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To perform the operation, the initiator invokes a routine identified by the add_config_option

field of the chapi_in descriptor. The initiator provides in the opt_name parameter the name

of configuration option to create, in the opt_type parameter the type of configuration option

to create (option_type_integer, option_type_boolean and option_type_string types are

supported), in the opt_vals_count the number of values in the option, in the opt_buffer

parameter the pointer to address where option value should be stored, and in opt_size

parameter the size of single option value. The size of whole storage, supplied in opt_buffer

is calculated as opt_vals_count * opt_size. The procedure is invoked as follows:

// Define option storage somewhere in loadable component implementation

int my_int_opt;

bool my_bool_opt[3];

char my_str_opt[256];

…

const chapi_in * ci = …;

if (ci->add_config_option) {

// Add scalar integer option

ci->add_config_option(ci, “int_opt”, option_type_integer, 1, &my_int_opt,

sizeof(my_int_opt));

// Add boolean option with three values

ci->add_config_option(ci, “bool_opt”, option_type_boolean, 3,

&my_bool_opt, sizeof(my_bool_opt));

// Add scalar string option

ci->add_config_option(ci, “str_opt”, option_type_string, 1,

&my_str_opt[0], sizeof(my_str_opt));

}

The example above shows that the CHARON core is not obliged to support the indicated

operation. It indicates why the device instance must remember the chapi_in descriptor. The

valid place to call described operation is loadable device initialization routine. Created

configuration options become available in configuration file (see 4.20.2 for example).

4.19.2 Setting option value

Setting option value belongs to the “A request to process loadable component defined

configuration options” class of operations. Such an operation is initiated by the device

instance. The CHARON core is defined as a target of the operation.

To perform the operation, the initiator invokes a routine identified by the set_option_value

field of the chapi_in descriptor. The initiator provides in the opt_name parameter the name

of configuration option to set, in the opt_val_idx the index of option value to set (from 0 to

opt_vals_count - 1) and in the val parameter the address of buffer where the option value to

set is located. The procedure is invoked as follows assuming that described in the

previous chapter options are added during the loadable module initialization:

// Define option storage somewhere in loadable component implementation

int my_int_opt;

bool my_bool_opt[3];

char my_str_opt[256];