gdbstub/gdbstub/internals.h

/*
 * gdbstub internals
 *
 * Copyright (c) 2022 Linaro Ltd
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#ifndef GDBSTUB_INTERNALS_H
#define GDBSTUB_INTERNALS_H

#include "cpu.h"
#include "utils/conn.h"

#define MAX_PACKET_LENGTH 131104

enum {
  GDB_SIGNAL_0 = 0,
  GDB_SIGNAL_INT = 2,
  GDB_SIGNAL_QUIT = 3,
  GDB_SIGNAL_TRAP = 5,
  GDB_SIGNAL_ABRT = 6,
  GDB_SIGNAL_ALRM = 14,
  GDB_SIGNAL_STOP = 17,
  GDB_SIGNAL_IO = 23,
  GDB_SIGNAL_XCPU = 24,
  GDB_SIGNAL_UNKNOWN = 143
};

typedef struct GDBProcess {
  uint32_t pid;
  bool attached;
  char *target_xml;
} GDBProcess;

enum RSState {
  RS_INACTIVE,
  RS_IDLE,
  RS_GETLINE,
  RS_GETLINE_ESC,
  RS_GETLINE_RLE,
  RS_CHKSUM1,
  RS_CHKSUM2,
};

typedef struct GDBFeature {
  const char *xmlname;
  const char *xml;
  const char *name;
  const char *const *regs;
  int num_regs;
} GDBFeature;

typedef struct GDBFeatureBuilder {
  GDBFeature *feature;
  GPtrArray *xml;
  GPtrArray *regs;
  int base_reg;
} GDBFeatureBuilder;

/* Get or set a register.  Returns the size of the register.  */
typedef int (*gdb_get_reg_cb)(CPUState *cpu, GByteArray *buf, int reg);
typedef int (*gdb_set_reg_cb)(CPUState *cpu, uint8_t *buf, int reg);

typedef struct GDBRegisterState {
  int base_reg;
  gdb_get_reg_cb get_reg;
  gdb_set_reg_cb set_reg;
  const GDBFeature *feature;
} GDBRegisterState;

typedef struct GDBState {
  bool init; /* have we been initialised? */
  CPUState *c_cpu;
  CPUState *query_cpu;
  enum RSState state; /* parsing state */
  char line_buf[MAX_PACKET_LENGTH];
  int line_buf_index;
  int line_sum;  /* running checksum */
  int line_csum; /* checksum at the end of the packet */
  GByteArray *last_packet;
  int signal;
  GDBProcess *processes;
  int process_num;
  GString *str_buf;
  GByteArray *mem_buf;
  int sstep_flags;
  int supported_sstep_flags;
  conn_t *conn;
  /*
   * Whether we are allowed to send a stop reply packet at this moment.
   * Must be set off after sending the stop reply itself.
   */
  bool allow_stop_reply;
} GDBState;

/* lives in main gdbstub.c */
extern GDBState gdb_state;

/*
 * Inline utility function, convert from int to hex and back
 */

static inline int fromhex(int v) {
  if (v >= '0' && v <= '9') {
    return v - '0';
  } else if (v >= 'A' && v <= 'F') {
    return v - 'A' + 10;
  } else if (v >= 'a' && v <= 'f') {
    return v - 'a' + 10;
  } else {
    return 0;
  }
}

static inline int tohex(int v) {
  if (v < 10) {
    return v + '0';
  } else {
    return v - 10 + 'a';
  }
}

/*
 * Connection helpers for both system and user backends
 */

void gdb_put_strbuf(void);
void gdb_hextomem(GByteArray *mem, const char *buf, int len);
void gdb_read_byte(uint8_t ch);

void gdb_init_cpu();

void gdb_register_coprocessor(CPUState *cpu, gdb_get_reg_cb get_reg, gdb_set_reg_cb set_reg, const GDBFeature *feature,
                              int g_pos);

void gdb_unregister_coprocessor_all(CPUState *cpu);

/**
 * gdb_feature_builder_append_tag() - Append a tag.
 * @builder: The builder.
 * @format: The format of the tag.
 * @...: The values to be formatted.
 */
void G_GNUC_PRINTF(2, 3) gdb_feature_builder_append_tag(const GDBFeatureBuilder *builder, const char *format, ...);

/**
 * gdb_feature_builder_append_reg() - Append a register.
 * @builder: The builder.
 * @name: The register's name; it must be unique within a CPU.
 * @bitsize: The register's size, in bits.
 * @regnum: The offset of the register's number in the feature.
 * @type: The type of the register.
 * @group: The register group to which this register belongs; it can be NULL.
 */
void gdb_feature_builder_append_reg(const GDBFeatureBuilder *builder, const char *name, int bitsize, int regnum,
                                    const char *type, const char *group);

void gdb_feature_builder_end(const GDBFeatureBuilder *builder);

const GDBFeature *gdb_find_static_feature(const char *xmlname);

int gdb_read_register(CPUState *cpu, GByteArray *buf, int reg);

int gdb_write_register(CPUState *cpu, uint8_t *mem_buf, int reg);

typedef struct {
  int gdb_reg;
  const char *name;
  const char *feature_name;
} GDBRegDesc;

GArray *gdb_get_register_list(CPUState *cpu);

/* in gdbstub-xml.c, generated by scripts/feature_to_c.py */
extern const GDBFeature gdb_static_features[];

void gdb_chr_receive(const uint8_t *buf, int size);
bool gdb_got_immediate_ack(void);

int gdb_put_packet(const char *buf);

/* utility helpers */
GDBProcess *gdb_get_process();
void gdb_append_thread_id(CPUState *cpu, GString *buf);
unsigned int gdb_get_max_cpus(void); /* both */

void gdb_create_default_process(GDBState *s);

int gdb_signal_to_target(int sig);

void gdb_continue(void);

int gdb_continue_partial(char *newstates);

void gdb_init_gdb_state(void);

void gdb_handle_query_rcmd(GArray *params, void *ctx); /* system */

void gdb_handle_query_attached(GArray *params, void *ctx); /* both */

/* system only */
void gdb_handle_query_qemu_phy_mem_mode(GArray *params, void *ctx);
void gdb_handle_set_qemu_phy_mem_mode(GArray *params, void *ctx);

/* sycall handling */
void gdb_handle_file_io(GArray *params, void *user_ctx);
void gdb_disable_syscalls(void);

// TODO
bool runstate_is_running();
void vm_stop();
void vm_start();
void cpu_synchronize_state(CPUState *cpu);
void gdb_exit(int i);
void gdb_qemu_exit(int i);

CPUState *get_cpu();
void gdb_breakpoint_remove_all(CPUState *cs);
bool gdb_supports_guest_debug(void);
int gdb_breakpoint_insert(CPUState *cs, int type, vaddr addr, vaddr len);
int gdb_breakpoint_remove(CPUState *cs, int type, vaddr addr, vaddr len);

void gdb_put_buffer(const uint8_t *buf, int len);

static inline void cpu_physical_memory_write(hwaddr addr, const void *buf, hwaddr len);
static inline void cpu_physical_memory_read(hwaddr addr, const void *buf, hwaddr len);

bool runstate_needs_reset(void);
bool vm_prepare_start(bool step_requested);
void qemu_clock_enable();

int gdb_target_memory_rw_debug(CPUState *cs, hwaddr addr, uint8_t *buf, int len, bool is_write);

const char *get_feature_xml(const char *p, const char **newp, GDBProcess *process);

const char *gdb_get_core_xml_file(CPUState *cpu);

void cpu_register_gdb_commands();


int cpu_common_gdb_read_register(CPUState *cpu, GByteArray *buf, int reg);
int cpu_common_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);

#endif /* GDBSTUB_INTERNALS_H */