/* * This file is part of the MicroPython project, http://micropython.org/ * * The MIT License (MIT) * * Copyright (c) 2013-2017 Damien P. George * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ // Options to control how MicroPython is built for this port, // overriding defaults in py/mpconfig.h. // board specific definitions #include "mpconfigboard.h" #include "mpconfigboard_common.h" // memory allocation policies #ifndef MICROPY_GC_STACK_ENTRY_TYPE #if MICROPY_HW_SDRAM_SIZE #define MICROPY_GC_STACK_ENTRY_TYPE uint32_t #else #define MICROPY_GC_STACK_ENTRY_TYPE uint16_t #endif #endif #define MICROPY_ALLOC_PATH_MAX (128) // emitters #define MICROPY_PERSISTENT_CODE_LOAD (1) #ifndef MICROPY_EMIT_THUMB #define MICROPY_EMIT_THUMB (1) #endif #ifndef MICROPY_EMIT_INLINE_THUMB #define MICROPY_EMIT_INLINE_THUMB (1) #endif // compiler configuration #define MICROPY_COMP_MODULE_CONST (1) #define MICROPY_COMP_TRIPLE_TUPLE_ASSIGN (1) #define MICROPY_COMP_RETURN_IF_EXPR (1) // optimisations #ifndef MICROPY_OPT_COMPUTED_GOTO #define MICROPY_OPT_COMPUTED_GOTO (1) #endif #define MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE (0) #define MICROPY_OPT_MPZ_BITWISE (1) #define MICROPY_OPT_MATH_FACTORIAL (1) // Python internal features #define MICROPY_READER_VFS (1) #define MICROPY_ENABLE_GC (1) #define MICROPY_ENABLE_FINALISER (1) #define MICROPY_STACK_CHECK (1) #define MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF (1) #define MICROPY_EMERGENCY_EXCEPTION_BUF_SIZE (0) #define MICROPY_KBD_EXCEPTION (1) #define MICROPY_HELPER_REPL (1) #define MICROPY_REPL_INFO (1) #define MICROPY_REPL_EMACS_KEYS (1) #define MICROPY_REPL_AUTO_INDENT (1) #define MICROPY_LONGINT_IMPL (MICROPY_LONGINT_IMPL_MPZ) #define MICROPY_ENABLE_SOURCE_LINE (1) #ifndef MICROPY_FLOAT_IMPL // can be configured by each board via mpconfigboard.mk #define MICROPY_FLOAT_IMPL (MICROPY_FLOAT_IMPL_FLOAT) #endif #define MICROPY_STREAMS_NON_BLOCK (1) #define MICROPY_MODULE_BUILTIN_INIT (1) #define MICROPY_MODULE_WEAK_LINKS (1) #define MICROPY_CAN_OVERRIDE_BUILTINS (1) #define MICROPY_USE_INTERNAL_ERRNO (1) #define MICROPY_ENABLE_SCHEDULER (1) #define MICROPY_SCHEDULER_DEPTH (8) #define MICROPY_VFS (1) // control over Python builtins #define MICROPY_PY_FUNCTION_ATTRS (1) #define MICROPY_PY_DESCRIPTORS (1) #define MICROPY_PY_DELATTR_SETATTR (1) #ifndef MICROPY_PY_FSTRINGS #define MICROPY_PY_FSTRINGS (1) #endif #define MICROPY_PY_BUILTINS_STR_UNICODE (1) #define MICROPY_PY_BUILTINS_STR_CENTER (1) #define MICROPY_PY_BUILTINS_STR_PARTITION (1) #define MICROPY_PY_BUILTINS_STR_SPLITLINES (1) #define MICROPY_PY_BUILTINS_MEMORYVIEW (1) #define MICROPY_PY_BUILTINS_FROZENSET (1) #define MICROPY_PY_BUILTINS_SLICE_ATTRS (1) #define MICROPY_PY_BUILTINS_SLICE_INDICES (1) #define MICROPY_PY_BUILTINS_ROUND_INT (1) #define MICROPY_PY_ALL_SPECIAL_METHODS (1) #define MICROPY_PY_REVERSE_SPECIAL_METHODS (1) #define MICROPY_PY_BUILTINS_COMPILE (MICROPY_ENABLE_COMPILER) #define MICROPY_PY_BUILTINS_EXECFILE (MICROPY_ENABLE_COMPILER) #define MICROPY_PY_BUILTINS_NOTIMPLEMENTED (1) #define MICROPY_PY_BUILTINS_INPUT (1) #define MICROPY_PY_BUILTINS_POW3 (1) #define MICROPY_PY_BUILTINS_HELP (1) #ifndef MICROPY_PY_BUILTINS_HELP_TEXT #define MICROPY_PY_BUILTINS_HELP_TEXT stm32_help_text #endif #define MICROPY_PY_BUILTINS_HELP_MODULES (1) #define MICROPY_PY_MICROPYTHON_MEM_INFO (1) #define MICROPY_PY_ARRAY_SLICE_ASSIGN (1) #define MICROPY_PY_COLLECTIONS_DEQUE (1) #define MICROPY_PY_COLLECTIONS_ORDEREDDICT (1) #define MICROPY_PY_MATH_SPECIAL_FUNCTIONS (1) #define MICROPY_PY_MATH_ISCLOSE (1) #define MICROPY_PY_MATH_FACTORIAL (1) #define MICROPY_PY_CMATH (1) #define MICROPY_PY_IO (1) #define MICROPY_PY_IO_IOBASE (1) #define MICROPY_PY_IO_FILEIO (MICROPY_VFS_FAT || MICROPY_VFS_LFS1 || MICROPY_VFS_LFS2) #define MICROPY_PY_SYS_MAXSIZE (1) #define MICROPY_PY_SYS_EXIT (1) #define MICROPY_PY_SYS_STDFILES (1) #define MICROPY_PY_SYS_STDIO_BUFFER (1) #ifndef MICROPY_PY_SYS_PLATFORM // let boards override it if they want #define MICROPY_PY_SYS_PLATFORM "pyboard" #endif #define MICROPY_PY_UERRNO (1) #ifndef MICROPY_PY_THREAD #define MICROPY_PY_THREAD (0) #endif // extended modules #ifndef MICROPY_PY_UASYNCIO #define MICROPY_PY_UASYNCIO (1) #endif #ifndef MICROPY_PY_UCTYPES #define MICROPY_PY_UCTYPES (1) #endif #ifndef MICROPY_PY_UZLIB #define MICROPY_PY_UZLIB (1) #endif #ifndef MICROPY_PY_UJSON #define MICROPY_PY_UJSON (1) #endif #ifndef MICROPY_PY_URE #define MICROPY_PY_URE (1) #endif #ifndef MICROPY_PY_URE_SUB #define MICROPY_PY_URE_SUB (1) #endif #ifndef MICROPY_PY_UHEAPQ #define MICROPY_PY_UHEAPQ (1) #endif #ifndef MICROPY_PY_UHASHLIB #define MICROPY_PY_UHASHLIB (1) #endif #define MICROPY_PY_UHASHLIB_MD5 (MICROPY_PY_USSL) #define MICROPY_PY_UHASHLIB_SHA1 (MICROPY_PY_USSL) #define MICROPY_PY_UCRYPTOLIB (MICROPY_PY_USSL) #ifndef MICROPY_PY_UBINASCII #define MICROPY_PY_UBINASCII (1) #define MICROPY_PY_UBINASCII_CRC32 (1) #endif #ifndef MICROPY_PY_UOS #define MICROPY_PY_UOS (1) #endif #define MICROPY_PY_OS_DUPTERM (3) #define MICROPY_PY_UOS_DUPTERM_BUILTIN_STREAM (1) #ifndef MICROPY_PY_URANDOM #define MICROPY_PY_URANDOM (1) #define MICROPY_PY_URANDOM_SEED_INIT_FUNC (rng_get()) #endif #ifndef MICROPY_PY_URANDOM_EXTRA_FUNCS #define MICROPY_PY_URANDOM_EXTRA_FUNCS (1) #endif #define MICROPY_PY_USELECT (1) #ifndef MICROPY_PY_UTIME #define MICROPY_PY_UTIME (1) #endif #define MICROPY_PY_UTIME_MP_HAL (MICROPY_PY_UTIME) #ifndef MICROPY_PY_UTIMEQ #define MICROPY_PY_UTIMEQ (1) #endif #define MICROPY_PY_LWIP_SOCK_RAW (MICROPY_PY_LWIP) #ifndef MICROPY_PY_MACHINE #define MICROPY_PY_MACHINE (1) #ifndef MICROPY_PY_MACHINE_BITSTREAM #define MICROPY_PY_MACHINE_BITSTREAM (1) #endif #define MICROPY_PY_MACHINE_PULSE (1) #define MICROPY_PY_MACHINE_PIN_MAKE_NEW mp_pin_make_new #define MICROPY_PY_MACHINE_I2C (1) #define MICROPY_PY_MACHINE_SOFTI2C (1) #define MICROPY_PY_MACHINE_SPI (1) #define MICROPY_PY_MACHINE_SPI_MSB (SPI_FIRSTBIT_MSB) #define MICROPY_PY_MACHINE_SPI_LSB (SPI_FIRSTBIT_LSB) #define MICROPY_PY_MACHINE_SOFTSPI (1) #endif #define MICROPY_HW_SOFTSPI_MIN_DELAY (0) #define MICROPY_HW_SOFTSPI_MAX_BAUDRATE (HAL_RCC_GetSysClockFreq() / 48) #define MICROPY_PY_UWEBSOCKET (MICROPY_PY_LWIP) #define MICROPY_PY_WEBREPL (MICROPY_PY_LWIP) #ifndef MICROPY_PY_FRAMEBUF #define MICROPY_PY_FRAMEBUF (1) #endif #ifndef MICROPY_PY_USOCKET #define MICROPY_PY_USOCKET (1) #endif #ifndef MICROPY_PY_NETWORK #define MICROPY_PY_NETWORK (1) #endif #ifndef MICROPY_PY_ONEWIRE #define MICROPY_PY_ONEWIRE (1) #endif // fatfs configuration used in ffconf.h #define MICROPY_FATFS_ENABLE_LFN (1) #define MICROPY_FATFS_LFN_CODE_PAGE 437 /* 1=SFN/ANSI 437=LFN/U.S.(OEM) */ #define MICROPY_FATFS_USE_LABEL (1) #define MICROPY_FATFS_RPATH (2) #define MICROPY_FATFS_MULTI_PARTITION (1) // TODO these should be generic, not bound to a particular FS implementation #if MICROPY_VFS_FAT #define mp_type_fileio mp_type_vfs_fat_fileio #define mp_type_textio mp_type_vfs_fat_textio #elif MICROPY_VFS_LFS1 #define mp_type_fileio mp_type_vfs_lfs1_fileio #define mp_type_textio mp_type_vfs_lfs1_textio #elif MICROPY_VFS_LFS2 #define mp_type_fileio mp_type_vfs_lfs2_fileio #define mp_type_textio mp_type_vfs_lfs2_textio #endif // use vfs's functions for import stat and builtin open #define mp_import_stat mp_vfs_import_stat #define mp_builtin_open mp_vfs_open #define mp_builtin_open_obj mp_vfs_open_obj // extra built in names to add to the global namespace #define MICROPY_PORT_BUILTINS \ { MP_ROM_QSTR(MP_QSTR_open), MP_ROM_PTR(&mp_builtin_open_obj) }, // extra built in modules to add to the list of known ones extern const struct _mp_obj_module_t machine_module; extern const struct _mp_obj_module_t pyb_module; extern const struct _mp_obj_module_t stm_module; extern const struct _mp_obj_module_t mp_module_ubinascii; extern const struct _mp_obj_module_t mp_module_ure; extern const struct _mp_obj_module_t mp_module_uzlib; extern const struct _mp_obj_module_t mp_module_ujson; extern const struct _mp_obj_module_t mp_module_uheapq; extern const struct _mp_obj_module_t mp_module_uhashlib; extern const struct _mp_obj_module_t mp_module_uos; extern const struct _mp_obj_module_t mp_module_utime; extern const struct _mp_obj_module_t mp_module_usocket; extern const struct _mp_obj_module_t mp_module_network; extern const struct _mp_obj_module_t mp_module_onewire; #if MICROPY_PY_PYB #define PYB_BUILTIN_MODULE { MP_ROM_QSTR(MP_QSTR_pyb), MP_ROM_PTR(&pyb_module) }, #else #define PYB_BUILTIN_MODULE #endif #if MICROPY_PY_STM #define STM_BUILTIN_MODULE { MP_ROM_QSTR(MP_QSTR_stm), MP_ROM_PTR(&stm_module) }, #else #define STM_BUILTIN_MODULE #endif #if MICROPY_PY_MACHINE #define MACHINE_BUILTIN_MODULE { MP_ROM_QSTR(MP_QSTR_umachine), MP_ROM_PTR(&machine_module) }, #define MACHINE_BUILTIN_MODULE_CONSTANTS { MP_ROM_QSTR(MP_QSTR_machine), MP_ROM_PTR(&machine_module) }, #else #define MACHINE_BUILTIN_MODULE #define MACHINE_BUILTIN_MODULE_CONSTANTS #endif #if MICROPY_PY_UOS #define UOS_BUILTIN_MODULE { MP_ROM_QSTR(MP_QSTR_uos), MP_ROM_PTR(&mp_module_uos) }, #else #define UOS_BUILTIN_MODULE #endif #if MICROPY_PY_UTIME #define UTIME_BUILTIN_MODULE { MP_ROM_QSTR(MP_QSTR_utime), MP_ROM_PTR(&mp_module_utime) }, #else #define UTIME_BUILTIN_MODULE #endif #if MICROPY_PY_USOCKET && MICROPY_PY_LWIP // usocket implementation provided by lwIP #define SOCKET_BUILTIN_MODULE { MP_ROM_QSTR(MP_QSTR_usocket), MP_ROM_PTR(&mp_module_lwip) }, #elif MICROPY_PY_USOCKET // usocket implementation provided by skeleton wrapper #define SOCKET_BUILTIN_MODULE { MP_ROM_QSTR(MP_QSTR_usocket), MP_ROM_PTR(&mp_module_usocket) }, #else // no usocket module #define SOCKET_BUILTIN_MODULE #endif #if MICROPY_PY_NETWORK #define NETWORK_BUILTIN_MODULE { MP_ROM_QSTR(MP_QSTR_network), MP_ROM_PTR(&mp_module_network) }, #else #define NETWORK_BUILTIN_MODULE #endif #if MICROPY_PY_ONEWIRE #define ONEWIRE_BUILTIN_MODULE { MP_ROM_QSTR(MP_QSTR__onewire), MP_ROM_PTR(&mp_module_onewire) }, #else #define ONEWIRE_BUILTIN_MODULE #endif #if defined(MICROPY_HW_ETH_MDC) extern const struct _mp_obj_type_t network_lan_type; #define MICROPY_HW_NIC_ETH { MP_ROM_QSTR(MP_QSTR_LAN), MP_ROM_PTR(&network_lan_type) }, #else #define MICROPY_HW_NIC_ETH #endif #if MICROPY_PY_NETWORK_CYW43 extern const struct _mp_obj_type_t mp_network_cyw43_type; #define MICROPY_HW_NIC_CYW43 { MP_ROM_QSTR(MP_QSTR_WLAN), MP_ROM_PTR(&mp_network_cyw43_type) }, #else #define MICROPY_HW_NIC_CYW43 #endif #if MICROPY_PY_WIZNET5K extern const struct _mod_network_nic_type_t mod_network_nic_type_wiznet5k; #define MICROPY_HW_NIC_WIZNET5K { MP_ROM_QSTR(MP_QSTR_WIZNET5K), MP_ROM_PTR(&mod_network_nic_type_wiznet5k) }, #else #define MICROPY_HW_NIC_WIZNET5K #endif #if MICROPY_PY_CC3K extern const struct _mod_network_nic_type_t mod_network_nic_type_cc3k; #define MICROPY_HW_NIC_CC3K { MP_ROM_QSTR(MP_QSTR_CC3K), MP_ROM_PTR(&mod_network_nic_type_cc3k) }, #else #define MICROPY_HW_NIC_CC3K #endif #define MICROPY_PORT_BUILTIN_MODULES \ MACHINE_BUILTIN_MODULE \ PYB_BUILTIN_MODULE \ STM_BUILTIN_MODULE \ UOS_BUILTIN_MODULE \ UTIME_BUILTIN_MODULE \ SOCKET_BUILTIN_MODULE \ NETWORK_BUILTIN_MODULE \ ONEWIRE_BUILTIN_MODULE \ // extra constants #define MICROPY_PORT_CONSTANTS \ MACHINE_BUILTIN_MODULE \ MACHINE_BUILTIN_MODULE_CONSTANTS \ PYB_BUILTIN_MODULE \ STM_BUILTIN_MODULE \ #define MICROPY_PORT_NETWORK_INTERFACES \ MICROPY_HW_NIC_ETH \ MICROPY_HW_NIC_CYW43 \ MICROPY_HW_NIC_WIZNET5K \ MICROPY_HW_NIC_CC3K \ #define MP_STATE_PORT MP_STATE_VM #if MICROPY_SSL_MBEDTLS #define MICROPY_PORT_ROOT_POINTER_MBEDTLS void **mbedtls_memory; #else #define MICROPY_PORT_ROOT_POINTER_MBEDTLS #endif #if MICROPY_BLUETOOTH_NIMBLE struct _mp_bluetooth_nimble_root_pointers_t; struct _mp_bluetooth_nimble_malloc_t; #define MICROPY_PORT_ROOT_POINTER_BLUETOOTH_NIMBLE struct _mp_bluetooth_nimble_malloc_t *bluetooth_nimble_memory; struct _mp_bluetooth_nimble_root_pointers_t *bluetooth_nimble_root_pointers; #else #define MICROPY_PORT_ROOT_POINTER_BLUETOOTH_NIMBLE #endif #if MICROPY_BLUETOOTH_BTSTACK struct _mp_bluetooth_btstack_root_pointers_t; #define MICROPY_PORT_ROOT_POINTER_BLUETOOTH_BTSTACK struct _mp_bluetooth_btstack_root_pointers_t *bluetooth_btstack_root_pointers; #else #define MICROPY_PORT_ROOT_POINTER_BLUETOOTH_BTSTACK #endif #ifndef MICROPY_BOARD_ROOT_POINTERS #define MICROPY_BOARD_ROOT_POINTERS #endif #define MICROPY_PORT_ROOT_POINTERS \ const char *readline_hist[8]; \ \ mp_obj_t pyb_hid_report_desc; \ \ mp_obj_t pyb_config_main; \ \ mp_obj_t pyb_switch_callback; \ \ mp_obj_t pin_class_mapper; \ mp_obj_t pin_class_map_dict; \ \ mp_obj_t pyb_extint_callback[PYB_EXTI_NUM_VECTORS]; \ \ /* pointers to all Timer objects (if they have been created) */ \ struct _pyb_timer_obj_t *pyb_timer_obj_all[MICROPY_HW_MAX_TIMER]; \ \ /* stdio is repeated on this UART object if it's not null */ \ struct _pyb_uart_obj_t *pyb_stdio_uart; \ \ /* pointers to all UART objects (if they have been created) */ \ struct _pyb_uart_obj_t *pyb_uart_obj_all[MICROPY_HW_MAX_UART + MICROPY_HW_MAX_LPUART]; \ \ /* pointers to all CAN objects (if they have been created) */ \ struct _pyb_can_obj_t *pyb_can_obj_all[MICROPY_HW_MAX_CAN]; \ \ /* USB_VCP IRQ callbacks (if they have been set) */ \ mp_obj_t pyb_usb_vcp_irq[MICROPY_HW_USB_CDC_NUM]; \ \ /* list of registered NICs */ \ mp_obj_list_t mod_network_nic_list; \ \ /* root pointers for sub-systems */ \ MICROPY_PORT_ROOT_POINTER_MBEDTLS \ MICROPY_PORT_ROOT_POINTER_BLUETOOTH_NIMBLE \ MICROPY_PORT_ROOT_POINTER_BLUETOOTH_BTSTACK \ \ /* root pointers defined by a board */ \ MICROPY_BOARD_ROOT_POINTERS \ // type definitions for the specific machine #define MICROPY_MAKE_POINTER_CALLABLE(p) ((void *)((uint32_t)(p) | 1)) #define MP_SSIZE_MAX (0x7fffffff) // Assume that if we already defined the obj repr then we also defined these items #ifndef MICROPY_OBJ_REPR #define UINT_FMT "%u" #define INT_FMT "%d" typedef int mp_int_t; // must be pointer size typedef unsigned int mp_uint_t; // must be pointer size #endif typedef long mp_off_t; // We have inlined IRQ functions for efficiency (they are generally // 1 machine instruction). // // Note on IRQ state: you should not need to know the specific // value of the state variable, but rather just pass the return // value from disable_irq back to enable_irq. If you really need // to know the machine-specific values, see irq.h. static inline void enable_irq(mp_uint_t state) { __set_PRIMASK(state); } static inline mp_uint_t disable_irq(void) { mp_uint_t state = __get_PRIMASK(); __disable_irq(); return state; } #define MICROPY_BEGIN_ATOMIC_SECTION() disable_irq() #define MICROPY_END_ATOMIC_SECTION(state) enable_irq(state) #if MICROPY_PY_THREAD #define MICROPY_EVENT_POLL_HOOK \ do { \ extern void mp_handle_pending(bool); \ mp_handle_pending(true); \ if (pyb_thread_enabled) { \ MP_THREAD_GIL_EXIT(); \ pyb_thread_yield(); \ MP_THREAD_GIL_ENTER(); \ } else { \ __WFI(); \ } \ } while (0); #define MICROPY_THREAD_YIELD() pyb_thread_yield() #else #define MICROPY_EVENT_POLL_HOOK \ do { \ extern void mp_handle_pending(bool); \ mp_handle_pending(true); \ __WFI(); \ } while (0); #define MICROPY_THREAD_YIELD() #endif // For regular code that wants to prevent "background tasks" from running. // These background tasks (LWIP, Bluetooth) run in PENDSV context. #define MICROPY_PY_PENDSV_ENTER uint32_t atomic_state = raise_irq_pri(IRQ_PRI_PENDSV); #define MICROPY_PY_PENDSV_REENTER atomic_state = raise_irq_pri(IRQ_PRI_PENDSV); #define MICROPY_PY_PENDSV_EXIT restore_irq_pri(atomic_state); // Prevent the "LWIP task" from running. #define MICROPY_PY_LWIP_ENTER MICROPY_PY_PENDSV_ENTER #define MICROPY_PY_LWIP_REENTER MICROPY_PY_PENDSV_REENTER #define MICROPY_PY_LWIP_EXIT MICROPY_PY_PENDSV_EXIT #if MICROPY_PY_BLUETOOTH_USE_SYNC_EVENTS // Bluetooth code only runs in the scheduler, no locking/mutex required. #define MICROPY_PY_BLUETOOTH_ENTER uint32_t atomic_state = 0; #define MICROPY_PY_BLUETOOTH_EXIT (void)atomic_state; #else // When async events are enabled, need to prevent PendSV execution racing with // scheduler execution. #define MICROPY_PY_BLUETOOTH_ENTER MICROPY_PY_PENDSV_ENTER #define MICROPY_PY_BLUETOOTH_EXIT MICROPY_PY_PENDSV_EXIT #endif // We need an implementation of the log2 function which is not a macro #define MP_NEED_LOG2 (1) // We need to provide a declaration/definition of alloca() #include // Needed for MICROPY_PY_URANDOM_SEED_INIT_FUNC. uint32_t rng_get(void);