The first_child function returns the first description in the sequence of child descriptions of parent or NULL if parent has no children. Groups can have both registers and groups as children, registers can only have fields as children and fields cannot have any children. If parent is NULL, return the first description in the sequence of top-level descriptions.
Use next_description to deallocate the previous description and return the next description in the sequence or NULL if there are no more descriptions in the current sequence.
The free_description function is used to free the description without returning the next one in the sequence.
The first_named_value function returns the first named value in the sequence of named values for parent or NULL if there are no named values for parent. Only fields and registers can have named values.
Use next_named_value to deallocate the previous named value and return the next named value or NULL if there are no more named values in this sequence.
Use free_named_value to free the named value without returning the next one in the sequence.
The get and set functions are used to get and set the value of the register. To set the value pass in a bytes_t for the value. The value passed in must be long enough to contain the full value of the register. If the bytes_t is too long it will be truncated. To get the value pass in a buffer_t which is long enough to contain the register's value. The value is encoded in little endian byte order.
typedef enum {
Description_Type_Group,
Description_Type_Int_Reg,
Description_Type_Float_Reg,
Description_Type_Fields_Reg,
Description_Type_Int_Field,
Description_Type_Float_Field,
} description_type_t;typedef enum {
Reg_Role_None, /* No special role for the register. */
Reg_Role_Program_Counter /* The register is the program counter. */
} reg_role_t;typedef enum {
Reg_Bitorder_Little_Endian,
Reg_Bitorder_Big_Endian
} reg_bitorder_t;typedef struct {
const char *name;
const char *description;
const bytes_t value; /* Little endian byte order */
} named_value_t;typedef struct {
/* Common fields */
description_type_t type;
const char *name;
const char *description;
/* Register and field fields */
int16 dwarf_id; /* id used by dwarf for this register
or -1 if no such id is defined. This
is ABI specific, but the CPU will
give the ids for the most common ABI
for that architecture. */
reg_bitorder_t bitorder; /* Bitorder convention used in the
documentation for this register or
field. */
reg_role_t role; /* Role of this register in the ABI/HW. */
bool memory_mapped; /* True if the register is memory mapped. */
uint64 offset; /* Offset into the bank for memory mapped
registers. */
bool catchable; /* True if Core_Control_Register_Write and
Core_Control_Register_Read are triggered
when this register is written or read. */
int msb, lsb; /* Most and least significant bit of the
register or field. Always given in le
bitorder. For groups msb == -1 and
lsb == 0. */
int regsize; /* Number of bits in the register, or the
register this field is a part of. */
int reg_id; /* For registers and fields the id to pass
to the get and set methods to access the
register's value. Fields have the same
reg_id as the register they are a part
of. Not valid for groups.*/
} description_t;
SIM_INTERFACE(describe_registers) {
const description_t *(*first_child)(
conf_object_t *NOTNULL obj, const description_t *parent);
const description_t *(*next_description)(
conf_object_t *NOTNULL obj, const description_t *prev);
void (*free_description)(conf_object_t *NOTNULL obj,
const description_t *desc);
const named_value_t *(*first_named_value)(
conf_object_t *NOTNULL obj, const description_t *parent);
const named_value_t *(*next_named_value)(
conf_object_t *NOTNULL obj, const named_value_t *prev);
void (*free_named_value)(conf_object_t *NOTNULL obj,
const named_value_t *nv);
void (*get)(conf_object_t *NOTNULL obj, int reg_id, buffer_t dest);
void (*set)(conf_object_t *NOTNULL obj, int reg_id, bytes_t value);
};
#define DESCRIBE_REGISTERS_INTERFACE "describe_registers"