dmi_add_extension

Synopsis

#include <opendmi/context.h>

bool dmi_add_extension(dmi_context_t *context, const dmi_module_t *module);
bool dmi_has_extension(const dmi_context_t *context, const dmi_module_t *module);

Description

The dmi_add_extension function enables an extension module in a context, so that the structures of the types the module defines are decoded by its specifications. The modules of the vendors are declared in the headers under <opendmi/module/>, e.g. dmi_hpe_module in <opendmi/module/hpe.h>.

The specifications of the module are mapped to the type numbers they give, or to the ones the relocations of the enabled modules place them at, and the ones bound to a range of generations of a platform are mapped only if the generation of the platform lies within the range, see dmi_get_platform. Specifications told apart by their signatures share a type number, and the modules flagged with DMI_MODULE_FLAG_YIELD give way to the other enabled modules instead of conflicting with them.

The module is checked against the enabled ones before it is enabled, and is not enabled if a type number it maps a specification to is taken by another module. The structures decoded before are not decoded again, and keep the specifications they have been decoded by.

A module enabled this way stays enabled as the context is closed and opened again, until the context is destroyed. Its specifications are chosen again as the context is opened, once the platform is known, see dmi_open and dmi_load. The modules of the platform, which the context enables as it is opened when it has DMI_CONTEXT_FLAG_AUTO_MODULES, see dmi_create, stay enabled only until it is closed.

The dmi_has_extension function checks whether a module is enabled in a context, either with dmi_add_extension or for the platform as the context was opened. Modules are compared by address, so module is the very variable the module is declared as, e.g. &dmi_hpe_module.

Parameters

context: Context to enable the module in or to check, which may be open or closed.
module: Extension module to enable or to check.

Return value

The dmi_add_extension function returns true if the module has been enabled, and false otherwise. On failure, the enabled modules and the specifications chosen are left as they were.

The dmi_has_extension function returns true if the module is enabled, and false if it is not, or if context or module is nullptr.

Errors

DMI_ERROR_ARGUMENT_NULL: Raised by dmi_add_extension if module is nullptr.
DMI_ERROR_MODULE_CONFLICT: Module is enabled already, either with dmi_add_extension or for the platform as the context was opened, or its specifications have the same type numbers as the specifications of the enabled modules.
DMI_ERROR_OUT_OF_MEMORY: Memory is exhausted.

The dmi_has_extension function raises no errors.

Examples

#include <opendmi/module/hpe.h>

if (!dmi_add_extension(context, &dmi_hpe_module) ||
    !dmi_load(context, "dump.bin")) {
    const dmi_error_t *error;

    while ((error = dmi_error_get_first(context)) != nullptr)
        fprintf(stderr, "%s\n", dmi_error_message(error->reason));
}