xref: /netbsd-src/external/gpl3/gdb/dist/sim/or1k/or1k.c (revision 924795e69c8bb3f17afd8fcbb799710cc1719dc4)
1 /* OpenRISC simulator support code
2    Copyright (C) 2017-2023 Free Software Foundation, Inc.
3 
4    This file is part of GDB, the GNU debugger.
5 
6    This program is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License as published by
8    the Free Software Foundation; either version 3 of the License, or
9    (at your option) any later version.
10 
11    This program is distributed in the hope that it will be useful,
12    but WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14    GNU General Public License for more details.
15 
16    You should have received a copy of the GNU General Public License
17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
18 
19 /* This must come before any other includes.  */
20 #include "defs.h"
21 
22 #define WANT_CPU_OR1K32BF
23 #define WANT_CPU
24 
25 #include "sim-main.h"
26 #include "symcat.h"
27 #include "cgen-ops.h"
28 #include "cgen-mem.h"
29 #include "cpuall.h"
30 
31 #include <string.h>
32 
33 int
34 or1k32bf_fetch_register (sim_cpu *current_cpu, int rn, void *buf, int len)
35 {
36   if (rn < 32)
37     SETTWI (buf, GET_H_GPR (rn));
38   else
39     switch (rn)
40       {
41       case PPC_REGNUM:
42 	SETTWI (buf, GET_H_SYS_PPC ());
43 	break;
44       case PC_REGNUM:
45 	SETTWI (buf, GET_H_PC ());
46 	break;
47       case SR_REGNUM:
48 	SETTWI (buf, GET_H_SYS_SR ());
49 	break;
50       default:
51 	return 0;
52       }
53   return sizeof (WI);		/* WI from arch.h */
54 }
55 
56 int
57 or1k32bf_store_register (sim_cpu *current_cpu, int rn, const void *buf, int len)
58 {
59   if (rn < 32)
60     SET_H_GPR (rn, GETTWI (buf));
61   else
62     switch (rn)
63       {
64       case PPC_REGNUM:
65 	SET_H_SYS_PPC (GETTWI (buf));
66 	break;
67       case PC_REGNUM:
68 	SET_H_PC (GETTWI (buf));
69 	break;
70       case SR_REGNUM:
71 	SET_H_SYS_SR (GETTWI (buf));
72 	break;
73       default:
74 	return 0;
75       }
76   return sizeof (WI);		/* WI from arch.h */
77 }
78 
79 int
80 or1k32bf_model_or1200_u_exec (sim_cpu *current_cpu, const IDESC *idesc,
81 			      int unit_num, int referenced)
82 {
83   return -1;
84 }
85 
86 int
87 or1k32bf_model_or1200nd_u_exec (sim_cpu *current_cpu, const IDESC *idesc,
88 				int unit_num, int referenced)
89 {
90   return -1;
91 }
92 
93 void
94 or1k32bf_model_insn_before (sim_cpu *current_cpu, int first_p)
95 {
96 }
97 
98 void
99 or1k32bf_model_insn_after (sim_cpu *current_cpu, int last_p, int cycles)
100 {
101 }
102 
103 USI
104 or1k32bf_h_spr_get_raw (sim_cpu *current_cpu, USI addr)
105 {
106   SIM_DESC sd = CPU_STATE (current_cpu);
107   SIM_ASSERT (addr < NUM_SPR);
108   return current_cpu->spr[addr];
109 }
110 
111 void
112 or1k32bf_h_spr_set_raw (sim_cpu *current_cpu, USI addr, USI val)
113 {
114   SIM_DESC sd = CPU_STATE (current_cpu);
115   SIM_ASSERT (addr < NUM_SPR);
116   current_cpu->spr[addr] = val;
117 }
118 
119 USI
120 or1k32bf_h_spr_field_get_raw (sim_cpu *current_cpu, USI addr, int msb, int lsb)
121 {
122   SIM_DESC sd = CPU_STATE (current_cpu);
123   SIM_ASSERT (addr < NUM_SPR);
124   return LSEXTRACTED (current_cpu->spr[addr], msb, lsb);
125 }
126 
127 void
128 or1k32bf_h_spr_field_set_raw (sim_cpu *current_cpu, USI addr, int msb, int lsb,
129 			      USI val)
130 {
131   current_cpu->spr[addr] &= ~LSMASK32 (msb, lsb);
132   current_cpu->spr[addr] |= LSINSERTED (val, msb, lsb);
133 }
134 
135 /* Initialize a sim cpu object.  */
136 void
137 or1k_cpu_init (SIM_DESC sd, sim_cpu *current_cpu, const USI or1k_vr,
138 	       const USI or1k_upr, const USI or1k_cpucfgr)
139 {
140   /* Set the configuration registers passed from the user.  */
141   SET_H_SYS_VR (or1k_vr);
142   SET_H_SYS_UPR (or1k_upr);
143   SET_H_SYS_CPUCFGR (or1k_cpucfgr);
144 
145 #define CHECK_SPR_FIELD(GROUP, INDEX, FIELD, test) \
146   do \
147     { \
148       USI field = GET_H_##SYS##_##INDEX##_##FIELD (); \
149       if (!(test)) \
150 	sim_io_eprintf \
151 	  (sd, "WARNING: unsupported %s field in %s register: 0x%x\n", \
152 	   #FIELD, #INDEX, field); \
153     } while (0)
154 
155   /* Set flags indicating if we are in a delay slot or not.  */
156   current_cpu->next_delay_slot = 0;
157   current_cpu->delay_slot = 0;
158 
159   /* Verify any user passed fields and warn on configurations we don't
160      support.  */
161   CHECK_SPR_FIELD (SYS, UPR, UP, field == 1);
162   CHECK_SPR_FIELD (SYS, UPR, DCP, field == 0);
163   CHECK_SPR_FIELD (SYS, UPR, ICP, field == 0);
164   CHECK_SPR_FIELD (SYS, UPR, DMP, field == 0);
165   CHECK_SPR_FIELD (SYS, UPR, MP, field == 0);
166   CHECK_SPR_FIELD (SYS, UPR, IMP, field == 0);
167   CHECK_SPR_FIELD (SYS, UPR, DUP, field == 0);
168   CHECK_SPR_FIELD (SYS, UPR, PCUP, field == 0);
169   CHECK_SPR_FIELD (SYS, UPR, PICP, field == 0);
170   CHECK_SPR_FIELD (SYS, UPR, PMP, field == 0);
171   CHECK_SPR_FIELD (SYS, UPR, TTP, field == 0);
172   CHECK_SPR_FIELD (SYS, UPR, CUP, field == 0);
173 
174   CHECK_SPR_FIELD (SYS, CPUCFGR, NSGR, field == 0);
175   CHECK_SPR_FIELD (SYS, CPUCFGR, CGF, field == 0);
176   CHECK_SPR_FIELD (SYS, CPUCFGR, OB32S, field == 1);
177   CHECK_SPR_FIELD (SYS, CPUCFGR, OF32S, field == 1);
178   CHECK_SPR_FIELD (SYS, CPUCFGR, OB64S, field == 0);
179   CHECK_SPR_FIELD (SYS, CPUCFGR, OF64S, field == 0);
180   CHECK_SPR_FIELD (SYS, CPUCFGR, OV64S, field == 0);
181 
182 #undef CHECK_SPR_FIELD
183 
184   /* Configure the fpu operations and mark fpu available.  */
185   cgen_init_accurate_fpu (current_cpu, CGEN_CPU_FPU (current_cpu),
186 			  or1k32bf_fpu_error);
187   SET_H_SYS_CPUCFGR_OF32S (1);
188 
189   /* Set the UPR[UP] flag, even if the user tried to unset it, as we always
190      support the Unit Present Register.  */
191   SET_H_SYS_UPR_UP (1);
192 
193   /* Set the supervisor register to indicate we are in supervisor mode and
194      set the Fixed-One bit which must always be set.  */
195   SET_H_SYS_SR (SPR_FIELD_MASK_SYS_SR_SM | SPR_FIELD_MASK_SYS_SR_FO);
196 
197   /* Clear the floating point control status register.  */
198   SET_H_SYS_FPCSR (0);
199 }
200 
201 void
202 or1k32bf_insn_before (sim_cpu *current_cpu, SEM_PC vpc, const IDESC *idesc)
203 {
204   SIM_DESC sd = CPU_STATE (current_cpu);
205 
206   current_cpu->delay_slot = current_cpu->next_delay_slot;
207   current_cpu->next_delay_slot = 0;
208 
209   if (current_cpu->delay_slot &&
210       CGEN_ATTR_BOOLS (CGEN_INSN_ATTRS ((idesc)->idata)) &
211       CGEN_ATTR_MASK (CGEN_INSN_NOT_IN_DELAY_SLOT))
212     {
213       USI pc;
214 #ifdef WITH_SCACHE
215       pc = vpc->argbuf.addr;
216 #else
217       pc = vpc;
218 #endif
219       sim_io_error (sd, "invalid instruction in a delay slot at PC 0x%08x",
220 		    pc);
221     }
222 
223 }
224 
225 void
226 or1k32bf_insn_after (sim_cpu *current_cpu, SEM_PC vpc, const IDESC *idesc)
227 {
228   SIM_DESC sd = CPU_STATE (current_cpu);
229   USI ppc;
230 
231 #ifdef WITH_SCACHE
232   ppc = vpc->argbuf.addr;
233 #else
234   ppc = vpc;
235 #endif
236 
237   SET_H_SYS_PPC (ppc);
238 
239   if (!GET_H_SYS_CPUCFGR_ND () &&
240       CGEN_ATTR_BOOLS (CGEN_INSN_ATTRS ((idesc)->idata)) &
241       CGEN_ATTR_MASK (CGEN_INSN_DELAYED_CTI))
242     {
243       SIM_ASSERT (!current_cpu->delay_slot);
244       current_cpu->next_delay_slot = 1;
245     }
246 }
247 
248 void
249 or1k32bf_nop (sim_cpu *current_cpu, USI uimm16)
250 {
251   SIM_DESC sd = CPU_STATE (current_cpu);
252 
253   switch (uimm16)
254     {
255 
256     case NOP_NOP:
257       break;
258 
259     case NOP_EXIT:
260       sim_io_printf (CPU_STATE (current_cpu), "exit(%d)\n", GET_H_GPR (3));
261       /* fall through */
262     case NOP_EXIT_SILENT:
263       sim_engine_halt (sd, current_cpu, NULL, CPU_PC_GET (current_cpu),
264 		       sim_exited, GET_H_GPR (3));
265       break;
266 
267     case NOP_REPORT:
268       sim_io_printf (CPU_STATE (current_cpu), "report(0x%08x);\n",
269 		     GET_H_GPR (3));
270       break;
271 
272     case NOP_PUTC:
273       sim_io_printf (CPU_STATE (current_cpu), "%c",
274 		     (char) (GET_H_GPR (3) & 0xff));
275       break;
276 
277     default:
278       sim_io_eprintf (sd, "WARNING: l.nop with unsupported code 0x%08x\n",
279 		      uimm16);
280       break;
281     }
282 
283 }
284 
285 /* Build an address value used for load and store instructions.  For example,
286    the instruction 'l.lws rD, I(rA)' will require to load data from the 4 byte
287    address represented by rA + I.  Here the argument base is rA, offset is I
288    and the size is the read size in bytes.  Note, OpenRISC requires that word
289    and half-word access be word and half-word aligned respectively, the check
290    for alignment is not needed here.  */
291 
292 USI
293 or1k32bf_make_load_store_addr (sim_cpu *current_cpu, USI base, SI offset,
294 			       int size)
295 {
296   SIM_DESC sd = CPU_STATE (current_cpu);
297 
298   USI addr = base + offset;
299 
300   /* If little endian load/store is enabled we adjust the byte and half-word
301      addresses to the little endian equivalent.  */
302   if (GET_H_SYS_SR_LEE ())
303     {
304       switch (size)
305 	{
306 
307 	case 4: /* We are retrieving the entire word no adjustment.  */
308 	  break;
309 
310 	case 2: /* Perform half-word adjustment 0 -> 2, 2 -> 0.  */
311 	  addr ^= 0x2;
312 	  break;
313 
314 	case 1: /* Perform byte adjustment, 0 -> 3, 2 -> 3, etc.  */
315 	  addr ^= 0x3;
316 	  break;
317 
318 	default:
319 	  SIM_ASSERT (0);
320 	  return 0;
321 	}
322     }
323 
324   return addr;
325 }
326 
327 /* The find first 1 instruction returns the location of the first set bit
328    in the argument register.  */
329 
330 USI
331 or1k32bf_ff1 (sim_cpu *current_cpu, USI val)
332 {
333   USI bit;
334   USI ret;
335   for (bit = 1, ret = 1; bit; bit <<= 1, ret++)
336     {
337       if (val & bit)
338 	return ret;
339     }
340   return 0;
341 }
342 
343 /* The find last 1 instruction returns the location of the last set bit in
344    the argument register.  */
345 
346 USI
347 or1k32bf_fl1 (sim_cpu *current_cpu, USI val)
348 {
349   USI bit;
350   USI ret;
351   for (bit = 1 << 31, ret = 32; bit; bit >>= 1, ret--)
352     {
353       if (val & bit)
354 	return ret;
355     }
356   return 0;
357 }
358