target/arm: Add the XML dynamic generation

Generate an XML description for the cp-regs.
Register these regs with the gdb_register_coprocessor().
Add arm_gdb_get_sysreg() to use it as a callback to read those regs.
Add a dummy arm_gdb_set_sysreg().

Signed-off-by: Abdallah Bouassida <abdallah.bouassida@lauterbach.com>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1524153386-3550-4-git-send-email-abdallah.bouassida@lauterbach.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 76 insertions, 0 deletions

diff --git a/target/arm/gdbstub.c b/target/arm/gdbstub.c
index 04c1208d03..e80cfb47c7 100644
--- a/target/arm/gdbstub.c
+++ b/target/arm/gdbstub.c
@@ -22,6 +22,11 @@
 #include "cpu.h"
 #include "exec/gdbstub.h"
 
+typedef struct RegisterSysregXmlParam {
+    CPUState *cs;
+    GString *s;
+} RegisterSysregXmlParam;
+
 /* Old gdb always expect FPA registers.  Newer (xml-aware) gdb only expect
    whatever the target description contains.  Due to a historical mishap
    the FPA registers appear in between core integer regs and the CPSR.
@@ -101,3 +106,74 @@ int arm_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
     /* Unknown register.  */
     return 0;
 }
+
+static void arm_gen_one_xml_reg_tag(GString *s, DynamicGDBXMLInfo *dyn_xml,
+                                    ARMCPRegInfo *ri, uint32_t ri_key,
+                                    int bitsize)
+{
+    g_string_append_printf(s, "<reg name=\"%s\"", ri->name);
+    g_string_append_printf(s, " bitsize=\"%d\"", bitsize);
+    g_string_append_printf(s, " group=\"cp_regs\"/>");
+    dyn_xml->num_cpregs++;
+    dyn_xml->cpregs_keys[dyn_xml->num_cpregs - 1] = ri_key;
+}
+
+static void arm_register_sysreg_for_xml(gpointer key, gpointer value,
+                                        gpointer p)
+{
+    uint32_t ri_key = *(uint32_t *)key;
+    ARMCPRegInfo *ri = value;
+    RegisterSysregXmlParam *param = (RegisterSysregXmlParam *)p;
+    GString *s = param->s;
+    ARMCPU *cpu = ARM_CPU(param->cs);
+    CPUARMState *env = &cpu->env;
+    DynamicGDBXMLInfo *dyn_xml = &cpu->dyn_xml;
+
+    if (!(ri->type & (ARM_CP_NO_RAW | ARM_CP_NO_GDB))) {
+        if (arm_feature(env, ARM_FEATURE_AARCH64)) {
+            if (ri->state == ARM_CP_STATE_AA64) {
+                arm_gen_one_xml_reg_tag(s , dyn_xml, ri, ri_key, 64);
+            }
+        } else {
+            if (ri->state == ARM_CP_STATE_AA32) {
+                if (!arm_feature(env, ARM_FEATURE_EL3) &&
+                    (ri->secure & ARM_CP_SECSTATE_S)) {
+                    return;
+                }
+                if (ri->type & ARM_CP_64BIT) {
+                    arm_gen_one_xml_reg_tag(s , dyn_xml, ri, ri_key, 64);
+                } else {
+                    arm_gen_one_xml_reg_tag(s , dyn_xml, ri, ri_key, 32);
+                }
+            }
+        }
+    }
+}
+
+int arm_gen_dynamic_xml(CPUState *cs)
+{
+    ARMCPU *cpu = ARM_CPU(cs);
+    GString *s = g_string_new(NULL);
+    RegisterSysregXmlParam param = {cs, s};
+
+    cpu->dyn_xml.num_cpregs = 0;
+    cpu->dyn_xml.cpregs_keys = g_malloc(sizeof(uint32_t *) *
+                                        g_hash_table_size(cpu->cp_regs));
+    g_string_printf(s, "<?xml version=\"1.0\"?>");
+    g_string_append_printf(s, "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">");
+    g_string_append_printf(s, "<feature name=\"org.qemu.gdb.arm.sys.regs\">");
+    g_hash_table_foreach(cpu->cp_regs, arm_register_sysreg_for_xml, &param);
+    g_string_append_printf(s, "</feature>");
+    cpu->dyn_xml.desc = g_string_free(s, false);
+    return cpu->dyn_xml.num_cpregs;
+}
+
+const char *arm_gdb_get_dynamic_xml(CPUState *cs, const char *xmlname)
+{
+    ARMCPU *cpu = ARM_CPU(cs);
+
+    if (strcmp(xmlname, "system-registers.xml") == 0) {
+        return cpu->dyn_xml.desc;
+    }
+    return NULL;
+}