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circuitpython/supervisor/shared/external_flash/external_flash.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016, 2017 Scott Shawcroft for Adafruit Industries
*
* 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 "supervisor/shared/external_flash/external_flash.h"
#include <stdint.h>
#include <string.h>
#include "genhdr/devices.h"
#include "supervisor/flash.h"
#include "supervisor/spi_flash_api.h"
#include "supervisor/shared/external_flash/common_commands.h"
#include "extmod/vfs.h"
#include "extmod/vfs_fat.h"
#include "py/misc.h"
#include "py/obj.h"
#include "py/runtime.h"
#include "lib/oofatfs/ff.h"
#include "shared-bindings/microcontroller/__init__.h"
#include "supervisor/memory.h"
#define NO_SECTOR_LOADED 0xFFFFFFFF
// The currently cached sector in the cache, ram or flash based.
static uint32_t current_sector;
STATIC const external_flash_device possible_devices[] = {EXTERNAL_FLASH_DEVICES};
#define EXTERNAL_FLASH_DEVICE_COUNT MP_ARRAY_SIZE(possible_devices)
static const external_flash_device *flash_device = NULL;
// Track which blocks (up to 32) in the current sector currently live in the
// cache.
static uint32_t dirty_mask;
static supervisor_allocation *supervisor_cache = NULL;
// Wait until both the write enable and write in progress bits have cleared.
static bool wait_for_flash_ready(void) {
if (flash_device == NULL) {
return false;
}
bool ok = true;
// Both the write enable and write in progress bits should be low.
if (flash_device->no_ready_bit) {
// For NVM without a ready bit in status register
return ok;
}
uint8_t read_status_response[1] = {0x00};
do {
ok = spi_flash_read_command(CMD_READ_STATUS, read_status_response, 1);
} while (ok && (read_status_response[0] & 0x3) != 0);
return ok;
}
// Turn on the write enable bit so we can program and erase the flash.
static bool write_enable(void) {
return spi_flash_command(CMD_ENABLE_WRITE);
}
// Read data_length's worth of bytes starting at address into data.
static bool read_flash(uint32_t address, uint8_t *data, uint32_t data_length) {
if (flash_device == NULL) {
return false;
}
if (!wait_for_flash_ready()) {
return false;
}
return spi_flash_read_data(address, data, data_length);
}
// Writes data_length's worth of bytes starting at address from data. Assumes
// that the sector that address resides in has already been erased. So make sure
// to run erase_sector.
static bool write_flash(uint32_t address, const uint8_t *data, uint32_t data_length) {
if (flash_device == NULL) {
return false;
}
// Don't bother writing if the data is all 1s. That's equivalent to the flash
// state after an erase.
if (!flash_device->no_erase_cmd) {
// Only do this if the device has an erase command
bool all_ones = true;
for (uint16_t i = 0; i < data_length; i++) {
if (data[i] != 0xff) {
all_ones = false;
break;
}
}
if (all_ones) {
return true;
}
}
for (uint32_t bytes_written = 0;
bytes_written < data_length;
bytes_written += SPI_FLASH_PAGE_SIZE) {
if (!wait_for_flash_ready() || !write_enable()) {
return false;
}
if (!spi_flash_write_data(address + bytes_written, (uint8_t *)data + bytes_written,
SPI_FLASH_PAGE_SIZE)) {
return false;
}
}
return true;
}
static bool page_erased(uint32_t sector_address) {
// Check the first few bytes to catch the common case where there is data
// without using a bunch of memory.
if (flash_device->no_erase_cmd) {
// skip this if device doesn't have an erase command.
return true;
}
uint8_t short_buffer[4];
if (read_flash(sector_address, short_buffer, 4)) {
for (uint16_t i = 0; i < 4; i++) {
if (short_buffer[i] != 0xff) {
return false;
}
}
} else {
return false;
}
// Now check the full length.
uint8_t full_buffer[FILESYSTEM_BLOCK_SIZE];
if (read_flash(sector_address, full_buffer, FILESYSTEM_BLOCK_SIZE)) {
for (uint16_t i = 0; i < FILESYSTEM_BLOCK_SIZE; i++) {
if (short_buffer[i] != 0xff) {
return false;
}
}
} else {
return false;
}
return true;
}
// Erases the given sector. Make sure you copied all of the data out of it you
// need! Also note, sector_address is really 24 bits.
static bool erase_sector(uint32_t sector_address) {
// Before we erase the sector we need to wait for any writes to finish and
// and then enable the write again.
if (flash_device->no_erase_cmd) {
// skip this if device doesn't have an erase command.
return true;
}
if (!wait_for_flash_ready() || !write_enable()) {
return false;
}
if (flash_device->no_erase_cmd) {
return true;
}
spi_flash_sector_command(CMD_SECTOR_ERASE, sector_address);
return true;
}
// Sector is really 24 bits.
static bool copy_block(uint32_t src_address, uint32_t dest_address) {
// Copy page by page to minimize RAM buffer.
uint16_t page_size = SPI_FLASH_PAGE_SIZE;
uint8_t buffer[page_size];
for (uint32_t i = 0; i < FILESYSTEM_BLOCK_SIZE / page_size; i++) {
if (!read_flash(src_address + i * page_size, buffer, page_size)) {
return false;
}
if (!write_flash(dest_address + i * page_size, buffer, page_size)) {
return false;
}
}
return true;
}
#define READ_JEDEC_ID_RETRY_COUNT (100)
// If this fails, flash_device will remain NULL.
void supervisor_flash_init(void) {
if (flash_device != NULL) {
return;
}
// Delay to give the SPI Flash time to get going.
// TODO(tannewt): Only do this when we know power was applied vs a reset.
uint16_t max_start_up_delay_us = 0;
for (uint8_t i = 0; i < EXTERNAL_FLASH_DEVICE_COUNT; i++) {
if (possible_devices[i].start_up_time_us > max_start_up_delay_us) {
max_start_up_delay_us = possible_devices[i].start_up_time_us;
}
}
common_hal_mcu_delay_us(max_start_up_delay_us);
spi_flash_init();
#ifdef EXTERNAL_FLASH_NO_JEDEC
// For NVM that don't have JEDEC response
spi_flash_command(CMD_WAKE);
for (uint8_t i = 0; i < EXTERNAL_FLASH_DEVICE_COUNT; i++) {
const external_flash_device *possible_device = &possible_devices[i];
flash_device = possible_device;
break;
}
#else
// The response will be 0xff if the flash needs more time to start up.
uint8_t jedec_id_response[3] = {0xff, 0xff, 0xff};
// Response can also be 0x00 if reading before ready. When compiled with `-O2`, typically
// takes three tries to read on Grand Central M4.
size_t count = READ_JEDEC_ID_RETRY_COUNT;
while ((count-- > 0) && (jedec_id_response[0] == 0xff || jedec_id_response[2] == 0x00)) {
spi_flash_read_command(CMD_READ_JEDEC_ID, jedec_id_response, 3);
}
for (uint8_t i = 0; i < EXTERNAL_FLASH_DEVICE_COUNT; i++) {
const external_flash_device *possible_device = &possible_devices[i];
if (jedec_id_response[0] == possible_device->manufacturer_id &&
jedec_id_response[1] == possible_device->memory_type &&
jedec_id_response[2] == possible_device->capacity) {
flash_device = possible_device;
break;
}
}
#endif
if (flash_device == NULL) {
// Flash did not respond. Give up.
return;
}
// We don't know what state the flash is in so wait for any remaining writes and then reset.
uint8_t read_status_response[1] = {0x00};
// The write in progress bit should be low.
do {
spi_flash_read_command(CMD_READ_STATUS, read_status_response, 1);
} while ((read_status_response[0] & 0x1) != 0);
if (!flash_device->single_status_byte) {
// The suspended write/erase bit should be low.
do {
spi_flash_read_command(CMD_READ_STATUS2, read_status_response, 1);
} while ((read_status_response[0] & 0x80) != 0);
}
if (!(flash_device->no_reset_cmd)) {
spi_flash_command(CMD_ENABLE_RESET);
spi_flash_command(CMD_RESET);
}
// Wait 30us for the reset
common_hal_mcu_delay_us(30);
spi_flash_init_device(flash_device);
// Activity LED for flash writes.
#ifdef MICROPY_HW_LED_MSC
gpio_set_pin_function(SPI_FLASH_CS_PIN, GPIO_PIN_FUNCTION_OFF);
gpio_set_pin_direction(MICROPY_HW_LED_MSC, GPIO_DIRECTION_OUT);
// There's already a pull-up on the board.
gpio_set_pin_level(MICROPY_HW_LED_MSC, false);
#endif
if (flash_device->has_sector_protection) {
write_enable();
// Turn off sector protection
uint8_t data[1] = {0x00};
spi_flash_write_command(CMD_WRITE_STATUS_BYTE1, data, 1);
}
// Turn off writes in case this is a microcontroller only reset.
spi_flash_command(CMD_DISABLE_WRITE);
wait_for_flash_ready();
current_sector = NO_SECTOR_LOADED;
dirty_mask = 0;
MP_STATE_VM(flash_ram_cache) = NULL;
}
// The size of each individual block.
uint32_t supervisor_flash_get_block_size(void) {
return FILESYSTEM_BLOCK_SIZE;
}
// The total number of available blocks.
uint32_t supervisor_flash_get_block_count(void) {
if (flash_device == NULL) {
return 0;
}
// We subtract one erase sector size because we may use it as a staging area
// for writes.
return (flash_device->total_size - SPI_FLASH_ERASE_SIZE) / FILESYSTEM_BLOCK_SIZE;
}
// Flush the cache that was written to the scratch portion of flash. Only used
// when ram is tight.
static bool flush_scratch_flash(void) {
if (current_sector == NO_SECTOR_LOADED) {
return true;
}
// First, copy out any blocks that we haven't touched from the sector we've
// cached.
bool copy_to_scratch_ok = true;
uint32_t scratch_sector = flash_device->total_size - SPI_FLASH_ERASE_SIZE;
for (uint8_t i = 0; i < SPI_FLASH_ERASE_SIZE / FILESYSTEM_BLOCK_SIZE; i++) {
if ((dirty_mask & (1 << i)) == 0) {
copy_to_scratch_ok = copy_to_scratch_ok &&
copy_block(current_sector + i * FILESYSTEM_BLOCK_SIZE,
scratch_sector + i * FILESYSTEM_BLOCK_SIZE);
}
}
if (!copy_to_scratch_ok) {
// TODO(tannewt): Do more here. We opted to not erase and copy bad data
// in. We still risk losing the data written to the scratch sector.
return false;
}
// Second, erase the current sector.
erase_sector(current_sector);
// Finally, copy the new version into it.
for (uint8_t i = 0; i < SPI_FLASH_ERASE_SIZE / FILESYSTEM_BLOCK_SIZE; i++) {
copy_block(scratch_sector + i * FILESYSTEM_BLOCK_SIZE,
current_sector + i * FILESYSTEM_BLOCK_SIZE);
}
return true;
}
// Attempts to allocate a new set of page buffers for caching a full sector in
// ram. Each page is allocated separately so that the GC doesn't need to provide
// one huge block. We can free it as we write if we want to also.
static bool allocate_ram_cache(void) {
uint8_t blocks_per_sector = SPI_FLASH_ERASE_SIZE / FILESYSTEM_BLOCK_SIZE;
uint8_t pages_per_block = FILESYSTEM_BLOCK_SIZE / SPI_FLASH_PAGE_SIZE;
uint32_t table_size = blocks_per_sector * pages_per_block * sizeof(uint32_t);
// Attempt to allocate outside the heap first.
supervisor_cache = allocate_memory(table_size + SPI_FLASH_ERASE_SIZE, false, false);
if (supervisor_cache != NULL) {
MP_STATE_VM(flash_ram_cache) = (uint8_t **)supervisor_cache->ptr;
uint8_t *page_start = (uint8_t *)supervisor_cache->ptr + table_size;
for (uint8_t i = 0; i < blocks_per_sector; i++) {
for (uint8_t j = 0; j < pages_per_block; j++) {
uint32_t offset = i * pages_per_block + j;
MP_STATE_VM(flash_ram_cache)[offset] = page_start + offset * SPI_FLASH_PAGE_SIZE;
}
}
return true;
}
if (MP_STATE_MEM(gc_pool_start) == 0) {
return false;
}
MP_STATE_VM(flash_ram_cache) = m_malloc_maybe(blocks_per_sector * pages_per_block * sizeof(uint32_t), false);
if (MP_STATE_VM(flash_ram_cache) == NULL) {
return false;
}
// Declare i and j outside the loops in case we fail to allocate everything
// we need. In that case we'll give it back.
uint8_t i = 0;
uint8_t j = 0;
bool success = true;
for (i = 0; i < blocks_per_sector; i++) {
for (j = 0; j < pages_per_block; j++) {
uint8_t *page_cache = m_malloc_maybe(SPI_FLASH_PAGE_SIZE, false);
if (page_cache == NULL) {
success = false;
break;
}
MP_STATE_VM(flash_ram_cache)[i * pages_per_block + j] = page_cache;
}
if (!success) {
break;
}
}
// We couldn't allocate enough so give back what we got.
if (!success) {
// We add 1 so that we delete 0 when i is 1. Going to zero (i >= 0)
// would never stop because i is unsigned.
i++;
for (; i > 0; i--) {
for (; j > 0; j--) {
m_free(MP_STATE_VM(flash_ram_cache)[(i - 1) * pages_per_block + (j - 1)]);
}
j = pages_per_block;
}
m_free(MP_STATE_VM(flash_ram_cache));
MP_STATE_VM(flash_ram_cache) = NULL;
}
return success;
}
static void release_ram_cache(void) {
if (supervisor_cache != NULL) {
free_memory(supervisor_cache);
supervisor_cache = NULL;
} else if (MP_STATE_MEM(gc_pool_start)) {
m_free(MP_STATE_VM(flash_ram_cache));
}
MP_STATE_VM(flash_ram_cache) = NULL;
}
// Flush the cached sector from ram onto the flash. We'll free the cache unless
// keep_cache is true.
static bool flush_ram_cache(bool keep_cache) {
if (current_sector == NO_SECTOR_LOADED) {
if (!keep_cache) {
release_ram_cache();
}
return true;
}
// First, copy out any blocks that we haven't touched from the sector
// we've cached. If we don't do this we'll erase the data during the sector
// erase below.
bool copy_to_ram_ok = true;
uint8_t pages_per_block = FILESYSTEM_BLOCK_SIZE / SPI_FLASH_PAGE_SIZE;
for (uint8_t i = 0; i < SPI_FLASH_ERASE_SIZE / FILESYSTEM_BLOCK_SIZE; i++) {
if ((dirty_mask & (1 << i)) == 0) {
for (uint8_t j = 0; j < pages_per_block; j++) {
copy_to_ram_ok = read_flash(
current_sector + (i * pages_per_block + j) * SPI_FLASH_PAGE_SIZE,
MP_STATE_VM(flash_ram_cache)[i * pages_per_block + j],
SPI_FLASH_PAGE_SIZE);
if (!copy_to_ram_ok) {
break;
}
}
}
if (!copy_to_ram_ok) {
break;
}
}
if (!copy_to_ram_ok) {
return false;
}
// Second, erase the current sector.
erase_sector(current_sector);
// Lastly, write all the data in ram that we've cached.
for (uint8_t i = 0; i < SPI_FLASH_ERASE_SIZE / FILESYSTEM_BLOCK_SIZE; i++) {
for (uint8_t j = 0; j < pages_per_block; j++) {
write_flash(current_sector + (i * pages_per_block + j) * SPI_FLASH_PAGE_SIZE,
MP_STATE_VM(flash_ram_cache)[i * pages_per_block + j],
SPI_FLASH_PAGE_SIZE);
if (!keep_cache && supervisor_cache == NULL && MP_STATE_MEM(gc_pool_start)) {
m_free(MP_STATE_VM(flash_ram_cache)[i * pages_per_block + j]);
}
}
}
// We're done with the cache for now so give it back.
if (!keep_cache) {
release_ram_cache();
}
return true;
}
// Delegates to the correct flash flush method depending on the existing cache.
// TODO Don't blink the status indicator if we don't actually do any writing (hard to tell right now).
static void spi_flash_flush_keep_cache(bool keep_cache) {
#ifdef MICROPY_HW_LED_MSC
port_pin_set_output_level(MICROPY_HW_LED_MSC, true);
#endif
// If we've cached to the flash itself flush from there.
if (MP_STATE_VM(flash_ram_cache) == NULL) {
flush_scratch_flash();
} else {
flush_ram_cache(keep_cache);
}
current_sector = NO_SECTOR_LOADED;
#ifdef MICROPY_HW_LED_MSC
port_pin_set_output_level(MICROPY_HW_LED_MSC, false);
#endif
}
void supervisor_external_flash_flush(void) {
spi_flash_flush_keep_cache(true);
}
void supervisor_flash_release_cache(void) {
spi_flash_flush_keep_cache(false);
}
static int32_t convert_block_to_flash_addr(uint32_t block) {
if (0 <= block && block < supervisor_flash_get_block_count()) {
// a block in partition 1
return block * FILESYSTEM_BLOCK_SIZE;
}
// bad block
return -1;
}
static bool external_flash_read_block(uint8_t *dest, uint32_t block) {
int32_t address = convert_block_to_flash_addr(block);
if (address == -1) {
// bad block number
return false;
}
// Mask out the lower bits that designate the address within the sector.
uint32_t this_sector = address & (~(SPI_FLASH_ERASE_SIZE - 1));
uint8_t block_index = (address / FILESYSTEM_BLOCK_SIZE) % (SPI_FLASH_ERASE_SIZE / FILESYSTEM_BLOCK_SIZE);
uint8_t mask = 1 << (block_index);
// We're reading from the currently cached sector.
if (current_sector == this_sector && (mask & dirty_mask) > 0) {
if (MP_STATE_VM(flash_ram_cache) != NULL) {
uint8_t pages_per_block = FILESYSTEM_BLOCK_SIZE / SPI_FLASH_PAGE_SIZE;
for (int i = 0; i < pages_per_block; i++) {
memcpy(dest + i * SPI_FLASH_PAGE_SIZE,
MP_STATE_VM(flash_ram_cache)[block_index * pages_per_block + i],
SPI_FLASH_PAGE_SIZE);
}
return true;
} else {
uint32_t scratch_address = flash_device->total_size - SPI_FLASH_ERASE_SIZE + block_index * FILESYSTEM_BLOCK_SIZE;
return read_flash(scratch_address, dest, FILESYSTEM_BLOCK_SIZE);
}
}
return read_flash(address, dest, FILESYSTEM_BLOCK_SIZE);
}
static bool external_flash_write_block(const uint8_t *data, uint32_t block) {
// Non-MBR block, copy to cache
int32_t address = convert_block_to_flash_addr(block);
if (address == -1) {
// bad block number
return false;
}
// Wait for any previous writes to finish.
wait_for_flash_ready();
// Mask out the lower bits that designate the address within the sector.
uint32_t this_sector = address & (~(SPI_FLASH_ERASE_SIZE - 1));
uint8_t block_index = (address / FILESYSTEM_BLOCK_SIZE) % (SPI_FLASH_ERASE_SIZE / FILESYSTEM_BLOCK_SIZE);
uint8_t mask = 1 << (block_index);
// Flush the cache if we're moving onto a sector or we're writing the
// same block again.
if (current_sector != this_sector || (mask & dirty_mask) > 0) {
// Check to see if we'd write to an erased page. In that case we
// can write directly.
if (page_erased(address)) {
return write_flash(address, data, FILESYSTEM_BLOCK_SIZE);
}
if (current_sector != NO_SECTOR_LOADED) {
supervisor_flash_flush();
}
if (MP_STATE_VM(flash_ram_cache) == NULL && !allocate_ram_cache()) {
erase_sector(flash_device->total_size - SPI_FLASH_ERASE_SIZE);
wait_for_flash_ready();
}
current_sector = this_sector;
dirty_mask = 0;
}
dirty_mask |= mask;
// Copy the block to the appropriate cache.
if (MP_STATE_VM(flash_ram_cache) != NULL) {
uint8_t pages_per_block = FILESYSTEM_BLOCK_SIZE / SPI_FLASH_PAGE_SIZE;
for (int i = 0; i < pages_per_block; i++) {
memcpy(MP_STATE_VM(flash_ram_cache)[block_index * pages_per_block + i],
data + i * SPI_FLASH_PAGE_SIZE,
SPI_FLASH_PAGE_SIZE);
}
return true;
} else {
uint32_t scratch_address = flash_device->total_size - SPI_FLASH_ERASE_SIZE + block_index * FILESYSTEM_BLOCK_SIZE;
return write_flash(scratch_address, data, FILESYSTEM_BLOCK_SIZE);
}
}
mp_uint_t supervisor_flash_read_blocks(uint8_t *dest, uint32_t block_num, uint32_t num_blocks) {
for (size_t i = 0; i < num_blocks; i++) {
if (!external_flash_read_block(dest + i * FILESYSTEM_BLOCK_SIZE, block_num + i)) {
return 1; // error
}
}
return 0; // success
}
mp_uint_t supervisor_flash_write_blocks(const uint8_t *src, uint32_t block_num, uint32_t num_blocks) {
for (size_t i = 0; i < num_blocks; i++) {
if (!external_flash_write_block(src + i * FILESYSTEM_BLOCK_SIZE, block_num + i)) {
return 1; // error
}
}
return 0; // success
}
void MP_WEAK external_flash_setup(void) {
}
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