1 /* 2 * QEMU AVR CPU helpers 3 * 4 * Copyright (c) 2016-2020 Michael Rolnik 5 * 6 * This library is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * This library 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 GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with this library; if not, see 18 * <http://www.gnu.org/licenses/lgpl-2.1.html> 19 */ 20 21 #include "qemu/osdep.h" 22 #include "cpu.h" 23 #include "exec/exec-all.h" 24 #include "exec/helper-proto.h" 25 26 bool avr_cpu_exec_interrupt(CPUState *cs, int interrupt_request) 27 { 28 bool ret = false; 29 CPUClass *cc = CPU_GET_CLASS(cs); 30 AVRCPU *cpu = AVR_CPU(cs); 31 CPUAVRState *env = &cpu->env; 32 33 if (interrupt_request & CPU_INTERRUPT_RESET) { 34 if (cpu_interrupts_enabled(env)) { 35 cs->exception_index = EXCP_RESET; 36 cc->do_interrupt(cs); 37 38 cs->interrupt_request &= ~CPU_INTERRUPT_RESET; 39 40 ret = true; 41 } 42 } 43 if (interrupt_request & CPU_INTERRUPT_HARD) { 44 if (cpu_interrupts_enabled(env) && env->intsrc != 0) { 45 int index = ctz32(env->intsrc); 46 cs->exception_index = EXCP_INT(index); 47 cc->do_interrupt(cs); 48 49 env->intsrc &= env->intsrc - 1; /* clear the interrupt */ 50 cs->interrupt_request &= ~CPU_INTERRUPT_HARD; 51 52 ret = true; 53 } 54 } 55 return ret; 56 } 57 58 void avr_cpu_do_interrupt(CPUState *cs) 59 { 60 AVRCPU *cpu = AVR_CPU(cs); 61 CPUAVRState *env = &cpu->env; 62 63 uint32_t ret = env->pc_w; 64 int vector = 0; 65 int size = avr_feature(env, AVR_FEATURE_JMP_CALL) ? 2 : 1; 66 int base = 0; 67 68 if (cs->exception_index == EXCP_RESET) { 69 vector = 0; 70 } else if (env->intsrc != 0) { 71 vector = ctz32(env->intsrc) + 1; 72 } 73 74 if (avr_feature(env, AVR_FEATURE_3_BYTE_PC)) { 75 cpu_stb_data(env, env->sp--, (ret & 0x0000ff)); 76 cpu_stb_data(env, env->sp--, (ret & 0x00ff00) >> 8); 77 cpu_stb_data(env, env->sp--, (ret & 0xff0000) >> 16); 78 } else if (avr_feature(env, AVR_FEATURE_2_BYTE_PC)) { 79 cpu_stb_data(env, env->sp--, (ret & 0x0000ff)); 80 cpu_stb_data(env, env->sp--, (ret & 0x00ff00) >> 8); 81 } else { 82 cpu_stb_data(env, env->sp--, (ret & 0x0000ff)); 83 } 84 85 env->pc_w = base + vector * size; 86 env->sregI = 0; /* clear Global Interrupt Flag */ 87 88 cs->exception_index = -1; 89 } 90