CircuitPython

Source code browser

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
/*
 * 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 <stdint.h>
#include <string.h>

#include "py/obj.h"
#include "py/runtime.h"
#include "lib/fatfs/ff.h"
#include "extmod/fsusermount.h"

#include "systick.h"
#include "led.h"
#include "flash.h"
#include "storage.h"
#include "irq.h"

#if defined(STM32F405xx) || defined(STM32F415xx) || defined(STM32F407xx)

#define CACHE_MEM_START_ADDR (0x10000000) // CCM data RAM, 64k
#define FLASH_SECTOR_SIZE_MAX (0x10000) // 64k max, size of CCM
#define FLASH_MEM_SEG1_START_ADDR (0x08004000) // sector 1
#define FLASH_MEM_SEG1_NUM_BLOCKS (224) // sectors 1,2,3,4: 16k+16k+16k+64k=112k

// enable this to get an extra 64k of storage (uses the last sector of the flash)
#if 0
#define FLASH_MEM_SEG2_START_ADDR (0x080e0000) // sector 11
#define FLASH_MEM_SEG2_NUM_BLOCKS (128) // sector 11: 128k
#endif

#elif defined(STM32F401xE) || defined(STM32F411xE)

STATIC byte flash_cache_mem[0x4000] __attribute__((aligned(4))); // 16k
#define CACHE_MEM_START_ADDR (&flash_cache_mem[0])
#define FLASH_SECTOR_SIZE_MAX (0x4000) // 16k max due to size of cache buffer
#define FLASH_MEM_SEG1_START_ADDR (0x08004000) // sector 1
#define FLASH_MEM_SEG1_NUM_BLOCKS (128) // sectors 1,2,3,4: 16k+16k+16k+16k(of 64k)=64k

#elif defined(STM32F429xx)

#define CACHE_MEM_START_ADDR (0x10000000) // CCM data RAM, 64k
#define FLASH_SECTOR_SIZE_MAX (0x10000) // 64k max, size of CCM
#define FLASH_MEM_SEG1_START_ADDR (0x08004000) // sector 1
#define FLASH_MEM_SEG1_NUM_BLOCKS (224) // sectors 1,2,3,4: 16k+16k+16k+64k=112k

#elif defined(STM32F439xx)

#define CACHE_MEM_START_ADDR (0x10000000) // CCM data RAM, 64k
#define FLASH_SECTOR_SIZE_MAX (0x10000) // 64k max, size of CCM
#define FLASH_MEM_SEG1_START_ADDR (0x08100000) // sector 12
#define FLASH_MEM_SEG1_NUM_BLOCKS (384) // sectors 12,13,14,15,16,17: 16k+16k+16k+16k+64k+64k(of 128k)=192k
#define FLASH_MEM_SEG2_START_ADDR (0x08140000) // sector 18
#define FLASH_MEM_SEG2_NUM_BLOCKS (128) // sector 18: 64k(of 128k)

#elif defined(STM32F746xx) || defined(STM32F767xx) || defined(STM32F769xx)

// The STM32F746 doesn't really have CCRAM, so we use the 64K DTCM for this.

#define CACHE_MEM_START_ADDR (0x20000000) // DTCM data RAM, 64k
#define FLASH_SECTOR_SIZE_MAX (0x08000) // 32k max
#define FLASH_MEM_SEG1_START_ADDR (0x08008000) // sector 1
#define FLASH_MEM_SEG1_NUM_BLOCKS (192) // sectors 1,2,3: 32k+32k+32=96k

#elif defined(STM32L476xx)

extern uint8_t _flash_fs_start;
extern uint8_t _flash_fs_end;

// The STM32L476 doesn't have CCRAM, so we use the 32K SRAM2 for this.
#define CACHE_MEM_START_ADDR (0x10000000)       // SRAM2 data RAM, 32k
#define FLASH_SECTOR_SIZE_MAX (0x00800)         // 2k max
#define FLASH_MEM_SEG1_START_ADDR ((long)&_flash_fs_start)
#define FLASH_MEM_SEG1_NUM_BLOCKS ((&_flash_fs_end - &_flash_fs_start) / 512)

#else
#error "no storage support for this MCU"
#endif

#if !defined(FLASH_MEM_SEG2_START_ADDR)
#define FLASH_MEM_SEG2_START_ADDR (0) // no second segment
#define FLASH_MEM_SEG2_NUM_BLOCKS (0) // no second segment
#endif

#define FLASH_PART1_START_BLOCK (0x100)
#define FLASH_PART1_NUM_BLOCKS (FLASH_MEM_SEG1_NUM_BLOCKS + FLASH_MEM_SEG2_NUM_BLOCKS)

#define FLASH_FLAG_DIRTY        (1)
#define FLASH_FLAG_FORCE_WRITE  (2)
#define FLASH_FLAG_ERASED       (4)
static bool flash_is_initialised = false;
static __IO uint8_t flash_flags = 0;
static uint32_t flash_cache_sector_id;
static uint32_t flash_cache_sector_start;
static uint32_t flash_cache_sector_size;
static uint32_t flash_tick_counter_last_write;

static void flash_cache_flush(void) {
    if (flash_flags & FLASH_FLAG_DIRTY) {
        flash_flags |= FLASH_FLAG_FORCE_WRITE;
        while (flash_flags & FLASH_FLAG_DIRTY) {
           NVIC->STIR = FLASH_IRQn;
        }
    }
}

static uint8_t *flash_cache_get_addr_for_write(uint32_t flash_addr) {
    uint32_t flash_sector_start;
    uint32_t flash_sector_size;
    uint32_t flash_sector_id = flash_get_sector_info(flash_addr, &flash_sector_start, &flash_sector_size);
    if (flash_sector_size > FLASH_SECTOR_SIZE_MAX) {
        flash_sector_size = FLASH_SECTOR_SIZE_MAX;
    }
    if (flash_cache_sector_id != flash_sector_id) {
        flash_cache_flush();
        memcpy((void*)CACHE_MEM_START_ADDR, (const void*)flash_sector_start, flash_sector_size);
        flash_cache_sector_id = flash_sector_id;
        flash_cache_sector_start = flash_sector_start;
        flash_cache_sector_size = flash_sector_size;
    }
    flash_flags |= FLASH_FLAG_DIRTY;
    led_state(PYB_LED_R1, 1); // indicate a dirty cache with LED on
    flash_tick_counter_last_write = HAL_GetTick();
    return (uint8_t*)CACHE_MEM_START_ADDR + flash_addr - flash_sector_start;
}

static uint8_t *flash_cache_get_addr_for_read(uint32_t flash_addr) {
    uint32_t flash_sector_start;
    uint32_t flash_sector_size;
    uint32_t flash_sector_id = flash_get_sector_info(flash_addr, &flash_sector_start, &flash_sector_size);
    if (flash_cache_sector_id == flash_sector_id) {
        // in cache, copy from there
        return (uint8_t*)CACHE_MEM_START_ADDR + flash_addr - flash_sector_start;
    }
    // not in cache, copy straight from flash
    return (uint8_t*)flash_addr;
}

void storage_init(void) {
    if (!flash_is_initialised) {
        flash_flags = 0;
        flash_cache_sector_id = 0;
        flash_tick_counter_last_write = 0;
        flash_is_initialised = true;
    }

    // Enable the flash IRQ, which is used to also call our storage IRQ handler
    // It needs to go at a higher priority than all those components that rely on
    // the flash storage (eg higher than USB MSC).
    HAL_NVIC_SetPriority(FLASH_IRQn, IRQ_PRI_FLASH, IRQ_SUBPRI_FLASH);
    HAL_NVIC_EnableIRQ(FLASH_IRQn);
}

uint32_t storage_get_block_size(void) {
    return FLASH_BLOCK_SIZE;
}

uint32_t storage_get_block_count(void) {
    return FLASH_PART1_START_BLOCK + FLASH_PART1_NUM_BLOCKS;
}

void storage_irq_handler(void) {
    if (!(flash_flags & FLASH_FLAG_DIRTY)) {
        return;
    }

    // This code uses interrupts to erase the flash
    /*
    if (flash_erase_state == 0) {
        flash_erase_it(flash_cache_sector_start, (const uint32_t*)CACHE_MEM_START_ADDR, flash_cache_sector_size / 4);
        flash_erase_state = 1;
        return;
    }

    if (flash_erase_state == 1) {
        // wait for erase
        // TODO add timeout
        #define flash_erase_done() (__HAL_FLASH_GET_FLAG(FLASH_FLAG_BSY) == RESET)
        if (!flash_erase_done()) {
            return;
        }
        flash_erase_state = 2;
    }
    */

    // This code erases the flash directly, waiting for it to finish
    if (!(flash_flags & FLASH_FLAG_ERASED)) {
        flash_erase(flash_cache_sector_start, (const uint32_t*)CACHE_MEM_START_ADDR, flash_cache_sector_size / 4);
        flash_flags |= FLASH_FLAG_ERASED;
        return;
    }

    // If not a forced write, wait at least 5 seconds after last write to flush
    // On file close and flash unmount we get a forced write, so we can afford to wait a while
    if ((flash_flags & FLASH_FLAG_FORCE_WRITE) || sys_tick_has_passed(flash_tick_counter_last_write, 5000)) {
        // sync the cache RAM buffer by writing it to the flash page
        flash_write(flash_cache_sector_start, (const uint32_t*)CACHE_MEM_START_ADDR, flash_cache_sector_size / 4);
        // clear the flash flags now that we have a clean cache
        flash_flags = 0;
        // indicate a clean cache with LED off
        led_state(PYB_LED_R1, 0);
    }
}

void storage_flush(void) {
    flash_cache_flush();
}

static void build_partition(uint8_t *buf, int boot, int type, uint32_t start_block, uint32_t num_blocks) {
    buf[0] = boot;

    if (num_blocks == 0) {
        buf[1] = 0;
        buf[2] = 0;
        buf[3] = 0;
    } else {
        buf[1] = 0xff;
        buf[2] = 0xff;
        buf[3] = 0xff;
    }

    buf[4] = type;

    if (num_blocks == 0) {
        buf[5] = 0;
        buf[6] = 0;
        buf[7] = 0;
    } else {
        buf[5] = 0xff;
        buf[6] = 0xff;
        buf[7] = 0xff;
    }

    buf[8] = start_block;
    buf[9] = start_block >> 8;
    buf[10] = start_block >> 16;
    buf[11] = start_block >> 24;

    buf[12] = num_blocks;
    buf[13] = num_blocks >> 8;
    buf[14] = num_blocks >> 16;
    buf[15] = num_blocks >> 24;
}

static uint32_t convert_block_to_flash_addr(uint32_t block) {
    if (FLASH_PART1_START_BLOCK <= block && block < FLASH_PART1_START_BLOCK + FLASH_PART1_NUM_BLOCKS) {
        // a block in partition 1
        block -= FLASH_PART1_START_BLOCK;
        if (block < FLASH_MEM_SEG1_NUM_BLOCKS) {
            return FLASH_MEM_SEG1_START_ADDR + block * FLASH_BLOCK_SIZE;
        } else if (block < FLASH_MEM_SEG1_NUM_BLOCKS + FLASH_MEM_SEG2_NUM_BLOCKS) {
            return FLASH_MEM_SEG2_START_ADDR + (block - FLASH_MEM_SEG1_NUM_BLOCKS) * FLASH_BLOCK_SIZE;
        }
        // can add more flash segments here if needed, following above pattern
    }
    // bad block
    return -1;
}

bool storage_read_block(uint8_t *dest, uint32_t block) {
    //printf("RD %u\n", block);
    if (block == 0) {
        // fake the MBR so we can decide on our own partition table

        for (int i = 0; i < 446; i++) {
            dest[i] = 0;
        }

        build_partition(dest + 446, 0, 0x01 /* FAT12 */, FLASH_PART1_START_BLOCK, FLASH_PART1_NUM_BLOCKS);
        build_partition(dest + 462, 0, 0, 0, 0);
        build_partition(dest + 478, 0, 0, 0, 0);
        build_partition(dest + 494, 0, 0, 0, 0);

        dest[510] = 0x55;
        dest[511] = 0xaa;

        return true;

    } else {
        // non-MBR block, get data from flash memory, possibly via cache
        uint32_t flash_addr = convert_block_to_flash_addr(block);
        if (flash_addr == -1) {
            // bad block number
            return false;
        }
        uint8_t *src = flash_cache_get_addr_for_read(flash_addr);
        memcpy(dest, src, FLASH_BLOCK_SIZE);
        return true;
    }
}

bool storage_write_block(const uint8_t *src, uint32_t block) {
    //printf("WR %u\n", block);
    if (block == 0) {
        // can't write MBR, but pretend we did
        return true;

    } else {
        // non-MBR block, copy to cache
        uint32_t flash_addr = convert_block_to_flash_addr(block);
        if (flash_addr == -1) {
            // bad block number
            return false;
        }
        uint8_t *dest = flash_cache_get_addr_for_write(flash_addr);
        memcpy(dest, src, FLASH_BLOCK_SIZE);
        return true;
    }
}

mp_uint_t storage_read_blocks(uint8_t *dest, uint32_t block_num, uint32_t num_blocks) {
    for (size_t i = 0; i < num_blocks; i++) {
        if (!storage_read_block(dest + i * FLASH_BLOCK_SIZE, block_num + i)) {
            return 1; // error
        }
    }
    return 0; // success
}

mp_uint_t storage_write_blocks(const uint8_t *src, uint32_t block_num, uint32_t num_blocks) {
    for (size_t i = 0; i < num_blocks; i++) {
        if (!storage_write_block(src + i * FLASH_BLOCK_SIZE, block_num + i)) {
            return 1; // error
        }
    }
    return 0; // success
}

/******************************************************************************/
// MicroPython bindings
//
// Expose the flash as an object with the block protocol.

// there is a singleton Flash object
STATIC const mp_obj_base_t pyb_flash_obj = {&pyb_flash_type};

STATIC mp_obj_t pyb_flash_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
    // check arguments
    mp_arg_check_num(n_args, n_kw, 0, 0, false);

    // return singleton object
    return (mp_obj_t)&pyb_flash_obj;
}

STATIC mp_obj_t pyb_flash_readblocks(mp_obj_t self, mp_obj_t block_num, mp_obj_t buf) {
    mp_buffer_info_t bufinfo;
    mp_get_buffer_raise(buf, &bufinfo, MP_BUFFER_WRITE);
    mp_uint_t ret = storage_read_blocks(bufinfo.buf, mp_obj_get_int(block_num), bufinfo.len / FLASH_BLOCK_SIZE);
    return MP_OBJ_NEW_SMALL_INT(ret);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_3(pyb_flash_readblocks_obj, pyb_flash_readblocks);

STATIC mp_obj_t pyb_flash_writeblocks(mp_obj_t self, mp_obj_t block_num, mp_obj_t buf) {
    mp_buffer_info_t bufinfo;
    mp_get_buffer_raise(buf, &bufinfo, MP_BUFFER_READ);
    mp_uint_t ret = storage_write_blocks(bufinfo.buf, mp_obj_get_int(block_num), bufinfo.len / FLASH_BLOCK_SIZE);
    return MP_OBJ_NEW_SMALL_INT(ret);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_3(pyb_flash_writeblocks_obj, pyb_flash_writeblocks);

STATIC mp_obj_t pyb_flash_ioctl(mp_obj_t self, mp_obj_t cmd_in, mp_obj_t arg_in) {
    mp_int_t cmd = mp_obj_get_int(cmd_in);
    switch (cmd) {
        case BP_IOCTL_INIT: storage_init(); return MP_OBJ_NEW_SMALL_INT(0);
        case BP_IOCTL_DEINIT: storage_flush(); return MP_OBJ_NEW_SMALL_INT(0); // TODO properly
        case BP_IOCTL_SYNC: storage_flush(); return MP_OBJ_NEW_SMALL_INT(0);
        case BP_IOCTL_SEC_COUNT: return MP_OBJ_NEW_SMALL_INT(storage_get_block_count());
        case BP_IOCTL_SEC_SIZE: return MP_OBJ_NEW_SMALL_INT(storage_get_block_size());
        default: return mp_const_none;
    }
}
STATIC MP_DEFINE_CONST_FUN_OBJ_3(pyb_flash_ioctl_obj, pyb_flash_ioctl);

STATIC const mp_map_elem_t pyb_flash_locals_dict_table[] = {
    { MP_OBJ_NEW_QSTR(MP_QSTR_readblocks), (mp_obj_t)&pyb_flash_readblocks_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_writeblocks), (mp_obj_t)&pyb_flash_writeblocks_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_ioctl), (mp_obj_t)&pyb_flash_ioctl_obj },
};

STATIC MP_DEFINE_CONST_DICT(pyb_flash_locals_dict, pyb_flash_locals_dict_table);

const mp_obj_type_t pyb_flash_type = {
    { &mp_type_type },
    .name = MP_QSTR_Flash,
    .make_new = pyb_flash_make_new,
    .locals_dict = (mp_obj_t)&pyb_flash_locals_dict,
};

void pyb_flash_init_vfs(fs_user_mount_t *vfs) {
    vfs->flags |= FSUSER_NATIVE | FSUSER_HAVE_IOCTL;
    vfs->readblocks[0] = (mp_obj_t)&pyb_flash_readblocks_obj;
    vfs->readblocks[1] = (mp_obj_t)&pyb_flash_obj;
    vfs->readblocks[2] = (mp_obj_t)storage_read_blocks; // native version
    vfs->writeblocks[0] = (mp_obj_t)&pyb_flash_writeblocks_obj;
    vfs->writeblocks[1] = (mp_obj_t)&pyb_flash_obj;
    vfs->writeblocks[2] = (mp_obj_t)storage_write_blocks; // native version
    vfs->u.ioctl[0] = (mp_obj_t)&pyb_flash_ioctl_obj;
    vfs->u.ioctl[1] = (mp_obj_t)&pyb_flash_obj;
}