mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-12-23 14:58:09 +00:00
39c2766ae0
Contains a memcpy helper for zero-cost copying between two buffers (bytearray or memoryview).
71 lines
2.2 KiB
C
71 lines
2.2 KiB
C
/*
|
|
* Copyright (c) Jan Pochyla, SatoshiLabs
|
|
*
|
|
* Licensed under TREZOR License
|
|
* see LICENSE file for details
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <stdint.h>
|
|
|
|
#include "py/nlr.h"
|
|
#include "py/runtime.h"
|
|
#include "py/binary.h"
|
|
#include "py/objstr.h"
|
|
|
|
#if MICROPY_PY_TREZORUTILS
|
|
|
|
/// def trezor.utils.memcpy(dst: bytearray, dst_ofs: int,
|
|
/// src: bytearray, src_ofs: int,
|
|
// n: int) -> int:
|
|
/// '''
|
|
/// Copies at most `n` bytes from `src` at offset `src_ofs` to
|
|
/// `dst` at offset `dst_ofs`. Returns the number of actually
|
|
/// copied bytes.
|
|
/// '''
|
|
STATIC mp_obj_t mod_TrezorUtils_memcpy(size_t n_args, const mp_obj_t *args) {
|
|
mp_arg_check_num(n_args, 0, 5, 5, false);
|
|
|
|
mp_buffer_info_t dst;
|
|
mp_get_buffer_raise(args[0], &dst, MP_BUFFER_WRITE);
|
|
int dst_ofs = mp_obj_get_int(args[1]);
|
|
if (dst_ofs < 0) {
|
|
mp_raise_ValueError("Invalid dst offset (has to be >= 0)");
|
|
}
|
|
|
|
mp_buffer_info_t src;
|
|
mp_get_buffer_raise(args[2], &src, MP_BUFFER_READ);
|
|
int src_ofs = mp_obj_get_int(args[3]);
|
|
if (src_ofs < 0) {
|
|
mp_raise_ValueError("Invalid src offset (has to be >= 0)");
|
|
}
|
|
|
|
int n = mp_obj_get_int(args[4]);
|
|
if (n < 0) {
|
|
mp_raise_ValueError("Invalid byte count (has to be >= 0)");
|
|
}
|
|
size_t dst_rem = (dst_ofs < dst.len) ? dst.len - dst_ofs : 0;
|
|
size_t src_rem = (src_ofs < src.len) ? src.len - src_ofs : 0;
|
|
size_t ncpy = MIN(n, MIN(src_rem, dst_rem));
|
|
|
|
memmove(((char*)dst.buf) + dst_ofs, ((const char*)src.buf) + src_ofs, ncpy);
|
|
|
|
return mp_obj_new_int(ncpy);
|
|
}
|
|
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_TrezorUtils_memcpy_obj, 5, 5, mod_TrezorUtils_memcpy);
|
|
|
|
STATIC const mp_rom_map_elem_t mp_module_TrezorUtils_globals_table[] = {
|
|
{ MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_TrezorUtils) },
|
|
{ MP_ROM_QSTR(MP_QSTR_memcpy), MP_ROM_PTR(&mod_TrezorUtils_memcpy_obj) },
|
|
};
|
|
|
|
STATIC MP_DEFINE_CONST_DICT(mp_module_TrezorUtils_globals, mp_module_TrezorUtils_globals_table);
|
|
|
|
const mp_obj_module_t mp_module_TrezorUtils = {
|
|
.base = { &mp_type_module },
|
|
.globals = (mp_obj_dict_t*)&mp_module_TrezorUtils_globals,
|
|
};
|
|
|
|
#endif // MICROPY_PY_TREZORUTILS
|