656 	    for (i = 0; GET_BYTE (src + i) != 0; i++)
657 	      PUT_BYTE (dst + i, GET_BYTE (src + i));
658 	    PUT_BYTE (dst + i, 0);
659 	    ft32_cpu->regs[r_d] = dst + i;
660 	  }
661 	  break;
662 	case 0xe:
663 	  {
664 	    /* streamout instruction.  */
665 	    uint32_t i;
666 	    uint32_t src = ft32_cpu->regs[r_1];
667 	    for (i = 0; i < rimmv; i += (1 << dw))
668 	      {
669 		cpu_mem_write (sd,
670 			       dw,
671 			       ft32_cpu->regs[r_d],
672 			       cpu_mem_read (sd, dw, src));
673 		src += (1 << dw);
674 	      }
675 	  }
676 	  break;
677 	default:
678 	  sim_io_eprintf (sd, "Unhandled ffu %#x at %08x\n", al, insnpc);
679 	  ILLEGAL ();
680 	}
681       break;
682 
683     default:
684       sim_io_eprintf (sd, "Unhandled pattern %d at %08x\n", upper, insnpc);
685       ILLEGAL ();
686     }
687   ft32_cpu->num_i++;
688 
689 escape:
690   ;
691 }
692 
693 void
694 sim_engine_run (SIM_DESC sd,
695 		int next_cpu_nr,  /* ignore  */
696 		int nr_cpus,      /* ignore  */
697 		int siggnal)      /* ignore  */
698 {
699   SIM_ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
700 
701   while (1)
702     {
703       step_once (sd);
704       if (sim_events_tick (sd))
705 	sim_events_process (sd);
706     }
707 }
708 
709 static uint32_t *
710 ft32_lookup_register (SIM_CPU *cpu, int nr)
711 {
712   /* Handle the register number translation here.
713    * Sim registers are 0-31.
714    * Other tools (gcc, gdb) use:
715    * 0 - fp
716    * 1 - sp
717    * 2 - r0
718    * 31 - cc
719    */
720 
721   struct ft32_cpu_state *ft32_cpu = FT32_SIM_CPU (cpu);
722 
723   if ((nr < 0) || (nr > 32))
724     {
725       sim_io_eprintf (CPU_STATE (cpu), "unknown register %i\n", nr);
726       abort ();
727     }
728 
729   switch (nr)
730     {
731     case FT32_FP_REGNUM:
732       return &ft32_cpu->regs[FT32_HARD_FP];
733     case FT32_SP_REGNUM:
734       return &ft32_cpu->regs[FT32_HARD_SP];
735     case FT32_CC_REGNUM:
736       return &ft32_cpu->regs[FT32_HARD_CC];
737     case FT32_PC_REGNUM:
738       return &ft32_cpu->pc;
739     default:
740       return &ft32_cpu->regs[nr - 2];
741     }
742 }
743 
744 static int
745 ft32_reg_store (SIM_CPU *cpu,
746 		int rn,
747 		const void *memory,
748 		int length)
749 {
750   if (0 <= rn && rn <= 32)
751     {
752       if (length == 4)
753 	*ft32_lookup_register (cpu, rn) = ft32_extract_unsigned_integer (memory, 4);
754 
755       return 4;
756     }
757   else
758     return 0;
759 }
760 
761 static int
762 ft32_reg_fetch (SIM_CPU *cpu,
763 		int rn,
764 		void *memory,
765 		int length)
766 {
767   if (0 <= rn && rn <= 32)
768     {
769       if (length == 4)
770 	ft32_store_unsigned_integer (memory, 4, *ft32_lookup_register (cpu, rn));
771 
772       return 4;
773     }
774   else
775     return 0;
776 }
777 
778 static sim_cia
779 ft32_pc_get (SIM_CPU *cpu)
780 {
781   return FT32_SIM_CPU (cpu)->pc;
782 }
783 
784 static void
785 ft32_pc_set (SIM_CPU *cpu, sim_cia newpc)
786 {
787   FT32_SIM_CPU (cpu)->pc = newpc;
788 }
789 
790 /* Cover function of sim_state_free to free the cpu buffers as well.  */
791 
792 static void
793 free_state (SIM_DESC sd)
794 {
795   if (STATE_MODULES (sd) != NULL)
796     sim_module_uninstall (sd);
797   sim_cpu_free_all (sd);
798   sim_state_free (sd);
799 }
800 
801 SIM_DESC
802 sim_open (SIM_OPEN_KIND kind,
803 	  host_callback *cb,
804 	  struct bfd *abfd,
805 	  char * const *argv)
806 {
807   char c;
808   size_t i;
809   SIM_DESC sd = sim_state_alloc (kind, cb);
810 
811   /* Set default options before parsing user options.  */
812   current_alignment = STRICT_ALIGNMENT;
813   current_target_byte_order = BFD_ENDIAN_LITTLE;
814 
815   /* The cpu data is kept in a separately allocated chunk of memory.  */
816   if (sim_cpu_alloc_all_extra (sd, 0, sizeof (struct ft32_cpu_state))
817       != SIM_RC_OK)
818     {
819       free_state (sd);
820       return 0;
821     }
822 
823   if (sim_pre_argv_init (sd, argv[0]) != SIM_RC_OK)
824     {
825       free_state (sd);
826       return 0;
827     }
828 
829   /* The parser will print an error message for us, so we silently return.  */
830   if (sim_parse_args (sd, argv) != SIM_RC_OK)
831     {
832       free_state (sd);
833       return 0;
834     }
835 
836   /* Allocate external memory if none specified by user.
837      Use address 4 here in case the user wanted address 0 unmapped.  */
838   if (sim_core_read_buffer (sd, NULL, read_map, &c, 4, 1) == 0)
839     {
840       sim_do_command (sd, "memory region 0x00000000,0x40000");
841       sim_do_command (sd, "memory region 0x800000,0x10000");
842     }
843 
844   /* Check for/establish the reference program image.  */
845   if (sim_analyze_program (sd, STATE_PROG_FILE (sd), abfd) != SIM_RC_OK)
846     {
847       free_state (sd);
848       return 0;
849     }
850 
851   /* Configure/verify the target byte order and other runtime
852      configuration options.  */
853   if (sim_config (sd) != SIM_RC_OK)
854     {
855       free_state (sd);
856       return 0;
857     }
858 
859   if (sim_post_argv_init (sd) != SIM_RC_OK)
860     {
861       free_state (sd);
862       return 0;
863     }
864 
865   /* CPU specific initialization.  */
866   for (i = 0; i < MAX_NR_PROCESSORS; ++i)
867     {
868       SIM_CPU *cpu = STATE_CPU (sd, i);
869 
870       CPU_REG_FETCH (cpu) = ft32_reg_fetch;
871       CPU_REG_STORE (cpu) = ft32_reg_store;
872       CPU_PC_FETCH (cpu) = ft32_pc_get;
873       CPU_PC_STORE (cpu) = ft32_pc_set;
874     }
875 
876   return sd;
877 }
878 
879 SIM_RC
880 sim_create_inferior (SIM_DESC sd,
881 		     struct bfd *abfd,
882 		     char * const *argv,
883 		     char * const *env)
884 {
885   uint32_t addr;
886   sim_cpu *cpu = STATE_CPU (sd, 0);
887   struct ft32_cpu_state *ft32_cpu = FT32_SIM_CPU (cpu);
888   host_callback *cb = STATE_CALLBACK (sd);
889 
890   /* Set the PC.  */
891   if (abfd != NULL)
892     addr = bfd_get_start_address (abfd);
893   else
894     addr = 0;
895 
896   /* Standalone mode (i.e. `run`) will take care of the argv for us in
897      sim_open() -> sim_parse_args().  But in debug mode (i.e. 'target sim'
898      with `gdb`), we need to handle it because the user can change the
899      argv on the fly via gdb's 'run'.  */
900   if (STATE_PROG_ARGV (sd) != argv)
901     {
902       freeargv (STATE_PROG_ARGV (sd));
903       STATE_PROG_ARGV (sd) = dupargv (argv);
904     }
905 
906   if (STATE_PROG_ENVP (sd) != env)
907     {
908       freeargv (STATE_PROG_ENVP (sd));
909       STATE_PROG_ENVP (sd) = dupargv (env);
910     }
911 
912   cb->argv = STATE_PROG_ARGV (sd);
913   cb->envp = STATE_PROG_ENVP (sd);
914 
915   ft32_cpu->regs[FT32_HARD_SP] = addr;
916   ft32_cpu->num_i = 0;
917   ft32_cpu->cycles = 0;
918   ft32_cpu->next_tick_cycle = 100000;
919 
920   return SIM_RC_OK;
921 }
922