xref: /openbmc/qemu/bsd-user/arm/target_arch_cpu.h (revision 762c280d)
1 /*
2  *  arm cpu init and loop
3  *
4  *  Copyright (c) 2013 Stacey D. Son
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 2 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 
20 #ifndef _TARGET_ARCH_CPU_H_
21 #define _TARGET_ARCH_CPU_H_
22 
23 #include "target_arch.h"
24 #include "signal-common.h"
25 
26 #define TARGET_DEFAULT_CPU_MODEL "any"
27 
28 static inline void target_cpu_init(CPUARMState *env,
29         struct target_pt_regs *regs)
30 {
31     int i;
32 
33     cpsr_write(env, regs->uregs[16], CPSR_USER | CPSR_EXEC,
34                CPSRWriteByInstr);
35     for (i = 0; i < 16; i++) {
36         env->regs[i] = regs->uregs[i];
37     }
38 }
39 
40 static inline void target_cpu_loop(CPUARMState *env)
41 {
42     int trapnr, si_signo, si_code;
43     unsigned int n;
44     CPUState *cs = env_cpu(env);
45 
46     for (;;) {
47         cpu_exec_start(cs);
48         trapnr = cpu_exec(cs);
49         cpu_exec_end(cs);
50         process_queued_cpu_work(cs);
51         switch (trapnr) {
52         case EXCP_UDEF:
53         case EXCP_NOCP:
54         case EXCP_INVSTATE:
55             /*
56              * See arm/arm/undefined.c undefinedinstruction();
57              *
58              * A number of details aren't emulated (they likely don't matter):
59              * o Misaligned PC generates ILL_ILLADR (these can't come from qemu)
60              * o Thumb-2 instructions generate ILLADR
61              * o Both modes implement coprocessor instructions, which we don't
62              *   do here. FreeBSD just implements them for the VFP coprocessor
63              *   and special kernel breakpoints, trace points, dtrace, etc.
64              */
65             force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPC, env->regs[15]);
66             break;
67         case EXCP_SWI:
68             {
69                 n = env->regs[7];
70                 if (bsd_type == target_freebsd) {
71                     int ret;
72                     abi_ulong params = get_sp_from_cpustate(env);
73                     int32_t syscall_nr = n;
74                     int32_t arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8;
75 
76                     /* See arm/arm/syscall.c cpu_fetch_syscall_args() */
77                     if (syscall_nr == TARGET_FREEBSD_NR_syscall) {
78                         syscall_nr = env->regs[0];
79                         arg1 = env->regs[1];
80                         arg2 = env->regs[2];
81                         arg3 = env->regs[3];
82                         get_user_s32(arg4, params);
83                         params += sizeof(int32_t);
84                         get_user_s32(arg5, params);
85                         params += sizeof(int32_t);
86                         get_user_s32(arg6, params);
87                         params += sizeof(int32_t);
88                         get_user_s32(arg7, params);
89                         arg8 = 0;
90                     } else if (syscall_nr == TARGET_FREEBSD_NR___syscall) {
91                         syscall_nr = env->regs[0];
92                         arg1 = env->regs[2];
93                         arg2 = env->regs[3];
94                         get_user_s32(arg3, params);
95                         params += sizeof(int32_t);
96                         get_user_s32(arg4, params);
97                         params += sizeof(int32_t);
98                         get_user_s32(arg5, params);
99                         params += sizeof(int32_t);
100                         get_user_s32(arg6, params);
101                         arg7 = 0;
102                         arg8 = 0;
103                     } else {
104                         arg1 = env->regs[0];
105                         arg2 = env->regs[1];
106                         arg3 = env->regs[2];
107                         arg4 = env->regs[3];
108                         get_user_s32(arg5, params);
109                         params += sizeof(int32_t);
110                         get_user_s32(arg6, params);
111                         params += sizeof(int32_t);
112                         get_user_s32(arg7, params);
113                         params += sizeof(int32_t);
114                         get_user_s32(arg8, params);
115                     }
116                     ret = do_freebsd_syscall(env, syscall_nr, arg1, arg2, arg3,
117                             arg4, arg5, arg6, arg7, arg8);
118                     /*
119                      * Compare to arm/arm/vm_machdep.c
120                      * cpu_set_syscall_retval()
121                      */
122                     if (-TARGET_EJUSTRETURN == ret) {
123                         /*
124                          * Returning from a successful sigreturn syscall.
125                          * Avoid clobbering register state.
126                          */
127                         break;
128                     }
129                     if (-TARGET_ERESTART == ret) {
130                         env->regs[15] -= env->thumb ? 2 : 4;
131                         break;
132                     }
133                     if ((unsigned int)ret >= (unsigned int)(-515)) {
134                         ret = -ret;
135                         cpsr_write(env, CPSR_C, CPSR_C, CPSRWriteByInstr);
136                         env->regs[0] = ret;
137                     } else {
138                         cpsr_write(env, 0, CPSR_C, CPSRWriteByInstr);
139                         env->regs[0] = ret; /* XXX need to handle lseek()? */
140                         /* env->regs[1] = 0; */
141                     }
142                 } else {
143                     fprintf(stderr, "qemu: bsd_type (= %d) syscall "
144                             "not supported\n", bsd_type);
145                 }
146             }
147             break;
148         case EXCP_INTERRUPT:
149             /* just indicate that signals should be handled asap */
150             break;
151         case EXCP_PREFETCH_ABORT:
152         case EXCP_DATA_ABORT:
153             /*
154              * See arm/arm/trap-v6.c prefetch_abort_handler() and
155              * data_abort_handler()
156              *
157              * However, FreeBSD maps these to a generic value and then uses that
158              * to maybe fault in pages in vm/vm_fault.c:vm_fault_trap(). I
159              * believe that the indirection maps the same as Linux, but haven't
160              * chased down every single possible indirection.
161              */
162 
163             /* For user-only we don't set TTBCR_EAE, so look at the FSR. */
164             switch (env->exception.fsr & 0x1f) {
165             case 0x1: /* Alignment */
166                 si_signo = TARGET_SIGBUS;
167                 si_code = TARGET_BUS_ADRALN;
168                 break;
169             case 0x3: /* Access flag fault, level 1 */
170             case 0x6: /* Access flag fault, level 2 */
171             case 0x9: /* Domain fault, level 1 */
172             case 0xb: /* Domain fault, level 2 */
173             case 0xd: /* Permission fault, level 1 */
174             case 0xf: /* Permission fault, level 2 */
175                 si_signo = TARGET_SIGSEGV;
176                 si_code = TARGET_SEGV_ACCERR;
177                 break;
178             case 0x5: /* Translation fault, level 1 */
179             case 0x7: /* Translation fault, level 2 */
180                 si_signo = TARGET_SIGSEGV;
181                 si_code = TARGET_SEGV_MAPERR;
182                 break;
183             default:
184                 g_assert_not_reached();
185             }
186             force_sig_fault(si_signo, si_code, env->exception.vaddress);
187             break;
188         case EXCP_DEBUG:
189         case EXCP_BKPT:
190             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->regs[15]);
191             break;
192         case EXCP_YIELD:
193             /* nothing to do here for user-mode, just resume guest code */
194             break;
195         case EXCP_ATOMIC:
196             cpu_exec_step_atomic(cs);
197             break;
198         default:
199             fprintf(stderr, "qemu: unhandled CPU exception 0x%x - aborting\n",
200                     trapnr);
201             cpu_dump_state(cs, stderr, 0);
202             abort();
203         } /* switch() */
204         process_pending_signals(env);
205     } /* for (;;) */
206 }
207 
208 static inline void target_cpu_clone_regs(CPUARMState *env, target_ulong newsp)
209 {
210     if (newsp) {
211         env->regs[13] = newsp;
212     }
213     env->regs[0] = 0;
214 }
215 
216 static inline void target_cpu_reset(CPUArchState *env)
217 {
218 }
219 
220 #endif /* !_TARGET_ARCH_CPU_H */
221