RISC-V Debug Specification: https://github.com/riscv/riscv-debug-spec/releases/tag/1.0 Add helpers to enter/leave Debug Mode and to update dpc/dcsr. Model resume without a Debug Module by leaving Debug Mode at cpu_exec_enter and continuing from dpc. Signed-off-by: Chao Liu <chao.liu.zevorn@gmail.com> --- target/riscv/cpu.h | 3 ++ target/riscv/cpu_helper.c | 84 ++++++++++++++++++++++++++++++++++++++ target/riscv/debug.c | 5 +++ target/riscv/tcg/tcg-cpu.c | 14 +++++++ 4 files changed, 106 insertions(+) diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h index 2a265faae5..62732957a4 100644 --- a/target/riscv/cpu.h +++ b/target/riscv/cpu.h @@ -624,6 +624,9 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size, char *riscv_isa_string(RISCVCPU *cpu); int riscv_cpu_max_xlen(RISCVCPUClass *mcc); bool riscv_cpu_option_set(const char *optname); +void riscv_cpu_enter_debug_mode(CPURISCVState *env, target_ulong pc, + uint32_t cause); +void riscv_cpu_leave_debug_mode(CPURISCVState *env); #ifndef CONFIG_USER_ONLY void riscv_cpu_do_interrupt(CPUState *cpu); diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c index dd6c861a90..0e266ff3a9 100644 --- a/target/riscv/cpu_helper.c +++ b/target/riscv/cpu_helper.c @@ -136,6 +136,90 @@ bool riscv_env_smode_dbltrp_enabled(CPURISCVState *env, bool virt) #endif } +#ifndef CONFIG_USER_ONLY +static bool riscv_sdext_enabled(CPURISCVState *env) +{ + return riscv_cpu_cfg(env)->ext_sdext; +} +#endif + +void riscv_cpu_enter_debug_mode(CPURISCVState *env, target_ulong pc, + uint32_t cause) +{ +#ifndef CONFIG_USER_ONLY + if (!riscv_sdext_enabled(env)) { + return; + } + + env->debug_mode = true; + env->dpc = pc & get_xepc_mask(env); + env->dcsr &= ~(DCSR_CAUSE_MASK | DCSR_PRV_MASK | DCSR_V); + env->dcsr |= ((target_ulong)(cause & 0x7)) << DCSR_CAUSE_SHIFT; + env->dcsr |= env->priv & DCSR_PRV_MASK; + if (env->virt_enabled && riscv_has_ext(env, RVH)) { + env->dcsr |= DCSR_V; + } + + if (env_archcpu(env)->cfg.ext_zicfilp) { + if (env->elp) { + env->dcsr |= DCSR_PELP; + } else { + env->dcsr &= ~DCSR_PELP; + } + env->elp = false; + } +#endif +} + +void riscv_cpu_leave_debug_mode(CPURISCVState *env) +{ +#ifndef CONFIG_USER_ONLY + if (!riscv_sdext_enabled(env)) { + return; + } + + target_ulong new_priv = env->dcsr & DCSR_PRV_MASK; + bool new_virt = riscv_has_ext(env, RVH) && (env->dcsr & DCSR_V); + + if (new_priv > PRV_M) { + new_priv = PRV_M; + } + if (new_priv == PRV_M) { + new_virt = false; + } + + if (new_priv == PRV_S && !riscv_has_ext(env, RVS)) { + new_priv = PRV_M; + new_virt = false; + } else if (new_priv == PRV_U && !riscv_has_ext(env, RVU)) { + new_priv = riscv_has_ext(env, RVS) ? PRV_S : PRV_M; + new_virt = false; + } + + env->debug_mode = false; + riscv_cpu_set_mode(env, new_priv, new_virt); + + if (env_archcpu(env)->cfg.ext_zicfilp) { + env->elp = cpu_get_fcfien(env) && (env->dcsr & DCSR_PELP); + env->dcsr &= ~DCSR_PELP; + } + + if (new_priv != PRV_M) { + env->mstatus = set_field(env->mstatus, MSTATUS_MPRV, 0); + } + + if (env_archcpu(env)->cfg.ext_smdbltrp && new_priv != PRV_M) { + env->mstatus = set_field(env->mstatus, MSTATUS_MDT, 0); + } + if (env_archcpu(env)->cfg.ext_ssdbltrp && (new_priv == PRV_U || new_virt)) { + env->mstatus = set_field(env->mstatus, MSTATUS_SDT, 0); + if (new_virt && new_priv == PRV_U) { + env->vsstatus = set_field(env->vsstatus, MSTATUS_SDT, 0); + } + } +#endif +} + RISCVPmPmm riscv_pm_get_pmm(CPURISCVState *env) { #ifndef CONFIG_USER_ONLY diff --git a/target/riscv/debug.c b/target/riscv/debug.c index 5664466749..5877a60c50 100644 --- a/target/riscv/debug.c +++ b/target/riscv/debug.c @@ -927,6 +927,11 @@ void riscv_cpu_debug_excp_handler(CPUState *cs) RISCVCPU *cpu = RISCV_CPU(cs); CPURISCVState *env = &cpu->env; + /* Triggers must not match or fire while in Debug Mode. */ + if (env->debug_mode) { + return; + } + if (cs->watchpoint_hit) { if (cs->watchpoint_hit->flags & BP_CPU) { do_trigger_action(env, DBG_ACTION_BP); diff --git a/target/riscv/tcg/tcg-cpu.c b/target/riscv/tcg/tcg-cpu.c index d9fbb5bf58..f80e3413f8 100644 --- a/target/riscv/tcg/tcg-cpu.c +++ b/target/riscv/tcg/tcg-cpu.c @@ -266,6 +266,19 @@ static vaddr riscv_pointer_wrap(CPUState *cs, int mmu_idx, } return extract64(result, 0, 64 - pm_len); } + +static void riscv_cpu_exec_enter(CPUState *cs) +{ + RISCVCPU *cpu = RISCV_CPU(cs); + CPURISCVState *env = &cpu->env; + + if (!cpu->cfg.ext_sdext || !env->debug_mode) { + return; + } + target_ulong pc = env->dpc; + riscv_cpu_leave_debug_mode(env); + env->pc = pc; +} #endif const TCGCPUOps riscv_tcg_ops = { @@ -282,6 +295,7 @@ const TCGCPUOps riscv_tcg_ops = { #ifndef CONFIG_USER_ONLY .tlb_fill = riscv_cpu_tlb_fill, .pointer_wrap = riscv_pointer_wrap, + .cpu_exec_enter = riscv_cpu_exec_enter, .cpu_exec_interrupt = riscv_cpu_exec_interrupt, .cpu_exec_halt = riscv_cpu_has_work, .cpu_exec_reset = cpu_reset, -- 2.52.0