/** * @file config.dox * @page config MetalSVM feature configuration files * * @section main_config MetalSVM's main configuration file * * MetalSVM's configuration parameters and some features can be configured/activated * in the central configuration file located at \c include/metalsvm/config.h. * * The `config.h` is a usual C header file and the configuration items are usual * C preprocessor-definitions like the following: * \code #define CONFIGURATION_PARAMETER 123value /* A parameter with a value */ #define FEATURE_A /* An activated feature */ //#define FEATURE_B /* A deactivated feature */\endcode * * Just like the example suggests, features are deactivated by commenting them out. * * If you boot MetalSVM on the Intel SCC, you need to \b deactivate `CONFIG_PCI`, * `CONFIG_VGA`, `CONFIG_KEYBOARD`, and `CONFIG_MULTIBOOT` and * \b activate `CONFIG_ROCKCREEK`. Set `CACHE_LINE` to 32.\n * Activate `CONFIG_UART` if you are going to use software-UART and deactivate it if * not, to avoid unnecessary traffic. * * @section lwip_config LwIP configuration flags * * The networking subsystem, based on LwIP, can of course be influenced by various * feature flags. * * MetalSVM overrides various standard settings in `lwip/src/include/lwipopts.h`. * * If you chose `CONFIG_ROCKCREEK`, this leads to deactivation of `LWIP_DHCP`. * * If you chose `CONFIG_TICKLESS`, `NO_SYS` will be activated and the following * are deactivated: `LWIP_SOCKET`, `LWIP_NETCON`, `LWIP_NETIF_API`. * * Another interesting feature is `LWIP_CHECKSUM_ON_COPY`. Deactivating it leads * to higher network throughput for on-die communication. * * See LwIP documentation for more specific information about the individual effects of * manipulating the LwIP configuration flags/values. * * @section mmnif_config MMNIF configuration flags * Several flags in the file `drivers/net/mmnif.c` file influence the memory * mapped network interface's performance: * * - `USE_CACHE`: activates the cache for the memory mapped buffer region. * This improves the performance. * - `USE_MPB`: If activated, the buffer will be mapped onto the SCC's special MPB, * which improves the performance drastically. * * @section svm_config SVM configuration flags * * Although the choice between different shared memory release consistency models * is configured in the application code, there are 2 flags which influence the SVM * implementation. These are located in `arch/x86/mm/svm.c`: * * - `USE_PERFCOUNTERS`: Performance counters will help evaluating the performance * of the SVM implementation within the kernel. Deactivate to omit overhead. * * - `USE_RESP_MAIL`: Whenever a core requests access to a page it is not the owner * of, it sends an interrupt to the owner. The requesting core will then wait for the mail * indicating that it has become the new owner of the particular page, spinning on its mailbox. * When `USE_RESP_MAIL` is activated, other interrupts will be deactivated until the response * has arrived. * * */