[PATCH v1 2/4] target/microblaze: gdb: Extend the number of registers presented to GDB

[Joe Komlodi <joe.komlodi@xilinx.com>]

Increase the number of Microblaze registers QEMU will report when
talking to GDB.

Signed-off-by: Joe Komlodi <komlodi@xilinx.com>
---
 target/microblaze/cpu.c     |  2 +-
 target/microblaze/gdbstub.c | 52 ++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/target/microblaze/cpu.c b/target/microblaze/cpu.c
index 41cac1b..5b6ad5b 100644
--- a/target/microblaze/cpu.c
+++ b/target/microblaze/cpu.c
@@ -331,7 +331,7 @@ static void mb_cpu_class_init(ObjectClass *oc, void *data)
 #endif
     dc->vmsd = &vmstate_mb_cpu;
     device_class_set_props(dc, mb_properties);
-    cc->gdb_num_core_regs = 32 + 5;
+    cc->gdb_num_core_regs = 32 + 27;
     cc->gdb_get_dynamic_xml = mb_gdb_get_dynamic_xml;
     cc->gdb_core_xml_file = "microblaze-core.xml";
 
diff --git a/target/microblaze/gdbstub.c b/target/microblaze/gdbstub.c
index cdca434..af29f00 100644
--- a/target/microblaze/gdbstub.c
+++ b/target/microblaze/gdbstub.c
@@ -26,12 +26,37 @@ int mb_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
     CPUMBState *env = &cpu->env;
 
+    /*
+     * GDB expects registers to be reported in this order:
+     * R0-R31
+     * PC-BTR
+     * PVR0-PVR11
+     * EDR-TLBHI
+     * SLR-SHR
+     */
     if (n < 32) {
         return gdb_get_reg32(mem_buf, env->regs[n]);
     } else {
-        return gdb_get_reg32(mem_buf, env->sregs[n - 32]);
+        n -= 32;
+        switch (n) {
+        case 0 ... 5:
+            return gdb_get_reg32(mem_buf, env->sregs[n]);
+        /* PVR12 is intentionally skipped */
+        case 6 ... 17:
+            n -= 6;
+            return gdb_get_reg32(mem_buf, env->pvr.regs[n]);
+        case 18 ... 24:
+            /* Add an offset of 6 to resume where we left off with SRegs */
+            n = n - 18 + 6;
+            return gdb_get_reg32(mem_buf, env->sregs[n]);
+        case 25:
+            return gdb_get_reg32(mem_buf, env->slr);
+        case 26:
+            return gdb_get_reg32(mem_buf, env->shr);
+        default:
+            return 0;
+        }
     }
-    return 0;
 }
 
 int mb_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
@@ -50,7 +75,28 @@ int mb_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
     if (n < 32) {
         env->regs[n] = tmp;
     } else {
-        env->sregs[n - 32] = tmp;
+        n -= 32;
+        switch (n) {
+        case 0 ... 5:
+            env->sregs[n] = tmp;
+            break;
+        /* PVR12 is intentionally skipped */
+        case 6 ... 17:
+            n -= 6;
+            env->pvr.regs[n] = tmp;
+            break;
+        case 18 ... 24:
+            /* Add an offset of 6 to resume where we left off with SRegs */
+            n = n - 18 + 6;
+            env->sregs[n] = tmp;
+            break;
+        case 25:
+            env->slr = tmp;
+            break;
+        case 26:
+            env->shr = tmp;
+            break;
+        }
     }
     return 4;
 }
-- 
2.7.4