1 /*
2  *  i386 cpu init and loop
3  *
4  *
5  *  This program is free software; you can redistribute it and/or modify
6  *  it under the terms of the GNU General Public License as published by
7  *  the Free Software Foundation; either version 2 of the License, or
8  *  (at your option) any later version.
9  *
10  *  This program is distributed in the hope that it will be useful,
11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  *  GNU General Public License for more details.
14  *
15  *  You should have received a copy of the GNU General Public License
16  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #ifndef TARGET_ARCH_CPU_H
20 #define TARGET_ARCH_CPU_H
21 
22 #include "target_arch.h"
23 #include "signal-common.h"
24 
25 #define TARGET_DEFAULT_CPU_MODEL "qemu32"
26 
27 static inline void target_cpu_init(CPUX86State *env,
28         struct target_pt_regs *regs)
29 {
30     uint64_t *gdt_table;
31 
32     env->cr[0] = CR0_PG_MASK | CR0_WP_MASK | CR0_PE_MASK;
33     env->hflags |= HF_PE_MASK | HF_CPL_MASK;
34     if (env->features[FEAT_1_EDX] & CPUID_SSE) {
35         env->cr[4] |= CR4_OSFXSR_MASK;
36         env->hflags |= HF_OSFXSR_MASK;
37     }
38 
39     /* flags setup : we activate the IRQs by default as in user mode */
40     env->eflags |= IF_MASK;
41 
42     /* register setup */
43     env->regs[R_EAX] = regs->eax;
44     env->regs[R_EBX] = regs->ebx;
45     env->regs[R_ECX] = regs->ecx;
46     env->regs[R_EDX] = regs->edx;
47     env->regs[R_ESI] = regs->esi;
48     env->regs[R_EDI] = regs->edi;
49     env->regs[R_EBP] = regs->ebp;
50     env->regs[R_ESP] = regs->esp;
51     env->eip = regs->eip;
52 
53     /* interrupt setup */
54     env->idt.limit = 255;
55 
56     env->idt.base = target_mmap(0, sizeof(uint64_t) * (env->idt.limit + 1),
57         PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
58     bsd_i386_set_idt_base(env->idt.base);
59     bsd_i386_set_idt(0, 0);
60     bsd_i386_set_idt(1, 0);
61     bsd_i386_set_idt(2, 0);
62     bsd_i386_set_idt(3, 3);
63     bsd_i386_set_idt(4, 3);
64     bsd_i386_set_idt(5, 0);
65     bsd_i386_set_idt(6, 0);
66     bsd_i386_set_idt(7, 0);
67     bsd_i386_set_idt(8, 0);
68     bsd_i386_set_idt(9, 0);
69     bsd_i386_set_idt(10, 0);
70     bsd_i386_set_idt(11, 0);
71     bsd_i386_set_idt(12, 0);
72     bsd_i386_set_idt(13, 0);
73     bsd_i386_set_idt(14, 0);
74     bsd_i386_set_idt(15, 0);
75     bsd_i386_set_idt(16, 0);
76     bsd_i386_set_idt(17, 0);
77     bsd_i386_set_idt(18, 0);
78     bsd_i386_set_idt(19, 0);
79     bsd_i386_set_idt(0x80, 3);
80 
81     /* segment setup */
82     env->gdt.base = target_mmap(0, sizeof(uint64_t) * TARGET_GDT_ENTRIES,
83             PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
84     env->gdt.limit = sizeof(uint64_t) * TARGET_GDT_ENTRIES - 1;
85     gdt_table = g2h_untagged(env->gdt.base);
86 
87     bsd_i386_write_dt(&gdt_table[__USER_CS >> 3], 0, 0xfffff,
88             DESC_G_MASK | DESC_B_MASK | DESC_P_MASK | DESC_S_MASK |
89             (3 << DESC_DPL_SHIFT) | (0xa << DESC_TYPE_SHIFT));
90 
91     bsd_i386_write_dt(&gdt_table[__USER_DS >> 3], 0, 0xfffff,
92             DESC_G_MASK | DESC_B_MASK | DESC_P_MASK | DESC_S_MASK |
93             (3 << DESC_DPL_SHIFT) | (0x2 << DESC_TYPE_SHIFT));
94 
95     cpu_x86_load_seg(env, R_CS, __USER_CS);
96     cpu_x86_load_seg(env, R_SS, __USER_DS);
97     cpu_x86_load_seg(env, R_DS, __USER_DS);
98     cpu_x86_load_seg(env, R_ES, __USER_DS);
99     cpu_x86_load_seg(env, R_FS, __USER_DS);
100     cpu_x86_load_seg(env, R_GS, __USER_DS);
101     /* This hack makes Wine work... */
102     env->segs[R_FS].selector = 0;
103 }
104 
105 static inline void target_cpu_loop(CPUX86State *env)
106 {
107     CPUState *cs = env_cpu(env);
108     int trapnr;
109     abi_ulong pc;
110     /* target_siginfo_t info; */
111 
112     for (;;) {
113         cpu_exec_start(cs);
114         trapnr = cpu_exec(cs);
115         cpu_exec_end(cs);
116         process_queued_cpu_work(cs);
117 
118         switch (trapnr) {
119         case 0x80: {
120             /* syscall from int $0x80 */
121             abi_ulong params = (abi_ulong) env->regs[R_ESP] +
122                 sizeof(int32_t);
123             int32_t syscall_nr = env->regs[R_EAX];
124             int32_t arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8;
125 
126             if (syscall_nr == TARGET_FREEBSD_NR_syscall) {
127                 get_user_s32(syscall_nr, params);
128                 params += sizeof(int32_t);
129             } else if (syscall_nr == TARGET_FREEBSD_NR___syscall) {
130                 get_user_s32(syscall_nr, params);
131                 params += sizeof(int64_t);
132             }
133             get_user_s32(arg1, params);
134             params += sizeof(int32_t);
135             get_user_s32(arg2, params);
136             params += sizeof(int32_t);
137             get_user_s32(arg3, params);
138             params += sizeof(int32_t);
139             get_user_s32(arg4, params);
140             params += sizeof(int32_t);
141             get_user_s32(arg5, params);
142             params += sizeof(int32_t);
143             get_user_s32(arg6, params);
144             params += sizeof(int32_t);
145             get_user_s32(arg7, params);
146             params += sizeof(int32_t);
147             get_user_s32(arg8, params);
148             env->regs[R_EAX] = do_freebsd_syscall(env,
149                                                   syscall_nr,
150                                                   arg1,
151                                                   arg2,
152                                                   arg3,
153                                                   arg4,
154                                                   arg5,
155                                                   arg6,
156                                                   arg7,
157                                                   arg8);
158             }
159             if (((abi_ulong)env->regs[R_EAX]) >= (abi_ulong)(-515)) {
160                 env->regs[R_EAX] = -env->regs[R_EAX];
161                 env->eflags |= CC_C;
162             } else {
163                 env->eflags &= ~CC_C;
164             }
165             break;
166 
167         case EXCP_INTERRUPT:
168             /* just indicate that signals should be handled asap */
169             break;
170 
171         case EXCP_ATOMIC:
172             cpu_exec_step_atomic(cs);
173             break;
174 
175         default:
176             pc = env->segs[R_CS].base + env->eip;
177             fprintf(stderr, "qemu: 0x%08lx: unhandled CPU exception 0x%x - "
178                     "aborting\n", (long)pc, trapnr);
179             abort();
180         }
181         process_pending_signals(env);
182     }
183 }
184 
185 static inline void target_cpu_clone_regs(CPUX86State *env, target_ulong newsp)
186 {
187     if (newsp) {
188         env->regs[R_ESP] = newsp;
189     }
190     env->regs[R_EAX] = 0;
191 }
192 
193 static inline void target_cpu_reset(CPUArchState *env)
194 {
195     cpu_reset(env_cpu(env));
196 }
197 
198 #endif /* TARGET_ARCH_CPU_H */
199