[Qemu-riscv] [PATCH 4/5 v3] RISC-V: Add debug support for accessing CSRs.

[Jim Wilson]

Adds a debugger field to CPURISCVState.  Disable mode checks in riscv_csrrw
when true.

Signed-off-by: Jim Wilson <address@hidden>
---
 target/riscv/cpu.h |  3 +++
 target/riscv/csr.c | 16 ++++++++--------
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 743f02c..faa46d0 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -170,6 +170,9 @@ struct CPURISCVState {
 
     /* physical memory protection */
     pmp_table_t pmp_state;
+
+    /* True if in debugger mode.  */
+    bool debugger;
 #endif
 
     float_status fp_status;
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 5e7e7d1..04e6b59 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -46,7 +46,7 @@ void riscv_set_csr_ops(int csrno, riscv_csr_operations *ops)
 static int fs(CPURISCVState *env, int csrno)
 {
 #if !defined(CONFIG_USER_ONLY)
-    if (!(env->mstatus & MSTATUS_FS)) {
+    if (!env->debugger && !(env->mstatus & MSTATUS_FS)) {
         return -1;
     }
 #endif
@@ -58,7 +58,7 @@ static int ctr(CPURISCVState *env, int csrno)
 #if !defined(CONFIG_USER_ONLY)
     target_ulong ctr_en = env->priv == PRV_U ? env->scounteren :
                           env->priv == PRV_S ? env->mcounteren : -1U;
-    if (!(ctr_en & (1 << (csrno & 31)))) {
+    if (!env->debugger && !(ctr_en & (1 << (csrno & 31)))) {
         return -1;
     }
 #endif
@@ -86,7 +86,7 @@ static int pmp(CPURISCVState *env, int csrno)
 static int read_fflags(CPURISCVState *env, int csrno, target_ulong *val)
 {
 #if !defined(CONFIG_USER_ONLY)
-    if (!(env->mstatus & MSTATUS_FS)) {
+    if (!env->debugger && !(env->mstatus & MSTATUS_FS)) {
         return -1;
     }
 #endif
@@ -97,7 +97,7 @@ static int read_fflags(CPURISCVState *env, int csrno, 
target_ulong *val)
 static int write_fflags(CPURISCVState *env, int csrno, target_ulong val)
 {
 #if !defined(CONFIG_USER_ONLY)
-    if (!(env->mstatus & MSTATUS_FS)) {
+    if (!env->debugger && !(env->mstatus & MSTATUS_FS)) {
         return -1;
     }
     env->mstatus |= MSTATUS_FS;
@@ -109,7 +109,7 @@ static int write_fflags(CPURISCVState *env, int csrno, 
target_ulong val)
 static int read_frm(CPURISCVState *env, int csrno, target_ulong *val)
 {
 #if !defined(CONFIG_USER_ONLY)
-    if (!(env->mstatus & MSTATUS_FS)) {
+    if (!env->debugger && !(env->mstatus & MSTATUS_FS)) {
         return -1;
     }
 #endif
@@ -120,7 +120,7 @@ static int read_frm(CPURISCVState *env, int csrno, 
target_ulong *val)
 static int write_frm(CPURISCVState *env, int csrno, target_ulong val)
 {
 #if !defined(CONFIG_USER_ONLY)
-    if (!(env->mstatus & MSTATUS_FS)) {
+    if (!env->debugger && !(env->mstatus & MSTATUS_FS)) {
         return -1;
     }
     env->mstatus |= MSTATUS_FS;
@@ -132,7 +132,7 @@ static int write_frm(CPURISCVState *env, int csrno, 
target_ulong val)
 static int read_fcsr(CPURISCVState *env, int csrno, target_ulong *val)
 {
 #if !defined(CONFIG_USER_ONLY)
-    if (!(env->mstatus & MSTATUS_FS)) {
+    if (!env->debugger && !(env->mstatus & MSTATUS_FS)) {
         return -1;
     }
 #endif
@@ -144,7 +144,7 @@ static int read_fcsr(CPURISCVState *env, int csrno, 
target_ulong *val)
 static int write_fcsr(CPURISCVState *env, int csrno, target_ulong val)
 {
 #if !defined(CONFIG_USER_ONLY)
-    if (!(env->mstatus & MSTATUS_FS)) {
+    if (!env->debugger && !(env->mstatus & MSTATUS_FS)) {
         return -1;
     }
     env->mstatus |= MSTATUS_FS;
-- 
2.7.4