Merge branch 'feature/esptool_flash_encryption' into 'master'

Flash encryption support

Flash encryption support in build system, tooling

To come in future MR:
* On-device key generation on first boot (for production devices), need to finalise testing of bootloader entropy seeding.
* spi_flash_encrypted_write to support non-32-byte block writes (at least optionally.)
* I think a lot of the bootloader_support component can possibly be rolled into "spiflash" and other components, to use a common API.

See merge request !240

diff --cc components/bootloader/src/main/bootloader_start.c
index e567c78ef6413d691a0ec880229ee6f923f8a2fb,80b37db40c60daea759af5dc749af5d3760ef070..44de10e87dde3fd0636b9fc6cab151ab82f93a08
--- 1/components/bootloader/src/main/bootloader_start.c
--- 2/components/bootloader/src/main/bootloader_start.c
+++ b/components/bootloader/src/main/bootloader_start.c
@@@ -228,9 -225,10 +229,11 @@@ static bool ota_select_valid(const esp_
  
  void bootloader_main()
  {
 +    uart_console_configure();
      ESP_LOGI(TAG, "Espressif ESP32 2nd stage bootloader v. %s", BOOT_VERSION);
- 
+ #if defined(CONFIG_SECURE_BOOT_ENABLED) || defined(CONFIG_FLASH_ENCRYPTION_ENABLED)
+     esp_err_t err;
+ #endif
      esp_image_header_t fhdr;
      bootloader_state_t bs;
      SpiFlashOpResult spiRet1,spiRet2;

diff --cc components/esp32/include/rom/spi_flash.h
Simple merge

diff --cc components/esp32/include/soc/soc.h
Simple merge

diff --cc components/spi_flash/flash_ops.c
Simple merge