[Qemu-devel] [RFC 1/9] target-xtensa: add DEBUGCAUSE SR and configuration

[Max Filippov <jcmvbkbc@gmail.com>]

DEBUGCAUSE SR holds information about the most recent debug exception.
See ISA, 4.7.7 for more details.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 target-xtensa/cpu.h       |   15 +++++++++++++++
 target-xtensa/translate.c |    6 ++++++
 2 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/target-xtensa/cpu.h b/target-xtensa/cpu.h
index 0db83a6..25245d8 100644
--- a/target-xtensa/cpu.h
+++ b/target-xtensa/cpu.h
@@ -137,6 +137,7 @@ enum {
     PS = 230,
     VECBASE = 231,
     EXCCAUSE = 232,
+    DEBUGCAUSE = 233,
     CCOUNT = 234,
     PRID = 235,
     EXCVADDR = 238,
@@ -161,6 +162,15 @@ enum {
 
 #define PS_WOE 0x40000
 
+#define DEBUGCAUSE_IC 0x1
+#define DEBUGCAUSE_IB 0x2
+#define DEBUGCAUSE_DB 0x4
+#define DEBUGCAUSE_BI 0x8
+#define DEBUGCAUSE_BN 0x10
+#define DEBUGCAUSE_DI 0x20
+#define DEBUGCAUSE_DBNUM 0xf00
+#define DEBUGCAUSE_DBNUM_SHIFT 8
+
 #define MAX_NAREG 64
 #define MAX_NINTERRUPT 32
 #define MAX_NLEVEL 6
@@ -279,6 +289,11 @@ typedef struct XtensaConfig {
     uint32_t timerint[MAX_NCCOMPARE];
     unsigned nextint;
     unsigned extint[MAX_NINTERRUPT];
+
+    unsigned debug_level;
+    unsigned nibreak;
+    unsigned ndbreak;
+
     uint32_t clock_freq_khz;
 
     xtensa_tlb itlb;
diff --git a/target-xtensa/translate.c b/target-xtensa/translate.c
index c81450d..0786dd1 100644
--- a/target-xtensa/translate.c
+++ b/target-xtensa/translate.c
@@ -119,6 +119,7 @@ static const char * const sregnames[256] = {
     [PS] = "PS",
     [VECBASE] = "VECBASE",
     [EXCCAUSE] = "EXCCAUSE",
+    [DEBUGCAUSE] = "DEBUGCAUSE",
     [CCOUNT] = "CCOUNT",
     [PRID] = "PRID",
     [EXCVADDR] = "EXCVADDR",
@@ -535,6 +536,10 @@ static void gen_wsr_ps(DisasContext *dc, uint32_t sr, TCGv_i32 v)
     gen_jumpi_check_loop_end(dc, -1);
 }
 
+static void gen_wsr_debugcause(DisasContext *dc, uint32_t sr, TCGv_i32 v)
+{
+}
+
 static void gen_wsr_prid(DisasContext *dc, uint32_t sr, TCGv_i32 v)
 {
 }
@@ -571,6 +576,7 @@ static void gen_wsr(DisasContext *dc, uint32_t sr, TCGv_i32 s)
         [INTCLEAR] = gen_wsr_intclear,
         [INTENABLE] = gen_wsr_intenable,
         [PS] = gen_wsr_ps,
+        [DEBUGCAUSE] = gen_wsr_debugcause,
         [PRID] = gen_wsr_prid,
         [CCOMPARE] = gen_wsr_ccompare,
         [CCOMPARE + 1] = gen_wsr_ccompare,
-- 
1.7.7.6