Abdallah Bouassida <abdallah.bouass...@lauterbach.com> writes:
> 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.bouass...@lauterbach.com>
> ---
> gdbstub.c | 10 ++++++++
> include/qom/cpu.h | 5 +++-
> target/arm/cpu.c | 1 +
> target/arm/cpu.h | 26 +++++++++++++++++++
> target/arm/gdbstub.c | 71
> ++++++++++++++++++++++++++++++++++++++++++++++++++++
> target/arm/helper.c | 27 ++++++++++++++++++++
> 6 files changed, 139 insertions(+), 1 deletion(-)
>
> diff --git a/gdbstub.c b/gdbstub.c
> index f1d5148..09065bc 100644
> --- a/gdbstub.c
> +++ b/gdbstub.c
> @@ -674,6 +674,16 @@ static const char *get_feature_xml(const char *p, const
> char **newp,
> }
> return target_xml;
> }
> + if (cc->gdb_get_dynamic_xml) {
> + CPUState *cpu = first_cpu;
> + char *xmlname = g_strndup(p, len);
> + const char *xml = cc->gdb_get_dynamic_xml(cpu, xmlname);
> +
> + free(xmlname);
g_free for a g_strndup'ed string please - although I'm confused as to
why you need to g_strdup the string. You already have p and its not like
gdb_get_dynamic_xml couldn't dup the string if it needed to (which it
doesn't seem to).
> + if (xml) {
> + return xml;
> + }
> + }
> for (i = 0; ; i++) {
> name = xml_builtin[i][0];
> if (!name || (strncmp(name, p, len) == 0 && strlen(name) == len))
> diff --git a/include/qom/cpu.h b/include/qom/cpu.h
> index dc6d495..be6d84d 100644
> --- a/include/qom/cpu.h
> +++ b/include/qom/cpu.h
> @@ -132,6 +132,9 @@ struct TranslationBlock;
> * before the insn which triggers a watchpoint rather than after
> it.
> * @gdb_arch_name: Optional callback that returns the architecture name known
> * to GDB. The caller must free the returned string with g_free.
> + * @gdb_get_dynamic_xml: Callback to return dynamically generated XML for the
> + * gdb stub. Returns a pointer to the XML contents for the specified XML
> file
> + * or NULL if the CPU doesn't have a dynamically generated content for it.
> * @cpu_exec_enter: Callback for cpu_exec preparation.
> * @cpu_exec_exit: Callback for cpu_exec cleanup.
> * @cpu_exec_interrupt: Callback for processing interrupts in cpu_exec.
> @@ -198,7 +201,7 @@ typedef struct CPUClass {
> const struct VMStateDescription *vmsd;
> const char *gdb_core_xml_file;
> gchar * (*gdb_arch_name)(CPUState *cpu);
> -
> + const char *(*gdb_get_dynamic_xml)(CPUState *cpu, const char *xmlname);
> void (*cpu_exec_enter)(CPUState *cpu);
> void (*cpu_exec_exit)(CPUState *cpu);
> bool (*cpu_exec_interrupt)(CPUState *cpu, int interrupt_request);
> diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> index 022d8c5..38b8b1c 100644
> --- a/target/arm/cpu.c
> +++ b/target/arm/cpu.c
> @@ -1879,6 +1879,7 @@ static void arm_cpu_class_init(ObjectClass *oc, void
> *data)
> cc->gdb_num_core_regs = 26;
> cc->gdb_core_xml_file = "arm-core.xml";
> cc->gdb_arch_name = arm_gdb_arch_name;
> + cc->gdb_get_dynamic_xml = arm_gdb_get_dynamic_xml;
> cc->gdb_stop_before_watchpoint = true;
> cc->debug_excp_handler = arm_debug_excp_handler;
> cc->debug_check_watchpoint = arm_debug_check_watchpoint;
> diff --git a/target/arm/cpu.h b/target/arm/cpu.h
> index 5a6ea24..5664f58 100644
> --- a/target/arm/cpu.h
> +++ b/target/arm/cpu.h
> @@ -133,6 +133,19 @@ enum {
> s<2n+1> maps to the most significant half of d<n>
> */
>
> +/**
> + * DynamicGDBXMLInfo:
> + * @desc: Contains the XML descriptions.
> + * @num_cpregs: Number of the Coprocessor registers seen by GDB.
> + * @cpregs_keys: Array that contains the corresponding Key of
> + * a given cpreg with the same order of the cpreg in the XML description.
> + */
> +typedef struct DynamicGDBXMLInfo {
> + char *desc;
> + int num_cpregs;
> + uint32_t *cpregs_keys;
> +} DynamicGDBXMLInfo;
> +
> /* CPU state for each instance of a generic timer (in cp15 c14) */
> typedef struct ARMGenericTimer {
> uint64_t cval; /* Timer CompareValue register */
> @@ -682,6 +695,8 @@ struct ARMCPU {
> uint64_t *cpreg_vmstate_values;
> int32_t cpreg_vmstate_array_len;
>
> + DynamicGDBXMLInfo dyn_xml;
> +
> /* Timers used by the generic (architected) timer */
> QEMUTimer *gt_timer[NUM_GTIMERS];
> /* GPIO outputs for generic timer */
> @@ -863,6 +878,17 @@ hwaddr arm_cpu_get_phys_page_attrs_debug(CPUState *cpu,
> vaddr addr,
> int arm_cpu_gdb_read_register(CPUState *cpu, uint8_t *buf, int reg);
> int arm_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
>
> +/* Dynamically generates for gdb stub an XML description of the sysregs from
> + * the cp_regs hashtable. Returns the registered sysregs number.
> + */
> +int arm_gen_dynamic_xml(CPUState *cpu);
> +
> +/* Returns the dynamically generated XML for the gdb stub.
> + * Returns a pointer to the XML contents for the specified XML file or NULL
> + * if the XML name doesn't match the predefined one.
> + */
> +const char *arm_gdb_get_dynamic_xml(CPUState *cpu, const char *xmlname);
> +
> int arm_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
> int cpuid, void *opaque);
> int arm_cpu_write_elf32_note(WriteCoreDumpFunction f, CPUState *cs,
> diff --git a/target/arm/gdbstub.c b/target/arm/gdbstub.c
> index 04c1208..fafc08b 100644
> --- a/target/arm/gdbstub.c
> +++ b/target/arm/gdbstub.c
> @@ -101,3 +101,74 @@ 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;
> + void **p_array = p;
> + ARMCPU *cpu = ARM_CPU((CPUState *)(p_array[0]));
This comes across as a little clumsy compared to casting p to a
structure that contains the correctly typed parameters.
> + CPUARMState *env = &cpu->env;
> + DynamicGDBXMLInfo *dyn_xml = &cpu->dyn_xml;
> + GString *s = (GString *)(p_array[1]);
> +
> + 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);
> + void *p_array[] = {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, p_array);
> + 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;
> +}
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index 1360a14..d3c40b7 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -220,6 +220,29 @@ static void write_raw_cp_reg(CPUARMState *env, const
> ARMCPRegInfo *ri,
> }
> }
>
> +static int arm_gdb_get_sysreg(CPUARMState *env, uint8_t *buf, int reg)
> +{
> + ARMCPU *cpu = arm_env_get_cpu(env);
> + const ARMCPRegInfo *ri;
> + uint32_t key;
> +
> + key = cpu->dyn_xml.cpregs_keys[reg];
> + ri = get_arm_cp_reginfo(cpu->cp_regs, key);
> + if (ri) {
> + if (cpreg_field_is_64bit(ri)) {
> + return gdb_get_reg64(buf, (uint64_t)read_raw_cp_reg(env, ri));
> + } else {
> + return gdb_get_reg32(buf, (uint32_t)read_raw_cp_reg(env, ri));
> + }
> + }
> + return 0;
There is something odd going on here because if I run a simple little
features binary
(https://github.com/stsquad/testcases/blob/master/aarch64/features.c) I
get:
ID_AA64ISAR0_EL1 : 0x0000000000011120
ID_AA64ISAR1_EL1 : 0x0000000000000000
ID_AA64MMFR0_EL1 : 0x00000000ff000000
ID_AA64MMFR1_EL1 : 0x0000000000000000
ID_AA64PFR0_EL1 : 0x0000000000000011
ID_AA64PFR1_EL1 : 0x0000000000000000
ID_AA64DFR0_EL1 : 0x0000000000000006
ID_AA64DFR1_EL1 : 0x0000000000000000
MIDR_EL1 : 0x00000000411fd070
MPIDR_EL1 : 0x0000000080000000
REVIDR_EL1 : 0x0000000000000000
However in the gdb output we see:
ID_AA64ISAR0_EL1 0x11120 69920
ID_AA64ISAR1_EL1 0x0 0
ID_AA64MMFR0_EL1 0x1124 4388 <-?
ID_AA64MMFR1_EL1 0x0 0
ID_PFR0 0x131 305 <-name and value?
ID_AA64PFR1_EL1 0x0 0
ID_AA64DFR0_EL1 0x10305106 271601926 <-?
ID_AA64DFR1_EL1 0x0 0
REVIDR_EL1 0x0 0
So why the discrepancies?
> +}
> +
> +static int arm_gdb_set_sysreg(CPUARMState *env, uint8_t *buf, int reg)
> +{
> + return 0;
> +}
> +
> static bool raw_accessors_invalid(const ARMCPRegInfo *ri)
> {
> /* Return true if the regdef would cause an assertion if you called
> @@ -5459,6 +5482,7 @@ void arm_cpu_register_gdb_regs_for_features(ARMCPU *cpu)
> {
> CPUState *cs = CPU(cpu);
> CPUARMState *env = &cpu->env;
> + int n;
>
> if (arm_feature(env, ARM_FEATURE_AARCH64)) {
> gdb_register_coprocessor(cs, aarch64_fpu_gdb_get_reg,
> @@ -5474,6 +5498,9 @@ void arm_cpu_register_gdb_regs_for_features(ARMCPU *cpu)
> gdb_register_coprocessor(cs, vfp_gdb_get_reg, vfp_gdb_set_reg,
> 19, "arm-vfp.xml", 0);
> }
> + n = arm_gen_dynamic_xml(cs);
> + gdb_register_coprocessor(cs, arm_gdb_get_sysreg, arm_gdb_set_sysreg,
> + n, "system-registers.xml", 0);
You could call arm_gen_dynamic_xml() direct when calling the register function
to save the intermediate n.
> }
>
> /* Sort alphabetically by type name, except for "any". */
--
Alex Bennée
