[PATCH 3/7] gdbstub: add support for the qRegisterInfo query

[Matheus Tavares Bernardino]

From: Brian Cain <bc...@quicinc.com>

Signed-off-by: Brian Cain <bc...@quicinc.com>
Signed-off-by: Matheus Tavares Bernardino <quic_mathb...@quicinc.com>
---
 include/hw/core/cpu.h |  4 ++++
 gdbstub/gdbstub.c     | 27 +++++++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index 821e937020..b16b4e0de5 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -124,6 +124,8 @@ struct SysemuCPUOps;
  *       its Harvard architecture split code and data.
  * @gdb_num_core_regs: Number of core registers accessible to GDB.
  * @gdb_core_xml_file: File name for core registers GDB XML description.
+ * @gdb_qreg_info_lines: Array of lines of registers qRegisterInfo description.
+ * @gdb_qreg_info_line_count: Count of lines for @gdb_qreg_info_lines.
  * @gdb_stop_before_watchpoint: Indicates whether GDB expects the CPU to stop
  *           before the insn which triggers a watchpoint rather than after it.
  * @gdb_arch_name: Optional callback that returns the architecture name known
@@ -159,6 +161,8 @@ struct CPUClass {
     vaddr (*gdb_adjust_breakpoint)(CPUState *cpu, vaddr addr);
 
     const char *gdb_core_xml_file;
+    const char **gdb_qreg_info_lines;
+    int gdb_qreg_info_line_count;
     gchar * (*gdb_arch_name)(CPUState *cpu);
     const char * (*gdb_get_dynamic_xml)(CPUState *cpu, const char *xmlname);
 
diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
index 9d326a1d2d..2edd7d6d88 100644
--- a/gdbstub/gdbstub.c
+++ b/gdbstub/gdbstub.c
@@ -1409,6 +1409,27 @@ static void handle_query_curr_tid(GArray *params, void 
*user_ctx)
     gdb_put_strbuf();
 }
 
+static void handle_query_regs(GArray *params, void *user_ctx)
+{
+    if (!params->len) {
+        return;
+    }
+
+    CPUClass *cc = CPU_GET_CLASS(gdbserver_state.g_cpu);
+    if (!cc->gdb_qreg_info_lines) {
+        gdb_put_packet("");
+        return;
+    }
+
+    int reg_num = get_param(params, 0)->val_ul;
+    if (reg_num >= cc->gdb_qreg_info_line_count) {
+        gdb_put_packet("");
+        return;
+    }
+
+    gdb_put_packet(cc->gdb_qreg_info_lines[reg_num]);
+}
+
 static void handle_query_threads(GArray *params, void *user_ctx)
 {
     if (!gdbserver_state.query_cpu) {
@@ -1578,6 +1599,12 @@ static const GdbCmdParseEntry gdb_gen_query_table[] = {
         .handler = handle_query_curr_tid,
         .cmd = "C",
     },
+    {
+        .handler = handle_query_regs,
+        .cmd = "RegisterInfo",
+        .cmd_startswith = 1,
+        .schema = "l0"
+    },
     {
         .handler = handle_query_threads,
         .cmd = "sThreadInfo",
-- 
2.39.1