UpdateClass - speedup flash erase/writes (espressif#7002)

 - on flash writes try to use large block erase - skip writing empty blocks of data after erase - more accurate block calculations

Author: vortigont

libraries/Update/src/Update.h

@@ -28,6 +28,9 @@
 
 #define ENCRYPTED_BLOCK_SIZE 16
 
+#define SPI_SECTORS_PER_BLOCK 16 // usually large erase block is 32k/64k
+#define SPI_FLASH_BLOCK_SIZE (SPI_SECTORS_PER_BLOCK*SPI_FLASH_SEC_SIZE)
+
 class UpdateClass {
  public:
  typedef std::function<void(size_t, size_t)> THandlerFunction_Progress;
@@ -166,6 +169,7 @@ class UpdateClass {
  bool _verifyHeader(uint8_t data);
  bool _verifyEnd();
  bool _enablePartition(const esp_partition_t* partition);
+ bool _chkDataInBlock(const uint8_t *data, size_t len) const; // check if block contains any data or is empty
 
 
  uint8_t _error;

libraries/Update/src/Updater.cpp

@@ -203,14 +203,23 @@ bool UpdateClass::_writeBuffer(){
  if (!_progress && _progress_callback) {
  _progress_callback(0, _size);
  }
- if(!ESP.partitionEraseRange(_partition, _progress, SPI_FLASH_SEC_SIZE)){
- _abort(UPDATE_ERROR_ERASE);
- return false;
+ size_t offset = _partition->address + _progress;
+ bool block_erase = (_size - _progress >= SPI_FLASH_BLOCK_SIZE) && (offset % SPI_FLASH_BLOCK_SIZE == 0); // if it's the block boundary, than erase the whole block from here
+ bool part_head_sectors = _partition->address % SPI_FLASH_BLOCK_SIZE && offset < (_partition->address / SPI_FLASH_BLOCK_SIZE + 1) * SPI_FLASH_BLOCK_SIZE; // sector belong to unaligned partition heading block
+ bool part_tail_sectors = offset >= (_partition->address + _size) / SPI_FLASH_BLOCK_SIZE * SPI_FLASH_BLOCK_SIZE; // sector belong to unaligned partition tailing block
+ if (block_erase || part_head_sectors || part_tail_sectors){
+ if(!ESP.partitionEraseRange(_partition, _progress, block_erase ? SPI_FLASH_BLOCK_SIZE : SPI_FLASH_SEC_SIZE)){
+ _abort(UPDATE_ERROR_ERASE);
+ return false;
+ }
  }
- if (!ESP.partitionWrite(_partition, _progress + skip, (uint32_t*)_buffer + skip/sizeof(uint32_t), _bufferLen - skip)) {
+
+ // try to skip empty blocks on unecrypted partitions
+ if ((_partition->encrypted || _chkDataInBlock(_buffer + skip/sizeof(uint32_t), _bufferLen - skip)) && !ESP.partitionWrite(_partition, _progress + skip, (uint32_t*)_buffer + skip/sizeof(uint32_t), _bufferLen - skip)) {
  _abort(UPDATE_ERROR_WRITE);
  return false;
  }
+
  //restore magic or md5 will fail
  if(!_progress && _command == U_FLASH){
  _buffer[0] = ESP_IMAGE_HEADER_MAGIC;
@@ -389,4 +398,20 @@ const char * UpdateClass::errorString(){
  return _err2str(_error);
 }
 
+bool UpdateClass::_chkDataInBlock(const uint8_t *data, size_t len) const {
+ // check 32-bit aligned blocks only
+ if (!len || len % sizeof(uint32_t))
+ return true;
+
+ size_t dwl = len / sizeof(uint32_t);
+
+ do {
+ if (*(uint32_t*)data ^ 0xffffffff) // for SPI NOR flash empty blocks are all one's, i.e. filled with 0xff byte
+ return true;
+
+ data += sizeof(uint32_t);
+ } while (--dwl);
+ return false;
+}
+
 UpdateClass Update;