target/loongarch: Add gdb support.

Signed-off-by: Xiaojuan Yang <yangxiaojuan@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220606124333.2060567-42-yangxiaojuan@loongson.cn>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 81 insertions, 0 deletions

diff --git a/target/loongarch/gdbstub.c b/target/loongarch/gdbstub.c
new file mode 100644
index 0000000..0c48834
--- /dev/null
+++ b/target/loongarch/gdbstub.c
@@ -0,0 +1,81 @@
+/*
+ * LOONGARCH gdb server stub
+ *
+ * Copyright (c) 2021 Loongson Technology Corporation Limited
+ *
+ * SPDX-License-Identifier: LGPL-2.1+
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "internals.h"
+#include "exec/gdbstub.h"
+
+int loongarch_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
+{
+    LoongArchCPU *cpu = LOONGARCH_CPU(cs);
+    CPULoongArchState *env = &cpu->env;
+
+    if (0 <= n && n < 32) {
+        return gdb_get_regl(mem_buf, env->gpr[n]);
+    } else if (n == 32) {
+        return gdb_get_regl(mem_buf, env->pc);
+    } else if (n == 33) {
+        return gdb_get_regl(mem_buf, env->badaddr);
+    }
+    return 0;
+}
+
+int loongarch_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
+{
+    LoongArchCPU *cpu = LOONGARCH_CPU(cs);
+    CPULoongArchState *env = &cpu->env;
+    target_ulong tmp = ldtul_p(mem_buf);
+    int length = 0;
+
+    if (0 <= n && n < 32) {
+        env->gpr[n] = tmp;
+        length = sizeof(target_ulong);
+    } else if (n == 32) {
+        env->pc = tmp;
+        length = sizeof(target_ulong);
+    }
+    return length;
+}
+
+static int loongarch_gdb_get_fpu(CPULoongArchState *env,
+                                 GByteArray *mem_buf, int n)
+{
+    if (0 <= n && n < 32) {
+        return gdb_get_reg64(mem_buf, env->fpr[n]);
+    } else if (32 <= n && n < 40) {
+        return gdb_get_reg8(mem_buf, env->cf[n - 32]);
+    } else if (n == 40) {
+        return gdb_get_reg32(mem_buf, env->fcsr0);
+    }
+    return 0;
+}
+
+static int loongarch_gdb_set_fpu(CPULoongArchState *env,
+                                 uint8_t *mem_buf, int n)
+{
+    int length = 0;
+
+    if (0 <= n && n < 32) {
+        env->fpr[n] = ldq_p(mem_buf);
+        length = 8;
+    } else if (32 <= n && n < 40) {
+        env->cf[n - 32] = ldub_p(mem_buf);
+        length = 1;
+    } else if (n == 40) {
+        env->fcsr0 = ldl_p(mem_buf);
+        length = 4;
+    }
+    return length;
+}
+
+void loongarch_cpu_register_gdb_regs_for_features(CPUState *cs)
+{
+    gdb_register_coprocessor(cs, loongarch_gdb_get_fpu, loongarch_gdb_set_fpu,
+                             41, "loongarch-fpu64.xml", 0);
+}