[RESEND PATCH v3 4/7] target/riscv: cpu: Add a config option for native debug

[Bin Meng]

From: Bin Meng <bin.m...@windriver.com>

Add a config option to enable support for native M-mode debug.
This is disabled by default and can be enabled with 'debug=true'.

Signed-off-by: Bin Meng <bin.m...@windriver.com>
Reviewed-by: Alistair Francis <alistair.fran...@wdc.com>
---

(no changes since v2)

Changes in v2:
- change the config option to 'disabled' by default

 target/riscv/cpu.h | 2 ++
 target/riscv/cpu.c | 5 +++++
 2 files changed, 7 insertions(+)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 0f3b3a4219..35445bbc86 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -75,6 +75,7 @@ enum {
     RISCV_FEATURE_MMU,
     RISCV_FEATURE_PMP,
     RISCV_FEATURE_EPMP,
+    RISCV_FEATURE_DEBUG,
     RISCV_FEATURE_MISA
 };
 
@@ -332,6 +333,7 @@ struct RISCVCPU {
         bool mmu;
         bool pmp;
         bool epmp;
+        bool debug;
         uint64_t resetvec;
     } cfg;
 };
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 3aa07bc019..d36c31ce9a 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -448,6 +448,10 @@ static void riscv_cpu_realize(DeviceState *dev, Error 
**errp)
         }
     }
 
+    if (cpu->cfg.debug) {
+        set_feature(env, RISCV_FEATURE_DEBUG);
+    }
+
     set_resetvec(env, cpu->cfg.resetvec);
 
     /* Validate that MISA_MXL is set properly. */
@@ -634,6 +638,7 @@ static Property riscv_cpu_properties[] = {
     DEFINE_PROP_BOOL("Zfhmin", RISCVCPU, cfg.ext_zfhmin, false),
     DEFINE_PROP_BOOL("mmu", RISCVCPU, cfg.mmu, true),
     DEFINE_PROP_BOOL("pmp", RISCVCPU, cfg.pmp, true),
+    DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, false),
 
     DEFINE_PROP_STRING("priv_spec", RISCVCPU, cfg.priv_spec),
     DEFINE_PROP_STRING("vext_spec", RISCVCPU, cfg.vext_spec),
-- 
2.25.1