Adress 0x40060000-0x4006FFFF 64 KB Reserved adresses & ESP32-S2

[Olof Astrand]

Hello,

When running an esp32 application in qemu
https://github.com/Ebiroll/qemu_esp32
I have noticed that it is not enough to dump only the official 384 KB of ROM as the ROM contains a call to adress 0x40062a6c which is contained in Reserved space.

Does anyone have a hint to what is located here, secret secure boot code?

Also I would like to buy an ESP32-S2.
Where and when will you be able to do that?

/Olof

[Olof Astrand]

Hello again, I found part of the answer.

0x40062a6c is marked as reserved, but is most likely part of the rom and related to the spi_flash functions.

https://github.com/pycom/esp-idf-2.0/bl ... p32.rom.ld

PROVIDE ( spi_flash_attach = 0x40062a6c );

void spi_flash_attach ( uint32_t ishspi,
bool legacy
)

SPI Flash init, clock divisor is 4, use 1 line Slow read mode. Please do not call this function in SDK.

[ESP_igrr]

Hi Olof,
This range is mapped to 64kB of ROM. There is another address range on the data bus which is mapped to the same physical 64kB range. Part of this range is occupied by code, part by rodata.
By the way, since you mentioned Qemu, I wanted to point you to https://github.com/espressif/qemu — it has only been recently published, but you may find something useful there.

Regarding ESP32-S2 (final, not ESP32-S2-beta), all I can suggest is to wait for announcements at Espressif website. We expect the chips to be available early next year.