text: /*
   * This file is part of the Micro Python project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2013, 2014 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.
   */
  
  #include <stdio.h>
  #include <stdint.h>
  
  #include "stm32f4xx_hal.h"
  
  #include "py/nlr.h"
  #include "py/obj.h"
  #include "portmodules.h"
  
  // To use compile-time constants we are restricted to 31-bit numbers (a small int,
  // so it fits in a Micro Python object pointer).  Thus, when extracting a constant
  // from an object, we must clear the MSB.
  
  STATIC uint32_t get_read_addr(mp_obj_t addr_o, uint align) {
      uint32_t addr = mp_obj_get_int(addr_o) & 0x7fffffff;
      /*
      if (addr < 0x10000000) {
          nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "cannot read from address %08x", addr));
      }
      */
      if ((addr & (align - 1)) != 0) {
          nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "address %08x is not aligned to %d bytes", addr, align));
      }
      return addr;
  }
  
  STATIC uint32_t get_write_addr(mp_obj_t addr_o, uint align) {
      uint32_t addr = mp_obj_get_int(addr_o) & 0x7fffffff;
      if (addr < 0x10000000) {
          // Everything below 0x10000000 is either ROM or aliased to something higher, so we don't
          // lose anything by restricting writes to this area, and we gain some safety.
          nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "cannot write to address %08x", addr));
      }
      if ((addr & (align - 1)) != 0) {
          nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "address %08x is not aligned to %d bytes", addr, align));
      }
      return addr;
  }
  
  typedef struct _stm_mem_obj_t {
      mp_obj_base_t base;
      uint32_t elem_size; // in bytes
  } stm_mem_obj_t;
  
  STATIC void stm_mem_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
      stm_mem_obj_t *self = self_in;
      mp_printf(print, "<%u-bit memory>", 8 * self->elem_size);
  }
  
  STATIC mp_obj_t stm_mem_subscr(mp_obj_t self_in, mp_obj_t index, mp_obj_t value) {
      // TODO support slice index to read/write multiple values at once
      stm_mem_obj_t *self = self_in;
      if (value == MP_OBJ_NULL) {
          // delete
          return MP_OBJ_NULL; // op not supported
      } else if (value == MP_OBJ_SENTINEL) {
          // load
          uint32_t addr = get_read_addr(index, self->elem_size);
          uint32_t val;
          switch (self->elem_size) {
              case 1: val = (*(uint8_t*)addr); break;
              case 2: val = (*(uint16_t*)addr); break;
              default: val = (*(uint32_t*)addr); break;
          }
          return mp_obj_new_int(val);
      } else {
          // store
          uint32_t addr = get_write_addr(index, self->elem_size);
          uint32_t val = mp_obj_get_int(value);
          switch (self->elem_size) {
              case 1: (*(uint8_t*)addr) = val; break;
              case 2: (*(uint16_t*)addr) = val; break;
              default: (*(uint32_t*)addr) = val; break;
          }
          return mp_const_none;
      }
  }
  
  STATIC const mp_obj_type_t stm_mem_type = {
      { &mp_type_type },
      .name = MP_QSTR_mem,
      .print = stm_mem_print,
      .subscr = stm_mem_subscr,
  };
  
  STATIC const stm_mem_obj_t stm_mem8_obj = {{&stm_mem_type}, 1};
  STATIC const stm_mem_obj_t stm_mem16_obj = {{&stm_mem_type}, 2};
  STATIC const stm_mem_obj_t stm_mem32_obj = {{&stm_mem_type}, 4};
  
  STATIC const mp_map_elem_t stm_module_globals_table[] = {
      { MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_stm) },
  
      { MP_OBJ_NEW_QSTR(MP_QSTR_mem8), (mp_obj_t)&stm_mem8_obj },
      { MP_OBJ_NEW_QSTR(MP_QSTR_mem16), (mp_obj_t)&stm_mem16_obj },
      { MP_OBJ_NEW_QSTR(MP_QSTR_mem32), (mp_obj_t)&stm_mem32_obj },
  
  #include "modstmconst.gen.c"
  };
  
  STATIC MP_DEFINE_CONST_DICT(stm_module_globals, stm_module_globals_table);
  
  const mp_obj_module_t stm_module = {
      .base = { &mp_type_module },
      .name = MP_QSTR_stm,
      .globals = (mp_obj_dict_t*)&stm_module_globals,
  };
  