On Sun, Oct 31, 2021 at 12:03 AM Bin Meng <bmeng...@gmail.com> wrote:
>
> This adds debug CSR read/write support to the RISC-V CSR RW table.
>
> Signed-off-by: Bin Meng <bin.m...@windriver.com>
> ---
>
> (no changes since v1)
>
> target/riscv/cpu.c | 6 +++++
> target/riscv/csr.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 63 insertions(+)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 84116768ce..6f69ef4f50 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -575,6 +575,12 @@ static void riscv_cpu_realize(DeviceState *dev, Error
> **errp)
>
> riscv_cpu_register_gdb_regs_for_features(cs);
>
> +#ifndef CONFIG_USER_ONLY
> + if (riscv_feature(env, RISCV_FEATURE_DEBUG)) {
> + riscv_trigger_init(env);
This function should be added here instead of patch 1
Alistair
> + }
> +#endif
> +
> qemu_init_vcpu(cs);
> cpu_reset(cs);
>
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 9f41954894..dc47ec8d3b 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -219,6 +219,15 @@ static RISCVException epmp(CPURISCVState *env, int csrno)
>
> return RISCV_EXCP_ILLEGAL_INST;
> }
> +
> +static RISCVException debug(CPURISCVState *env, int csrno)
> +{
> + if (riscv_feature(env, RISCV_FEATURE_DEBUG)) {
> + return RISCV_EXCP_NONE;
> + }
> +
> + return RISCV_EXCP_ILLEGAL_INST;
> +}
> #endif
>
> /* User Floating-Point CSRs */
> @@ -1435,6 +1444,48 @@ static RISCVException write_pmpaddr(CPURISCVState
> *env, int csrno,
> return RISCV_EXCP_NONE;
> }
>
> +static RISCVException read_tselect(CPURISCVState *env, int csrno,
> + target_ulong *val)
> +{
> + *val = tselect_csr_read(env);
> + return RISCV_EXCP_NONE;
> +}
> +
> +static RISCVException write_tselect(CPURISCVState *env, int csrno,
> + target_ulong val)
> +{
> + tselect_csr_write(env, val);
> + return RISCV_EXCP_NONE;
> +}
> +
> +static RISCVException read_tdata(CPURISCVState *env, int csrno,
> + target_ulong *val)
> +{
> + /* return 0 in tdata1 to end the trigger enumeration */
> + if (env->trigger_cur >= TRIGGER_NUM && csrno == CSR_TDATA1) {
> + *val = 0;
> + return RISCV_EXCP_NONE;
> + }
> +
> + if (!tdata_available(env, csrno - CSR_TDATA1)) {
> + return RISCV_EXCP_ILLEGAL_INST;
> + }
> +
> + *val = tdata_csr_read(env, csrno - CSR_TDATA1);
> + return RISCV_EXCP_NONE;
> +}
> +
> +static RISCVException write_tdata(CPURISCVState *env, int csrno,
> + target_ulong val)
> +{
> + if (!tdata_available(env, csrno - CSR_TDATA1)) {
> + return RISCV_EXCP_ILLEGAL_INST;
> + }
> +
> + tdata_csr_write(env, csrno - CSR_TDATA1, val);
> + return RISCV_EXCP_NONE;
> +}
> +
> /*
> * Functions to access Pointer Masking feature registers
> * We have to check if current priv lvl could modify
> @@ -1931,6 +1982,12 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
> [CSR_PMPADDR14] = { "pmpaddr14", pmp, read_pmpaddr, write_pmpaddr },
> [CSR_PMPADDR15] = { "pmpaddr15", pmp, read_pmpaddr, write_pmpaddr },
>
> + /* Debug CSRs */
> + [CSR_TSELECT] = { "tselect", debug, read_tselect, write_tselect },
> + [CSR_TDATA1] = { "tdata1", debug, read_tdata, write_tdata },
> + [CSR_TDATA2] = { "tdata2", debug, read_tdata, write_tdata },
> + [CSR_TDATA3] = { "tdata3", debug, read_tdata, write_tdata },
> +
> /* User Pointer Masking */
> [CSR_UMTE] = { "umte", pointer_masking, read_umte,
> write_umte },
> [CSR_UPMMASK] = { "upmmask", pointer_masking, read_upmmask,
> write_upmmask },
> --
> 2.25.1
>
>
