2 releases
0.1.1 | Aug 29, 2021 |
---|---|
0.1.0 | Aug 29, 2021 |
#5 in #esp32-c3
46KB
672 lines
Contains (static library, 8KB) bin/riscv32imc-unknown-none-elf.a
esp32c-rt
Minimal runtime / startup for RISC-V-based CPU's of the ESP32-C SoC series.
This project is a fork of the riscv-rt
crate and provides modifications specific
to the ESP32-C series on top of this crate.
At this point in time, only the ESP32-C3 has been released. However, in the future a ESP32-C6 version is planned and it is expected that this SoC will also be compatible with this crate.
Modifications
Compared to the riscv-rt
crate, the following modifications have been implemented:
- Only prepare the binary blobs containing the reset and startup routine for the
rv32imc
architecture. This is the ESP32-C SoC series architecture. - Exclude
mie
andmip
machine interrupt registers from the the startup reset routine. These registers are not implemented by the SoCs and would result in ainvalid instruction
exception if not removed. - Add a feature
directboot
(by default enabled) that alters the link script so that magic numbers are included that boot the EPS32-C SoC in direct-boot mode. This simplifies the boot and setup effort significantly, but breaks compatibility with numerous ESP-IDF features (secure boot etc.). More details on the direct-boot mode are available in the esp32c3-direct-boot-example repository. This mode is only supported for SoC >= rev. 3 - Add a feature
esp32c3
(by default enabled at this point in time) that includes the memory layout of the ESP32-C3 for the linker so that this file does not have to be supplemented by downstream projects.
ESP32-C3 Memory Layout
The following memory layout is assumed when the feature esp32c3
is enabled:
MEMORY
{
irom (x): ORIGIN = 0x42000000, LENGTH = 0x400000
drom (r): ORIGIN = 0x3C000000, LENGTH = 0x400000
ram (rw): ORIGIN = 0x3FC80000, LENGTH = 0x50000
rtc_ram (rx): ORIGIN = 0x50000000, LENGTH = 0x2000
}
Documentation
The rust documentation can be found here
Minimum Supported Rust Version (MSRV)
This crate is guaranteed to compile on stable Rust 1.42.0 and up. It might compile with older versions but that may change in any new patch release.
License
See LICENSE.md
Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion
in the repository by you, shall also be licensed under the ISC license as described in
LICENSE.md
, without any additional terms or conditions.
Code of Conduct
Contribution to this crate is organized under the terms of the Rust Code of Conduct, the maintainer of this crate, promises to intervene to uphold that code of conduct.
Dependencies
~2.5MB
~60K SLoC