nuttx/Documentation/platforms/risc-v/esp32c3/index.rst
Michał Łyszczek a5bcb2dc46 Documentation: fix multiple errors and warnings
Multiple files were badly formatted, which resulted in many
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What's worse, badly formatted text resulted in butchered
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This patch fixes most of the errors, but alas, not all of
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Signed-off-by: Michał Łyszczek <michal.lyszczek@bofc.pl>
2022-06-08 03:02:32 +08:00

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==================
Espressif ESP32-C3
==================
The ESP32-C3 is an ultra-low-power and highly integrated SoC with a RISC-V
core and supports 2.4 GHz Wi-Fi and Bluetooth Low Energy.
* Address Space
- 800 KB of internal memory address space accessed from the instruction bus
- 560 KB of internal memory address space accessed from the data bus
- 1016 KB of peripheral address space
- 8 MB of external memory virtual address space accessed from the instruction bus
- 8 MB of external memory virtual address space accessed from the data bus
- 480 KB of internal DMA address space
* Internal Memory
- 384 KB ROM
- 400 KB SRAM (16 KB can be configured as Cache)
- 8 KB of SRAM in RTC
* External Memory
- Up to 16 MB of external flash
* Peripherals
- 35 peripherals
* GDMA
- 7 modules are capable of DMA operations.
ESP32-C3 Toolchain
==================
A generic RISC-V toolchain can be used to build ESP32-C3 projects.
SiFive's toolchain can be downloaded from: https://github.com/sifive/freedom-tools/releases
Second stage bootloader and partition table
===========================================
The NuttX port for now relies on IDF's second stage bootloader to carry on some hardware
initializations. The binaries for the bootloader and the partition table can be found in
this repository: https://github.com/espressif/esp-nuttx-bootloader
That repository contains a dummy IDF project that's used to build the bootloader and
partition table, these are then presented as Github assets and can be downloaded
from: https://github.com/espressif/esp-nuttx-bootloader/releases
Download ``bootloader-esp32c3.bin`` and ``partition-table-esp32c3.bin`` and place them
in a folder, the path to this folder will be used later to program them. This
can be: ``../esp-bins``
Building and flashing
=====================
First make sure that ``esptool.py`` is installed. This tool is used to convert
the ELF to a compatible ESP32 image and to flash the image into the board.
It can be installed with: ``pip install esptool``.
Configure the NUttX project: ``./tools/configure.sh esp32c3-devkit:nsh``
Run ``make`` to build the project. Note that the conversion mentioned above is
included in the build process.
The `esptool.py` command to flash all the binaries is::
esptool.py --chip esp32c3 --port /dev/ttyUSBXX --baud 921600 write_flash 0x0 bootloader.bin 0x8000 partition-table.bin 0x10000 nuttx.bin
However, this is also included in the build process and we can build and flash with::
make flash ESPTOOL_PORT=<port> ESPTOOL_BINDIR=../esp-bins
Where ``<port>`` is typically ``/dev/ttyUSB0`` or similar and ``../esp-bins`` is
the path to the folder containing the bootloader and the partition table
for the ESP32-C3 as explained above.
Note that this step is required only one time. Once the bootloader and partition
table are flashed, we don't need to flash them again. So subsequent builds
would just require: ``make flash ESPTOOL_PORT=/dev/ttyUSBXX``
Debugging with OpenOCD
======================
Download and build OpenOCD from Espressif, that can be found in
https://github.com/espressif/openocd-esp32
If you have an ESP32-C3 ECO3, no external JTAG is required to debug, the ESP32-C3
integrates a USB-to-JTAG adapter.
OpenOCD can then be used::
openocd -c 'set ESP_RTOS none' -f board/esp32c3-builtin.cfg
For versions prior to ESP32-C3 ECO3, an external JTAG adapter is needed.
It can be connected as follows::
TMS -> GPIO4
TDI -> GPIO5
TCK -> GPIO6
TDO -> GPIO7
Furthermore, an efuse needs to be burnt to be able to debug::
espefuse.py -p <port> burn_efuse DIS_USB_JTAG
OpenOCD can then be used::
openocd -c 'set ESP_RTOS none' -f board/esp32c3-ftdi.cfg
Peripheral Support
==================
The following list indicates the state of peripherals' support in NuttX:
=========== ======= =====
Peripheral Support NOTES
=========== ======= =====
GPIO Yes
UART Yes
SPI Yes
I2C Yes
DMA Yes
Wifi Yes
SPIFLASH Yes
Timers Yes
Watchdog Yes
RTC Yes
RNG Yes
AES Yes
eFuse Yes
ADC Yes
Bluetooth Yes
LED_PWM Yes
SHA Yes
RSA Yes
CDC Console Yes Rev.3
=========== ======= =====
Supported Boards
================
.. toctree::
:glob:
:maxdepth: 1
boards/*/*