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Diffstat (limited to 'examples/natmod/features1/features1.c')
-rw-r--r-- | examples/natmod/features1/features1.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/examples/natmod/features1/features1.c b/examples/natmod/features1/features1.c new file mode 100644 index 0000000000..1bfbe50b95 --- /dev/null +++ b/examples/natmod/features1/features1.c @@ -0,0 +1,106 @@ +/* This example demonstrates the following features in a native module: + - defining simple functions exposed to Python + - defining local, helper C functions + - defining constant integers and strings exposed to Python + - getting and creating integer objects + - creating Python lists + - raising exceptions + - allocating memory + - BSS and constant data (rodata) + - relocated pointers in rodata +*/ + +// Include the header file to get access to the MicroPython API +#include "py/dynruntime.h" + +// BSS (zero) data +uint16_t data16[4]; + +// Constant data (rodata) +const uint8_t table8[] = { 0, 1, 1, 2, 3, 5, 8, 13 }; +const uint16_t table16[] = { 0x1000, 0x2000 }; + +// Constant data pointing to BSS/constant data +uint16_t *const table_ptr16a[] = { &data16[0], &data16[1], &data16[2], &data16[3] }; +const uint16_t *const table_ptr16b[] = { &table16[0], &table16[1] }; + +// A simple function that adds its 2 arguments (must be integers) +STATIC mp_obj_t add(mp_obj_t x_in, mp_obj_t y_in) { + mp_int_t x = mp_obj_get_int(x_in); + mp_int_t y = mp_obj_get_int(y_in); + return mp_obj_new_int(x + y); +} +STATIC MP_DEFINE_CONST_FUN_OBJ_2(add_obj, add); + +// A local helper function (not exposed to Python) +STATIC mp_int_t fibonacci_helper(mp_int_t x) { + if (x < MP_ARRAY_SIZE(table8)) { + return table8[x]; + } else { + return fibonacci_helper(x - 1) + fibonacci_helper(x - 2); + } +} + +// A function which computes Fibonacci numbers +STATIC mp_obj_t fibonacci(mp_obj_t x_in) { + mp_int_t x = mp_obj_get_int(x_in); + if (x < 0) { + mp_raise_ValueError("can't compute negative Fibonacci number"); + } + return mp_obj_new_int(fibonacci_helper(x)); +} +STATIC MP_DEFINE_CONST_FUN_OBJ_1(fibonacci_obj, fibonacci); + +// A function that accesses the BSS data +STATIC mp_obj_t access(size_t n_args, const mp_obj_t *args) { + if (n_args == 0) { + // Create a list holding all items from data16 + mp_obj_list_t *lst = MP_OBJ_TO_PTR(mp_obj_new_list(MP_ARRAY_SIZE(data16), NULL)); + for (int i = 0; i < MP_ARRAY_SIZE(data16); ++i) { + lst->items[i] = mp_obj_new_int(data16[i]); + } + return MP_OBJ_FROM_PTR(lst); + } else if (n_args == 1) { + // Get one item from data16 + mp_int_t idx = mp_obj_get_int(args[0]) & 3; + return mp_obj_new_int(data16[idx]); + } else { + // Set one item in data16 (via table_ptr16a) + mp_int_t idx = mp_obj_get_int(args[0]) & 3; + *table_ptr16a[idx] = mp_obj_get_int(args[1]); + return mp_const_none; + } +} +STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(access_obj, 0, 2, access); + +// A function that allocates memory and creates a bytearray +STATIC mp_obj_t make_array(void) { + uint16_t *ptr = m_new(uint16_t, MP_ARRAY_SIZE(table_ptr16b)); + for (int i = 0; i < MP_ARRAY_SIZE(table_ptr16b); ++i) { + ptr[i] = *table_ptr16b[i]; + } + return mp_obj_new_bytearray_by_ref(sizeof(uint16_t) * MP_ARRAY_SIZE(table_ptr16b), ptr); +} +STATIC MP_DEFINE_CONST_FUN_OBJ_0(make_array_obj, make_array); + +// This is the entry point and is called when the module is imported +mp_obj_t mpy_init(mp_obj_fun_bc_t *self, size_t n_args, size_t n_kw, mp_obj_t *args) { + // This must be first, it sets up the globals dict and other things + MP_DYNRUNTIME_INIT_ENTRY + + // Messages can be printed as usualy + mp_printf(&mp_plat_print, "initialising module self=%p\n", self); + + // Make the functions available in the module's namespace + mp_store_global(MP_QSTR_add, MP_OBJ_FROM_PTR(&add_obj)); + mp_store_global(MP_QSTR_fibonacci, MP_OBJ_FROM_PTR(&fibonacci_obj)); + mp_store_global(MP_QSTR_access, MP_OBJ_FROM_PTR(&access_obj)); + mp_store_global(MP_QSTR_make_array, MP_OBJ_FROM_PTR(&make_array_obj)); + + // Add some constants to the module's namespace + mp_store_global(MP_QSTR_VAL, MP_OBJ_NEW_SMALL_INT(42)); + mp_store_global(MP_QSTR_MSG, MP_OBJ_NEW_QSTR(MP_QSTR_HELLO_MICROPYTHON)); + + // This must be last, it restores the globals dict + MP_DYNRUNTIME_INIT_EXIT +} |