80 lines
3.0 KiB
Plaintext
80 lines
3.0 KiB
Plaintext
README for the Espressif ESP32 Ethernet Kit
|
|
==============================================
|
|
|
|
The ESP32 is a dual-core system from Espressif with two Harvard
|
|
architecture Xtensa LX6 CPUs. All embedded memory, external memory and
|
|
peripherals are located on the data bus and/or the instruction bus of
|
|
these CPUs. With some minor exceptions, the address mapping of two CPUs
|
|
is symmetric, meaning they use the same addresses to access the same
|
|
memory. Multiple peripherals in the system can access embedded memory via
|
|
DMA.
|
|
|
|
The ESP32-Ethernet-Kit is an Ethernet-to-Wi-Fi development board that enables
|
|
Ethernet devices to be interconnected over Wi-Fi. At the same time, to provide
|
|
more flexible power supply options, the ESP32-Ethernet-Kit also supports power
|
|
over Ethernet (PoE).
|
|
|
|
Buttons and LEDs
|
|
================
|
|
|
|
Buttons
|
|
-------
|
|
There are two buttons labeled Boot and EN. The EN button is not available
|
|
to software. It pulls the chip enable line that doubles as a reset line.
|
|
|
|
The BOOT button is connected to IO0. On reset it is used as a strapping
|
|
pin to determine whether the chip boots normally or into the serial
|
|
bootloader. After reset, however, the BOOT button can be used for software
|
|
input.
|
|
|
|
LEDs
|
|
----
|
|
There are several on-board LEDs for that indicate the presence of power
|
|
and USB activity. None of these are available for use by software.
|
|
|
|
Ethernet
|
|
========
|
|
|
|
ESP32 has a 802.11 hardware MAC, so just connects to external PHY chip.
|
|
Due to the limited number of GPIOs in ESP32, it's recommended to use RMII to
|
|
connect to an external PHY chip. Current driver also only supports RMII option.
|
|
|
|
The RMII GPIO pins are fixed, but the SMI and functional GPIO pins are optional.
|
|
|
|
RMII GPIO pins are as following:
|
|
|
|
ESP32 GPIO PHY Chip GPIO
|
|
IO25 <--> RXD[0]
|
|
IO26 <--> RXD[1]
|
|
IO27 <--> CRS_DV
|
|
IO0 <--> REF_CLK
|
|
IO19 <--> TXD[0]
|
|
IO21 <--> TX_EN
|
|
IO22 <--> TXD[1]
|
|
|
|
SMI GPIO pins (default option) are as following:
|
|
|
|
ESP32 GPIO PHY Chip GPIO
|
|
IO18 <--> MDIO
|
|
IO23 <--> MDC
|
|
|
|
Functional GPIO pins(default option) are as following:
|
|
|
|
ESP32 GPIO PHY Chip GPIO
|
|
IO5 <--> Reset_N
|
|
|
|
Using QEMU:
|
|
==========
|
|
|
|
First follow the instructions at https://github.com/espressif/qemu/wiki to build QEMU.
|
|
Enable the ESP32_QEMU_IMAGE config found in "Board Selection -> ESP32 binary image for QEMU".
|
|
Download the bootloader and the partition table from https://github.com/espressif/esp-nuttx-bootloader/releases
|
|
and place them in a directory, say ../esp-bins.
|
|
Build and generate the QEMU image: `make ESPTOOL_BINDIR=../esp-bins`
|
|
A new image "esp32_qemu_image.bin" will be created. It can be run as:
|
|
|
|
~/PATH_TO_QEMU/qemu/build/xtensa-softmmu/qemu-system-xtensa -nographic \
|
|
-machine esp32 \
|
|
-drive file=esp32_qemu_image.bin,if=mtd,format=raw
|
|
|