Esp32s2 support

[MabezDev]

A WIP PR for esp32s2 support.

• Removes the DATE_REG detection in favour of the CHIP_DETECT magic instead.
• Adds the esp32s2 module for s2 support.

I can't actually flash anything at the moment, the bootloader returns InvalidMessage:

Command: (10, DATA, 0)
Detected Esp32s2
Command: (13, DATA, 0)
Command: (10, DATA, 0)
Command: (10, DATA, 0)
Command: (9, DATA, 0)
Command: (9, DATA, 0)
Command: (9, DATA, 0)
Command: (9, DATA, 0)
Command: (9, DATA, 0)
Command: (10, DATA, 0)
Command: (10, DATA, 0)
Command: (9, DATA, 0)
Command: (9, DATA, 0)
Command: (13, DATA, 0)
Erase size: 12288
Command: (2, DATA, 0)
Error: bootloader returned an error: InvalidMessage

Any ideas?

Once I figure out whats going on, I think we can probably merge the esp32 & esp32s2 modules by expanding the Chip trait.

Builds on top of #29 & #30

[jessebraham]

Refer to the following lines in esptool.py:

params = struct.pack('<IIII', erase_size, num_blocks, self.FLASH_WRITE_SIZE, offset)
if isinstance(self, (ESP32S2ROM, ESP32S3BETA2ROM, ESP32S3ROM, ESP32C3ROM, ESP32C6BETAROM, ESP32H2ROM)) and not self.IS_STUB:
     params += struct.pack('<I', 1 if begin_rom_encrypted else 0)

Chips newer than the ESP32 must have an additional field in BeginParams denoting whether or not ROM encryption is being used. The command is being rejected by the bootloader because its length is 4 bytes too short.

Unfortunately, since the chip is defined at runtime we can't #[cfg()] gate this field, so this then causes compatibility issues for the older chips. Some additional restructuring may be required to support both generations of chips.

[icewind1991]

added the rom encryption parameter in a very hacky way for now, the flashing looks to go fine now.

It now crashes in the bootloader with an "invalid partition table error"

I (24) boot: ESP-IDF v4.4-dev-1404-gc13afea635-dirty 2nd stage bootloader
I (24) boot: compile time 20:23:13
I (25) boot: chip revision: 0
I (29) boot.esp32s2: SPI Speed      : 80MHz
I (33) boot.esp32s2: SPI Mode       : DIO
I (38) boot.esp32s2: SPI Flash Size : 2MB
I (43) boot: Enabling RNG early entropy source...
E (48) flash_parts: partition 0 invalid - offset 0x10000 size 0x3f0000 exceeds flash chip size 0x200000
E (58) boot: Failed to verify partition table
E (63) boot: load partition table error!

[jessebraham]

This encrypted field applies to all chips except the ESP8266/ESP32 as far as I know. This should probably be the default struct, and we can have a BeginParamsLegacy or something to that effect instead for the older chips.

[icewind1991]

I was thinking of having some way of having per-chip command/parameter structs or otherwise moving some of the flashing logic to the chips.