src/lib/OPTIONS/EspFlashStream.cpp

   1 #if !defined(UNIT_TEST)
   2
   3 #include "EspFlashStream.h"
   4
   5 EspFlashStream::EspFlashStream()
   6 {
   7     setBaseAddress(0);
   8 }
   9
  10 void EspFlashStream::fillBuffer()
  11 {
  12     // Could also use spi_flash_read() here, but the return values differ between ESP (SPI_FLASH_RESULT_OK) and ESP32 (ESP_OK)
  13     if (ESP.flashRead(_flashBase + _flashOffset, (uint32_t *)_buffer, sizeof(_buffer)))
  14     {
  15         _bufferPos = 0;
  16     }
  17     else
  18     {
  19         // _bufferPos > sizeof() indicates error
  20         _bufferPos = sizeof(_buffer) + 1;
  21     }
  22 }
  23
  24 void EspFlashStream::setBaseAddress(size_t base)
  25 {
  26     _flashBase = base;
  27     _flashOffset = 0 - sizeof(_buffer); // underflow intentionally so offset+pos = 0
  28     _bufferPos = sizeof(_buffer);
  29 }
  30
  31 void EspFlashStream::setPosition(size_t offset)
  32 {
  33     // align(4), rounding down
  34     _flashOffset = (offset >> 2) << 2;
  35     // capture the new bufferPos before fill advances it
  36     uint8_t newBufferPos = offset - _flashOffset;
  37
  38     fillBuffer();
  39     _bufferPos = newBufferPos;
  40 }
  41
  42 int EspFlashStream::read()
  43 {
  44     int retVal = peek();
  45     ++_bufferPos;
  46     return retVal;
  47 }
  48
  49 int EspFlashStream::peek()
  50 {
  51     if (_bufferPos == sizeof(_buffer))
  52     {
  53         _flashOffset += sizeof(_buffer);
  54         fillBuffer();
  55     }
  56     return _buffer[_bufferPos];
  57 }
  58
  59 #endif