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Diffstat (limited to 'target/avr/helper.c')
| -rw-r--r-- | target/avr/helper.c | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/target/avr/helper.c b/target/avr/helper.c new file mode 100644 index 0000000000..d96d14372b --- /dev/null +++ b/target/avr/helper.c @@ -0,0 +1,348 @@ +/* + * QEMU AVR CPU helpers + * + * Copyright (c) 2016-2020 Michael Rolnik + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see + * <http://www.gnu.org/licenses/lgpl-2.1.html> + */ + +#include "qemu/osdep.h" +#include "cpu.h" +#include "exec/exec-all.h" +#include "exec/address-spaces.h" +#include "exec/helper-proto.h" + +bool avr_cpu_exec_interrupt(CPUState *cs, int interrupt_request) +{ + bool ret = false; + CPUClass *cc = CPU_GET_CLASS(cs); + AVRCPU *cpu = AVR_CPU(cs); + CPUAVRState *env = &cpu->env; + + if (interrupt_request & CPU_INTERRUPT_RESET) { + if (cpu_interrupts_enabled(env)) { + cs->exception_index = EXCP_RESET; + cc->do_interrupt(cs); + + cs->interrupt_request &= ~CPU_INTERRUPT_RESET; + + ret = true; + } + } + if (interrupt_request & CPU_INTERRUPT_HARD) { + if (cpu_interrupts_enabled(env) && env->intsrc != 0) { + int index = ctz32(env->intsrc); + cs->exception_index = EXCP_INT(index); + cc->do_interrupt(cs); + + env->intsrc &= env->intsrc - 1; /* clear the interrupt */ + cs->interrupt_request &= ~CPU_INTERRUPT_HARD; + + ret = true; + } + } + return ret; +} + +void avr_cpu_do_interrupt(CPUState *cs) +{ + AVRCPU *cpu = AVR_CPU(cs); + CPUAVRState *env = &cpu->env; + + uint32_t ret = env->pc_w; + int vector = 0; + int size = avr_feature(env, AVR_FEATURE_JMP_CALL) ? 2 : 1; + int base = 0; + + if (cs->exception_index == EXCP_RESET) { + vector = 0; + } else if (env->intsrc != 0) { + vector = ctz32(env->intsrc) + 1; + } + + if (avr_feature(env, AVR_FEATURE_3_BYTE_PC)) { + cpu_stb_data(env, env->sp--, (ret & 0x0000ff)); + cpu_stb_data(env, env->sp--, (ret & 0x00ff00) >> 8); + cpu_stb_data(env, env->sp--, (ret & 0xff0000) >> 16); + } else if (avr_feature(env, AVR_FEATURE_2_BYTE_PC)) { + cpu_stb_data(env, env->sp--, (ret & 0x0000ff)); + cpu_stb_data(env, env->sp--, (ret & 0x00ff00) >> 8); + } else { + cpu_stb_data(env, env->sp--, (ret & 0x0000ff)); + } + + env->pc_w = base + vector * size; + env->sregI = 0; /* clear Global Interrupt Flag */ + + cs->exception_index = -1; +} + +int avr_cpu_memory_rw_debug(CPUState *cs, vaddr addr, uint8_t *buf, + int len, bool is_write) +{ + return cpu_memory_rw_debug(cs, addr, buf, len, is_write); +} + +hwaddr avr_cpu_get_phys_page_debug(CPUState *cs, vaddr addr) +{ + return addr; /* I assume 1:1 address correspondance */ +} + +bool avr_cpu_tlb_fill(CPUState *cs, vaddr address, int size, + MMUAccessType access_type, int mmu_idx, + bool probe, uintptr_t retaddr) +{ + int prot = 0; + MemTxAttrs attrs = {}; + uint32_t paddr; + + address &= TARGET_PAGE_MASK; + + if (mmu_idx == MMU_CODE_IDX) { + /* access to code in flash */ + paddr = OFFSET_CODE + address; + prot = PAGE_READ | PAGE_EXEC; + if (paddr + TARGET_PAGE_SIZE > OFFSET_DATA) { + error_report("execution left flash memory"); + abort(); + } + } else if (address < NUMBER_OF_CPU_REGISTERS + NUMBER_OF_IO_REGISTERS) { + /* + * access to CPU registers, exit and rebuilt this TB to use full access + * incase it touches specially handled registers like SREG or SP + */ + AVRCPU *cpu = AVR_CPU(cs); + CPUAVRState *env = &cpu->env; + env->fullacc = 1; + cpu_loop_exit_restore(cs, retaddr); + } else { + /* access to memory. nothing special */ + paddr = OFFSET_DATA + address; + prot = PAGE_READ | PAGE_WRITE; + } + + tlb_set_page_with_attrs(cs, address, paddr, attrs, prot, + mmu_idx, TARGET_PAGE_SIZE); + + return true; +} + +/* + * helpers + */ + +void helper_sleep(CPUAVRState *env) +{ + CPUState *cs = env_cpu(env); + + cs->exception_index = EXCP_HLT; + cpu_loop_exit(cs); +} + +void helper_unsupported(CPUAVRState *env) +{ + CPUState *cs = env_cpu(env); + + /* + * I count not find what happens on the real platform, so + * it's EXCP_DEBUG for meanwhile + */ + cs->exception_index = EXCP_DEBUG; + if (qemu_loglevel_mask(LOG_UNIMP)) { + qemu_log("UNSUPPORTED\n"); + cpu_dump_state(cs, stderr, 0); + } + cpu_loop_exit(cs); +} + +void helper_debug(CPUAVRState *env) +{ + CPUState *cs = env_cpu(env); + + cs->exception_index = EXCP_DEBUG; + cpu_loop_exit(cs); +} + +void helper_break(CPUAVRState *env) +{ + CPUState *cs = env_cpu(env); + + cs->exception_index = EXCP_DEBUG; + cpu_loop_exit(cs); +} + +void helper_wdr(CPUAVRState *env) +{ + CPUState *cs = env_cpu(env); + + /* WD is not implemented yet, placeholder */ + cs->exception_index = EXCP_DEBUG; + cpu_loop_exit(cs); +} + +/* + * This function implements IN instruction + * + * It does the following + * a. if an IO register belongs to CPU, its value is read and returned + * b. otherwise io address is translated to mem address and physical memory + * is read. + * c. it caches the value for sake of SBI, SBIC, SBIS & CBI implementation + * + */ +target_ulong helper_inb(CPUAVRState *env, uint32_t port) +{ + target_ulong data = 0; + + switch (port) { + case 0x38: /* RAMPD */ + data = 0xff & (env->rampD >> 16); + break; + case 0x39: /* RAMPX */ + data = 0xff & (env->rampX >> 16); + break; + case 0x3a: /* RAMPY */ + data = 0xff & (env->rampY >> 16); + break; + case 0x3b: /* RAMPZ */ + data = 0xff & (env->rampZ >> 16); + break; + case 0x3c: /* EIND */ + data = 0xff & (env->eind >> 16); + break; + case 0x3d: /* SPL */ + data = env->sp & 0x00ff; + break; + case 0x3e: /* SPH */ + data = env->sp >> 8; + break; + case 0x3f: /* SREG */ + data = cpu_get_sreg(env); + break; + default: + /* not a special register, pass to normal memory access */ + data = address_space_ldub(&address_space_memory, + OFFSET_IO_REGISTERS + port, + MEMTXATTRS_UNSPECIFIED, NULL); + } + + return data; +} + +/* + * This function implements OUT instruction + * + * It does the following + * a. if an IO register belongs to CPU, its value is written into the register + * b. otherwise io address is translated to mem address and physical memory + * is written. + * c. it caches the value for sake of SBI, SBIC, SBIS & CBI implementation + * + */ +void helper_outb(CPUAVRState *env, uint32_t port, uint32_t data) +{ + data &= 0x000000ff; + + switch (port) { + case 0x38: /* RAMPD */ + if (avr_feature(env, AVR_FEATURE_RAMPD)) { + env->rampD = (data & 0xff) << 16; + } + break; + case 0x39: /* RAMPX */ + if (avr_feature(env, AVR_FEATURE_RAMPX)) { + env->rampX = (data & 0xff) << 16; + } + break; + case 0x3a: /* RAMPY */ + if (avr_feature(env, AVR_FEATURE_RAMPY)) { + env->rampY = (data & 0xff) << 16; + } + break; + case 0x3b: /* RAMPZ */ + if (avr_feature(env, AVR_FEATURE_RAMPZ)) { + env->rampZ = (data & 0xff) << 16; + } + break; + case 0x3c: /* EIDN */ + env->eind = (data & 0xff) << 16; + break; + case 0x3d: /* SPL */ + env->sp = (env->sp & 0xff00) | (data); + break; + case 0x3e: /* SPH */ + if (avr_feature(env, AVR_FEATURE_2_BYTE_SP)) { + env->sp = (env->sp & 0x00ff) | (data << 8); + } + break; + case 0x3f: /* SREG */ + cpu_set_sreg(env, data); + break; + default: + /* not a special register, pass to normal memory access */ + address_space_stb(&address_space_memory, OFFSET_IO_REGISTERS + port, + data, MEMTXATTRS_UNSPECIFIED, NULL); + } +} + +/* + * this function implements LD instruction when there is a posibility to read + * from a CPU register + */ +target_ulong helper_fullrd(CPUAVRState *env, uint32_t addr) +{ + uint8_t data; + + env->fullacc = false; + + if (addr < NUMBER_OF_CPU_REGISTERS) { + /* CPU registers */ + data = env->r[addr]; + } else if (addr < NUMBER_OF_CPU_REGISTERS + NUMBER_OF_IO_REGISTERS) { + /* IO registers */ + data = helper_inb(env, addr - NUMBER_OF_CPU_REGISTERS); + } else { + /* memory */ + data = address_space_ldub(&address_space_memory, OFFSET_DATA + addr, + MEMTXATTRS_UNSPECIFIED, NULL); + } + return data; +} + +/* + * this function implements ST instruction when there is a posibility to write + * into a CPU register + */ +void helper_fullwr(CPUAVRState *env, uint32_t data, uint32_t addr) +{ + env->fullacc = false; + + /* Following logic assumes this: */ + assert(OFFSET_CPU_REGISTERS == OFFSET_DATA); + assert(OFFSET_IO_REGISTERS == OFFSET_CPU_REGISTERS + + NUMBER_OF_CPU_REGISTERS); + + if (addr < NUMBER_OF_CPU_REGISTERS) { + /* CPU registers */ + env->r[addr] = data; + } else if (addr < NUMBER_OF_CPU_REGISTERS + NUMBER_OF_IO_REGISTERS) { + /* IO registers */ + helper_outb(env, addr - NUMBER_OF_CPU_REGISTERS, data); + } else { + /* memory */ + address_space_stb(&address_space_memory, OFFSET_DATA + addr, data, + MEMTXATTRS_UNSPECIFIED, NULL); + } +} |