circuitpython/extmod/modmachine.c

141 lines
4.8 KiB
C

/*
* 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 "py/nlr.h"
#include "py/obj.h"
#if MICROPY_PLAT_DEV_MEM
#include <errno.h>
#include <fcntl.h>
#include <sys/mman.h>
#endif
#if MICROPY_PY_MACHINE
#define PAGE_SIZE 4096
#define PAGE_MASK (PAGE_SIZE - 1)
STATIC mp_uint_t get_addr(mp_obj_t addr_o, uint align) {
mp_uint_t addr = mp_obj_int_get_truncated(addr_o);
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));
}
#if MICROPY_PLAT_DEV_MEM
{
// Not thread-safe
static int fd;
static mp_uint_t last_base = (mp_uint_t)-1;
static mp_uint_t map_page;
if (!fd) {
fd = open("/dev/mem", O_RDWR | O_SYNC);
if (fd == -1) {
nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError, MP_OBJ_NEW_SMALL_INT(errno)));
}
}
mp_uint_t cur_base = addr & ~PAGE_MASK;
if (cur_base != last_base) {
map_page = (mp_uint_t)mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, cur_base);
last_base = cur_base;
}
addr = map_page + (addr & PAGE_MASK);
}
#endif
return addr;
}
typedef struct _machine_mem_obj_t {
mp_obj_base_t base;
unsigned elem_size; // in bytes
} machine_mem_obj_t;
STATIC void machine_mem_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
(void)kind;
machine_mem_obj_t *self = self_in;
mp_printf(print, "<%u-bit memory>", 8 * self->elem_size);
}
STATIC mp_obj_t machine_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
machine_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
mp_uint_t addr = get_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
mp_uint_t addr = get_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 machine_mem_type = {
{ &mp_type_type },
.name = MP_QSTR_mem,
.print = machine_mem_print,
.subscr = machine_mem_subscr,
};
STATIC const machine_mem_obj_t machine_mem8_obj = {{&machine_mem_type}, 1};
STATIC const machine_mem_obj_t machine_mem16_obj = {{&machine_mem_type}, 2};
STATIC const machine_mem_obj_t machine_mem32_obj = {{&machine_mem_type}, 4};
STATIC const mp_map_elem_t machine_module_globals_table[] = {
{ MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_machine) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_mem8), (mp_obj_t)&machine_mem8_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_mem16), (mp_obj_t)&machine_mem16_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_mem32), (mp_obj_t)&machine_mem32_obj },
};
STATIC MP_DEFINE_CONST_DICT(machine_module_globals, machine_module_globals_table);
const mp_obj_module_t mp_module_machine = {
.base = { &mp_type_module },
.name = MP_QSTR_machine,
.globals = (mp_obj_dict_t*)&machine_module_globals,
};
#endif // MICROPY_PY_MACHINE